Trade: support for texture array layers in all MaterialData attributes.

Logic mostly the same as with MaterialAttribute::*TextureCoordinates --
attribute not present is treated the same way as if the layer was 0
(since that's what a 2D non-array texture is, a single-slice array), and
conversely if the attribute is 0 it's the same as if it would be not
present at all. Plus it also gets checked in queries for packed
textures, if everything is the same but the layer is different, then
it's not a packed texture.

The rest of the commit is just busywork for convenience APIs.

src/Magnum/Trade/FlatMaterialData.cpp

@@ -49,6 +49,12 @@ bool FlatMaterialData::hasTextureCoordinates() const {
         attributeOr(MaterialAttribute::TextureCoordinates, 0u);
 }
 
+bool FlatMaterialData::hasTextureLayer() const {
+    return (hasAttribute(MaterialAttribute::BaseColorTexture) && attributeOr(MaterialAttribute::BaseColorTextureLayer, 0u)) ||
+        (hasAttribute(MaterialAttribute::DiffuseTexture) && attributeOr(MaterialAttribute::DiffuseTextureLayer, 0u)) ||
+        attributeOr(MaterialAttribute::TextureLayer, 0u);
+}
+
 Color4 FlatMaterialData::color() const {
     /* If the material has a texture, return the color that matches it */
     if(hasAttribute(MaterialAttribute::BaseColorTexture))
@@ -104,4 +110,20 @@ UnsignedInt FlatMaterialData::textureCoordinates() const {
     CORRADE_ASSERT_UNREACHABLE("Trade::FlatMaterialData::textureCoordinates(): the material doesn't have a texture", {});
 }
 
+UnsignedInt FlatMaterialData::textureLayer() const {
+    if(hasAttribute(MaterialAttribute::BaseColorTexture)) {
+        if(Containers::Optional<UnsignedInt> value = tryAttribute<UnsignedInt>(MaterialAttribute::BaseColorTextureLayer))
+            return *value;
+        return attributeOr(MaterialAttribute::TextureLayer, 0u);
+    }
+
+    if(hasAttribute(MaterialAttribute::DiffuseTexture)) {
+        if(Containers::Optional<UnsignedInt> value = tryAttribute<UnsignedInt>(MaterialAttribute::DiffuseTextureLayer))
+            return *value;
+        return attributeOr(MaterialAttribute::TextureLayer, 0u);
+    }
+
+    CORRADE_ASSERT_UNREACHABLE("Trade::FlatMaterialData::textureLayer(): the material doesn't have a texture", {});
+}
+
 }}

src/Magnum/Trade/FlatMaterialData.h

@@ -102,6 +102,21 @@ class MAGNUM_TRADE_EXPORT FlatMaterialData: public MaterialData {
          */
         bool hasTextureCoordinates() const;
 
+        /**
+         * @brief Whether the material uses array texture layers
+         *
+         * Returns @cpp true @ce if the material is textured and a
+         * @ref MaterialAttribute::BaseColorTextureLayer,
+         * @ref MaterialAttribute::DiffuseTextureLayer or
+         * @ref MaterialAttribute::TextureLayer attribute matching the texture
+         * is present and has a non-zero value, @cpp false @ce otherwise. In
+         * particular, if there's for example a
+         * @ref MaterialAttribute::BaseColorTexture but only a
+         * @ref MaterialAttribute::DiffuseTextureLayer, returns @cpp false @ce.
+         * @see @ref textureLayer()
+         */
+        bool hasTextureLayer() const;
+
         /**
          * @brief Color
          *
@@ -156,6 +171,21 @@ class MAGNUM_TRADE_EXPORT FlatMaterialData: public MaterialData {
          * @see @ref hasTexture()
          */
         UnsignedInt textureCoordinates() const;
+
+        /**
+         * @brief Array texture layer
+         *
+         * Convenience access to the @ref MaterialAttribute::DiffuseTextureLayer
+         * / @ref MaterialAttribute::BaseColorTextureLayer /
+         * @ref MaterialAttribute::TextureLayer attributes, picking the one
+         * matching the texture (instead of combining e.g. a
+         * @ref MaterialAttribute::BaseColorTexture with
+         * @ref MaterialAttribute::DiffuseTextureLayer). If no matching
+         * attribute is present, the default is @cpp 0 @ce. Available only if
+         * the material has a texture.
+         * @see @ref hasTexture()
+         */
+        UnsignedInt textureLayer() const;
 };
 
 }}

src/Magnum/Trade/Implementation/materialAttributeProperties.hpp

@@ -33,56 +33,68 @@ _c(AmbientColor,Vector4)
 _c(AmbientTexture,UnsignedInt)
 _c(AmbientTextureMatrix,Matrix3x3)
 _c(AmbientTextureCoordinates,UnsignedInt)
+_c(AmbientTextureLayer,UnsignedInt)
 _c(DiffuseColor,Vector4)
 _c(DiffuseTexture,UnsignedInt)
 _c(DiffuseTextureMatrix,Matrix3x3)
 _c(DiffuseTextureCoordinates,UnsignedInt)
+_c(DiffuseTextureLayer,UnsignedInt)
 _c(SpecularColor,Vector4)
 _c(SpecularTexture,UnsignedInt)
 _ct(SpecularTextureSwizzle,TextureSwizzle,MaterialTextureSwizzle)
 _c(SpecularTextureMatrix,Matrix3x3)
 _c(SpecularTextureCoordinates,UnsignedInt)
+_c(SpecularTextureLayer,UnsignedInt)
 _c(Shininess,Float)
 _c(BaseColor,Vector4)
 _c(BaseColorTexture,UnsignedInt)
 _c(BaseColorTextureMatrix,Matrix3x3)
 _c(BaseColorTextureCoordinates,UnsignedInt)
+_c(BaseColorTextureLayer,UnsignedInt)
 _c(Metalness,Float)
 _c(MetalnessTexture,UnsignedInt)
 _ct(MetalnessTextureSwizzle,TextureSwizzle,MaterialTextureSwizzle)
 _c(MetalnessTextureMatrix,Matrix3x3)
 _c(MetalnessTextureCoordinates,UnsignedInt)
+_c(MetalnessTextureLayer,UnsignedInt)
 _c(Roughness,Float)
 _c(RoughnessTexture,UnsignedInt)
 _ct(RoughnessTextureSwizzle,TextureSwizzle,MaterialTextureSwizzle)
 _c(RoughnessTextureMatrix,Matrix3x3)
 _c(RoughnessTextureCoordinates,UnsignedInt)
+_c(RoughnessTextureLayer,UnsignedInt)
 _c(NoneRoughnessMetallicTexture,UnsignedInt)
 _c(Glossiness,Float)
 _c(GlossinessTexture,UnsignedInt)
 _ct(GlossinessTextureSwizzle,TextureSwizzle,MaterialTextureSwizzle)
 _c(GlossinessTextureMatrix,Matrix3x3)
 _c(GlossinessTextureCoordinates,UnsignedInt)
+_c(GlossinessTextureLayer,UnsignedInt)
 _c(SpecularGlossinessTexture,UnsignedInt)
 _c(NormalTexture,UnsignedInt)
 _c(NormalTextureScale,Float)
 _ct(NormalTextureSwizzle,TextureSwizzle,MaterialTextureSwizzle)
 _c(NormalTextureMatrix,Matrix3x3)
 _c(NormalTextureCoordinates,UnsignedInt)
+_c(NormalTextureLayer,UnsignedInt)
 _c(OcclusionTexture,UnsignedInt)
 _c(OcclusionTextureStrength,Float)
 _ct(OcclusionTextureSwizzle,TextureSwizzle,MaterialTextureSwizzle)
 _c(OcclusionTextureMatrix,Matrix3x3)
 _c(OcclusionTextureCoordinates,UnsignedInt)
+_c(OcclusionTextureLayer,UnsignedInt)
 _c(EmissiveColor,Vector3)
 _c(EmissiveTexture,UnsignedInt)
 _c(EmissiveTextureMatrix,Matrix3x3)
 _c(EmissiveTextureCoordinates,UnsignedInt)
+_c(EmissiveTextureLayer,UnsignedInt)
 _c(LayerFactor,Float)
 _c(LayerFactorTexture,UnsignedInt)
 _ct(LayerFactorTextureSwizzle,TextureSwizzle,MaterialTextureSwizzle)
 _c(LayerFactorTextureMatrix,Matrix3x3)
 _c(LayerFactorTextureCoordinates,UnsignedInt)
+_c(LayerFactorTextureLayer,UnsignedInt)
 _c(TextureMatrix,Matrix3x3)
 _c(TextureCoordinates,UnsignedInt)
+_c(TextureLayer,UnsignedInt)
 #endif

src/Magnum/Trade/MaterialData.cpp

@@ -491,6 +491,39 @@ UnsignedInt MaterialData::layerFactorTextureCoordinates(const MaterialLayer laye
     return layerFactorTextureCoordinates(string);
 }
 
+UnsignedInt MaterialData::layerFactorTextureLayer(const UnsignedInt layer) const {
+    CORRADE_ASSERT(layer < layerCount(),
+        "Trade::MaterialData::layerFactorTextureLayer(): index" << layer << "out of range for" << layerCount() << "layers", {});
+    CORRADE_ASSERT(hasAttribute(layer, MaterialAttribute::LayerFactorTexture),
+        "Trade::MaterialData::layerFactorTextureLayer(): layer" << layer << "doesn't have a factor texture", {});
+    if(Containers::Optional<UnsignedInt> value = tryAttribute<UnsignedInt>(layer, MaterialAttribute::LayerFactorTextureLayer))
+        return *value;
+    if(Containers::Optional<UnsignedInt> value = tryAttribute<UnsignedInt>(layer, MaterialAttribute::TextureLayer))
+        return *value;
+    return attributeOr(0, MaterialAttribute::TextureLayer, 0u);
+}
+
+UnsignedInt MaterialData::layerFactorTextureLayer(const Containers::StringView layer) const {
+    const UnsignedInt layerId = layerFor(layer);
+    CORRADE_ASSERT(layerId != ~UnsignedInt{},
+        "Trade::MaterialData::layerFactorTextureLayer(): layer" << layer << "not found", {});
+    CORRADE_ASSERT(hasAttribute(layerId, MaterialAttribute::LayerFactorTexture),
+        "Trade::MaterialData::layerFactorTextureLayer(): layer" << layer << "doesn't have a factor texture", {});
+    /* Not delegating into layerFactorTextureLayer() because we have a
+       different variant of the assert here */
+    if(Containers::Optional<UnsignedInt> value = tryAttribute<UnsignedInt>(layerId, MaterialAttribute::LayerFactorTextureLayer))
+        return *value;
+    if(Containers::Optional<UnsignedInt> value = tryAttribute<UnsignedInt>(layerId, MaterialAttribute::TextureLayer))
+        return *value;
+    return attributeOr(0, MaterialAttribute::TextureLayer, 0u);
+}
+
+UnsignedInt MaterialData::layerFactorTextureLayer(const MaterialLayer layer) const {
+    const Containers::StringView string = layerString(layer);
+    CORRADE_ASSERT(string, "Trade::MaterialData::layerFactorTextureLayer(): invalid name" << layer, {});
+    return layerFactorTextureLayer(string);
+}
+
 UnsignedInt MaterialData::attributeCount(const UnsignedInt layer) const {
     CORRADE_ASSERT(layer < layerCount(),
         "Trade::MaterialData::attributeCount(): index" << layer << "out of range for" << layerCount() << "layers", {});

src/Magnum/Trade/MaterialData.h

@@ -186,6 +186,16 @@ enum class MaterialAttribute: UnsignedInt {
      */
     AmbientTextureCoordinates,
 
+    /**
+     * Ambient texture array layer for Phong materials,
+     * @ref MaterialAttributeType::UnsignedInt.
+     *
+     * Has a precedence over @ref MaterialAttribute::TextureLayer if both are
+     * present.
+     * @see @ref PhongMaterialData::ambientTextureLayer()
+     */
+    AmbientTextureLayer,
+
     /**
      * Diffuse color for Phong or PBR specular/glossiness materials,
      * @ref MaterialAttributeType::Vector4.
@@ -234,6 +244,16 @@ enum class MaterialAttribute: UnsignedInt {
      */
     DiffuseTextureCoordinates,
 
+    /**
+     * Diffuse texture array layer for Phong materials,
+     * @ref MaterialAttributeType::UnsignedInt.
+     *
+     * Has a precedence over @ref MaterialAttribute::TextureLayer if both are
+     * present.
+     * @see @ref PhongMaterialData::diffuseTextureLayer()
+     */
+    DiffuseTextureLayer,
+
     /**
      * Specular color for Phong or PBR specular/glossiness materials,
      * @ref MaterialAttributeType::Vector4. Alpha is commonly zero to not
@@ -301,6 +321,17 @@ enum class MaterialAttribute: UnsignedInt {
      */
     SpecularTextureCoordinates,
 
+    /**
+     * Specular texture array layer for Phong materials,
+     * @ref MaterialAttributeType::UnsignedInt.
+     *
+     * Has a precedence over @ref MaterialAttribute::TextureLayer if both are
+     * present.
+     * @see @ref PhongMaterialData::specularTextureLayer(),
+     *      @ref PbrSpecularGlossinessMaterialData::specularTextureLayer()
+     */
+    SpecularTextureLayer,
+
     /**
      * Shininess value for Phong materials, @ref MaterialAttributeType::Float.
      *
@@ -352,6 +383,17 @@ enum class MaterialAttribute: UnsignedInt {
      */
     BaseColorTextureCoordinates,
 
+    /**
+     * Base color texture array layer for PBR metallic/roughness materials,
+     * @ref MaterialAttributeType::UnsignedInt.
+     *
+     * Has a precedence over @ref MaterialAttribute::TextureLayer if both are
+     * present.
+     * @see @ref FlatMaterialData::textureLayer(),
+     *      @ref PbrMetallicRoughnessMaterialData::baseColorTextureLayer()
+     */
+    BaseColorTextureLayer,
+
     /**
      * Metalness for PBR metallic/roughness materials,
      * @ref MaterialAttributeType::Float.
@@ -416,6 +458,16 @@ enum class MaterialAttribute: UnsignedInt {
      */
     MetalnessTextureCoordinates,
 
+    /**
+     * Metalness texture array layer for PBR metallic/roughness materials,
+     * @ref MaterialAttributeType::UnsignedInt.
+     *
+     * Has a precedence over @ref MaterialAttribute::TextureLayer if both are
+     * present.
+     * @see @ref PbrMetallicRoughnessMaterialData::metalnessTextureLayer()
+     */
+    MetalnessTextureLayer,
+
     /**
      * Roughness for PBR metallic/roughness materials,
      * @ref MaterialAttributeType::Float.
@@ -480,6 +532,16 @@ enum class MaterialAttribute: UnsignedInt {
      */
     RoughnessTextureCoordinates,
 
+    /**
+     * Roughness texture array layer for PBR metallic/roughness materials,
+     * @ref MaterialAttributeType::UnsignedInt.
+     *
+     * Has a precedence over @ref MaterialAttribute::TextureLayer if both are
+     * present.
+     * @see @ref PbrMetallicRoughnessMaterialData::roughnessTextureLayer()
+     */
+    RoughnessTextureLayer,
+
     /**
      * Combined roughness/metallic texture index for PBR metallic/roughness
      * materials with metalness in the blue channel and roughness in the green
@@ -513,9 +575,10 @@ enum class MaterialAttribute: UnsignedInt {
     NoneRoughnessMetallicTexture,
 
     /* DiffuseColor, DiffuseTexture, DiffuseTextureMatrix,
-       DiffuseTextureCoordinates, SpecularColor, SpecularTexture,
-       SpecularTextureSwizzle, SpecularTextureMatrix,
-       SpecularTextureCoordinates specified above for Phong already */
+       DiffuseTextureCoordinates, DiffuseTextureLayer, SpecularColor,
+       SpecularTexture, SpecularTextureSwizzle, SpecularTextureMatrix,
+       SpecularTextureCoordinates, SpecularTextureLayer specified above for
+       Phong already */
 
     /**
      * Glossiness for PBR specular/glossiness materials,
@@ -577,6 +640,16 @@ enum class MaterialAttribute: UnsignedInt {
      */
     GlossinessTextureCoordinates,
 
+    /**
+     * Metalness texture array layer for PBR specular/glossiness materials,
+     * @ref MaterialAttributeType::UnsignedInt.
+     *
+     * Has a precedence over @ref MaterialAttribute::TextureLayer if both are
+     * present.
+     * @see @ref PbrSpecularGlossinessMaterialData::glossinessTextureLayer()
+     */
+    GlossinessTextureLayer,
+
     /**
      * Combined specular/glossiness texture index for PBR specular/glossiness
      * materials with specular color in the RGB channels and glossiness in
@@ -687,6 +760,17 @@ enum class MaterialAttribute: UnsignedInt {
      */
     NormalTextureCoordinates,
 
+    /**
+     * Normal texture array layer, @ref MaterialAttributeType::UnsignedInt.
+     *
+     * Has a precedence over @ref MaterialAttribute::TextureLayer if both are
+     * present.
+     * @see @ref PhongMaterialData::normalTextureLayer(),
+     *      @ref PbrMetallicRoughnessMaterialData::normalTextureLayer(),
+     *      @ref PbrSpecularGlossinessMaterialData::normalTextureLayer()
+     */
+    NormalTextureLayer,
+
     /**
      * Occlusion texture index,
      * @ref MaterialAttributeType::UnsignedInt.
@@ -754,6 +838,16 @@ enum class MaterialAttribute: UnsignedInt {
      */
     OcclusionTextureCoordinates,
 
+    /**
+     * Occlusion texture array layer, @ref MaterialAttributeType::UnsignedInt.
+     *
+     * Has a precedence over @ref MaterialAttribute::TextureLayer if both are
+     * present.
+     * @see @ref PbrMetallicRoughnessMaterialData::occlusionTextureLayer(),
+     *      @ref PbrSpecularGlossinessMaterialData::occlusionTextureLayer()
+     */
+    OcclusionTextureLayer,
+
     /**
      * Emissive color,
      * @ref MaterialAttributeType::Vector3.
@@ -801,6 +895,16 @@ enum class MaterialAttribute: UnsignedInt {
      */
     EmissiveTextureCoordinates,
 
+    /**
+     * Emissive texture array layer, @ref MaterialAttributeType::UnsignedInt.
+     *
+     * Has a precedence over @ref MaterialAttribute::TextureLayer if both are
+     * present.
+     * @see @ref PbrMetallicRoughnessMaterialData::emissiveTextureLayer(),
+     *      @ref PbrSpecularGlossinessMaterialData::emissiveTextureLayer()
+     */
+    EmissiveTextureLayer,
+
     /**
      * Layer intensity. @ref MaterialAttributeType::Float.
      *
@@ -855,6 +959,17 @@ enum class MaterialAttribute: UnsignedInt {
      */
     LayerFactorTextureCoordinates,
 
+    /**
+     * Layer intensity texture array layer,
+     * @ref MaterialAttributeType::UnsignedInt.
+     *
+     * Expected to be contained in additional layers, not the base material.
+     * Has a precedence over @ref MaterialAttribute::TextureLayer if both are
+     * present.
+     * @see @ref MaterialData::layerFactorTextureLayer()
+     */
+    LayerFactorTextureLayer,
+
     /**
      * Common texture transformation matrix for all textures,
      * @ref MaterialAttributeType::Matrix3x3.
@@ -908,6 +1023,33 @@ enum class MaterialAttribute: UnsignedInt {
      *      @ref FlatMaterialData::textureCoordinates()
      */
     TextureCoordinates,
+
+    /**
+     * Common texture array layer for all textures,
+     * @ref MaterialAttributeType::UnsignedInt.
+     *
+     * @ref MaterialAttribute::AmbientTextureLayer /
+     * @ref MaterialAttribute::DiffuseTextureLayer /
+     * @ref MaterialAttribute::SpecularTextureLayer /
+     * @ref MaterialAttribute::MetalnessTextureLayer /
+     * @ref MaterialAttribute::RoughnessTextureLayer /
+     * @ref MaterialAttribute::GlossinessTextureLayer /
+     * @ref MaterialAttribute::NormalTextureLayer /
+     * @ref MaterialAttribute::OcclusionTextureLayer /
+     * @ref MaterialAttribute::EmissiveTextureLayer /
+     * @ref MaterialAttribute::LayerFactorTextureLayer have a precedence over
+     * this attribute for given texture, if present.
+     * @see @ref PhongMaterialData::hasCommonTextureLayer(),
+     *      @ref PbrMetallicRoughnessMaterialData::hasCommonTextureLayer(),
+     *      @ref PbrSpecularGlossinessMaterialData::hasCommonTextureLayer(),
+     *      @ref PbrClearCoatMaterialData::hasCommonTextureLayer(),
+     *      @ref PhongMaterialData::commonTextureLayer(),
+     *      @ref PbrMetallicRoughnessMaterialData::commonTextureLayer(),
+     *      @ref PbrSpecularGlossinessMaterialData::commonTextureLayer(),
+     *      @ref PbrClearCoatMaterialData::commonTextureLayer(),
+     *      @ref FlatMaterialData::textureLayer()
+     */
+    TextureLayer,
 };
 
 /**
@@ -2052,6 +2194,34 @@ class MAGNUM_TRADE_EXPORT MaterialData {
         UnsignedInt layerFactorTextureCoordinates(Containers::StringView layer) const;
         UnsignedInt layerFactorTextureCoordinates(MaterialLayer layer) const; /**< @overload */
 
+        /**
+         * @brief Factor array texture layer for given layer
+         *
+         * Convenience access to the @ref MaterialAttribute::LayerFactorTextureLayer
+         * / @ref MaterialAttribute::TextureLayer attributes in given layer or
+         * a @ref MaterialAttribute::TextureLayer attribute in the base
+         * material. If neither is present, the default is @cpp 0 @ce.
+         * Available only if the @ref MaterialAttribute::LayerFactorTexture
+         * attribute is present. The @p layer is expected to be smaller than
+         * @ref layerCount().
+         * @see @ref hasAttribute()
+         */
+        UnsignedInt layerFactorTextureLayer(UnsignedInt layer) const;
+
+        /**
+         * @brief Factor array texture layer for a named layer
+         *
+         * Convenience access to the @ref MaterialAttribute::LayerFactorTextureLayer
+         * / @ref MaterialAttribute::TextureLayer attributes in given layer or
+         * a @ref MaterialAttribute::TextureLayer attribute in the base
+         * material. If neither is present, the default is @cpp 0 @ce.
+         * Available only if the @ref MaterialAttribute::LayerFactorTexture
+         * attribute is present. The @p layer is expected to exist.
+         * @see @ref hasLayer(), @ref hasAttribute()
+         */
+        UnsignedInt layerFactorTextureLayer(Containers::StringView layer) const;
+        UnsignedInt layerFactorTextureLayer(MaterialLayer layer) const; /**< @overload */
+
         /**
          * @brief Attribute count in given layer
          *

src/Magnum/Trade/MaterialLayerData.h

@@ -110,6 +110,16 @@ template<MaterialLayer layer> class MaterialLayerData: public MaterialData {
             return MaterialData::layerFactorTextureCoordinates(layer);
         }
 
+        /**
+         * @brief Layer factor array texture layer
+         *
+         * Same as calling @ref MaterialData::layerFactorTextureLayer() with
+         * @p layer.
+         */
+        UnsignedInt layerFactorTextureLayer() const {
+            return MaterialData::layerFactorTextureLayer(layer);
+        }
+
         /**
          * @brief Attribute count in this layer
          *
@@ -271,6 +281,7 @@ template<MaterialLayer layer> class MaterialLayerData: public MaterialData {
         using MaterialData::layerFactorTextureSwizzle;
         using MaterialData::layerFactorTextureMatrix;
         using MaterialData::layerFactorTextureCoordinates;
+        using MaterialData::layerFactorTextureLayer;
         /* MSVC is so damn unbelievably stupid it's setting my ass on fire.
            https://en.cppreference.com/w/cpp/language/using_declaration says
            that "If the derived class already has a member with the same name,

src/Magnum/Trade/PbrClearCoatMaterialData.cpp

@@ -34,7 +34,8 @@ bool PbrClearCoatMaterialData::hasLayerFactorRoughnessTexture() const {
         layerFactorTextureSwizzle() == MaterialTextureSwizzle::R &&
         roughnessTextureSwizzle() == MaterialTextureSwizzle::G &&
         layerFactorTextureMatrix() == roughnessTextureMatrix() &&
-        layerFactorTextureCoordinates() == roughnessTextureCoordinates();
+        layerFactorTextureCoordinates() == roughnessTextureCoordinates() &&
+        layerFactorTextureLayer() == roughnessTextureLayer();
 }
 
 bool PbrClearCoatMaterialData::hasTextureTransformation() const {
@@ -95,6 +96,35 @@ bool PbrClearCoatMaterialData::hasCommonTextureCoordinates() const {
     return true;
 }
 
+bool PbrClearCoatMaterialData::hasTextureLayer() const {
+    return attributeOr(MaterialAttribute::LayerFactorTextureLayer, 0u) ||
+        attributeOr(MaterialAttribute::RoughnessTextureLayer, 0u) ||
+        attributeOr(MaterialAttribute::NormalTextureLayer, 0u) ||
+        attributeOr(MaterialAttribute::TextureLayer, 0u) ||
+        attributeOr(0, MaterialAttribute::TextureLayer, 0u);
+}
+
+bool PbrClearCoatMaterialData::hasCommonTextureLayer() const {
+    auto check = [](Containers::Optional<UnsignedInt>& layer, UnsignedInt current) {
+        if(!layer) {
+            layer = current;
+            return true;
+        }
+        return layer == current;
+    };
+
+    Containers::Optional<UnsignedInt> layer;
+    /* First one can't fail */
+    if(hasAttribute(MaterialAttribute::LayerFactorTexture) && !check(layer, layerFactorTextureLayer()))
+        CORRADE_INTERNAL_ASSERT_UNREACHABLE(); /* LCOV_EXCL_LINE */
+    if(hasAttribute(MaterialAttribute::RoughnessTexture) && !check(layer, roughnessTextureLayer()))
+        return false;
+    if(hasAttribute(MaterialAttribute::NormalTexture) && !check(layer, normalTextureLayer()))
+        return false;
+
+    return true;
+}
+
 Float PbrClearCoatMaterialData::roughness() const {
     return attributeOr(MaterialAttribute::Roughness, 0.0f);
 }
@@ -129,6 +159,16 @@ UnsignedInt PbrClearCoatMaterialData::roughnessTextureCoordinates() const {
     return attributeOr(0, MaterialAttribute::TextureCoordinates, 0u);
 }
 
+UnsignedInt PbrClearCoatMaterialData::roughnessTextureLayer() const {
+    CORRADE_ASSERT(hasAttribute(MaterialAttribute::RoughnessTexture),
+        "Trade::PbrClearCoatMaterialData::roughnessTextureLayer(): the layer doesn't have a roughness texture", {});
+    if(Containers::Optional<UnsignedInt> value = tryAttribute<UnsignedInt>(MaterialAttribute::RoughnessTextureLayer))
+        return *value;
+    if(Containers::Optional<UnsignedInt> value = tryAttribute<UnsignedInt>(MaterialAttribute::TextureLayer))
+        return *value;
+    return attributeOr(0, MaterialAttribute::TextureLayer, 0u);
+}
+
 UnsignedInt PbrClearCoatMaterialData::normalTexture() const {
     return attribute<UnsignedInt>(MaterialAttribute::NormalTexture);
 }
@@ -165,6 +205,16 @@ UnsignedInt PbrClearCoatMaterialData::normalTextureCoordinates() const {
     return attributeOr(0, MaterialAttribute::TextureCoordinates, 0u);
 }
 
+UnsignedInt PbrClearCoatMaterialData::normalTextureLayer() const {
+    CORRADE_ASSERT(hasAttribute(MaterialAttribute::NormalTexture),
+        "Trade::PbrClearCoatMaterialData::normalTextureLayer(): the layer doesn't have a normal texture", {});
+    if(Containers::Optional<UnsignedInt> value = tryAttribute<UnsignedInt>(MaterialAttribute::NormalTextureLayer))
+        return *value;
+    if(Containers::Optional<UnsignedInt> value = tryAttribute<UnsignedInt>(MaterialAttribute::TextureLayer))
+        return *value;
+    return attributeOr(0, MaterialAttribute::TextureLayer, 0u);
+}
+
 Matrix3 PbrClearCoatMaterialData::commonTextureMatrix() const {
     CORRADE_ASSERT(hasCommonTextureTransformation(),
         "Trade::PbrClearCoatMaterialData::commonTextureMatrix(): the layer doesn't have a common texture coordinate transformation", {});
@@ -193,4 +243,18 @@ UnsignedInt PbrClearCoatMaterialData::commonTextureCoordinates() const {
     return attributeOr(0, MaterialAttribute::TextureCoordinates, 0u);
 }
 
+UnsignedInt PbrClearCoatMaterialData::commonTextureLayer() const {
+    CORRADE_ASSERT(hasCommonTextureLayer(),
+        "Trade::PbrClearCoatMaterialData::commonTextureLayer(): the layer doesn't have a common array texture layer", {});
+    if(hasAttribute(MaterialAttribute::LayerFactorTexture))
+        return layerFactorTextureLayer();
+    if(hasAttribute(MaterialAttribute::RoughnessTexture))
+        return roughnessTextureLayer();
+    if(hasAttribute(MaterialAttribute::NormalTexture))
+        return normalTextureLayer();
+    if(Containers::Optional<UnsignedInt> value = tryAttribute<UnsignedInt>(MaterialAttribute::TextureLayer))
+        return *value;
+    return attributeOr(0, MaterialAttribute::TextureLayer, 0u);
+}
+
 }}

src/Magnum/Trade/PbrClearCoatMaterialData.h

@@ -69,17 +69,21 @@ class MAGNUM_TRADE_EXPORT PbrClearCoatMaterialData: public MaterialLayerData<Mat
          * @ref MaterialTextureSwizzle::G, and additionally
          * @ref MaterialAttribute::LayerFactorTextureMatrix and
          * @ref MaterialAttribute::RoughnessTextureMatrix are both either not
-         * present or have the same value, and
+         * present or have the same value,
          * @ref MaterialAttribute::LayerFactorTextureCoordinates and
          * @ref MaterialAttribute::RoughnessTextureCoordinates are both either
-         * not present or have the same value; @cpp false @ce otherwise.
+         * not present or have the same value, and
+         * @ref MaterialAttribute::LayerFactorTextureLayer and
+         * @ref MaterialAttribute::RoughnessTextureLayer are both either not
+         * present or have the same value; @cpp false @ce otherwise.
          *
          * In other words, if this function returns @cpp true @ce,
-         * @ref layerFactorTexture(), @ref layerFactorTextureMatrix() and
-         * @ref layerFactorTextureCoordinates() return values common for both
-         * layer factor and roughness texture, and the two are packed together
-         * with layer factor occupying the R channel and roughness the G
-         * channel. This check is present in order to provide support for the
+         * @ref layerFactorTexture(), @ref layerFactorTextureMatrix(),
+         * @ref layerFactorTextureCoordinates() and
+         * @ref layerFactorTextureLayer() return values common for both layer
+         * factor and roughness texture, and the two are packed together with
+         * layer factor occupying the R channel and roughness the G channel.
+         * This check is present in order to provide support for the
          * [KHR_materials_clearcoat](https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md)
          * glTF extension.
          * @see @ref hasAttribute()
@@ -142,6 +146,33 @@ class MAGNUM_TRADE_EXPORT PbrClearCoatMaterialData: public MaterialLayerData<Mat
          */
         bool hasCommonTextureCoordinates() const;
 
+        /**
+         * @brief Whether the material uses array texture layers
+         *
+         * Returns @cpp true @ce if any of the
+         * @ref MaterialAttribute::LayerFactorTextureLayer,
+         * @ref MaterialAttribute::RoughnessTextureLayer,
+         * @ref MaterialAttribute::NormalTextureLayer or
+         * @ref MaterialAttribute::TextureLayer attributes are present in this
+         * material or if @ref MaterialAttribute::TextureLayer is present in
+         * the base material, @cpp false @ce otherwise.
+         * @see @ref hasCommonTextureLayer()
+         */
+        bool hasTextureLayer() const;
+
+        /**
+         * @brief Whether the material has a common array texture layer for all textures
+         *
+         * Returns @cpp true @ce if, for each texture that is present,
+         * @ref layerFactorTextureLayer(), @ref roughnessTextureLayer() and
+         * @ref normalTextureLayer() have the same value, @cpp false @ce
+         * otherwise. In particular, returns @cpp true @ce also if there's no
+         * array texture layer used at all. Use @ref hasTextureLayer() to
+         * distinguish that case.
+         * @see @ref commonTextureLayer()
+         */
+        bool hasCommonTextureLayer() const;
+
         /**
          * @brief Roughness factor
          *
@@ -199,6 +230,18 @@ class MAGNUM_TRADE_EXPORT PbrClearCoatMaterialData: public MaterialLayerData<Mat
          */
         UnsignedInt roughnessTextureCoordinates() const;
 
+        /**
+         * @brief Roughness array texture layer
+         *
+         * Convenience access to the @ref MaterialAttribute::RoughnessTextureLayer
+         * / @ref MaterialAttribute::TextureLayer attributes in this layer or a
+         * @ref MaterialAttribute::TextureLayer attribute in the base material.
+         * If neither is present, the default is @cpp 0 @ce. Available only if
+         * @ref MaterialAttribute::RoughnessTexture is present in this layer.
+         * @see @ref hasAttribute()
+         */
+        UnsignedInt roughnessTextureLayer() const;
+
         /**
          * @brief Normal texture ID
          *
@@ -260,6 +303,18 @@ class MAGNUM_TRADE_EXPORT PbrClearCoatMaterialData: public MaterialLayerData<Mat
          */
         UnsignedInt normalTextureCoordinates() const;
 
+        /**
+         * @brief Normal array texture layer
+         *
+         * Convenience access to the @ref MaterialAttribute::NormalTextureLayer
+         * / @ref MaterialAttribute::TextureLayer attributes in this layer or a
+         * @ref MaterialAttribute::TextureLayer attribute in the base material.
+         * If neither is present, the default is @cpp 0 @ce. Available only if
+         * @ref MaterialAttribute::NormalTexture is present in this layer.
+         * @see @ref hasAttribute()
+         */
+        UnsignedInt normalTextureLayer() const;
+
         /**
          * @brief Common texture coordinate transformation matrix for all textures
          *
@@ -282,6 +337,16 @@ class MAGNUM_TRADE_EXPORT PbrClearCoatMaterialData: public MaterialLayerData<Mat
          * texture is present, returns @cpp 0 @ce.
          */
         UnsignedInt commonTextureCoordinates() const;
+
+        /**
+         * @brief Common array texture layer for all textures
+         *
+         * Expects that @ref hasCommonTextureLayer() is @cpp true @ce; returns
+         * a layer that's the same for all of @ref layerFactorTextureLayer(),
+         * @ref roughnessTextureLayer() and @ref normalTextureLayer() where a
+         * texture is present. If no texture is present, returns @cpp 0 @ce.
+         */
+        UnsignedInt commonTextureLayer() const;
 };
 
 }}

src/Magnum/Trade/PbrMetallicRoughnessMaterialData.cpp

@@ -50,7 +50,8 @@ bool PbrMetallicRoughnessMaterialData::hasNoneRoughnessMetallicTexture() const {
         roughnessTextureSwizzle() == MaterialTextureSwizzle::G &&
         metalnessTextureSwizzle() == MaterialTextureSwizzle::B)) &&
        roughnessTextureMatrix() == metalnessTextureMatrix() &&
-       roughnessTextureCoordinates() == metalnessTextureCoordinates();
+       roughnessTextureCoordinates() == metalnessTextureCoordinates() &&
+       roughnessTextureLayer() == metalnessTextureLayer();
 }
 
 bool PbrMetallicRoughnessMaterialData::hasRoughnessMetallicOcclusionTexture() const {
@@ -69,10 +70,13 @@ bool PbrMetallicRoughnessMaterialData::hasRoughnessMetallicOcclusionTexture() co
 
     const Matrix3 roughnessTextureMatrix = this->roughnessTextureMatrix();
     const UnsignedInt roughnessTextureCoordinates = this->roughnessTextureCoordinates();
+    const UnsignedInt roughnessTextureLayer = this->roughnessTextureLayer();
     return metalnessTextureMatrix() == roughnessTextureMatrix &&
         occlusionTextureMatrix() == roughnessTextureMatrix &&
         metalnessTextureCoordinates() == roughnessTextureCoordinates &&
-        occlusionTextureCoordinates() == roughnessTextureCoordinates;
+        occlusionTextureCoordinates() == roughnessTextureCoordinates &&
+        metalnessTextureLayer() == roughnessTextureLayer &&
+        occlusionTextureLayer() == roughnessTextureLayer;
 }
 
 bool PbrMetallicRoughnessMaterialData::hasOcclusionRoughnessMetallicTexture() const {
@@ -91,10 +95,13 @@ bool PbrMetallicRoughnessMaterialData::hasOcclusionRoughnessMetallicTexture() co
 
     const Matrix3 occlusionTextureMatrix = this->occlusionTextureMatrix();
     const UnsignedInt occlusionTextureCoordinates = this->occlusionTextureCoordinates();
+    const UnsignedInt occlusionTextureLayer = this->occlusionTextureLayer();
     return roughnessTextureMatrix() == occlusionTextureMatrix &&
         metalnessTextureMatrix() == occlusionTextureMatrix &&
         roughnessTextureCoordinates() == occlusionTextureCoordinates &&
-        metalnessTextureCoordinates() == occlusionTextureCoordinates;
+        metalnessTextureCoordinates() == occlusionTextureCoordinates &&
+        roughnessTextureLayer() == occlusionTextureLayer &&
+        metalnessTextureLayer() == occlusionTextureLayer;
 }
 
 bool PbrMetallicRoughnessMaterialData::hasNormalRoughnessMetallicTexture() const {
@@ -113,10 +120,13 @@ bool PbrMetallicRoughnessMaterialData::hasNormalRoughnessMetallicTexture() const
 
     const Matrix3 normalTextureMatrix = this->normalTextureMatrix();
     const UnsignedInt normalTextureCoordinates = this->normalTextureCoordinates();
+    const UnsignedInt normalTextureLayer = this->normalTextureLayer();
     return roughnessTextureMatrix() == normalTextureMatrix &&
         metalnessTextureMatrix() == normalTextureMatrix &&
         roughnessTextureCoordinates() == normalTextureCoordinates &&
-        metalnessTextureCoordinates() == normalTextureCoordinates;
+        metalnessTextureCoordinates() == normalTextureCoordinates &&
+        roughnessTextureLayer() == normalTextureLayer &&
+        metalnessTextureLayer() == normalTextureLayer;
 }
 
 bool PbrMetallicRoughnessMaterialData::hasTextureTransformation() const {
@@ -193,6 +203,43 @@ bool PbrMetallicRoughnessMaterialData::hasCommonTextureCoordinates() const {
     return true;
 }
 
+bool PbrMetallicRoughnessMaterialData::hasTextureLayer() const {
+    return attributeOr(MaterialAttribute::TextureLayer, 0u) ||
+        attributeOr(MaterialAttribute::BaseColorTextureLayer, 0u) ||
+        attributeOr(MaterialAttribute::MetalnessTextureLayer, 0u) ||
+        attributeOr(MaterialAttribute::RoughnessTextureLayer, 0u) ||
+        attributeOr(MaterialAttribute::NormalTextureLayer, 0u) ||
+        attributeOr(MaterialAttribute::OcclusionTextureLayer, 0u) ||
+        attributeOr(MaterialAttribute::EmissiveTextureLayer, 0u);
+}
+
+bool PbrMetallicRoughnessMaterialData::hasCommonTextureLayer() const {
+    auto check = [](Containers::Optional<UnsignedInt>& layer, UnsignedInt current) {
+        if(!layer) {
+            layer = current;
+            return true;
+        }
+        return layer == current;
+    };
+
+    Containers::Optional<UnsignedInt> layer;
+    /* First one can't fail */
+    if(hasAttribute(MaterialAttribute::BaseColorTexture) && !check(layer, baseColorTextureLayer()))
+        CORRADE_INTERNAL_ASSERT_UNREACHABLE(); /* LCOV_EXCL_LINE */
+    if(hasMetalnessTexture() && !check(layer, metalnessTextureLayer()))
+        return false;
+    if(hasRoughnessTexture() && !check(layer, roughnessTextureLayer()))
+        return false;
+    if(hasAttribute(MaterialAttribute::NormalTexture) && !check(layer, normalTextureLayer()))
+        return false;
+    if(hasAttribute(MaterialAttribute::OcclusionTexture) && !check(layer, occlusionTextureLayer()))
+        return false;
+    if(hasAttribute(MaterialAttribute::EmissiveTexture) && !check(layer, emissiveTextureLayer()))
+        return false;
+
+    return true;
+}
+
 Color4 PbrMetallicRoughnessMaterialData::baseColor() const {
     return attributeOr(MaterialAttribute::BaseColor, 0xffffffff_rgbaf);
 }
@@ -217,6 +264,14 @@ UnsignedInt PbrMetallicRoughnessMaterialData::baseColorTextureCoordinates() cons
     return attributeOr(MaterialAttribute::TextureCoordinates, 0u);
 }
 
+UnsignedInt PbrMetallicRoughnessMaterialData::baseColorTextureLayer() const {
+    CORRADE_ASSERT(hasAttribute(MaterialAttribute::BaseColorTexture),
+        "Trade::PbrMetallicRoughnessMaterialData::baseColorTextureLayer(): the material doesn't have a base color texture", {});
+    if(Containers::Optional<UnsignedInt> value = tryAttribute<UnsignedInt>(MaterialAttribute::BaseColorTextureLayer))
+        return *value;
+    return attributeOr(MaterialAttribute::TextureLayer, 0u);
+}
+
 Float PbrMetallicRoughnessMaterialData::metalness() const {
     return attributeOr(MaterialAttribute::Metalness, 1.0f);
 }
@@ -256,6 +311,14 @@ UnsignedInt PbrMetallicRoughnessMaterialData::metalnessTextureCoordinates() cons
     return attributeOr(MaterialAttribute::TextureCoordinates, 0u);
 }
 
+UnsignedInt PbrMetallicRoughnessMaterialData::metalnessTextureLayer() const {
+    CORRADE_ASSERT(hasMetalnessTexture(),
+        "Trade::PbrMetallicRoughnessMaterialData::metalnessTextureLayer(): the material doesn't have a metalness texture", {});
+    if(Containers::Optional<UnsignedInt> value = tryAttribute<UnsignedInt>(MaterialAttribute::MetalnessTextureLayer))
+        return *value;
+    return attributeOr(MaterialAttribute::TextureLayer, 0u);
+}
+
 Float PbrMetallicRoughnessMaterialData::roughness() const {
     return attributeOr(MaterialAttribute::Roughness, 1.0f);
 }
@@ -295,6 +358,14 @@ UnsignedInt PbrMetallicRoughnessMaterialData::roughnessTextureCoordinates() cons
     return attributeOr(MaterialAttribute::TextureCoordinates, 0u);
 }
 
+UnsignedInt PbrMetallicRoughnessMaterialData::roughnessTextureLayer() const {
+    CORRADE_ASSERT(hasRoughnessTexture(),
+        "Trade::PbrMetallicRoughnessMaterialData::roughnessTextureLayer(): the material doesn't have a roughness texture", {});
+    if(Containers::Optional<UnsignedInt> value = tryAttribute<UnsignedInt>(MaterialAttribute::RoughnessTextureLayer))
+        return *value;
+    return attributeOr(MaterialAttribute::TextureLayer, 0u);
+}
+
 UnsignedInt PbrMetallicRoughnessMaterialData::normalTexture() const {
     return attribute<UnsignedInt>(MaterialAttribute::NormalTexture);
 }
@@ -327,6 +398,14 @@ UnsignedInt PbrMetallicRoughnessMaterialData::normalTextureCoordinates() const {
     return attributeOr(MaterialAttribute::TextureCoordinates, 0u);
 }
 
+UnsignedInt PbrMetallicRoughnessMaterialData::normalTextureLayer() const {
+    CORRADE_ASSERT(hasAttribute(MaterialAttribute::NormalTexture),
+        "Trade::PbrMetallicRoughnessMaterialData::normalTextureLayer(): the material doesn't have a normal texture", {});
+    if(Containers::Optional<UnsignedInt> value = tryAttribute<UnsignedInt>(MaterialAttribute::NormalTextureLayer))
+        return *value;
+    return attributeOr(MaterialAttribute::TextureLayer, 0u);
+}
+
 UnsignedInt PbrMetallicRoughnessMaterialData::occlusionTexture() const {
     return attribute<UnsignedInt>(MaterialAttribute::OcclusionTexture);
 }
@@ -359,6 +438,14 @@ UnsignedInt PbrMetallicRoughnessMaterialData::occlusionTextureCoordinates() cons
     return attributeOr(MaterialAttribute::TextureCoordinates, 0u);
 }
 
+UnsignedInt PbrMetallicRoughnessMaterialData::occlusionTextureLayer() const {
+    CORRADE_ASSERT(hasAttribute(MaterialAttribute::OcclusionTexture),
+        "Trade::PbrMetallicRoughnessMaterialData::occlusionTextureLayer(): the material doesn't have an occlusion texture", {});
+    if(Containers::Optional<UnsignedInt> value = tryAttribute<UnsignedInt>(MaterialAttribute::OcclusionTextureLayer))
+        return *value;
+    return attributeOr(MaterialAttribute::TextureLayer, 0u);
+}
+
 Color3 PbrMetallicRoughnessMaterialData::emissiveColor() const {
     return attributeOr(MaterialAttribute::EmissiveColor, 0x000000_srgbf);
 }
@@ -383,6 +470,14 @@ UnsignedInt PbrMetallicRoughnessMaterialData::emissiveTextureCoordinates() const
     return attributeOr(MaterialAttribute::TextureCoordinates, 0u);
 }
 
+UnsignedInt PbrMetallicRoughnessMaterialData::emissiveTextureLayer() const {
+    CORRADE_ASSERT(hasAttribute(MaterialAttribute::EmissiveTexture),
+        "Trade::PbrMetallicRoughnessMaterialData::emissiveTextureLayer(): the material doesn't have an emissive texture", {});
+    if(Containers::Optional<UnsignedInt> value = tryAttribute<UnsignedInt>(MaterialAttribute::EmissiveTextureLayer))
+        return *value;
+    return attributeOr(MaterialAttribute::TextureLayer, 0u);
+}
+
 Matrix3 PbrMetallicRoughnessMaterialData::commonTextureMatrix() const {
     CORRADE_ASSERT(hasCommonTextureTransformation(),
         "Trade::PbrMetallicRoughnessMaterialData::commonTextureMatrix(): the material doesn't have a common texture coordinate transformation", {});
@@ -419,4 +514,22 @@ UnsignedInt PbrMetallicRoughnessMaterialData::commonTextureCoordinates() const {
     return attributeOr(MaterialAttribute::TextureCoordinates, 0u);
 }
 
+UnsignedInt PbrMetallicRoughnessMaterialData::commonTextureLayer() const {
+    CORRADE_ASSERT(hasCommonTextureLayer(),
+        "Trade::PbrMetallicRoughnessMaterialData::commonTextureLayer(): the material doesn't have a common array texture layer", {});
+    if(hasAttribute(MaterialAttribute::BaseColorTexture))
+        return baseColorTextureLayer();
+    if(hasMetalnessTexture())
+        return metalnessTextureLayer();
+    if(hasRoughnessTexture())
+        return roughnessTextureLayer();
+    if(hasAttribute(MaterialAttribute::NormalTexture))
+        return normalTextureLayer();
+    if(hasAttribute(MaterialAttribute::OcclusionTexture))
+        return occlusionTextureLayer();
+    if(hasAttribute(MaterialAttribute::EmissiveTexture))
+        return emissiveTextureLayer();
+    return attributeOr(MaterialAttribute::TextureLayer, 0u);
+}
+
 }}

src/Magnum/Trade/PbrMetallicRoughnessMaterialData.h

@@ -92,19 +92,23 @@ class MAGNUM_TRADE_EXPORT PbrMetallicRoughnessMaterialData: public MaterialData
          * @ref MaterialTextureSwizzle::B, and ddditionally
          * @ref MaterialAttribute::RoughnessTextureMatrix and
          * @ref MaterialAttribute::MetalnessTextureMatrix are both either not
-         * present or have the same value, and
+         * present or have the same value,
          * @ref MaterialAttribute::RoughnessTextureCoordinates and
          * @ref MaterialAttribute::MetalnessTextureCoordinates are both either
-         * not present or have the same value; @cpp false @ce otherwise.
+         * not present or have the same value, and
+         * @ref MaterialAttribute::RoughnessTextureLayer and
+         * @ref MaterialAttribute::MetalnessTextureLayer are both either not
+         * present or have the same value; @cpp false @ce otherwise.
          *
          * In other words, if this function returns @cpp true @ce,
-         * @ref roughnessTexture(), @ref roughnessTextureMatrix() and
-         * @ref roughnessTextureCoordinates() return values common for both
-         * metalness and roughness texture, and the two are packed together
-         * with roughness occupying the G channel and metalness the B channel.
-         * This packing is common in glTF metallic/roughness materials, which
-         * in turn is compatible with how UE4 assets are usually packed.
-         * Original rationale for this [can be seen here](https://github.com/KhronosGroup/glTF/issues/857).
+         * @ref roughnessTexture(), @ref roughnessTextureMatrix(),
+         * @ref roughnessTextureCoordinates() and @ref roughnessTextureLayer()
+         * return values common for both metalness and roughness texture, and
+         * the two are packed together with roughness occupying the G channel
+         * and metalness the B channel. This packing is common in glTF
+         * metallic/roughness materials, which in turn is compatible with how
+         * UE4 assets are usually packed. Original rationale for this
+         * [can be seen here](https://github.com/KhronosGroup/glTF/issues/857).
          *
          * The red and alpha channels are ignored and can be repurposed for
          * other maps such as occlusion or transmission. This check is a subset
@@ -131,21 +135,25 @@ class MAGNUM_TRADE_EXPORT PbrMetallicRoughnessMaterialData: public MaterialData
          * @ref MaterialAttribute::OcclusionTextureMatrix,
          * @ref MaterialAttribute::RoughnessTextureMatrix and
          * @ref MaterialAttribute::MetalnessTextureMatrix are all other not
-         * present or have the same value, and
+         * present or have the same value,
          * @ref MaterialAttribute::OcclusionTextureCoordinates,
          * @ref MaterialAttribute::RoughnessTextureCoordinates and
          * @ref MaterialAttribute::MetalnessTextureCoordinates are all either
-         * not present or have the same value; @cpp false @ce otherwise.
+         * not present or have the same value, and
+         * @ref MaterialAttribute::OcclusionTextureLayer,
+         * @ref MaterialAttribute::RoughnessTextureLayer and
+         * @ref MaterialAttribute::MetalnessTextureLayer are all either not
+         * present or have the same value; @cpp false @ce otherwise.
          *
          * In other words, if this function returns @cpp true @ce,
-         * @ref occlusionTexture(), @ref occlusionTextureMatrix() and
-         * @ref occlusionTextureCoordinates() return values common for
-         * occlusion, roughness and metalness textures, and the three are
-         * packed together with occlusion occupying the R channel, roughness
-         * the G channel and metalness the B channel. This packing is common in
-         * glTF metallic/roughness materials, which in turn is compatible with
-         * how UE4 assets are usually packed. Original rationale for this [can
-         * be seen here](https://github.com/KhronosGroup/glTF/issues/857),
+         * @ref occlusionTexture(), @ref occlusionTextureMatrix(),
+         * @ref occlusionTextureCoordinates() and @ref occlusionTextureLayer()
+         * return values common for occlusion, roughness and metalness
+         * textures, and the three are packed together with occlusion occupying
+         * the R channel, roughness the G channel and metalness the B channel.
+         * This packing is common in glTF metallic/roughness materials, which
+         * in turn is compatible with how UE4 assets are usually packed.
+         * Original rationale for this [can be seen here](https://github.com/KhronosGroup/glTF/issues/857),
          * there's also a [MSFT_packing_occlusionRoughnessMetallic](https://github.com/KhronosGroup/glTF/blob/master/extensions/2.0/Vendor/MSFT_packing_occlusionRoughnessMetallic/README.md)
          * glTF extension using this packing in a more explicit way.
          *
@@ -175,19 +183,23 @@ class MAGNUM_TRADE_EXPORT PbrMetallicRoughnessMaterialData: public MaterialData
          * @ref MaterialAttribute::RoughnessTextureMatrix,
          * @ref MaterialAttribute::MetalnessTextureMatrix and
          * @ref MaterialAttribute::OcclusionTextureMatrix are all other not
-         * present or have the same value, and
+         * present or have the same value,
          * @ref MaterialAttribute::RoughnessTextureCoordinates,
          * @ref MaterialAttribute::MetalnessTextureCoordinates and
          * @ref MaterialAttribute::OcclusionTextureCoordinates are all either
-         * not present or have the same value; @cpp false @ce otherwise.
+         * not present or have the same value, and
+         * @ref MaterialAttribute::RoughnessTextureLayer,
+         * @ref MaterialAttribute::MetalnessTextureLayer and
+         * @ref MaterialAttribute::OcclusionTextureLayer are all either not
+         * present or have the same value; @cpp false @ce otherwise.
          *
          * In other words, if this function returns @cpp true @ce,
-         * @ref roughnessTexture(), @ref roughnessTextureMatrix() and
-         * @ref roughnessTextureCoordinates() return values common for
-         * roughness, metalness and occlusion textures, and the three are
-         * packed together with roughness occupying the R channel, metalness
-         * the G channel and occlusion the B channel. This check is present in
-         * order to provide support for the [MSFT_packing_occlusionRoughnessMetallic](https://github.com/KhronosGroup/glTF/blob/master/extensions/2.0/Vendor/MSFT_packing_occlusionRoughnessMetallic/README.md)
+         * @ref roughnessTexture(), @ref roughnessTextureMatrix(),
+         * @ref roughnessTextureCoordinates() and @ref roughnessTextureLayer()
+         * return values common for roughness, metalness and occlusion
+         * textures, and the three are packed together with roughness occupying
+         * the R channel, metalness the G channel and occlusion the B channel.
+         * This check is present in order to provide support for the [MSFT_packing_occlusionRoughnessMetallic](https://github.com/KhronosGroup/glTF/blob/master/extensions/2.0/Vendor/MSFT_packing_occlusionRoughnessMetallic/README.md)
          * glTF extension.
          *
          * The alpha channel is ignored and can be repurposed for other maps
@@ -214,19 +226,24 @@ class MAGNUM_TRADE_EXPORT PbrMetallicRoughnessMaterialData: public MaterialData
          * @ref MaterialAttribute::NormalTextureMatrix,
          * @ref MaterialAttribute::RoughnessTextureMatrix and
          * @ref MaterialAttribute::MetalnessTextureMatrix are all other not
-         * present or have the same value, and
+         * present or have the same value,
          * @ref MaterialAttribute::NormalTextureCoordinates,
          * @ref MaterialAttribute::RoughnessTextureCoordinates and
          * @ref MaterialAttribute::MetalnessTextureCoordinates are all either
-         * not present or have the same value; @cpp false @ce otherwise.
+         * not present or have the same value, and
+         * @ref MaterialAttribute::NormalTextureLayer,
+         * @ref MaterialAttribute::RoughnessTextureLayer and
+         * @ref MaterialAttribute::MetalnessTextureLayer are all either not
+         * present or have the same value; @cpp false @ce otherwise.
          *
          * In other words, if this function returns @cpp true @ce,
-         * @ref normalTexture(), @ref normalTextureMatrix() and
-         * @ref normalTextureCoordinates() return values common for normal,
-         * roughness and metalness textures, and the three are packed together
-         * with normals occupying the RG channel, roughness the B channel and
-         * metalness the A channel. This check is present in order to provide
-         * support for the [MSFT_packing_normalRoughnessMetallic](https://github.com/KhronosGroup/glTF/blob/master/extensions/2.0/Vendor/MSFT_packing_normalRoughnessMetallic/README.md)
+         * @ref normalTexture(), @ref normalTextureMatrix(),
+         * @ref normalTextureCoordinates() and @ref normalTextureLayer() return
+         * values common for normal, roughness and metalness textures, and the
+         * three are packed together with normals occupying the RG channel,
+         * roughness the B channel and metalness the A channel. This check is
+         * present in order to provide support for the
+         * [MSFT_packing_normalRoughnessMetallic](https://github.com/KhronosGroup/glTF/blob/master/extensions/2.0/Vendor/MSFT_packing_normalRoughnessMetallic/README.md)
          * glTF extension.
          *
          * @see @ref hasMetalnessTexture(), @ref hasRoughnessTexture(),
@@ -297,6 +314,36 @@ class MAGNUM_TRADE_EXPORT PbrMetallicRoughnessMaterialData: public MaterialData
          */
         bool hasCommonTextureCoordinates() const;
 
+        /**
+         * @brief Whether the material uses array texture layers
+         *
+         * Returns @cpp true @ce if any of the
+         * @ref MaterialAttribute::BaseColorTextureLayer,
+         * @ref MaterialAttribute::MetalnessTextureLayer,
+         * @ref MaterialAttribute::RoughnessTextureLayer,
+         * @ref MaterialAttribute::NormalTextureLayer,
+         * @ref MaterialAttribute::OcclusionTextureLayer,
+         * @ref MaterialAttribute::EmissiveTextureLayer or
+         * @ref MaterialAttribute::TextureLayer attributes is present and has a
+         * non-zero value, @cpp false @ce otherwise.
+         * @see @ref hasCommonTextureLayer()
+         */
+        bool hasTextureLayer() const;
+
+        /**
+         * @brief Whether the material has a common array texture layer for all textures
+         *
+         * Returns @cpp true @ce if, for each texture that is present,
+         * @ref baseColorTextureLayer(), @ref metalnessTextureLayer(),
+         * @ref roughnessTextureLayer(), @ref normalTextureLayer(),
+         * @ref occlusionTextureLayer() and @ref emissiveTextureLayer() have
+         * the same value, @cpp false @ce otherwise. In particular, returns
+         * @cpp true @ce also if there's no array texture layer used at all.
+         * Use @ref hasTextureLayer() to distinguish that case.
+         * @see @ref commonTextureLayer()
+         */
+        bool hasCommonTextureLayer() const;
+
         /**
          * @brief Base color
          *
@@ -339,6 +386,17 @@ class MAGNUM_TRADE_EXPORT PbrMetallicRoughnessMaterialData: public MaterialData
          */
         UnsignedInt baseColorTextureCoordinates() const;
 
+        /**
+         * @brief Base color array texture layer
+         *
+         * Convenience access to the @ref MaterialAttribute::BaseColorTextureLayer
+         * / @ref MaterialAttribute::TextureLayer attributes. If neither is
+         * present, the default is @cpp 0 @ce. Available only if the material
+         * has @ref MaterialAttribute::BaseColorTexture.
+         * @see @ref hasAttribute()
+         */
+        UnsignedInt baseColorTextureLayer() const;
+
         /**
          * @brief Metalness factor
          *
@@ -395,6 +453,17 @@ class MAGNUM_TRADE_EXPORT PbrMetallicRoughnessMaterialData: public MaterialData
          */
         UnsignedInt metalnessTextureCoordinates() const;
 
+        /**
+         * @brief Metalness array texture layer
+         *
+         * Convenience access to the @ref MaterialAttribute::MetalnessTextureLayer
+         * / @ref MaterialAttribute::TextureLayer attributes. If neither is
+         * present, the default is @cpp 0 @ce. Available only if the material
+         * has a metalness texture.
+         * @see @ref hasMetalnessTexture()
+         */
+        UnsignedInt metalnessTextureLayer() const;
+
         /**
          * @brief Roughness factor
          *
@@ -451,6 +520,17 @@ class MAGNUM_TRADE_EXPORT PbrMetallicRoughnessMaterialData: public MaterialData
          */
         UnsignedInt roughnessTextureCoordinates() const;
 
+        /**
+         * @brief Roughness array texture layer
+         *
+         * Convenience access to the @ref MaterialAttribute::RoughnessTextureLayer
+         * / @ref MaterialAttribute::TextureLayer attributes. If neither is
+         * present, the default is @cpp 0 @ce. Available only if the material
+         * has a roughness texture.
+         * @see @ref hasRoughnessTexture()
+         */
+        UnsignedInt roughnessTextureLayer() const;
+
         /**
          * @brief Normal texture ID
          *
@@ -503,6 +583,17 @@ class MAGNUM_TRADE_EXPORT PbrMetallicRoughnessMaterialData: public MaterialData
          */
         UnsignedInt normalTextureCoordinates() const;
 
+        /**
+         * @brief Normal array texture layer
+         *
+         * Convenience access to the @ref MaterialAttribute::NormalTextureLayer
+         * / @ref MaterialAttribute::TextureLayer attributes. If neither is
+         * present, the default is @cpp 0 @ce. Available only if the material
+         * has @ref MaterialAttribute::NormalTexture.
+         * @see @ref hasAttribute()
+         */
+        UnsignedInt normalTextureLayer() const;
+
         /**
          * @brief Occlusion texture ID
          *
@@ -555,6 +646,17 @@ class MAGNUM_TRADE_EXPORT PbrMetallicRoughnessMaterialData: public MaterialData
          */
         UnsignedInt occlusionTextureCoordinates() const;
 
+        /**
+         * @brief Occlusion array texture layer
+         *
+         * Convenience access to the @ref MaterialAttribute::OcclusionTextureLayer
+         * / @ref MaterialAttribute::TextureLayer attributes. If neither is
+         * present, the default is @cpp 0 @ce. Available only if the material
+         * has @ref MaterialAttribute::OcclusionTexture.
+         * @see @ref hasAttribute()
+         */
+        UnsignedInt occlusionTextureLayer() const;
+
         /**
          * @brief Emissive color
          *
@@ -600,6 +702,17 @@ class MAGNUM_TRADE_EXPORT PbrMetallicRoughnessMaterialData: public MaterialData
          */
         UnsignedInt emissiveTextureCoordinates() const;
 
+        /**
+         * @brief Emissive array texture layer
+         *
+         * Convenience access to the @ref MaterialAttribute::EmissiveTextureLayer
+         * / @ref MaterialAttribute::TextureLayer attributes. If neither is
+         * present, the default is @cpp 0 @ce. Available only if the material
+         * has @ref MaterialAttribute::EmissiveTexture.
+         * @see @ref hasAttribute()
+         */
+        UnsignedInt emissiveTextureLayer() const;
+
         /**
          * @brief Common texture coordinate transformation matrix for all textures
          *
@@ -625,6 +738,18 @@ class MAGNUM_TRADE_EXPORT PbrMetallicRoughnessMaterialData: public MaterialData
          * @cpp 0 @ce.
          */
         UnsignedInt commonTextureCoordinates() const;
+
+        /**
+         * @brief Common array texture layer for all textures
+         *
+         * Expects that @ref hasCommonTextureLayer() is @cpp true @ce; returns
+         * a layer that's the same for all of @ref baseColorTextureLayer(),
+         * @ref metalnessTextureLayer(), @ref roughnessTextureLayer(),
+         * @ref normalTextureLayer(), @ref occlusionTextureLayer() and
+         * @ref emissiveTextureLayer() where a texture is present. If no
+         * texture is present, returns @cpp 0 @ce.
+         */
+        UnsignedInt commonTextureLayer() const;
 };
 
 }}

src/Magnum/Trade/PbrSpecularGlossinessMaterialData.cpp

@@ -50,7 +50,8 @@ bool PbrSpecularGlossinessMaterialData::hasSpecularGlossinessTexture() const {
         specularTextureSwizzle() == MaterialTextureSwizzle::RGB &&
         glossinessTextureSwizzle() == MaterialTextureSwizzle::A)) &&
        specularTextureMatrix() == glossinessTextureMatrix() &&
-       specularTextureCoordinates() == glossinessTextureCoordinates();
+       specularTextureCoordinates() == glossinessTextureCoordinates() &&
+       specularTextureLayer() == glossinessTextureLayer();
 }
 
 bool PbrSpecularGlossinessMaterialData::hasTextureTransformation() const {
@@ -127,6 +128,43 @@ bool PbrSpecularGlossinessMaterialData::hasCommonTextureCoordinates() const {
     return true;
 }
 
+bool PbrSpecularGlossinessMaterialData::hasTextureLayer() const {
+    return attributeOr(MaterialAttribute::TextureLayer, 0u) ||
+        attributeOr(MaterialAttribute::DiffuseTextureLayer, 0u) ||
+        attributeOr(MaterialAttribute::SpecularTextureLayer, 0u) ||
+        attributeOr(MaterialAttribute::GlossinessTextureLayer, 0u) ||
+        attributeOr(MaterialAttribute::NormalTextureLayer, 0u) ||
+        attributeOr(MaterialAttribute::OcclusionTextureLayer, 0u) ||
+        attributeOr(MaterialAttribute::EmissiveTextureLayer, 0u);
+}
+
+bool PbrSpecularGlossinessMaterialData::hasCommonTextureLayer() const {
+    auto check = [](Containers::Optional<UnsignedInt>& layer, UnsignedInt current) {
+        if(!layer) {
+            layer = current;
+            return true;
+        }
+        return layer == current;
+    };
+
+    Containers::Optional<UnsignedInt> layer;
+    /* First one can't fail */
+    if(hasAttribute(MaterialAttribute::DiffuseTexture) && !check(layer, diffuseTextureLayer()))
+        CORRADE_INTERNAL_ASSERT_UNREACHABLE(); /* LCOV_EXCL_LINE */
+    if(hasSpecularTexture() && !check(layer, specularTextureLayer()))
+        return false;
+    if(hasGlossinessTexture() && !check(layer, glossinessTextureLayer()))
+        return false;
+    if(hasAttribute(MaterialAttribute::NormalTexture) && !check(layer, normalTextureLayer()))
+        return false;
+    if(hasAttribute(MaterialAttribute::OcclusionTexture) && !check(layer, occlusionTextureLayer()))
+        return false;
+    if(hasAttribute(MaterialAttribute::EmissiveTexture) && !check(layer, emissiveTextureLayer()))
+        return false;
+
+    return true;
+}
+
 Color4 PbrSpecularGlossinessMaterialData::diffuseColor() const {
     return attributeOr(MaterialAttribute::DiffuseColor, 0xffffffff_srgbaf);
 }
@@ -151,6 +189,14 @@ UnsignedInt PbrSpecularGlossinessMaterialData::diffuseTextureCoordinates() const
     return attributeOr(MaterialAttribute::TextureCoordinates, 0u);
 }
 
+UnsignedInt PbrSpecularGlossinessMaterialData::diffuseTextureLayer() const {
+    CORRADE_ASSERT(hasAttribute(MaterialAttribute::DiffuseTexture),
+        "Trade::PbrSpecularGlossinessMaterialData::diffuseTextureLayer(): the material doesn't have a diffuse texture", {});
+    if(Containers::Optional<UnsignedInt> value = tryAttribute<UnsignedInt>(MaterialAttribute::DiffuseTextureLayer))
+        return *value;
+    return attributeOr(MaterialAttribute::TextureLayer, 0u);
+}
+
 Color4 PbrSpecularGlossinessMaterialData::specularColor() const {
     return attributeOr(MaterialAttribute::SpecularColor, 0xffffff00_srgbaf);
 }
@@ -190,6 +236,14 @@ UnsignedInt PbrSpecularGlossinessMaterialData::specularTextureCoordinates() cons
     return attributeOr(MaterialAttribute::TextureCoordinates, 0u);
 }
 
+UnsignedInt PbrSpecularGlossinessMaterialData::specularTextureLayer() const {
+    CORRADE_ASSERT(hasSpecularTexture(),
+        "Trade::PbrSpecularGlossinessMaterialData::specularTextureLayer(): the material doesn't have a specular texture", {});
+    if(Containers::Optional<UnsignedInt> value = tryAttribute<UnsignedInt>(MaterialAttribute::SpecularTextureLayer))
+        return *value;
+    return attributeOr(MaterialAttribute::TextureLayer, 0u);
+}
+
 Float PbrSpecularGlossinessMaterialData::glossiness() const {
     return attributeOr(MaterialAttribute::Glossiness, 1.0f);
 }
@@ -229,6 +283,14 @@ UnsignedInt PbrSpecularGlossinessMaterialData::glossinessTextureCoordinates() co
     return attributeOr(MaterialAttribute::TextureCoordinates, 0u);
 }
 
+UnsignedInt PbrSpecularGlossinessMaterialData::glossinessTextureLayer() const {
+    CORRADE_ASSERT(hasGlossinessTexture(),
+        "Trade::PbrSpecularGlossinessMaterialData::glossinessTextureLayer(): the material doesn't have a glossiness texture", {});
+    if(Containers::Optional<UnsignedInt> value = tryAttribute<UnsignedInt>(MaterialAttribute::GlossinessTextureLayer))
+        return *value;
+    return attributeOr(MaterialAttribute::TextureLayer, 0u);
+}
+
 UnsignedInt PbrSpecularGlossinessMaterialData::normalTexture() const {
     return attribute<UnsignedInt>(MaterialAttribute::NormalTexture);
 }
@@ -261,6 +323,14 @@ UnsignedInt PbrSpecularGlossinessMaterialData::normalTextureCoordinates() const
     return attributeOr(MaterialAttribute::TextureCoordinates, 0u);
 }
 
+UnsignedInt PbrSpecularGlossinessMaterialData::normalTextureLayer() const {
+    CORRADE_ASSERT(hasAttribute(MaterialAttribute::NormalTexture),
+        "Trade::PbrSpecularGlossinessMaterialData::normalTextureLayer(): the material doesn't have a normal texture", {});
+    if(Containers::Optional<UnsignedInt> value = tryAttribute<UnsignedInt>(MaterialAttribute::NormalTextureLayer))
+        return *value;
+    return attributeOr(MaterialAttribute::TextureLayer, 0u);
+}
+
 UnsignedInt PbrSpecularGlossinessMaterialData::occlusionTexture() const {
     return attribute<UnsignedInt>(MaterialAttribute::OcclusionTexture);
 }
@@ -293,6 +363,14 @@ UnsignedInt PbrSpecularGlossinessMaterialData::occlusionTextureCoordinates() con
     return attributeOr(MaterialAttribute::TextureCoordinates, 0u);
 }
 
+UnsignedInt PbrSpecularGlossinessMaterialData::occlusionTextureLayer() const {
+    CORRADE_ASSERT(hasAttribute(MaterialAttribute::OcclusionTexture),
+        "Trade::PbrSpecularGlossinessMaterialData::occlusionTextureLayer(): the material doesn't have an occlusion texture", {});
+    if(Containers::Optional<UnsignedInt> value = tryAttribute<UnsignedInt>(MaterialAttribute::OcclusionTextureLayer))
+        return *value;
+    return attributeOr(MaterialAttribute::TextureLayer, 0u);
+}
+
 Color3 PbrSpecularGlossinessMaterialData::emissiveColor() const {
     return attributeOr(MaterialAttribute::EmissiveColor, 0x000000_srgbf);
 }
@@ -317,6 +395,14 @@ UnsignedInt PbrSpecularGlossinessMaterialData::emissiveTextureCoordinates() cons
     return attributeOr(MaterialAttribute::TextureCoordinates, 0u);
 }
 
+UnsignedInt PbrSpecularGlossinessMaterialData::emissiveTextureLayer() const {
+    CORRADE_ASSERT(hasAttribute(MaterialAttribute::EmissiveTexture),
+        "Trade::PbrSpecularGlossinessMaterialData::emissiveTextureLayer(): the material doesn't have an emissive texture", {});
+    if(Containers::Optional<UnsignedInt> value = tryAttribute<UnsignedInt>(MaterialAttribute::EmissiveTextureLayer))
+        return *value;
+    return attributeOr(MaterialAttribute::TextureLayer, 0u);
+}
+
 Matrix3 PbrSpecularGlossinessMaterialData::commonTextureMatrix() const {
     CORRADE_ASSERT(hasCommonTextureTransformation(),
         "Trade::PbrSpecularGlossinessMaterialData::commonTextureMatrix(): the material doesn't have a common texture coordinate transformation", {});
@@ -353,4 +439,22 @@ UnsignedInt PbrSpecularGlossinessMaterialData::commonTextureCoordinates() const
     return attributeOr(MaterialAttribute::TextureCoordinates, 0u);
 }
 
+UnsignedInt PbrSpecularGlossinessMaterialData::commonTextureLayer() const {
+    CORRADE_ASSERT(hasCommonTextureLayer(),
+        "Trade::PbrSpecularGlossinessMaterialData::commonTextureLayer(): the material doesn't have a common array texture layer", {});
+    if(hasAttribute(MaterialAttribute::DiffuseTexture))
+        return diffuseTextureLayer();
+    if(hasSpecularTexture())
+        return specularTextureLayer();
+    if(hasGlossinessTexture())
+        return glossinessTextureLayer();
+    if(hasAttribute(MaterialAttribute::NormalTexture))
+        return normalTextureLayer();
+    if(hasAttribute(MaterialAttribute::OcclusionTexture))
+        return occlusionTextureLayer();
+    if(hasAttribute(MaterialAttribute::EmissiveTexture))
+        return emissiveTextureLayer();
+    return attributeOr(MaterialAttribute::TextureLayer, 0u);
+}
+
 }}

src/Magnum/Trade/PbrSpecularGlossinessMaterialData.h

@@ -90,16 +90,20 @@ class MAGNUM_TRADE_EXPORT PbrSpecularGlossinessMaterialData: public MaterialData
          * is set to @ref MaterialTextureSwizzle::A, and ddditionally
          * @ref MaterialAttribute::SpecularTextureMatrix and
          * @ref MaterialAttribute::GlossinessTextureMatrix are both either not
-         * present or have the same value, and
+         * present or have the same value,
          * @ref MaterialAttribute::SpecularTextureCoordinates and
          * @ref MaterialAttribute::GlossinessTextureCoordinates are both either
-         * not present or have the same value; @cpp false @ce otherwise.
+         * not present or have the same value, and
+         * @ref MaterialAttribute::SpecularTextureLayer and
+         * @ref MaterialAttribute::GlossinessTextureLayer are both either not
+         * present or have the same value; @cpp false @ce otherwise.
          *
          * In other words, if this function returns @cpp true @ce,
-         * @ref specularTexture(), @ref specularTextureMatrix() and
-         * @ref specularTextureCoordinates() return values common for both
-         * specular and glossiness texture, and the two are packed together
-         * with specular occupying the RGB channels and glossiness the alpha.
+         * @ref specularTexture(), @ref specularTextureMatrix(),
+         * @ref specularTextureCoordinates() and @ref specularTextureLayer()
+         * return values common for both specular and glossiness texture, and
+         * the two are packed together with specular occupying the RGB channels
+         * and glossiness the alpha.
          * @see @ref hasSpecularTexture(), @ref hasGlossinessTexture()
          */
         bool hasSpecularGlossinessTexture() const;
@@ -165,6 +169,36 @@ class MAGNUM_TRADE_EXPORT PbrSpecularGlossinessMaterialData: public MaterialData
          */
         bool hasCommonTextureCoordinates() const;
 
+        /**
+         * @brief Whether the material uses array texture layers
+         *
+         * Returns @cpp true @ce if any of the
+         * @ref MaterialAttribute::DiffuseTextureLayer,
+         * @ref MaterialAttribute::SpecularTextureLayer,
+         * @ref MaterialAttribute::GlossinessTextureLayer,
+         * @ref MaterialAttribute::NormalTextureLayer,
+         * @ref MaterialAttribute::OcclusionTextureLayer,
+         * @ref MaterialAttribute::EmissiveTextureLayer or
+         * @ref MaterialAttribute::TextureLayer attributes is present and has a
+         * non-zero value, @cpp false @ce otherwise.
+         * @see @ref hasCommonTextureLayer()
+         */
+        bool hasTextureLayer() const;
+
+        /**
+         * @brief Whether the material has a common array texture layer for all textures
+         *
+         * Returns @cpp true @ce if, for each texture that is present,
+         * @ref diffuseTextureLayer(), @ref specularTextureLayer(),
+         * @ref glossinessTextureLayer(), @ref normalTextureLayer(),
+         * @ref occlusionTextureLayer() and @ref emissiveTextureLayer() have
+         * the same value, @cpp false @ce otherwise. In particular, returns
+         * @cpp true @ce also if there's no array texture layer used at all.
+         * Use @ref hasTextureLayer() to distinguish that case.
+         * @see @ref commonTextureLayer()
+         */
+        bool hasCommonTextureLayer() const;
+
         /**
          * @brief Diffuse color
          *
@@ -207,6 +241,17 @@ class MAGNUM_TRADE_EXPORT PbrSpecularGlossinessMaterialData: public MaterialData
          */
         UnsignedInt diffuseTextureCoordinates() const;
 
+        /**
+         * @brief Diffuse array texture layer
+         *
+         * Convenience access to the @ref MaterialAttribute::DiffuseTextureLayer
+         * / @ref MaterialAttribute::TextureLayer attributes. If neither is
+         * present, the default is @cpp 0 @ce. Available only if the material
+         * has @ref MaterialAttribute::DiffuseTexture.
+         * @see @ref hasAttribute()
+         */
+        UnsignedInt diffuseTextureLayer() const;
+
         /**
          * @brief Specular color
          *
@@ -263,6 +308,17 @@ class MAGNUM_TRADE_EXPORT PbrSpecularGlossinessMaterialData: public MaterialData
          */
         UnsignedInt specularTextureCoordinates() const;
 
+        /**
+         * @brief Specular array texture layer
+         *
+         * Convenience access to the @ref MaterialAttribute::SpecularTextureLayer
+         * / @ref MaterialAttribute::TextureLayer attributes. If neither is
+         * present, the default is @cpp 0 @ce. Available only if the material
+         * has a specular texture.
+         * @see @ref hasSpecularTexture()
+         */
+        UnsignedInt specularTextureLayer() const;
+
         /**
          * @brief Glossiness factor
          *
@@ -319,6 +375,17 @@ class MAGNUM_TRADE_EXPORT PbrSpecularGlossinessMaterialData: public MaterialData
          */
         UnsignedInt glossinessTextureCoordinates() const;
 
+        /**
+         * @brief Glossiness array texture layer
+         *
+         * Convenience access to the @ref MaterialAttribute::GlossinessTextureLayer
+         * / @ref MaterialAttribute::TextureLayer attributes. If neither is
+         * present, the default is @cpp 0 @ce. Available only if the material
+         * has a glossiness texture.
+         * @see @ref hasGlossinessTexture()
+         */
+        UnsignedInt glossinessTextureLayer() const;
+
         /**
          * @brief Normal texture ID
          *
@@ -370,6 +437,17 @@ class MAGNUM_TRADE_EXPORT PbrSpecularGlossinessMaterialData: public MaterialData
          */
         UnsignedInt normalTextureCoordinates() const;
 
+        /**
+         * @brief Normal array texture layer
+         *
+         * Convenience access to the @ref MaterialAttribute::NormalTextureLayer
+         * / @ref MaterialAttribute::TextureLayer attributes. If neither is
+         * present, the default is @cpp 0 @ce. Available only if the material
+         * has @ref MaterialAttribute::NormalTexture.
+         * @see @ref hasAttribute()
+         */
+        UnsignedInt normalTextureLayer() const;
+
         /**
          * @brief Occlusion texture ID
          *
@@ -422,6 +500,17 @@ class MAGNUM_TRADE_EXPORT PbrSpecularGlossinessMaterialData: public MaterialData
          */
         UnsignedInt occlusionTextureCoordinates() const;
 
+        /**
+         * @brief Occlusion array texture layer
+         *
+         * Convenience access to the @ref MaterialAttribute::OcclusionTextureLayer
+         * / @ref MaterialAttribute::TextureLayer attributes. If neither is
+         * present, the default is @cpp 0 @ce. Available only if the material
+         * has @ref MaterialAttribute::OcclusionTexture.
+         * @see @ref hasAttribute()
+         */
+        UnsignedInt occlusionTextureLayer() const;
+
         /**
          * @brief Emissive color
          *
@@ -467,6 +556,17 @@ class MAGNUM_TRADE_EXPORT PbrSpecularGlossinessMaterialData: public MaterialData
          */
         UnsignedInt emissiveTextureCoordinates() const;
 
+        /**
+         * @brief Emissive array texture layer
+         *
+         * Convenience access to the @ref MaterialAttribute::EmissiveTextureLayer
+         * / @ref MaterialAttribute::TextureLayer attributes. If neither is
+         * present, the default is @cpp 0 @ce. Available only if the
+         * material has @ref MaterialAttribute::EmissiveTexture.
+         * @see @ref hasAttribute()
+         */
+        UnsignedInt emissiveTextureLayer() const;
+
         /**
          * @brief Common texture coordinate transformation matrix for all textures
          *
@@ -492,6 +592,18 @@ class MAGNUM_TRADE_EXPORT PbrSpecularGlossinessMaterialData: public MaterialData
          * no texture is present, returns @cpp 0 @ce.
          */
         UnsignedInt commonTextureCoordinates() const;
+
+        /**
+         * @brief Common array texture layer for all textures
+         *
+         * Expects that @ref hasCommonTextureLayer() is @cpp true @ce; returns
+         * a layer that's the same for all of @ref diffuseTextureLayer(),
+         * @ref specularTextureLayer(), @ref glossinessTextureLayer(),
+         * @ref normalTextureLayer(), @ref occlusionTextureLayer() and
+         * @ref emissiveTextureLayer() where a texture is present. If no
+         * texture is present, returns @cpp 0 @ce.
+         */
+        UnsignedInt commonTextureLayer() const;
 };
 
 }}

src/Magnum/Trade/PhongMaterialData.cpp

@@ -196,6 +196,37 @@ bool PhongMaterialData::hasCommonTextureCoordinates() const {
     return true;
 }
 
+bool PhongMaterialData::hasTextureLayer() const {
+    return attributeOr(MaterialAttribute::AmbientTextureLayer, 0u) ||
+        attributeOr(MaterialAttribute::DiffuseTextureLayer, 0u) ||
+        attributeOr(MaterialAttribute::SpecularTextureLayer, 0u) ||
+        attributeOr(MaterialAttribute::NormalTextureLayer, 0u) ||
+        attributeOr(MaterialAttribute::TextureLayer, 0u);
+}
+
+bool PhongMaterialData::hasCommonTextureLayer() const {
+    auto check = [](Containers::Optional<UnsignedInt>& layer, UnsignedInt current) {
+        if(!layer) {
+            layer = current;
+            return true;
+        }
+        return layer == current;
+    };
+
+    Containers::Optional<UnsignedInt> layer;
+    /* First one can't fail */
+    if(hasAttribute(MaterialAttribute::AmbientTexture) && !check(layer, ambientTextureLayer()))
+        CORRADE_INTERNAL_ASSERT_UNREACHABLE(); /* LCOV_EXCL_LINE */
+    if(hasAttribute(MaterialAttribute::DiffuseTexture) && !check(layer, diffuseTextureLayer()))
+        return false;
+    if(hasSpecularTexture() && !check(layer, specularTextureLayer()))
+        return false;
+    if(hasAttribute(MaterialAttribute::NormalTexture) && !check(layer, normalTextureLayer()))
+        return false;
+
+    return true;
+}
+
 Color4 PhongMaterialData::ambientColor() const {
     return attributeOr(MaterialAttribute::AmbientColor,
         hasAttribute(MaterialAttribute::AmbientTexture) ? 0xffffffff_rgbaf : 0x000000ff_rgbaf);
@@ -221,6 +252,14 @@ UnsignedInt PhongMaterialData::ambientTextureCoordinates() const {
     return attributeOr(MaterialAttribute::TextureCoordinates, 0u);
 }
 
+UnsignedInt PhongMaterialData::ambientTextureLayer() const {
+    CORRADE_ASSERT(hasAttribute(MaterialAttribute::AmbientTexture),
+        "Trade::PhongMaterialData::ambientTextureLayer(): the material doesn't have an ambient texture", {});
+    if(Containers::Optional<UnsignedInt> set = tryAttribute<UnsignedInt>(MaterialAttribute::AmbientTextureLayer))
+        return *set;
+    return attributeOr(MaterialAttribute::TextureLayer, 0u);
+}
+
 Color4 PhongMaterialData::diffuseColor() const {
     return attributeOr(MaterialAttribute::DiffuseColor, 0xffffffff_rgbaf);
 }
@@ -245,6 +284,14 @@ UnsignedInt PhongMaterialData::diffuseTextureCoordinates() const {
     return attributeOr(MaterialAttribute::TextureCoordinates, 0u);
 }
 
+UnsignedInt PhongMaterialData::diffuseTextureLayer() const {
+    CORRADE_ASSERT(hasAttribute(MaterialAttribute::DiffuseTexture),
+        "Trade::PhongMaterialData::diffuseTextureLayer(): the material doesn't have a diffuse texture", {});
+    if(Containers::Optional<UnsignedInt> set = tryAttribute<UnsignedInt>(MaterialAttribute::DiffuseTextureLayer))
+        return *set;
+    return attributeOr(MaterialAttribute::TextureLayer, 0u);
+}
+
 Color4 PhongMaterialData::specularColor() const {
     return attributeOr(MaterialAttribute::SpecularColor, 0xffffff00_rgbaf);
 }
@@ -284,6 +331,14 @@ UnsignedInt PhongMaterialData::specularTextureCoordinates() const {
     return attributeOr(MaterialAttribute::TextureCoordinates, 0u);
 }
 
+UnsignedInt PhongMaterialData::specularTextureLayer() const {
+    CORRADE_ASSERT(hasSpecularTexture(),
+        "Trade::PhongMaterialData::specularTextureLayer(): the material doesn't have a specular texture", {});
+    if(Containers::Optional<UnsignedInt> set = tryAttribute<UnsignedInt>(MaterialAttribute::SpecularTextureLayer))
+        return *set;
+    return attributeOr(MaterialAttribute::TextureLayer, 0u);
+}
+
 UnsignedInt PhongMaterialData::normalTexture() const {
     return attribute<UnsignedInt>(MaterialAttribute::NormalTexture);
 }
@@ -316,6 +371,14 @@ UnsignedInt PhongMaterialData::normalTextureCoordinates() const {
     return attributeOr(MaterialAttribute::TextureCoordinates, 0u);
 }
 
+UnsignedInt PhongMaterialData::normalTextureLayer() const {
+    CORRADE_ASSERT(hasAttribute(MaterialAttribute::NormalTexture),
+        "Trade::PhongMaterialData::normalTextureLayer(): the material doesn't have a normal texture", {});
+    if(Containers::Optional<UnsignedInt> set = tryAttribute<UnsignedInt>(MaterialAttribute::NormalTextureLayer))
+        return *set;
+    return attributeOr(MaterialAttribute::TextureLayer, 0u);
+}
+
 Matrix3 PhongMaterialData::commonTextureMatrix() const {
     CORRADE_ASSERT(hasCommonTextureTransformation(),
         "Trade::PhongMaterialData::commonTextureMatrix(): the material doesn't have a common texture coordinate transformation", {});
@@ -351,6 +414,20 @@ UnsignedInt PhongMaterialData::commonTextureCoordinates() const {
     return attributeOr(MaterialAttribute::TextureCoordinates, 0u);
 }
 
+UnsignedInt PhongMaterialData::commonTextureLayer() const {
+    CORRADE_ASSERT(hasCommonTextureLayer(),
+        "Trade::PhongMaterialData::commonTextureLayer(): the material doesn't have a common array texture layer", {});
+    if(hasAttribute(MaterialAttribute::AmbientTexture))
+        return ambientTextureLayer();
+    if(hasAttribute(MaterialAttribute::DiffuseTexture))
+        return diffuseTextureLayer();
+    if(hasSpecularTexture())
+        return specularTextureLayer();
+    if(hasAttribute(MaterialAttribute::NormalTexture))
+        return normalTextureLayer();
+    return attributeOr(MaterialAttribute::TextureLayer, 0u);
+}
+
 Float PhongMaterialData::shininess() const {
     return attributeOr(MaterialAttribute::Shininess, 80.0f);
 }

src/Magnum/Trade/PhongMaterialData.h

@@ -301,6 +301,35 @@ class MAGNUM_TRADE_EXPORT PhongMaterialData: public MaterialData {
          */
         bool hasCommonTextureCoordinates() const;
 
+        /**
+         * @brief Whether the material uses array texture layers
+         * @m_since_latest
+         *
+         * Returns @cpp true @ce if any of the
+         * @ref MaterialAttribute::AmbientTextureLayer,
+         * @ref MaterialAttribute::DiffuseTextureLayer,
+         * @ref MaterialAttribute::SpecularTextureLayer,
+         * @ref MaterialAttribute::NormalTextureLayer or
+         * @ref MaterialAttribute::TextureLayer attributes is present and has a
+         * non-zero value, @cpp false @ce otherwise.
+         * @see @ref hasCommonTextureLayer()
+         */
+        bool hasTextureLayer() const;
+
+        /**
+         * @brief Whether the material has a common array texture layer for all textures
+         * @m_since_latest
+         *
+         * Returns @cpp true @ce if, for each texture that is present,
+         * @ref ambientTextureLayer(), @ref diffuseTextureLayer(),
+         * @ref specularTextureLayer() and @ref normalTextureLayer() have the
+         * same value, @cpp false @ce otherwise. In particular, returns
+         * @cpp true @ce also if there's no extra texture coordinate set used
+         * at all. Use @ref hasTextureLayer() to distinguish that case.
+         * @see @ref commonTextureLayer()
+         */
+        bool hasCommonTextureLayer() const;
+
         #ifdef MAGNUM_BUILD_DEPRECATED
         /**
          * @brief Material flags
@@ -376,6 +405,18 @@ class MAGNUM_TRADE_EXPORT PhongMaterialData: public MaterialData {
         }
         #endif
 
+        /**
+         * @brief Ambient array texture layer
+         * @m_since_latest
+         *
+         * Convenience access to the @ref MaterialAttribute::AmbientTextureLayer
+         * / @ref MaterialAttribute::TextureLayer attributes. If neither is
+         * present, the default is @cpp 0 @ce. Available only if the material
+         * has @ref MaterialAttribute::AmbientTexture.
+         * @see @ref hasAttribute()
+         */
+        UnsignedInt ambientTextureLayer() const;
+
         /**
          * @brief Diffuse color
          *
@@ -432,6 +473,18 @@ class MAGNUM_TRADE_EXPORT PhongMaterialData: public MaterialData {
         }
         #endif
 
+        /**
+         * @brief Diffuse array texture layer
+         * @m_since_latest
+         *
+         * Convenience access to the @ref MaterialAttribute::DiffuseTextureLayer
+         * / @ref MaterialAttribute::TextureLayer attributes. If neither is
+         * present, the default is @cpp 0 @ce. Available only if the material
+         * has @ref MaterialAttribute::DiffuseTexture.
+         * @see @ref hasAttribute()
+         */
+        UnsignedInt diffuseTextureLayer() const;
+
         /**
          * @brief Specular color
          *
@@ -502,6 +555,18 @@ class MAGNUM_TRADE_EXPORT PhongMaterialData: public MaterialData {
         }
         #endif
 
+        /**
+         * @brief Specular array texture layer
+         * @m_since_latest
+         *
+         * Convenience access to the @ref MaterialAttribute::SpecularTextureLayer
+         * / @ref MaterialAttribute::TextureLayer attributes. If neither is
+         * present, the default is @cpp 0 @ce. Available only if the material
+         * has a specular texture.
+         * @see @ref hasSpecularTexture()
+         */
+        UnsignedInt specularTextureLayer() const;
+
         /**
          * @brief Normal texture ID
          * @m_since{2020,06}
@@ -569,6 +634,18 @@ class MAGNUM_TRADE_EXPORT PhongMaterialData: public MaterialData {
         }
         #endif
 
+        /**
+         * @brief Normal array texture layer
+         * @m_since_latest
+         *
+         * Convenience access to the @ref MaterialAttribute::NormalTextureLayer
+         * / @ref MaterialAttribute::TextureLayer attributes. If neither is
+         * present, the default is @cpp 0 @ce. Available only if the material
+         * has @ref MaterialAttribute::NormalTexture.
+         * @see @ref hasAttribute()
+         */
+        UnsignedInt normalTextureLayer() const;
+
         /**
          * @brief Common texture coordinate transformation matrix for all textures
          * @m_since_latest
@@ -609,6 +686,18 @@ class MAGNUM_TRADE_EXPORT PhongMaterialData: public MaterialData {
          */
         UnsignedInt commonTextureCoordinates() const;
 
+        /**
+         * @brief Common array texture layer for all textures
+         * @m_since_latest
+         *
+         * Expects that @ref hasCommonTextureLayer() is @cpp true @ce; returns
+         * a layer that's the same for all of @ref ambientTextureLayer(),
+         * @ref diffuseTextureLayer(), @ref specularTextureLayer() and
+         * @ref normalTextureLayer() where a texture is present. If no texture
+         * is present, returns @cpp 0 @ce.
+         */
+        UnsignedInt commonTextureLayer() const;
+
         /**
          * @brief Shininess
          *

src/Magnum/Trade/Test/FlatMaterialDataTest.cpp

@@ -43,10 +43,10 @@ class FlatMaterialDataTest: public TestSuite::Tester {
         void texturedBaseColor();
         void texturedDiffuseColor();
         void texturedDefaults();
-        void texturedBaseColorSingleMatrixCoordinates();
-        void texturedDiffuseColorSingleMatrixCoordinates();
-        void texturedMismatchedMatrixCoordinates();
-        void texturedImplicitCoordinates();
+        void texturedBaseColorSingleMatrixCoordinatesLayer();
+        void texturedDiffuseColorSingleMatrixCoordinatesLayer();
+        void texturedMismatchedMatrixCoordinatesLayer();
+        void texturedImplicitCoordinatesLayer();
         void invalidTextures();
 };
 
@@ -57,10 +57,10 @@ FlatMaterialDataTest::FlatMaterialDataTest() {
               &FlatMaterialDataTest::texturedBaseColor,
               &FlatMaterialDataTest::texturedDiffuseColor,
               &FlatMaterialDataTest::texturedDefaults,
-              &FlatMaterialDataTest::texturedBaseColorSingleMatrixCoordinates,
-              &FlatMaterialDataTest::texturedDiffuseColorSingleMatrixCoordinates,
-              &FlatMaterialDataTest::texturedMismatchedMatrixCoordinates,
-              &FlatMaterialDataTest::texturedImplicitCoordinates,
+              &FlatMaterialDataTest::texturedBaseColorSingleMatrixCoordinatesLayer,
+              &FlatMaterialDataTest::texturedDiffuseColorSingleMatrixCoordinatesLayer,
+              &FlatMaterialDataTest::texturedMismatchedMatrixCoordinatesLayer,
+              &FlatMaterialDataTest::texturedImplicitCoordinatesLayer,
               &FlatMaterialDataTest::invalidTextures});
 }
 
@@ -78,6 +78,7 @@ void FlatMaterialDataTest::baseColor() {
     CORRADE_VERIFY(!data.hasTexture());
     CORRADE_VERIFY(!data.hasTextureTransformation());
     CORRADE_VERIFY(!data.hasTextureCoordinates());
+    CORRADE_VERIFY(!data.hasTextureLayer());
     CORRADE_COMPARE(data.color(), 0xccffbb_rgbf);
 }
 
@@ -92,6 +93,7 @@ void FlatMaterialDataTest::diffuseColor() {
     CORRADE_VERIFY(!data.hasTexture());
     CORRADE_VERIFY(!data.hasTextureTransformation());
     CORRADE_VERIFY(!data.hasTextureCoordinates());
+    CORRADE_VERIFY(!data.hasTextureLayer());
     CORRADE_COMPARE(data.color(), 0xccffbb_rgbf);
 }
 
@@ -105,6 +107,7 @@ void FlatMaterialDataTest::defaults() {
     CORRADE_VERIFY(!data.hasTexture());
     CORRADE_VERIFY(!data.hasTextureTransformation());
     CORRADE_VERIFY(!data.hasTextureCoordinates());
+    CORRADE_VERIFY(!data.hasTextureLayer());
     CORRADE_COMPARE(data.color(), 0xffffff_rgbf);
 }
 
@@ -114,21 +117,25 @@ void FlatMaterialDataTest::texturedBaseColor() {
         {MaterialAttribute::BaseColorTexture, 5u},
         {MaterialAttribute::BaseColorTextureMatrix, Matrix3::scaling({0.5f, 1.0f})},
         {MaterialAttribute::BaseColorTextureCoordinates, 2u},
+        {MaterialAttribute::BaseColorTextureLayer, 17u},
 
         /* All this is ignored */
         {MaterialAttribute::DiffuseColor, 0x33556600_rgbaf},
         {MaterialAttribute::DiffuseTexture, 6u},
         {MaterialAttribute::DiffuseTextureMatrix, Matrix3::translation({0.5f, 1.0f})},
-        {MaterialAttribute::DiffuseTextureCoordinates, 3u}
+        {MaterialAttribute::DiffuseTextureCoordinates, 3u},
+        {MaterialAttribute::DiffuseTextureLayer, 66u},
     }};
 
     CORRADE_VERIFY(data.hasTexture());
     CORRADE_VERIFY(data.hasTextureTransformation());
     CORRADE_VERIFY(data.hasTextureCoordinates());
+    CORRADE_VERIFY(data.hasTextureLayer());
     CORRADE_COMPARE(data.color(), 0xccffbb_rgbf);
     CORRADE_COMPARE(data.texture(), 5);
     CORRADE_COMPARE(data.textureMatrix(), Matrix3::scaling({0.5f, 1.0f}));
     CORRADE_COMPARE(data.textureCoordinates(), 2);
+    CORRADE_COMPARE(data.textureLayer(), 17);
 }
 
 void FlatMaterialDataTest::texturedDiffuseColor() {
@@ -137,6 +144,7 @@ void FlatMaterialDataTest::texturedDiffuseColor() {
         {MaterialAttribute::DiffuseTexture, 5u},
         {MaterialAttribute::DiffuseTextureMatrix, Matrix3::scaling({0.5f, 1.0f})},
         {MaterialAttribute::DiffuseTextureCoordinates, 2u},
+        {MaterialAttribute::DiffuseTextureLayer, 17u},
 
         /* Ignored, as we have a diffuse texture */
         {MaterialAttribute::BaseColor, 0x33556600_rgbaf}
@@ -145,10 +153,12 @@ void FlatMaterialDataTest::texturedDiffuseColor() {
     CORRADE_VERIFY(data.hasTexture());
     CORRADE_VERIFY(data.hasTextureTransformation());
     CORRADE_VERIFY(data.hasTextureCoordinates());
+    CORRADE_VERIFY(data.hasTextureLayer());
     CORRADE_COMPARE(data.color(), 0xccffbb_rgbf);
     CORRADE_COMPARE(data.texture(), 5);
     CORRADE_COMPARE(data.textureMatrix(), Matrix3::scaling({0.5f, 1.0f}));
     CORRADE_COMPARE(data.textureCoordinates(), 2);
+    CORRADE_COMPARE(data.textureLayer(), 17);
 }
 
 void FlatMaterialDataTest::texturedDefaults() {
@@ -159,55 +169,65 @@ void FlatMaterialDataTest::texturedDefaults() {
     CORRADE_VERIFY(data.hasTexture());
     CORRADE_VERIFY(!data.hasTextureTransformation());
     CORRADE_VERIFY(!data.hasTextureCoordinates());
+    CORRADE_VERIFY(!data.hasTextureLayer());
     CORRADE_COMPARE(data.color(), 0xffffff_rgbf);
     CORRADE_COMPARE(data.texture(), 5);
     CORRADE_COMPARE(data.textureMatrix(), Matrix3{});
     CORRADE_COMPARE(data.textureCoordinates(), 0);
+    CORRADE_COMPARE(data.textureLayer(), 0);
 }
 
-void FlatMaterialDataTest::texturedBaseColorSingleMatrixCoordinates() {
+void FlatMaterialDataTest::texturedBaseColorSingleMatrixCoordinatesLayer() {
     FlatMaterialData data{{}, {
         {MaterialAttribute::BaseColor, 0xccffbbff_rgbaf},
         {MaterialAttribute::BaseColorTexture, 5u},
         {MaterialAttribute::TextureMatrix, Matrix3::scaling({0.5f, 1.0f})},
         {MaterialAttribute::TextureCoordinates, 2u},
+        {MaterialAttribute::TextureLayer, 17u},
 
         /* This is ignored because it doesn't match the texture */
         {MaterialAttribute::DiffuseTextureMatrix, Matrix3::translation({0.5f, 1.0f})},
-        {MaterialAttribute::DiffuseTextureCoordinates, 3u}
+        {MaterialAttribute::DiffuseTextureCoordinates, 3u},
+        {MaterialAttribute::DiffuseTextureLayer, 66u},
     }};
 
     CORRADE_VERIFY(data.hasTexture());
     CORRADE_VERIFY(data.hasTextureTransformation());
     CORRADE_VERIFY(data.hasTextureCoordinates());
+    CORRADE_VERIFY(data.hasTextureLayer());
     CORRADE_COMPARE(data.color(), 0xccffbb_rgbf);
     CORRADE_COMPARE(data.texture(), 5);
     CORRADE_COMPARE(data.textureMatrix(), Matrix3::scaling({0.5f, 1.0f}));
     CORRADE_COMPARE(data.textureCoordinates(), 2);
+    CORRADE_COMPARE(data.textureLayer(), 17);
 }
 
-void FlatMaterialDataTest::texturedDiffuseColorSingleMatrixCoordinates() {
+void FlatMaterialDataTest::texturedDiffuseColorSingleMatrixCoordinatesLayer() {
     FlatMaterialData data{{}, {
         {MaterialAttribute::DiffuseColor, 0xccffbbff_rgbaf},
         {MaterialAttribute::DiffuseTexture, 5u},
         {MaterialAttribute::TextureMatrix, Matrix3::scaling({0.5f, 1.0f})},
         {MaterialAttribute::TextureCoordinates, 2u},
+        {MaterialAttribute::TextureLayer, 17u},
 
         /* This is ignored because it doesn't match the texture */
         {MaterialAttribute::BaseColorTextureMatrix, Matrix3::translation({0.5f, 1.0f})},
-        {MaterialAttribute::BaseColorTextureCoordinates, 3u}
+        {MaterialAttribute::BaseColorTextureCoordinates, 3u},
+        {MaterialAttribute::BaseColorTextureLayer, 66u}
     }};
 
     CORRADE_VERIFY(data.hasTexture());
     CORRADE_VERIFY(data.hasTextureTransformation());
     CORRADE_VERIFY(data.hasTextureCoordinates());
+    CORRADE_VERIFY(data.hasTextureLayer());
     CORRADE_COMPARE(data.color(), 0xccffbb_rgbf);
     CORRADE_COMPARE(data.texture(), 5);
     CORRADE_COMPARE(data.textureMatrix(), Matrix3::scaling({0.5f, 1.0f}));
     CORRADE_COMPARE(data.textureCoordinates(), 2);
+    CORRADE_COMPARE(data.textureLayer(), 17);
 }
 
-void FlatMaterialDataTest::texturedMismatchedMatrixCoordinates() {
+void FlatMaterialDataTest::texturedMismatchedMatrixCoordinatesLayer() {
     {
         FlatMaterialData data{{}, {
             {MaterialAttribute::BaseColorTexture, 5u},
@@ -216,15 +236,18 @@ void FlatMaterialDataTest::texturedMismatchedMatrixCoordinates() {
             {MaterialAttribute::DiffuseColor, 0x33556600_rgbaf},
             {MaterialAttribute::DiffuseTextureMatrix, Matrix3::scaling({0.5f, 1.0f})},
             {MaterialAttribute::DiffuseTextureCoordinates, 2u},
+            {MaterialAttribute::DiffuseTextureLayer, 17u},
         }};
 
         CORRADE_VERIFY(data.hasTexture());
         CORRADE_VERIFY(!data.hasTextureTransformation());
         CORRADE_VERIFY(!data.hasTextureCoordinates());
+        CORRADE_VERIFY(!data.hasTextureLayer());
         CORRADE_COMPARE(data.color(), 0xffffff_rgbf);
         CORRADE_COMPARE(data.texture(), 5);
         CORRADE_COMPARE(data.textureMatrix(), Matrix3{});
         CORRADE_COMPARE(data.textureCoordinates(), 0);
+        CORRADE_COMPARE(data.textureLayer(), 0);
     } {
         FlatMaterialData data{{}, {
             {MaterialAttribute::DiffuseTexture, 5u},
@@ -233,43 +256,54 @@ void FlatMaterialDataTest::texturedMismatchedMatrixCoordinates() {
             {MaterialAttribute::BaseColor, 0x33556600_rgbaf},
             {MaterialAttribute::BaseColorTextureMatrix, Matrix3::scaling({0.5f, 1.0f})},
             {MaterialAttribute::BaseColorTextureCoordinates, 2u},
+            {MaterialAttribute::BaseColorTextureLayer, 17u},
         }};
 
         CORRADE_VERIFY(data.hasTexture());
         CORRADE_VERIFY(!data.hasTextureTransformation());
         CORRADE_VERIFY(!data.hasTextureCoordinates());
+        CORRADE_VERIFY(!data.hasTextureLayer());
         CORRADE_COMPARE(data.color(), 0xffffff_rgbf);
         CORRADE_COMPARE(data.texture(), 5);
         CORRADE_COMPARE(data.textureMatrix(), Matrix3{});
         CORRADE_COMPARE(data.textureCoordinates(), 0);
+        CORRADE_COMPARE(data.textureLayer(), 0);
     }
 }
 
-void FlatMaterialDataTest::texturedImplicitCoordinates() {
+void FlatMaterialDataTest::texturedImplicitCoordinatesLayer() {
     {
         FlatMaterialData data{{}, {
             {MaterialAttribute::BaseColorTexture, 5u},
             {MaterialAttribute::BaseColorTextureCoordinates, 0u},
+            {MaterialAttribute::BaseColorTextureLayer, 0u},
 
             /* This is ignored because it doesn't match the texture */
             {MaterialAttribute::DiffuseTextureCoordinates, 2u},
+            {MaterialAttribute::DiffuseTextureLayer, 17u},
         }};
 
         CORRADE_VERIFY(data.hasTexture());
         CORRADE_VERIFY(!data.hasTextureCoordinates());
+        CORRADE_VERIFY(!data.hasTextureLayer());
         CORRADE_COMPARE(data.textureCoordinates(), 0);
+        CORRADE_COMPARE(data.textureLayer(), 0);
     } {
         FlatMaterialData data{{}, {
             {MaterialAttribute::DiffuseTexture, 5u},
             {MaterialAttribute::DiffuseTextureCoordinates, 0u},
+            {MaterialAttribute::DiffuseTextureLayer, 0u},
 
             /* This is ignored because it doesn't match the texture */
             {MaterialAttribute::BaseColorTextureCoordinates, 2u},
+            {MaterialAttribute::BaseColorTextureLayer, 17u},
         }};
 
         CORRADE_VERIFY(data.hasTexture());
         CORRADE_VERIFY(!data.hasTextureCoordinates());
+        CORRADE_VERIFY(!data.hasTextureLayer());
         CORRADE_COMPARE(data.textureCoordinates(), 0);
+        CORRADE_COMPARE(data.textureLayer(), 0);
     }
 }
 
@@ -285,10 +319,12 @@ void FlatMaterialDataTest::invalidTextures() {
     data.texture();
     data.textureMatrix();
     data.textureCoordinates();
+    data.textureLayer();
     CORRADE_COMPARE(out.str(),
         "Trade::FlatMaterialData::texture(): the material doesn't have a texture\n"
         "Trade::FlatMaterialData::textureMatrix(): the material doesn't have a texture\n"
-        "Trade::FlatMaterialData::textureCoordinates(): the material doesn't have a texture\n");
+        "Trade::FlatMaterialData::textureCoordinates(): the material doesn't have a texture\n"
+        "Trade::FlatMaterialData::textureLayer(): the material doesn't have a texture\n");
 }
 
 }}}}

src/Magnum/Trade/Test/MaterialDataTest.cpp

@@ -124,8 +124,8 @@ class MaterialDataTest: public TestSuite::Tester {
         void accessLayersDefaults();
         void accessLayersTextured();
         void accessLayersTexturedDefault();
-        void accessLayersTexturedSingleMatrixCoordinates();
-        void accessLayersTexturedBaseMaterialMatrixCoordinates();
+        void accessLayersTexturedSingleMatrixCoordinatesLayer();
+        void accessLayersTexturedBaseMaterialMatrixCoordinatesLayer();
         void accessLayersInvalidTextures();
 
         void accessLayerLayerNameInBaseMaterial();
@@ -277,8 +277,8 @@ MaterialDataTest::MaterialDataTest() {
               &MaterialDataTest::accessLayersDefaults,
               &MaterialDataTest::accessLayersTextured,
               &MaterialDataTest::accessLayersTexturedDefault,
-              &MaterialDataTest::accessLayersTexturedSingleMatrixCoordinates,
-              &MaterialDataTest::accessLayersTexturedBaseMaterialMatrixCoordinates,
+              &MaterialDataTest::accessLayersTexturedSingleMatrixCoordinatesLayer,
+              &MaterialDataTest::accessLayersTexturedBaseMaterialMatrixCoordinatesLayer,
               &MaterialDataTest::accessLayersInvalidTextures,
 
               &MaterialDataTest::accessLayerLayerNameInBaseMaterial,
@@ -1984,8 +1984,9 @@ void MaterialDataTest::accessLayersTextured() {
         {MaterialAttribute::LayerFactorTextureSwizzle, MaterialTextureSwizzle::A},
         {MaterialAttribute::LayerFactorTextureMatrix, Matrix3::scaling({0.5f, 1.0f})},
         {MaterialAttribute::LayerFactorTextureCoordinates, 2u},
+        {MaterialAttribute::LayerFactorTextureLayer, 3u},
     }, {
-        0, 1, 7
+        0, 1, 8
     }};
 
     CORRADE_COMPARE(data.layerCount(), 3);
@@ -2009,6 +2010,10 @@ void MaterialDataTest::accessLayersTextured() {
     CORRADE_COMPARE(data.layerFactorTextureCoordinates(2), 2u);
     CORRADE_COMPARE(data.layerFactorTextureCoordinates("ClearCoat"), 2u);
     CORRADE_COMPARE(data.layerFactorTextureCoordinates(MaterialLayer::ClearCoat), 2u);
+
+    CORRADE_COMPARE(data.layerFactorTextureLayer(2), 3u);
+    CORRADE_COMPARE(data.layerFactorTextureLayer("ClearCoat"), 3u);
+    CORRADE_COMPARE(data.layerFactorTextureLayer(MaterialLayer::ClearCoat), 3u);
 }
 
 void MaterialDataTest::accessLayersTexturedDefault() {
@@ -2042,16 +2047,21 @@ void MaterialDataTest::accessLayersTexturedDefault() {
     CORRADE_COMPARE(data.layerFactorTextureCoordinates(2), 0);
     CORRADE_COMPARE(data.layerFactorTextureCoordinates("ClearCoat"), 0);
     CORRADE_COMPARE(data.layerFactorTextureCoordinates(MaterialLayer::ClearCoat), 0);
+
+    CORRADE_COMPARE(data.layerFactorTextureLayer(2), 0);
+    CORRADE_COMPARE(data.layerFactorTextureLayer("ClearCoat"), 0);
+    CORRADE_COMPARE(data.layerFactorTextureLayer(MaterialLayer::ClearCoat), 0);
 }
 
-void MaterialDataTest::accessLayersTexturedSingleMatrixCoordinates() {
+void MaterialDataTest::accessLayersTexturedSingleMatrixCoordinatesLayer() {
     MaterialData data{{}, {
         {MaterialAttribute::LayerName, "ClearCoat"},
         {MaterialAttribute::LayerFactorTexture, 4u},
         {MaterialAttribute::TextureMatrix, Matrix3::scaling({0.5f, 1.0f})},
         {MaterialAttribute::TextureCoordinates, 2u},
+        {MaterialAttribute::TextureLayer, 3u},
     }, {
-        0, 4
+        0, 5
     }};
 
     CORRADE_COMPARE(data.layerFactorTextureMatrix(1), Matrix3::scaling({0.5f, 1.0f}));
@@ -2061,17 +2071,22 @@ void MaterialDataTest::accessLayersTexturedSingleMatrixCoordinates() {
     CORRADE_COMPARE(data.layerFactorTextureCoordinates(1), 2u);
     CORRADE_COMPARE(data.layerFactorTextureCoordinates("ClearCoat"), 2u);
     CORRADE_COMPARE(data.layerFactorTextureCoordinates(MaterialLayer::ClearCoat), 2u);
+
+    CORRADE_COMPARE(data.layerFactorTextureLayer(1), 3u);
+    CORRADE_COMPARE(data.layerFactorTextureLayer("ClearCoat"), 3u);
+    CORRADE_COMPARE(data.layerFactorTextureLayer(MaterialLayer::ClearCoat), 3u);
 }
 
-void MaterialDataTest::accessLayersTexturedBaseMaterialMatrixCoordinates() {
+void MaterialDataTest::accessLayersTexturedBaseMaterialMatrixCoordinatesLayer() {
     MaterialData data{{}, {
         {MaterialAttribute::TextureMatrix, Matrix3::scaling({0.5f, 1.0f})},
         {MaterialAttribute::TextureCoordinates, 2u},
+        {MaterialAttribute::TextureLayer, 3u},
 
         {MaterialAttribute::LayerName, "ClearCoat"},
         {MaterialAttribute::LayerFactorTexture, 4u},
     }, {
-        2, 4
+        3, 5
     }};
 
     CORRADE_COMPARE(data.layerFactorTextureMatrix(1), Matrix3::scaling({0.5f, 1.0f}));
@@ -2081,6 +2096,10 @@ void MaterialDataTest::accessLayersTexturedBaseMaterialMatrixCoordinates() {
     CORRADE_COMPARE(data.layerFactorTextureCoordinates(1), 2u);
     CORRADE_COMPARE(data.layerFactorTextureCoordinates("ClearCoat"), 2u);
     CORRADE_COMPARE(data.layerFactorTextureCoordinates(MaterialLayer::ClearCoat), 2u);
+
+    CORRADE_COMPARE(data.layerFactorTextureLayer(1), 3u);
+    CORRADE_COMPARE(data.layerFactorTextureLayer("ClearCoat"), 3u);
+    CORRADE_COMPARE(data.layerFactorTextureLayer(MaterialLayer::ClearCoat), 3u);
 }
 
 void MaterialDataTest::accessLayersInvalidTextures() {
@@ -2106,6 +2125,9 @@ void MaterialDataTest::accessLayersInvalidTextures() {
     data.layerFactorTextureCoordinates(1);
     data.layerFactorTextureCoordinates("ClearCoat");
     data.layerFactorTextureCoordinates(MaterialLayer::ClearCoat);
+    data.layerFactorTextureLayer(1);
+    data.layerFactorTextureLayer("ClearCoat");
+    data.layerFactorTextureLayer(MaterialLayer::ClearCoat);
     CORRADE_COMPARE(out.str(),
         "Trade::MaterialData::attribute(): attribute LayerFactorTexture not found in layer 1\n"
         "Trade::MaterialData::attribute(): attribute LayerFactorTexture not found in layer ClearCoat\n"
@@ -2118,7 +2140,10 @@ void MaterialDataTest::accessLayersInvalidTextures() {
         "Trade::MaterialData::layerFactorTextureMatrix(): layer ClearCoat doesn't have a factor texture\n"
         "Trade::MaterialData::layerFactorTextureCoordinates(): layer 1 doesn't have a factor texture\n"
         "Trade::MaterialData::layerFactorTextureCoordinates(): layer ClearCoat doesn't have a factor texture\n"
-        "Trade::MaterialData::layerFactorTextureCoordinates(): layer ClearCoat doesn't have a factor texture\n");
+        "Trade::MaterialData::layerFactorTextureCoordinates(): layer ClearCoat doesn't have a factor texture\n"
+        "Trade::MaterialData::layerFactorTextureLayer(): layer 1 doesn't have a factor texture\n"
+        "Trade::MaterialData::layerFactorTextureLayer(): layer ClearCoat doesn't have a factor texture\n"
+        "Trade::MaterialData::layerFactorTextureLayer(): layer ClearCoat doesn't have a factor texture\n");
 }
 
 void MaterialDataTest::accessLayerLayerNameInBaseMaterial() {
@@ -2359,6 +2384,7 @@ void MaterialDataTest::accessLayerOutOfBounds() {
     data.layerFactorTextureSwizzle(2);
     data.layerFactorTextureMatrix(2);
     data.layerFactorTextureCoordinates(2);
+    data.layerFactorTextureLayer(2);
     data.attributeCount(2);
     data.hasAttribute(2, "AlphaMask");
     data.hasAttribute(2, MaterialAttribute::AlphaMask);
@@ -2395,6 +2421,7 @@ void MaterialDataTest::accessLayerOutOfBounds() {
         "Trade::MaterialData::layerFactorTextureSwizzle(): index 2 out of range for 2 layers\n"
         "Trade::MaterialData::layerFactorTextureMatrix(): index 2 out of range for 2 layers\n"
         "Trade::MaterialData::layerFactorTextureCoordinates(): index 2 out of range for 2 layers\n"
+        "Trade::MaterialData::layerFactorTextureLayer(): index 2 out of range for 2 layers\n"
         "Trade::MaterialData::attributeCount(): index 2 out of range for 2 layers\n"
         "Trade::MaterialData::hasAttribute(): index 2 out of range for 2 layers\n"
         "Trade::MaterialData::hasAttribute(): index 2 out of range for 2 layers\n"
@@ -2444,6 +2471,7 @@ void MaterialDataTest::accessLayerNotFound() {
     data.layerFactorTextureSwizzle("ClearCoat");
     data.layerFactorTextureMatrix("ClearCoat");
     data.layerFactorTextureCoordinates("ClearCoat");
+    data.layerFactorTextureLayer("ClearCoat");
     data.attributeCount("ClearCoat");
     data.hasAttribute("ClearCoat", "AlphaMask");
     data.hasAttribute("ClearCoat", MaterialAttribute::AlphaMask);
@@ -2480,6 +2508,7 @@ void MaterialDataTest::accessLayerNotFound() {
         "Trade::MaterialData::layerFactorTextureSwizzle(): layer ClearCoat not found\n"
         "Trade::MaterialData::layerFactorTextureMatrix(): layer ClearCoat not found\n"
         "Trade::MaterialData::layerFactorTextureCoordinates(): layer ClearCoat not found\n"
+        "Trade::MaterialData::layerFactorTextureLayer(): layer ClearCoat not found\n"
         "Trade::MaterialData::attributeCount(): layer ClearCoat not found\n"
         "Trade::MaterialData::hasAttribute(): layer ClearCoat not found\n"
         "Trade::MaterialData::hasAttribute(): layer ClearCoat not found\n"
@@ -2527,6 +2556,7 @@ void MaterialDataTest::accessInvalidLayerName() {
     data.layerFactorTextureSwizzle(MaterialLayer(0xfefe));
     data.layerFactorTextureMatrix(MaterialLayer(0xfefe));
     data.layerFactorTextureCoordinates(MaterialLayer(0xfefe));
+    data.layerFactorTextureLayer(MaterialLayer(0xfefe));
     data.attributeCount(MaterialLayer(0xfefe));
     data.hasAttribute(MaterialLayer(0xfefe), "AlphaMask");
     data.hasAttribute(MaterialLayer(0xfefe), MaterialAttribute::AlphaMask);
@@ -2564,6 +2594,7 @@ void MaterialDataTest::accessInvalidLayerName() {
         "Trade::MaterialData::layerFactorTextureSwizzle(): invalid name Trade::MaterialLayer(0xfefe)\n"
         "Trade::MaterialData::layerFactorTextureMatrix(): invalid name Trade::MaterialLayer(0xfefe)\n"
         "Trade::MaterialData::layerFactorTextureCoordinates(): invalid name Trade::MaterialLayer(0xfefe)\n"
+        "Trade::MaterialData::layerFactorTextureLayer(): invalid name Trade::MaterialLayer(0xfefe)\n"
         "Trade::MaterialData::attributeCount(): invalid name Trade::MaterialLayer(0xfefe)\n"
         "Trade::MaterialData::hasAttribute(): invalid name Trade::MaterialLayer(0xfefe)\n"
         "Trade::MaterialData::hasAttribute(): invalid name Trade::MaterialLayer(0xfefe)\n"
@@ -2910,7 +2941,8 @@ void MaterialDataTest::templateLayerAccess() {
         {MaterialAttribute::LayerFactorTextureSwizzle, MaterialTextureSwizzle::B},
         {MaterialAttribute::LayerFactorTextureMatrix, Matrix3::scaling({0.5f, 1.0f})},
         {MaterialAttribute::LayerFactorTextureCoordinates, 4u},
-    }, {1, 7}};
+        {MaterialAttribute::LayerFactorTextureLayer, 5u},
+    }, {1, 8}};
 
     CORRADE_COMPARE(data.layerName(), "ClearCoat");
     CORRADE_COMPARE(data.layerFactor(), 0.35f);
@@ -2918,8 +2950,9 @@ void MaterialDataTest::templateLayerAccess() {
     CORRADE_COMPARE(data.layerFactorTextureSwizzle(), MaterialTextureSwizzle::B);
     CORRADE_COMPARE(data.layerFactorTextureMatrix(), Matrix3::scaling({0.5f, 1.0f}));
     CORRADE_COMPARE(data.layerFactorTextureCoordinates(), 4u);
+    CORRADE_COMPARE(data.layerFactorTextureLayer(), 5u);
 
-    CORRADE_COMPARE(data.attributeCount(), 6);
+    CORRADE_COMPARE(data.attributeCount(), 7);
     CORRADE_VERIFY(data.hasAttribute(MaterialAttribute::LayerFactor));
     CORRADE_VERIFY(data.hasAttribute("LayerFactorTexture"));
     CORRADE_VERIFY(!data.hasAttribute(MaterialAttribute::BaseColor));

src/Magnum/Trade/Test/PbrClearCoatMaterialDataTest.cpp

@@ -41,14 +41,14 @@ class PbrClearCoatMaterialDataTest: public TestSuite::Tester {
         void textured();
         void texturedDefaults();
         void texturedExplicitPackedLayerFactorRoughness();
-        void texturedSingleMatrixCoordinates();
-        void texturedBaseMaterialMatrixCoordinates();
+        void texturedSingleMatrixCoordinatesLayer();
+        void texturedBaseMaterialMatrixCoordinatesLayer();
         void invalidTextures();
-        void commonTransformationCoordinatesNoTextures();
-        void commonTransformationCoordinatesOneTexture();
-        void commonTransformationCoordinatesOneDifferentTexture();
-        void commonCoordinatesImplicit();
-        void noCommonTransformationCoordinates();
+        void commonTransformationCoordinatesLayerNoTextures();
+        void commonTransformationCoordinatesLayerOneTexture();
+        void commonTransformationCoordinatesLayerOneDifferentTexture();
+        void commonCoordinatesLayerImplicit();
+        void noCommonTransformationCoordinatesLayer();
 };
 
 const Containers::StringView PbrClearCoatTextureData[] {
@@ -63,18 +63,18 @@ PbrClearCoatMaterialDataTest::PbrClearCoatMaterialDataTest() {
               &PbrClearCoatMaterialDataTest::textured,
               &PbrClearCoatMaterialDataTest::texturedDefaults,
               &PbrClearCoatMaterialDataTest::texturedExplicitPackedLayerFactorRoughness,
-              &PbrClearCoatMaterialDataTest::texturedSingleMatrixCoordinates,
-              &PbrClearCoatMaterialDataTest::texturedBaseMaterialMatrixCoordinates,
+              &PbrClearCoatMaterialDataTest::texturedSingleMatrixCoordinatesLayer,
+              &PbrClearCoatMaterialDataTest::texturedBaseMaterialMatrixCoordinatesLayer,
               &PbrClearCoatMaterialDataTest::invalidTextures,
-              &PbrClearCoatMaterialDataTest::commonTransformationCoordinatesNoTextures});
+              &PbrClearCoatMaterialDataTest::commonTransformationCoordinatesLayerNoTextures});
 
     addInstancedTests({
-        &PbrClearCoatMaterialDataTest::commonTransformationCoordinatesOneTexture,
-        &PbrClearCoatMaterialDataTest::commonTransformationCoordinatesOneDifferentTexture,
-        &PbrClearCoatMaterialDataTest::commonCoordinatesImplicit},
+        &PbrClearCoatMaterialDataTest::commonTransformationCoordinatesLayerOneTexture,
+        &PbrClearCoatMaterialDataTest::commonTransformationCoordinatesLayerOneDifferentTexture,
+        &PbrClearCoatMaterialDataTest::commonCoordinatesLayerImplicit},
         Containers::arraySize(PbrClearCoatTextureData));
 
-    addTests({&PbrClearCoatMaterialDataTest::noCommonTransformationCoordinates});
+    addTests({&PbrClearCoatMaterialDataTest::noCommonTransformationCoordinatesLayer});
 }
 
 using namespace Math::Literals;
@@ -90,6 +90,7 @@ void PbrClearCoatMaterialDataTest::basics() {
 
     CORRADE_VERIFY(!data.hasTextureTransformation());
     CORRADE_VERIFY(!data.hasTextureCoordinates());
+    CORRADE_VERIFY(!data.hasTextureLayer());
     CORRADE_COMPARE(data.roughness(), 0.7f);
 }
 
@@ -105,6 +106,7 @@ void PbrClearCoatMaterialDataTest::defaults() {
 
     CORRADE_VERIFY(!data.hasTextureTransformation());
     CORRADE_VERIFY(!data.hasTextureCoordinates());
+    CORRADE_VERIFY(!data.hasTextureLayer());
     CORRADE_COMPARE(data.layerFactor(), 1.0f);
     CORRADE_COMPARE(data.roughness(), 0.0f);
 }
@@ -117,25 +119,30 @@ void PbrClearCoatMaterialDataTest::textured() {
         {MaterialAttribute::RoughnessTextureSwizzle, MaterialTextureSwizzle::A},
         {MaterialAttribute::RoughnessTextureMatrix, Matrix3::translation({2.0f, 1.5f})},
         {MaterialAttribute::RoughnessTextureCoordinates, 6u},
+        {MaterialAttribute::RoughnessTextureLayer, 17u},
         {MaterialAttribute::NormalTexture, 3u},
         {MaterialAttribute::NormalTextureScale, 0.5f},
         {MaterialAttribute::NormalTextureSwizzle, MaterialTextureSwizzle::B},
         {MaterialAttribute::NormalTextureMatrix, Matrix3::translation({0.0f, 0.5f})},
         {MaterialAttribute::NormalTextureCoordinates, 7u},
-    }, {0, 11}};
+        {MaterialAttribute::NormalTextureLayer, 66u},
+    }, {0, 13}};
 
     CORRADE_VERIFY(data.hasTextureTransformation());
     CORRADE_VERIFY(data.hasTextureCoordinates());
+    CORRADE_VERIFY(data.hasTextureLayer());
     CORRADE_COMPARE(data.roughness(), 0.7f);
     CORRADE_COMPARE(data.roughnessTexture(), 2u);
     CORRADE_COMPARE(data.roughnessTextureSwizzle(), MaterialTextureSwizzle::A);
     CORRADE_COMPARE(data.roughnessTextureMatrix(), Matrix3::translation({2.0f, 1.5f}));
     CORRADE_COMPARE(data.roughnessTextureCoordinates(), 6u);
+    CORRADE_COMPARE(data.roughnessTextureLayer(), 17u);
     CORRADE_COMPARE(data.normalTexture(), 3u);
     CORRADE_COMPARE(data.normalTextureScale(), 0.5f);
     CORRADE_COMPARE(data.normalTextureSwizzle(), MaterialTextureSwizzle::B);
     CORRADE_COMPARE(data.normalTextureMatrix(), Matrix3::translation({0.0f, 0.5f}));
     CORRADE_COMPARE(data.normalTextureCoordinates(), 7u);
+    CORRADE_COMPARE(data.normalTextureLayer(), 66u);
 }
 
 void PbrClearCoatMaterialDataTest::texturedDefaults() {
@@ -147,16 +154,19 @@ void PbrClearCoatMaterialDataTest::texturedDefaults() {
 
     CORRADE_VERIFY(!data.hasTextureTransformation());
     CORRADE_VERIFY(!data.hasTextureCoordinates());
+    CORRADE_VERIFY(!data.hasTextureLayer());
     CORRADE_COMPARE(data.roughness(), 0.0f);
     CORRADE_COMPARE(data.roughnessTexture(), 2u);
     CORRADE_COMPARE(data.roughnessTextureSwizzle(), MaterialTextureSwizzle::R);
     CORRADE_COMPARE(data.roughnessTextureMatrix(), Matrix3{});
     CORRADE_COMPARE(data.roughnessTextureCoordinates(), 0u);
+    CORRADE_COMPARE(data.roughnessTextureLayer(), 0u);
     CORRADE_COMPARE(data.normalTexture(), 3u);
     CORRADE_COMPARE(data.normalTextureScale(), 1.0f);
     CORRADE_COMPARE(data.normalTextureSwizzle(), MaterialTextureSwizzle::RGB);
     CORRADE_COMPARE(data.normalTextureMatrix(), Matrix3{});
     CORRADE_COMPARE(data.normalTextureCoordinates(), 0u);
+    CORRADE_COMPARE(data.normalTextureLayer(), 0u);
 }
 
 void PbrClearCoatMaterialDataTest::texturedExplicitPackedLayerFactorRoughness() {
@@ -176,6 +186,7 @@ void PbrClearCoatMaterialDataTest::texturedExplicitPackedLayerFactorRoughness()
         CORRADE_COMPARE(data.roughnessTextureSwizzle(), MaterialTextureSwizzle::G);
         CORRADE_COMPARE(data.roughnessTextureMatrix(), Matrix3{});
         CORRADE_COMPARE(data.roughnessTextureCoordinates(), 0);
+        CORRADE_COMPARE(data.roughnessTextureLayer(), 0);
 
     /* Explicit parameters for everything, but all the same */
     } {
@@ -185,19 +196,23 @@ void PbrClearCoatMaterialDataTest::texturedExplicitPackedLayerFactorRoughness()
             {MaterialAttribute::LayerFactorTextureSwizzle, MaterialTextureSwizzle::R},
             {MaterialAttribute::LayerFactorTextureMatrix, Matrix3::scaling({0.5f, 0.5f})},
             {MaterialAttribute::LayerFactorTextureCoordinates, 3u},
+            {MaterialAttribute::LayerFactorTextureLayer, 17u},
             {MaterialAttribute::RoughnessTexture, 2u},
             {MaterialAttribute::RoughnessTextureSwizzle, MaterialTextureSwizzle::G},
             {MaterialAttribute::RoughnessTextureMatrix, Matrix3::scaling({0.5f, 0.5f})},
-            {MaterialAttribute::RoughnessTextureCoordinates, 3u}
-        }, {0, 9}};
+            {MaterialAttribute::RoughnessTextureCoordinates, 3u},
+            {MaterialAttribute::RoughnessTextureLayer, 17u}
+        }, {0, 11}};
         CORRADE_VERIFY(data.hasLayerFactorRoughnessTexture());
         CORRADE_COMPARE(data.layerFactorTexture(), 2);
         CORRADE_COMPARE(data.layerFactorTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
         CORRADE_COMPARE(data.layerFactorTextureCoordinates(), 3);
+        CORRADE_COMPARE(data.layerFactorTextureLayer(), 17);
         CORRADE_COMPARE(data.roughnessTexture(), 2);
         CORRADE_COMPARE(data.roughnessTextureSwizzle(), MaterialTextureSwizzle::G);
         CORRADE_COMPARE(data.roughnessTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
         CORRADE_COMPARE(data.roughnessTextureCoordinates(), 3);
+        CORRADE_COMPARE(data.roughnessTextureLayer(), 17);
 
     /* Different texture ID */
     } {
@@ -251,47 +266,68 @@ void PbrClearCoatMaterialDataTest::texturedExplicitPackedLayerFactorRoughness()
             {MaterialAttribute::RoughnessTextureCoordinates, 1u}
         }, {0, 5}};
         CORRADE_VERIFY(!data.hasLayerFactorRoughnessTexture());
+
+    /* Unexpected array texture layer */
+    } {
+        PbrClearCoatMaterialData data{{}, {
+            {MaterialLayer::ClearCoat},
+            {MaterialAttribute::LayerFactorTexture, 2u},
+            {MaterialAttribute::LayerFactorTextureLayer, 1u},
+            {MaterialAttribute::RoughnessTexture, 2u},
+            {MaterialAttribute::RoughnessTextureSwizzle, MaterialTextureSwizzle::G},
+        }, {0, 5}};
+        CORRADE_VERIFY(!data.hasLayerFactorRoughnessTexture());
     }
 }
 
-void PbrClearCoatMaterialDataTest::texturedSingleMatrixCoordinates() {
+void PbrClearCoatMaterialDataTest::texturedSingleMatrixCoordinatesLayer() {
     PbrClearCoatMaterialData data{{}, {
         {MaterialLayer::ClearCoat},
         {MaterialAttribute::RoughnessTexture, 2u},
         {MaterialAttribute::NormalTexture, 3u},
         {MaterialAttribute::TextureMatrix, Matrix3::translation({0.0f, 0.5f})},
         {MaterialAttribute::TextureCoordinates, 7u},
-    }, {0, 5}};
+        {MaterialAttribute::TextureLayer, 17u},
+    }, {0, 6}};
 
     CORRADE_VERIFY(data.hasTextureTransformation());
     CORRADE_VERIFY(data.hasTextureCoordinates());
+    CORRADE_VERIFY(data.hasTextureLayer());
     CORRADE_COMPARE(data.roughnessTextureMatrix(), Matrix3::translation({0.0f, 0.5f}));
     CORRADE_COMPARE(data.roughnessTextureCoordinates(), 7u);
+    CORRADE_COMPARE(data.roughnessTextureLayer(), 17u);
     CORRADE_COMPARE(data.normalTextureMatrix(), Matrix3::translation({0.0f, 0.5f}));
     CORRADE_COMPARE(data.normalTextureCoordinates(), 7u);
+    CORRADE_COMPARE(data.normalTextureLayer(), 17u);
 }
 
-void PbrClearCoatMaterialDataTest::texturedBaseMaterialMatrixCoordinates() {
+void PbrClearCoatMaterialDataTest::texturedBaseMaterialMatrixCoordinatesLayer() {
     PbrClearCoatMaterialData data{{}, {
         {MaterialAttribute::TextureMatrix, Matrix3::translation({0.0f, 0.5f})},
         {MaterialAttribute::TextureCoordinates, 7u},
+        {MaterialAttribute::TextureLayer, 17u},
 
         {MaterialLayer::ClearCoat},
         {MaterialAttribute::RoughnessTexture, 2u},
         {MaterialAttribute::NormalTexture, 3u},
-    }, {2, 5}};
+    }, {3, 6}};
 
     CORRADE_VERIFY(data.hasTextureTransformation());
     CORRADE_VERIFY(data.hasTextureCoordinates());
+    CORRADE_VERIFY(data.hasTextureLayer());
     CORRADE_COMPARE(data.roughnessTextureMatrix(), Matrix3::translation({0.0f, 0.5f}));
     CORRADE_COMPARE(data.roughnessTextureCoordinates(), 7u);
+    CORRADE_COMPARE(data.roughnessTextureLayer(), 17u);
     CORRADE_COMPARE(data.normalTextureMatrix(), Matrix3::translation({0.0f, 0.5f}));
     CORRADE_COMPARE(data.normalTextureCoordinates(), 7u);
+    CORRADE_COMPARE(data.normalTextureLayer(), 17u);
 
     CORRADE_VERIFY(data.hasCommonTextureTransformation());
     CORRADE_VERIFY(data.hasCommonTextureCoordinates());
+    CORRADE_VERIFY(data.hasCommonTextureLayer());
     CORRADE_COMPARE(data.commonTextureMatrix(), Matrix3::translation({0.0f, 0.5f}));
     CORRADE_COMPARE(data.commonTextureCoordinates(), 7);
+    CORRADE_COMPARE(data.commonTextureLayer(), 17);
 }
 
 void PbrClearCoatMaterialDataTest::invalidTextures() {
@@ -309,55 +345,67 @@ void PbrClearCoatMaterialDataTest::invalidTextures() {
     data.roughnessTextureSwizzle();
     data.roughnessTextureMatrix();
     data.roughnessTextureCoordinates();
+    data.roughnessTextureLayer();
     data.normalTexture();
     data.normalTextureScale();
     data.normalTextureSwizzle();
     data.normalTextureMatrix();
     data.normalTextureCoordinates();
+    data.normalTextureLayer();
     CORRADE_COMPARE(out.str(),
         "Trade::MaterialData::attribute(): attribute RoughnessTexture not found in layer ClearCoat\n"
         "Trade::PbrClearCoatMaterialData::roughnessTextureSwizzle(): the layer doesn't have a roughness texture\n"
         "Trade::PbrClearCoatMaterialData::roughnessTextureMatrix(): the layer doesn't have a roughness texture\n"
         "Trade::PbrClearCoatMaterialData::roughnessTextureCoordinates(): the layer doesn't have a roughness texture\n"
+        "Trade::PbrClearCoatMaterialData::roughnessTextureLayer(): the layer doesn't have a roughness texture\n"
         "Trade::MaterialData::attribute(): attribute NormalTexture not found in layer ClearCoat\n"
         "Trade::PbrClearCoatMaterialData::normalTextureScale(): the layer doesn't have a normal texture\n"
         "Trade::PbrClearCoatMaterialData::normalTextureSwizzle(): the layer doesn't have a normal texture\n"
         "Trade::PbrClearCoatMaterialData::normalTextureMatrix(): the layer doesn't have a normal texture\n"
-        "Trade::PbrClearCoatMaterialData::normalTextureCoordinates(): the layer doesn't have a normal texture\n");
+        "Trade::PbrClearCoatMaterialData::normalTextureCoordinates(): the layer doesn't have a normal texture\n"
+        "Trade::PbrClearCoatMaterialData::normalTextureLayer(): the layer doesn't have a normal texture\n");
 }
 
-void PbrClearCoatMaterialDataTest::commonTransformationCoordinatesNoTextures() {
+void PbrClearCoatMaterialDataTest::commonTransformationCoordinatesLayerNoTextures() {
     PbrClearCoatMaterialData a{{}, {
         {MaterialLayer::ClearCoat},
     }, {0, 1}};
     CORRADE_VERIFY(a.hasCommonTextureTransformation());
     CORRADE_VERIFY(a.hasCommonTextureCoordinates());
+    CORRADE_VERIFY(a.hasCommonTextureLayer());
     CORRADE_COMPARE(a.commonTextureMatrix(), Matrix3{});
     CORRADE_COMPARE(a.commonTextureCoordinates(), 0);
+    CORRADE_COMPARE(a.commonTextureLayer(), 0);
 
     PbrClearCoatMaterialData b{{}, {
         {MaterialAttribute::TextureMatrix, Matrix3::scaling({0.5f, 0.5f})},
         {MaterialAttribute::TextureCoordinates, 7u},
+        {MaterialAttribute::TextureLayer, 17u},
 
         {MaterialLayer::ClearCoat}
-    }, {2, 3}};
+    }, {3, 4}};
     CORRADE_VERIFY(b.hasCommonTextureTransformation());
     CORRADE_VERIFY(b.hasCommonTextureCoordinates());
+    CORRADE_VERIFY(b.hasCommonTextureLayer());
     CORRADE_COMPARE(b.commonTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
     CORRADE_COMPARE(b.commonTextureCoordinates(), 7);
+    CORRADE_COMPARE(b.commonTextureLayer(), 17);
 
     PbrClearCoatMaterialData c{{}, {
         {MaterialLayer::ClearCoat},
         {MaterialAttribute::TextureMatrix, Matrix3::scaling({0.5f, 0.5f})},
         {MaterialAttribute::TextureCoordinates, 7u},
-    }, {0, 3}};
+        {MaterialAttribute::TextureLayer, 17u},
+    }, {0, 4}};
     CORRADE_VERIFY(c.hasCommonTextureTransformation());
     CORRADE_VERIFY(c.hasCommonTextureCoordinates());
+    CORRADE_VERIFY(c.hasCommonTextureLayer());
     CORRADE_COMPARE(c.commonTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
     CORRADE_COMPARE(c.commonTextureCoordinates(), 7);
+    CORRADE_COMPARE(c.commonTextureLayer(), 17);
 }
 
-void PbrClearCoatMaterialDataTest::commonTransformationCoordinatesOneTexture() {
+void PbrClearCoatMaterialDataTest::commonTransformationCoordinatesLayerOneTexture() {
     Containers::StringView textureName = PbrClearCoatTextureData[testCaseInstanceId()];
     setTestCaseDescription(textureName);
 
@@ -365,20 +413,24 @@ void PbrClearCoatMaterialDataTest::commonTransformationCoordinatesOneTexture() {
         /* These shouldn't affect the below */
         {MaterialAttribute::TextureMatrix, Matrix3::translation({0.5f, 0.0f})},
         {MaterialAttribute::TextureCoordinates, 3u},
+        {MaterialAttribute::TextureLayer, 22u},
 
         {MaterialLayer::ClearCoat},
         {textureName, 5u},
         {textureName + "Matrix", Matrix3::scaling({0.5f, 1.0f})},
         {textureName + "Coordinates", 17u},
-    }, {2, 6}};
+        {textureName + "Layer", 66u},
+    }, {3, 8}};
 
     CORRADE_VERIFY(data.hasCommonTextureTransformation());
     CORRADE_COMPARE(data.commonTextureMatrix(), Matrix3::scaling({0.5f, 1.0f}));
     CORRADE_VERIFY(data.hasCommonTextureCoordinates());
     CORRADE_COMPARE(data.commonTextureCoordinates(), 17u);
+    CORRADE_VERIFY(data.hasCommonTextureLayer());
+    CORRADE_COMPARE(data.commonTextureLayer(), 66u);
 }
 
-void PbrClearCoatMaterialDataTest::commonTransformationCoordinatesOneDifferentTexture() {
+void PbrClearCoatMaterialDataTest::commonTransformationCoordinatesLayerOneDifferentTexture() {
     Containers::StringView textureName = PbrClearCoatTextureData[testCaseInstanceId()];
     setTestCaseDescription(textureName);
 
@@ -387,20 +439,23 @@ void PbrClearCoatMaterialDataTest::commonTransformationCoordinatesOneDifferentTe
            check */
         {MaterialAttribute::TextureMatrix, Matrix3::translation({0.5f, 0.0f})},
         {MaterialAttribute::TextureCoordinates, 3u},
+        {MaterialAttribute::TextureLayer, 22u},
 
         {MaterialLayer::ClearCoat},
         {MaterialAttribute::LayerFactorTexture, 2u},
         {MaterialAttribute::RoughnessTexture, 3u},
         {MaterialAttribute::NormalTexture, 5u},
         {textureName + "Matrix", Matrix3::scaling({0.5f, 1.0f})},
-        {textureName + "Coordinates", 17u}
-    }, {2, 8}};
+        {textureName + "Coordinates", 17u},
+        {textureName + "Layer", 66u},
+    }, {3, 10}};
 
     CORRADE_VERIFY(!data.hasCommonTextureTransformation());
     CORRADE_VERIFY(!data.hasCommonTextureCoordinates());
+    CORRADE_VERIFY(!data.hasCommonTextureLayer());
 }
 
-void PbrClearCoatMaterialDataTest::commonCoordinatesImplicit() {
+void PbrClearCoatMaterialDataTest::commonCoordinatesLayerImplicit() {
     Containers::StringView textureName = PbrClearCoatTextureData[testCaseInstanceId()];
     setTestCaseDescription(textureName);
 
@@ -410,16 +465,20 @@ void PbrClearCoatMaterialDataTest::commonCoordinatesImplicit() {
     PbrClearCoatMaterialData data{{}, {
         {MaterialLayer::ClearCoat},
         {textureName, 5u},
-        {textureName + "Coordinates", 0u}
+        {textureName + "Coordinates", 0u},
+        {textureName + "Layer", 0u},
     }, {0, 3}};
 
     /* Zero is treated same as if there would be no attribute at all */
     CORRADE_VERIFY(!data.hasTextureCoordinates());
+    CORRADE_VERIFY(!data.hasTextureLayer());
     CORRADE_VERIFY(data.hasCommonTextureCoordinates());
+    CORRADE_VERIFY(data.hasCommonTextureLayer());
     CORRADE_COMPARE(data.commonTextureCoordinates(), 0u);
+    CORRADE_COMPARE(data.commonTextureLayer(), 0u);
 }
 
-void PbrClearCoatMaterialDataTest::noCommonTransformationCoordinates() {
+void PbrClearCoatMaterialDataTest::noCommonTransformationCoordinatesLayer() {
     #ifdef CORRADE_NO_ASSERT
     CORRADE_SKIP("CORRADE_NO_ASSERT defined, can't test assertions");
     #endif
@@ -431,9 +490,10 @@ void PbrClearCoatMaterialDataTest::noCommonTransformationCoordinates() {
         {MaterialAttribute::LayerFactorTextureCoordinates, 3u},
         {MaterialAttribute::RoughnessTexture, 4u},
         {MaterialAttribute::RoughnessTextureMatrix, Matrix3::scaling({0.5f, 1.0f})},
+        {MaterialAttribute::RoughnessTextureLayer, 22u},
         {MaterialAttribute::NormalTexture, 5u},
         {MaterialAttribute::NormalTextureCoordinates, 17u}
-    }, {0, 8}};
+    }, {0, 9}};
 
     CORRADE_VERIFY(!data.hasCommonTextureTransformation());
     CORRADE_VERIFY(!data.hasCommonTextureCoordinates());
@@ -442,9 +502,11 @@ void PbrClearCoatMaterialDataTest::noCommonTransformationCoordinates() {
     Error redirectError{&out};
     data.commonTextureMatrix();
     data.commonTextureCoordinates();
+    data.commonTextureLayer();
     CORRADE_COMPARE(out.str(),
         "Trade::PbrClearCoatMaterialData::commonTextureMatrix(): the layer doesn't have a common texture coordinate transformation\n"
-        "Trade::PbrClearCoatMaterialData::commonTextureCoordinates(): the layer doesn't have a common texture coordinate set\n");
+        "Trade::PbrClearCoatMaterialData::commonTextureCoordinates(): the layer doesn't have a common texture coordinate set\n"
+        "Trade::PbrClearCoatMaterialData::commonTextureLayer(): the layer doesn't have a common array texture layer\n");
 }
 
 }}}}

src/Magnum/Trade/Test/PbrMetallicRoughnessMaterialDataTest.cpp

@@ -47,13 +47,13 @@ class PbrMetallicRoughnessMaterialDataTest: public TestSuite::Tester {
         void texturedExplicitPackedRoughnessMetallicOcclusion();
         void texturedExplicitPackedOcclusionRoughnessMetallic();
         void texturedExplicitPackedNormalRoughnessMetallic();
-        void texturedSingleMatrixCoordinates();
+        void texturedSingleMatrixCoordinatesLayer();
         void invalidTextures();
-        void commonTransformationCoordinatesNoTextures();
-        void commonTransformationCoordinatesOneTexture();
-        void commonTransformationCoordinatesOneDifferentTexture();
-        void commonCoordinatesImplicit();
-        void noCommonTransformationCoordinates();
+        void commonTransformationCoordinatesLayerNoTextures();
+        void commonTransformationCoordinatesLayerOneTexture();
+        void commonTransformationCoordinatesLayerOneDifferentTexture();
+        void commonCoordinatesLayerImplicit();
+        void noCommonTransformationCoordinatesLayer();
 };
 
 const Containers::StringView PbrMetallicRoughnessTextureData[] {
@@ -75,17 +75,17 @@ PbrMetallicRoughnessMaterialDataTest::PbrMetallicRoughnessMaterialDataTest() {
               &PbrMetallicRoughnessMaterialDataTest::texturedExplicitPackedRoughnessMetallicOcclusion,
               &PbrMetallicRoughnessMaterialDataTest::texturedExplicitPackedOcclusionRoughnessMetallic,
               &PbrMetallicRoughnessMaterialDataTest::texturedExplicitPackedNormalRoughnessMetallic,
-              &PbrMetallicRoughnessMaterialDataTest::texturedSingleMatrixCoordinates,
+              &PbrMetallicRoughnessMaterialDataTest::texturedSingleMatrixCoordinatesLayer,
               &PbrMetallicRoughnessMaterialDataTest::invalidTextures,
-              &PbrMetallicRoughnessMaterialDataTest::commonTransformationCoordinatesNoTextures});
+              &PbrMetallicRoughnessMaterialDataTest::commonTransformationCoordinatesLayerNoTextures});
 
     addInstancedTests({
-        &PbrMetallicRoughnessMaterialDataTest::commonTransformationCoordinatesOneTexture,
-        &PbrMetallicRoughnessMaterialDataTest::commonTransformationCoordinatesOneDifferentTexture,
-        &PbrMetallicRoughnessMaterialDataTest::commonCoordinatesImplicit},
+        &PbrMetallicRoughnessMaterialDataTest::commonTransformationCoordinatesLayerOneTexture,
+        &PbrMetallicRoughnessMaterialDataTest::commonTransformationCoordinatesLayerOneDifferentTexture,
+        &PbrMetallicRoughnessMaterialDataTest::commonCoordinatesLayerImplicit},
         Containers::arraySize(PbrMetallicRoughnessTextureData));
 
-    addTests({&PbrMetallicRoughnessMaterialDataTest::noCommonTransformationCoordinates});
+    addTests({&PbrMetallicRoughnessMaterialDataTest::noCommonTransformationCoordinatesLayer});
 }
 
 using namespace Math::Literals;
@@ -109,6 +109,7 @@ void PbrMetallicRoughnessMaterialDataTest::basics() {
     CORRADE_VERIFY(!data.hasNormalRoughnessMetallicTexture());
     CORRADE_VERIFY(!data.hasTextureTransformation());
     CORRADE_VERIFY(!data.hasTextureCoordinates());
+    CORRADE_VERIFY(!data.hasTextureLayer());
     CORRADE_COMPARE(data.baseColor(), 0xccffbbff_rgbaf);
     CORRADE_COMPARE(data.metalness(), 0.5f);
     CORRADE_COMPARE(data.roughness(), 0.79f);
@@ -130,6 +131,7 @@ void PbrMetallicRoughnessMaterialDataTest::defaults() {
     CORRADE_VERIFY(!data.hasNormalRoughnessMetallicTexture());
     CORRADE_VERIFY(!data.hasTextureTransformation());
     CORRADE_VERIFY(!data.hasTextureCoordinates());
+    CORRADE_VERIFY(!data.hasTextureLayer());
     CORRADE_COMPARE(data.baseColor(), 0xffffffff_rgbaf);
     CORRADE_COMPARE(data.metalness(), 1.0f);
     CORRADE_COMPARE(data.roughness(), 1.0f);
@@ -142,30 +144,36 @@ void PbrMetallicRoughnessMaterialDataTest::textured() {
         {MaterialAttribute::BaseColorTexture, 0u},
         {MaterialAttribute::BaseColorTextureMatrix, Matrix3::scaling({0.5f, 1.0f})},
         {MaterialAttribute::BaseColorTextureCoordinates, 2u},
+        {MaterialAttribute::BaseColorTextureLayer, 8u},
         {MaterialAttribute::Metalness, 0.5f},
         {MaterialAttribute::MetalnessTexture, 1u},
         {MaterialAttribute::MetalnessTextureSwizzle, MaterialTextureSwizzle::G},
         {MaterialAttribute::MetalnessTextureMatrix, Matrix3::scaling({0.5f, 0.5f})},
         {MaterialAttribute::MetalnessTextureCoordinates, 3u},
+        {MaterialAttribute::MetalnessTextureLayer, 9u},
         {MaterialAttribute::Roughness, 0.79f},
         {MaterialAttribute::RoughnessTexture, 2u},
         {MaterialAttribute::RoughnessTextureSwizzle, MaterialTextureSwizzle::A},
         {MaterialAttribute::RoughnessTextureMatrix, Matrix3::scaling({1.0f, 1.0f})},
         {MaterialAttribute::RoughnessTextureCoordinates, 4u},
+        {MaterialAttribute::RoughnessTextureLayer, 10u},
         {MaterialAttribute::NormalTexture, 3u},
         {MaterialAttribute::NormalTextureScale, 0.35f},
         {MaterialAttribute::NormalTextureSwizzle, MaterialTextureSwizzle::BA},
         {MaterialAttribute::NormalTextureMatrix, Matrix3::scaling({1.0f, 0.5f})},
         {MaterialAttribute::NormalTextureCoordinates, 5u},
+        {MaterialAttribute::NormalTextureLayer, 11u},
         {MaterialAttribute::OcclusionTexture, 4u},
         {MaterialAttribute::OcclusionTextureStrength, 0.66f},
         {MaterialAttribute::OcclusionTextureSwizzle, MaterialTextureSwizzle::B},
         {MaterialAttribute::OcclusionTextureMatrix, Matrix3::scaling({1.0f, 0.75f})},
         {MaterialAttribute::OcclusionTextureCoordinates, 6u},
+        {MaterialAttribute::OcclusionTextureLayer, 12u},
         {MaterialAttribute::EmissiveColor, 0x111111_rgbf},
         {MaterialAttribute::EmissiveTexture, 5u},
         {MaterialAttribute::EmissiveTextureMatrix, Matrix3::scaling({0.75f, 0.5f})},
-        {MaterialAttribute::EmissiveTextureCoordinates, 7u}
+        {MaterialAttribute::EmissiveTextureCoordinates, 7u},
+        {MaterialAttribute::EmissiveTextureLayer, 13u}
     }};
 
     CORRADE_VERIFY(data.hasMetalnessTexture());
@@ -176,34 +184,41 @@ void PbrMetallicRoughnessMaterialDataTest::textured() {
     CORRADE_VERIFY(!data.hasNormalRoughnessMetallicTexture());
     CORRADE_VERIFY(data.hasTextureTransformation());
     CORRADE_VERIFY(data.hasTextureCoordinates());
+    CORRADE_VERIFY(data.hasTextureLayer());
     CORRADE_COMPARE(data.baseColor(), 0xccffbbff_rgbaf);
     CORRADE_COMPARE(data.baseColorTexture(), 0);
     CORRADE_COMPARE(data.baseColorTextureMatrix(), Matrix3::scaling({0.5f, 1.0f}));
     CORRADE_COMPARE(data.baseColorTextureCoordinates(), 2);
+    CORRADE_COMPARE(data.baseColorTextureLayer(), 8);
     CORRADE_COMPARE(data.metalness(), 0.5f);
     CORRADE_COMPARE(data.metalnessTexture(), 1);
     CORRADE_COMPARE(data.metalnessTextureSwizzle(), MaterialTextureSwizzle::G);
     CORRADE_COMPARE(data.metalnessTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
     CORRADE_COMPARE(data.metalnessTextureCoordinates(), 3);
+    CORRADE_COMPARE(data.metalnessTextureLayer(), 9);
     CORRADE_COMPARE(data.roughness(), 0.79f);
     CORRADE_COMPARE(data.roughnessTexture(), 2);
     CORRADE_COMPARE(data.roughnessTextureSwizzle(), MaterialTextureSwizzle::A);
     CORRADE_COMPARE(data.roughnessTextureMatrix(), Matrix3::scaling({1.0f, 1.0f}));
     CORRADE_COMPARE(data.roughnessTextureCoordinates(), 4);
+    CORRADE_COMPARE(data.roughnessTextureLayer(), 10);
     CORRADE_COMPARE(data.normalTexture(), 3);
     CORRADE_COMPARE(data.normalTextureScale(), 0.35f);
     CORRADE_COMPARE(data.normalTextureSwizzle(), MaterialTextureSwizzle::BA);
     CORRADE_COMPARE(data.normalTextureMatrix(), Matrix3::scaling({1.0f, 0.5f}));
     CORRADE_COMPARE(data.normalTextureCoordinates(), 5);
+    CORRADE_COMPARE(data.normalTextureLayer(), 11);
     CORRADE_COMPARE(data.occlusionTexture(), 4);
     CORRADE_COMPARE(data.occlusionTextureStrength(), 0.66f);
     CORRADE_COMPARE(data.occlusionTextureMatrix(), Matrix3::scaling({1.0f, 0.75f}));
     CORRADE_COMPARE(data.occlusionTextureSwizzle(), MaterialTextureSwizzle::B);
     CORRADE_COMPARE(data.occlusionTextureCoordinates(), 6);
+    CORRADE_COMPARE(data.occlusionTextureLayer(), 12);
     CORRADE_COMPARE(data.emissiveColor(), 0x111111_rgbf);
     CORRADE_COMPARE(data.emissiveTextureMatrix(), Matrix3::scaling({0.75f, 0.5f}));
     CORRADE_COMPARE(data.emissiveTexture(), 5);
     CORRADE_COMPARE(data.emissiveTextureCoordinates(), 7);
+    CORRADE_COMPARE(data.emissiveTextureLayer(), 13);
 }
 
 void PbrMetallicRoughnessMaterialDataTest::texturedDefaults() {
@@ -224,37 +239,44 @@ void PbrMetallicRoughnessMaterialDataTest::texturedDefaults() {
     CORRADE_VERIFY(!data.hasNormalRoughnessMetallicTexture());
     CORRADE_VERIFY(!data.hasTextureTransformation());
     CORRADE_VERIFY(!data.hasTextureCoordinates());
+    CORRADE_VERIFY(!data.hasTextureLayer());
     CORRADE_COMPARE(data.baseColor(), 0xffffffff_rgbaf);
     CORRADE_COMPARE(data.baseColorTexture(), 1);
     CORRADE_COMPARE(data.baseColorTextureMatrix(), Matrix3{});
     CORRADE_COMPARE(data.baseColorTextureCoordinates(), 0);
+    CORRADE_COMPARE(data.baseColorTextureLayer(), 0);
     CORRADE_COMPARE(data.metalness(), 1.0f);
     CORRADE_COMPARE(data.metalnessTexture(), 2);
     CORRADE_COMPARE(data.metalnessTextureSwizzle(), MaterialTextureSwizzle::R);
     CORRADE_COMPARE(data.metalnessTextureMatrix(), Matrix3{});
     CORRADE_COMPARE(data.metalnessTextureCoordinates(), 0);
+    CORRADE_COMPARE(data.metalnessTextureLayer(), 0);
     CORRADE_COMPARE(data.roughness(), 1.0f);
     CORRADE_COMPARE(data.roughnessTexture(), 3);
     CORRADE_COMPARE(data.roughnessTextureSwizzle(), MaterialTextureSwizzle::R);
     CORRADE_COMPARE(data.roughnessTextureMatrix(), Matrix3{});
     CORRADE_COMPARE(data.roughnessTextureCoordinates(), 0);
+    CORRADE_COMPARE(data.roughnessTextureLayer(), 0);
     CORRADE_COMPARE(data.normalTexture(), 4);
     CORRADE_COMPARE(data.normalTextureScale(), 1.0f);
     CORRADE_COMPARE(data.normalTextureSwizzle(), MaterialTextureSwizzle::RGB);
     CORRADE_COMPARE(data.normalTextureMatrix(), Matrix3{});
     CORRADE_COMPARE(data.normalTextureCoordinates(), 0);
+    CORRADE_COMPARE(data.normalTextureLayer(), 0);
     CORRADE_COMPARE(data.occlusionTexture(), 5);
     CORRADE_COMPARE(data.occlusionTextureStrength(), 1.0f);
     CORRADE_COMPARE(data.occlusionTextureSwizzle(), MaterialTextureSwizzle::R);
     CORRADE_COMPARE(data.occlusionTextureMatrix(), Matrix3{});
     CORRADE_COMPARE(data.occlusionTextureCoordinates(), 0);
+    CORRADE_COMPARE(data.occlusionTextureLayer(), 0);
     CORRADE_COMPARE(data.emissiveColor(), 0x000000_rgbf);
     CORRADE_COMPARE(data.emissiveTexture(), 6);
     CORRADE_COMPARE(data.emissiveTextureMatrix(), Matrix3{});
     CORRADE_COMPARE(data.emissiveTextureCoordinates(), 0);
+    CORRADE_COMPARE(data.emissiveTextureLayer(), 0);
 }
 
-void PbrMetallicRoughnessMaterialDataTest::texturedSingleMatrixCoordinates() {
+void PbrMetallicRoughnessMaterialDataTest::texturedSingleMatrixCoordinatesLayer() {
     PbrMetallicRoughnessMaterialData data{{}, {
         {MaterialAttribute::BaseColorTexture, 1u},
         {MaterialAttribute::MetalnessTexture, 2u},
@@ -263,21 +285,28 @@ void PbrMetallicRoughnessMaterialDataTest::texturedSingleMatrixCoordinates() {
         {MaterialAttribute::OcclusionTexture, 5u},
         {MaterialAttribute::EmissiveTexture, 6u},
         {MaterialAttribute::TextureMatrix, Matrix3::scaling({0.5f, 0.5f})},
-        {MaterialAttribute::TextureCoordinates, 7u}
+        {MaterialAttribute::TextureCoordinates, 7u},
+        {MaterialAttribute::TextureLayer, 8u},
     }};
 
     CORRADE_COMPARE(data.baseColorTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
     CORRADE_COMPARE(data.baseColorTextureCoordinates(), 7);
+    CORRADE_COMPARE(data.baseColorTextureLayer(), 8);
     CORRADE_COMPARE(data.metalnessTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
     CORRADE_COMPARE(data.metalnessTextureCoordinates(), 7);
+    CORRADE_COMPARE(data.metalnessTextureLayer(), 8);
     CORRADE_COMPARE(data.roughnessTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
     CORRADE_COMPARE(data.roughnessTextureCoordinates(), 7);
+    CORRADE_COMPARE(data.roughnessTextureLayer(), 8);
     CORRADE_COMPARE(data.normalTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
     CORRADE_COMPARE(data.normalTextureCoordinates(), 7);
+    CORRADE_COMPARE(data.normalTextureLayer(), 8);
     CORRADE_COMPARE(data.occlusionTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
     CORRADE_COMPARE(data.occlusionTextureCoordinates(), 7);
+    CORRADE_COMPARE(data.occlusionTextureLayer(), 8);
     CORRADE_COMPARE(data.emissiveTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
     CORRADE_COMPARE(data.emissiveTextureCoordinates(), 7);
+    CORRADE_COMPARE(data.emissiveTextureLayer(), 8);
 }
 
 void PbrMetallicRoughnessMaterialDataTest::texturedImplicitPackedMetallicRoughness() {
@@ -291,10 +320,12 @@ void PbrMetallicRoughnessMaterialDataTest::texturedImplicitPackedMetallicRoughne
         CORRADE_COMPARE(data.roughnessTextureSwizzle(), MaterialTextureSwizzle::G);
         CORRADE_COMPARE(data.roughnessTextureMatrix(), Matrix3{});
         CORRADE_COMPARE(data.roughnessTextureCoordinates(), 0);
+        CORRADE_COMPARE(data.roughnessTextureLayer(), 0);
         CORRADE_COMPARE(data.metalnessTexture(), 2);
         CORRADE_COMPARE(data.metalnessTextureSwizzle(), MaterialTextureSwizzle::B);
         CORRADE_COMPARE(data.metalnessTextureMatrix(), Matrix3{});
         CORRADE_COMPARE(data.metalnessTextureCoordinates(), 0);
+        CORRADE_COMPARE(data.metalnessTextureLayer(), 0);
 
     /* Explicit parameters for everything, but all the same */
     } {
@@ -303,19 +334,23 @@ void PbrMetallicRoughnessMaterialDataTest::texturedImplicitPackedMetallicRoughne
             {MaterialAttribute::RoughnessTextureSwizzle, MaterialTextureSwizzle::G},
             {MaterialAttribute::RoughnessTextureMatrix, Matrix3::scaling({0.5f, 0.5f})},
             {MaterialAttribute::RoughnessTextureCoordinates, 3u},
+            {MaterialAttribute::RoughnessTextureLayer, 17u},
             {MaterialAttribute::MetalnessTextureMatrix, Matrix3::scaling({0.5f, 0.5f})},
             {MaterialAttribute::MetalnessTextureSwizzle, MaterialTextureSwizzle::B},
-            {MaterialAttribute::MetalnessTextureCoordinates, 3u}
+            {MaterialAttribute::MetalnessTextureCoordinates, 3u},
+            {MaterialAttribute::MetalnessTextureLayer, 17u},
         }};
         CORRADE_VERIFY(data.hasNoneRoughnessMetallicTexture());
         CORRADE_COMPARE(data.roughnessTexture(), 2);
         CORRADE_COMPARE(data.roughnessTextureSwizzle(), MaterialTextureSwizzle::G);
         CORRADE_COMPARE(data.roughnessTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
         CORRADE_COMPARE(data.roughnessTextureCoordinates(), 3);
+        CORRADE_COMPARE(data.roughnessTextureLayer(), 17);
         CORRADE_COMPARE(data.metalnessTexture(), 2);
         CORRADE_COMPARE(data.metalnessTextureSwizzle(), MaterialTextureSwizzle::B);
         CORRADE_COMPARE(data.metalnessTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
         CORRADE_COMPARE(data.metalnessTextureCoordinates(), 3);
+        CORRADE_COMPARE(data.metalnessTextureLayer(), 17);
 
     /* Swizzle is ignored when the combined texture is specified, so this is
        fine */
@@ -341,6 +376,14 @@ void PbrMetallicRoughnessMaterialDataTest::texturedImplicitPackedMetallicRoughne
             {MaterialAttribute::RoughnessTextureCoordinates, 1u},
         }};
         CORRADE_VERIFY(!data.hasNoneRoughnessMetallicTexture());
+
+    /* Unexpected array texture layer */
+    } {
+        PbrMetallicRoughnessMaterialData data{{}, {
+            {MaterialAttribute::NoneRoughnessMetallicTexture, 2u},
+            {MaterialAttribute::MetalnessTextureLayer, 1u},
+        }};
+        CORRADE_VERIFY(!data.hasNoneRoughnessMetallicTexture());
     }
 }
 
@@ -362,10 +405,12 @@ void PbrMetallicRoughnessMaterialDataTest::texturedExplicitPackedMetallicRoughne
             {MaterialAttribute::RoughnessTextureSwizzle, MaterialTextureSwizzle::G},
             {MaterialAttribute::RoughnessTextureMatrix, Matrix3::scaling({0.5f, 0.5f})},
             {MaterialAttribute::RoughnessTextureCoordinates, 3u},
+            {MaterialAttribute::RoughnessTextureLayer, 7u},
             {MaterialAttribute::MetalnessTexture, 2u},
             {MaterialAttribute::MetalnessTextureMatrix, Matrix3::scaling({0.5f, 0.5f})},
             {MaterialAttribute::MetalnessTextureSwizzle, MaterialTextureSwizzle::B},
-            {MaterialAttribute::MetalnessTextureCoordinates, 3u}
+            {MaterialAttribute::MetalnessTextureCoordinates, 3u},
+            {MaterialAttribute::MetalnessTextureLayer, 7u}
         }};
         CORRADE_VERIFY(data.hasNoneRoughnessMetallicTexture());
 
@@ -418,6 +463,17 @@ void PbrMetallicRoughnessMaterialDataTest::texturedExplicitPackedMetallicRoughne
             {MaterialAttribute::MetalnessTextureSwizzle, MaterialTextureSwizzle::B},
         }};
         CORRADE_VERIFY(!data.hasNoneRoughnessMetallicTexture());
+
+    /* Unexpected array texture layer */
+    } {
+        PbrMetallicRoughnessMaterialData data{{}, {
+            {MaterialAttribute::RoughnessTexture, 2u},
+            {MaterialAttribute::RoughnessTextureSwizzle, MaterialTextureSwizzle::G},
+            {MaterialAttribute::MetalnessTexture, 2u},
+            {MaterialAttribute::MetalnessTextureSwizzle, MaterialTextureSwizzle::B},
+            {MaterialAttribute::MetalnessTextureLayer, 1u},
+        }};
+        CORRADE_VERIFY(!data.hasNoneRoughnessMetallicTexture());
     }
 }
 
@@ -442,14 +498,17 @@ void PbrMetallicRoughnessMaterialDataTest::texturedExplicitPackedRoughnessMetall
             {MaterialAttribute::RoughnessTextureSwizzle, MaterialTextureSwizzle::R},
             {MaterialAttribute::RoughnessTextureMatrix, Matrix3::scaling({0.5f, 0.5f})},
             {MaterialAttribute::RoughnessTextureCoordinates, 3u},
+            {MaterialAttribute::RoughnessTextureLayer, 7u},
             {MaterialAttribute::MetalnessTexture, 2u},
             {MaterialAttribute::MetalnessTextureMatrix, Matrix3::scaling({0.5f, 0.5f})},
             {MaterialAttribute::MetalnessTextureSwizzle, MaterialTextureSwizzle::G},
             {MaterialAttribute::MetalnessTextureCoordinates, 3u},
+            {MaterialAttribute::MetalnessTextureLayer, 7u},
             {MaterialAttribute::OcclusionTexture, 2u},
             {MaterialAttribute::OcclusionTextureSwizzle, MaterialTextureSwizzle::B},
             {MaterialAttribute::OcclusionTextureMatrix, Matrix3::scaling({0.5f, 0.5f})},
-            {MaterialAttribute::OcclusionTextureCoordinates, 3u}
+            {MaterialAttribute::OcclusionTextureCoordinates, 3u},
+            {MaterialAttribute::OcclusionTextureLayer, 7u},
         }};
         CORRADE_VERIFY(data.hasRoughnessMetallicOcclusionTexture());
         /* This isn't a superset */
@@ -506,9 +565,21 @@ void PbrMetallicRoughnessMaterialDataTest::texturedExplicitPackedRoughnessMetall
             {MaterialAttribute::RoughnessTexture, 2u},
             {MaterialAttribute::MetalnessTexture, 2u},
             {MaterialAttribute::MetalnessTextureSwizzle, MaterialTextureSwizzle::G},
+            {MaterialAttribute::MetalnessTextureCoordinates, 1u},
+            {MaterialAttribute::OcclusionTexture, 2u},
+            {MaterialAttribute::OcclusionTextureSwizzle, MaterialTextureSwizzle::B},
+        }};
+        CORRADE_VERIFY(!data.hasRoughnessMetallicOcclusionTexture());
+
+    /* Unexpected array texture layer */
+    } {
+        PbrMetallicRoughnessMaterialData data{{}, {
+            {MaterialAttribute::RoughnessTexture, 2u},
+            {MaterialAttribute::RoughnessTextureLayer, 1u},
+            {MaterialAttribute::MetalnessTexture, 2u},
+            {MaterialAttribute::MetalnessTextureSwizzle, MaterialTextureSwizzle::G},
             {MaterialAttribute::OcclusionTexture, 2u},
             {MaterialAttribute::OcclusionTextureSwizzle, MaterialTextureSwizzle::B},
-            {MaterialAttribute::MetalnessTextureCoordinates, 1u},
         }};
         CORRADE_VERIFY(!data.hasRoughnessMetallicOcclusionTexture());
     }
@@ -604,6 +675,18 @@ void PbrMetallicRoughnessMaterialDataTest::texturedExplicitPackedOcclusionRoughn
             {MaterialAttribute::MetalnessTextureCoordinates, 1u},
         }};
         CORRADE_VERIFY(!data.hasOcclusionRoughnessMetallicTexture());
+
+    /* Unexpected array texture layer */
+    } {
+        PbrMetallicRoughnessMaterialData data{{}, {
+            {MaterialAttribute::OcclusionTexture, 2u},
+            {MaterialAttribute::OcclusionTextureLayer, 1u},
+            {MaterialAttribute::RoughnessTexture, 2u},
+            {MaterialAttribute::RoughnessTextureSwizzle, MaterialTextureSwizzle::G},
+            {MaterialAttribute::MetalnessTexture, 2u},
+            {MaterialAttribute::MetalnessTextureSwizzle, MaterialTextureSwizzle::B},
+        }};
+        CORRADE_VERIFY(!data.hasOcclusionRoughnessMetallicTexture());
     }
 }
 
@@ -697,6 +780,19 @@ void PbrMetallicRoughnessMaterialDataTest::texturedExplicitPackedNormalRoughness
             {MaterialAttribute::MetalnessTextureCoordinates, 1u},
         }};
         CORRADE_VERIFY(!data.hasNormalRoughnessMetallicTexture());
+
+    /* Unexpected array texture layer */
+    } {
+        PbrMetallicRoughnessMaterialData data{{}, {
+            {MaterialAttribute::NormalTexture, 2u},
+            {MaterialAttribute::NormalTextureSwizzle, MaterialTextureSwizzle::RG},
+            {MaterialAttribute::RoughnessTexture, 2u},
+            {MaterialAttribute::RoughnessTextureSwizzle, MaterialTextureSwizzle::B},
+            {MaterialAttribute::RoughnessTextureLayer, 1u},
+            {MaterialAttribute::MetalnessTexture, 2u},
+            {MaterialAttribute::MetalnessTextureSwizzle, MaterialTextureSwizzle::A},
+        }};
+        CORRADE_VERIFY(!data.hasNormalRoughnessMetallicTexture());
     }
 }
 
@@ -712,72 +808,89 @@ void PbrMetallicRoughnessMaterialDataTest::invalidTextures() {
     data.baseColorTexture();
     data.baseColorTextureMatrix();
     data.baseColorTextureCoordinates();
+    data.baseColorTextureLayer();
     data.metalnessTexture();
     data.metalnessTextureSwizzle();
     data.metalnessTextureMatrix();
     data.metalnessTextureCoordinates();
+    data.metalnessTextureLayer();
     data.roughnessTexture();
     data.roughnessTextureSwizzle();
     data.roughnessTextureMatrix();
     data.roughnessTextureCoordinates();
+    data.roughnessTextureLayer();
     data.normalTexture();
     data.normalTextureScale();
     data.normalTextureSwizzle();
     data.normalTextureMatrix();
     data.normalTextureCoordinates();
+    data.normalTextureLayer();
     data.occlusionTexture();
     data.occlusionTextureStrength();
     data.occlusionTextureSwizzle();
     data.occlusionTextureMatrix();
     data.occlusionTextureCoordinates();
+    data.occlusionTextureLayer();
     data.emissiveTexture();
     data.emissiveTextureMatrix();
     data.emissiveTextureCoordinates();
+    data.emissiveTextureLayer();
     CORRADE_COMPARE(out.str(),
         "Trade::MaterialData::attribute(): attribute BaseColorTexture not found in layer 0\n"
         "Trade::PbrMetallicRoughnessMaterialData::baseColorTextureMatrix(): the material doesn't have a base color texture\n"
         "Trade::PbrMetallicRoughnessMaterialData::baseColorTextureCoordinates(): the material doesn't have a base color texture\n"
+        "Trade::PbrMetallicRoughnessMaterialData::baseColorTextureLayer(): the material doesn't have a base color texture\n"
         "Trade::PbrMetallicRoughnessMaterialData::metalnessTexture(): the material doesn't have a metalness texture\n"
         "Trade::PbrMetallicRoughnessMaterialData::metalnessTextureSwizzle(): the material doesn't have a metalness texture\n"
         "Trade::PbrMetallicRoughnessMaterialData::metalnessTextureMatrix(): the material doesn't have a metalness texture\n"
         "Trade::PbrMetallicRoughnessMaterialData::metalnessTextureCoordinates(): the material doesn't have a metalness texture\n"
+        "Trade::PbrMetallicRoughnessMaterialData::metalnessTextureLayer(): the material doesn't have a metalness texture\n"
         "Trade::PbrMetallicRoughnessMaterialData::roughnessTexture(): the material doesn't have a roughness texture\n"
         "Trade::PbrMetallicRoughnessMaterialData::roughnessTextureSwizzle(): the material doesn't have a roughness texture\n"
         "Trade::PbrMetallicRoughnessMaterialData::roughnessTextureMatrix(): the material doesn't have a roughness texture\n"
         "Trade::PbrMetallicRoughnessMaterialData::roughnessTextureCoordinates(): the material doesn't have a roughness texture\n"
+        "Trade::PbrMetallicRoughnessMaterialData::roughnessTextureLayer(): the material doesn't have a roughness texture\n"
         "Trade::MaterialData::attribute(): attribute NormalTexture not found in layer 0\n"
         "Trade::PbrMetallicRoughnessMaterialData::normalTextureScale(): the material doesn't have a normal texture\n"
         "Trade::PbrMetallicRoughnessMaterialData::normalTextureSwizzle(): the material doesn't have a normal texture\n"
         "Trade::PbrMetallicRoughnessMaterialData::normalTextureMatrix(): the material doesn't have a normal texture\n"
         "Trade::PbrMetallicRoughnessMaterialData::normalTextureCoordinates(): the material doesn't have a normal texture\n"
+        "Trade::PbrMetallicRoughnessMaterialData::normalTextureLayer(): the material doesn't have a normal texture\n"
         "Trade::MaterialData::attribute(): attribute OcclusionTexture not found in layer 0\n"
         "Trade::PbrMetallicRoughnessMaterialData::occlusionTextureStrength(): the material doesn't have an occlusion texture\n"
         "Trade::PbrMetallicRoughnessMaterialData::occlusionTextureSwizzle(): the material doesn't have an occlusion texture\n"
         "Trade::PbrMetallicRoughnessMaterialData::occlusionTextureMatrix(): the material doesn't have an occlusion texture\n"
         "Trade::PbrMetallicRoughnessMaterialData::occlusionTextureCoordinates(): the material doesn't have an occlusion texture\n"
+        "Trade::PbrMetallicRoughnessMaterialData::occlusionTextureLayer(): the material doesn't have an occlusion texture\n"
         "Trade::MaterialData::attribute(): attribute EmissiveTexture not found in layer 0\n"
         "Trade::PbrMetallicRoughnessMaterialData::emissiveTextureMatrix(): the material doesn't have an emissive texture\n"
-        "Trade::PbrMetallicRoughnessMaterialData::emissiveTextureCoordinates(): the material doesn't have an emissive texture\n");
+        "Trade::PbrMetallicRoughnessMaterialData::emissiveTextureCoordinates(): the material doesn't have an emissive texture\n"
+        "Trade::PbrMetallicRoughnessMaterialData::emissiveTextureLayer(): the material doesn't have an emissive texture\n");
 }
 
-void PbrMetallicRoughnessMaterialDataTest::commonTransformationCoordinatesNoTextures() {
+void PbrMetallicRoughnessMaterialDataTest::commonTransformationCoordinatesLayerNoTextures() {
     PbrMetallicRoughnessMaterialData a{{}, {}};
     CORRADE_VERIFY(a.hasCommonTextureTransformation());
     CORRADE_VERIFY(a.hasCommonTextureCoordinates());
+    CORRADE_VERIFY(a.hasCommonTextureLayer());
     CORRADE_COMPARE(a.commonTextureMatrix(), Matrix3{});
     CORRADE_COMPARE(a.commonTextureCoordinates(), 0);
+    CORRADE_COMPARE(a.commonTextureLayer(), 0);
 
     PbrMetallicRoughnessMaterialData b{{}, {
         {MaterialAttribute::TextureMatrix, Matrix3::scaling({0.5f, 0.5f})},
-        {MaterialAttribute::TextureCoordinates, 7u}
+        {MaterialAttribute::TextureCoordinates, 7u},
+        {MaterialAttribute::TextureLayer, 22u}
     }};
     CORRADE_VERIFY(b.hasCommonTextureTransformation());
     CORRADE_VERIFY(b.hasCommonTextureCoordinates());
+    CORRADE_VERIFY(b.hasCommonTextureLayer());
     CORRADE_COMPARE(b.commonTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
     CORRADE_COMPARE(b.commonTextureCoordinates(), 7);
+    CORRADE_COMPARE(b.commonTextureLayer(), 22);
 }
 
-void PbrMetallicRoughnessMaterialDataTest::commonTransformationCoordinatesOneTexture() {
+void PbrMetallicRoughnessMaterialDataTest::commonTransformationCoordinatesLayerOneTexture() {
     Containers::StringView textureName = PbrMetallicRoughnessTextureData[testCaseInstanceId()];
     setTestCaseDescription(textureName);
 
@@ -785,19 +898,23 @@ void PbrMetallicRoughnessMaterialDataTest::commonTransformationCoordinatesOneTex
         {textureName, 5u},
         {textureName + "Matrix", Matrix3::scaling({0.5f, 1.0f})},
         {textureName + "Coordinates", 17u},
+        {textureName + "Layer", 22u},
 
         /* These shouldn't affect the above */
         {MaterialAttribute::TextureMatrix, Matrix3::translation({0.5f, 0.0f})},
-        {MaterialAttribute::TextureCoordinates, 3u}
+        {MaterialAttribute::TextureCoordinates, 3u},
+        {MaterialAttribute::TextureLayer, 66u},
     }};
 
     CORRADE_VERIFY(data.hasCommonTextureTransformation());
     CORRADE_COMPARE(data.commonTextureMatrix(), Matrix3::scaling({0.5f, 1.0f}));
     CORRADE_VERIFY(data.hasCommonTextureCoordinates());
     CORRADE_COMPARE(data.commonTextureCoordinates(), 17u);
+    CORRADE_VERIFY(data.hasCommonTextureLayer());
+    CORRADE_COMPARE(data.commonTextureLayer(), 22u);
 }
 
-void PbrMetallicRoughnessMaterialDataTest::commonTransformationCoordinatesOneDifferentTexture() {
+void PbrMetallicRoughnessMaterialDataTest::commonTransformationCoordinatesLayerOneDifferentTexture() {
     Containers::StringView textureName = PbrMetallicRoughnessTextureData[testCaseInstanceId()];
     setTestCaseDescription(textureName);
 
@@ -810,18 +927,21 @@ void PbrMetallicRoughnessMaterialDataTest::commonTransformationCoordinatesOneDif
         {MaterialAttribute::EmissiveTexture, 7u},
         {textureName + "Matrix", Matrix3::scaling({0.5f, 1.0f})},
         {textureName + "Coordinates", 17u},
+        {textureName + "Layer", 22u},
 
         /* These are used by all textures except the one above, failing the
            check */
         {MaterialAttribute::TextureMatrix, Matrix3::translation({0.5f, 0.0f})},
-        {MaterialAttribute::TextureCoordinates, 3u}
+        {MaterialAttribute::TextureCoordinates, 3u},
+        {MaterialAttribute::TextureLayer, 66u},
     }};
 
     CORRADE_VERIFY(!data.hasCommonTextureTransformation());
     CORRADE_VERIFY(!data.hasCommonTextureCoordinates());
+    CORRADE_VERIFY(!data.hasCommonTextureLayer());
 }
 
-void PbrMetallicRoughnessMaterialDataTest::commonCoordinatesImplicit() {
+void PbrMetallicRoughnessMaterialDataTest::commonCoordinatesLayerImplicit() {
     Containers::StringView textureName = PbrMetallicRoughnessTextureData[testCaseInstanceId()];
     setTestCaseDescription(textureName);
 
@@ -830,16 +950,20 @@ void PbrMetallicRoughnessMaterialDataTest::commonCoordinatesImplicit() {
 
     PbrMetallicRoughnessMaterialData data{{}, {
         {textureName, 5u},
-        {textureName + "Coordinates", 0u}
+        {textureName + "Coordinates", 0u},
+        {textureName + "Layer", 0u},
     }};
 
     /* Zero is treated same as if there would be no attribute at all */
     CORRADE_VERIFY(!data.hasTextureCoordinates());
+    CORRADE_VERIFY(!data.hasTextureLayer());
     CORRADE_VERIFY(data.hasCommonTextureCoordinates());
+    CORRADE_VERIFY(data.hasCommonTextureLayer());
     CORRADE_COMPARE(data.commonTextureCoordinates(), 0u);
+    CORRADE_COMPARE(data.commonTextureLayer(), 0u);
 }
 
-void PbrMetallicRoughnessMaterialDataTest::noCommonTransformationCoordinates() {
+void PbrMetallicRoughnessMaterialDataTest::noCommonTransformationCoordinatesLayer() {
     #ifdef CORRADE_NO_ASSERT
     CORRADE_SKIP("CORRADE_NO_ASSERT defined, can't test assertions");
     #endif
@@ -850,20 +974,24 @@ void PbrMetallicRoughnessMaterialDataTest::noCommonTransformationCoordinates() {
         {MaterialAttribute::BaseColorTextureCoordinates, 3u},
         {MaterialAttribute::MetalnessTexture, 4u},
         {MaterialAttribute::MetalnessTextureMatrix, Matrix3::scaling({0.5f, 1.0f})},
+        {MaterialAttribute::MetalnessTextureLayer, 22u},
         {MaterialAttribute::RoughnessTexture, 5u},
         {MaterialAttribute::RoughnessTextureCoordinates, 17u}
     }};
 
     CORRADE_VERIFY(!data.hasCommonTextureTransformation());
     CORRADE_VERIFY(!data.hasCommonTextureCoordinates());
+    CORRADE_VERIFY(!data.hasCommonTextureLayer());
 
     std::ostringstream out;
     Error redirectError{&out};
     data.commonTextureMatrix();
     data.commonTextureCoordinates();
+    data.commonTextureLayer();
     CORRADE_COMPARE(out.str(),
         "Trade::PbrMetallicRoughnessMaterialData::commonTextureMatrix(): the material doesn't have a common texture coordinate transformation\n"
-        "Trade::PbrMetallicRoughnessMaterialData::commonTextureCoordinates(): the material doesn't have a common texture coordinate set\n");
+        "Trade::PbrMetallicRoughnessMaterialData::commonTextureCoordinates(): the material doesn't have a common texture coordinate set\n"
+        "Trade::PbrMetallicRoughnessMaterialData::commonTextureLayer(): the material doesn't have a common array texture layer\n");
 }
 
 }}}}

src/Magnum/Trade/Test/PbrSpecularGlossinessMaterialDataTest.cpp

@@ -44,13 +44,13 @@ class PbrSpecularGlossinessMaterialDataTest: public TestSuite::Tester {
         void texturedDefaults();
         void texturedImplicitPackedSpecularGlossiness();
         void texturedExplicitPackedSpecularGlossiness();
-        void texturedSingleMatrixCoordinates();
+        void texturedSingleMatrixCoordinatesLayer();
         void invalidTextures();
-        void commonTransformationCoordinatesNoTextures();
-        void commonTransformationCoordinatesOneTexture();
-        void commonTransformationCoordinatesOneDifferentTexture();
-        void commonCoordinatesImplicit();
-        void noCommonTransformationCoordinates();
+        void commonTransformationCoordinatesLayerNoTextures();
+        void commonTransformationCoordinatesLayerOneTexture();
+        void commonTransformationCoordinatesLayerOneDifferentTexture();
+        void commonCoordinatesLayerImplicit();
+        void noCommonTransformationCoordinatesLayer();
 };
 
 const Containers::StringView PbrSpecularGlossinessTextureData[] {
@@ -69,17 +69,17 @@ PbrSpecularGlossinessMaterialDataTest::PbrSpecularGlossinessMaterialDataTest() {
               &PbrSpecularGlossinessMaterialDataTest::texturedDefaults,
               &PbrSpecularGlossinessMaterialDataTest::texturedImplicitPackedSpecularGlossiness,
               &PbrSpecularGlossinessMaterialDataTest::texturedExplicitPackedSpecularGlossiness,
-              &PbrSpecularGlossinessMaterialDataTest::texturedSingleMatrixCoordinates,
+              &PbrSpecularGlossinessMaterialDataTest::texturedSingleMatrixCoordinatesLayer,
               &PbrSpecularGlossinessMaterialDataTest::invalidTextures,
-              &PbrSpecularGlossinessMaterialDataTest::commonTransformationCoordinatesNoTextures});
+              &PbrSpecularGlossinessMaterialDataTest::commonTransformationCoordinatesLayerNoTextures});
 
     addInstancedTests({
-        &PbrSpecularGlossinessMaterialDataTest::commonTransformationCoordinatesOneTexture,
-        &PbrSpecularGlossinessMaterialDataTest::commonTransformationCoordinatesOneDifferentTexture,
-        &PbrSpecularGlossinessMaterialDataTest::commonCoordinatesImplicit},
+        &PbrSpecularGlossinessMaterialDataTest::commonTransformationCoordinatesLayerOneTexture,
+        &PbrSpecularGlossinessMaterialDataTest::commonTransformationCoordinatesLayerOneDifferentTexture,
+        &PbrSpecularGlossinessMaterialDataTest::commonCoordinatesLayerImplicit},
         Containers::arraySize(PbrSpecularGlossinessTextureData));
 
-    addTests({&PbrSpecularGlossinessMaterialDataTest::noCommonTransformationCoordinates});
+    addTests({&PbrSpecularGlossinessMaterialDataTest::noCommonTransformationCoordinatesLayer});
 }
 
 using namespace Math::Literals;
@@ -100,6 +100,7 @@ void PbrSpecularGlossinessMaterialDataTest::basics() {
     CORRADE_VERIFY(!data.hasSpecularGlossinessTexture());
     CORRADE_VERIFY(!data.hasTextureTransformation());
     CORRADE_VERIFY(!data.hasTextureCoordinates());
+    CORRADE_VERIFY(!data.hasTextureLayer());
     CORRADE_COMPARE(data.diffuseColor(), 0xccffbbff_rgbaf);
     CORRADE_COMPARE(data.specularColor(), 0xff336600_rgbaf);
     CORRADE_COMPARE(data.glossiness(), 0.79f);
@@ -117,6 +118,7 @@ void PbrSpecularGlossinessMaterialDataTest::defaults() {
     CORRADE_VERIFY(!data.hasSpecularGlossinessTexture());
     CORRADE_VERIFY(!data.hasTextureTransformation());
     CORRADE_VERIFY(!data.hasTextureCoordinates());
+    CORRADE_VERIFY(!data.hasTextureLayer());
     CORRADE_COMPARE(data.diffuseColor(), 0xffffffff_rgbaf);
     CORRADE_COMPARE(data.specularColor(), 0xffffff00_rgbaf);
     CORRADE_COMPARE(data.glossiness(), 1.0f);
@@ -128,30 +130,36 @@ void PbrSpecularGlossinessMaterialDataTest::textured() {
         {MaterialAttribute::DiffuseTexture, 0u},
         {MaterialAttribute::DiffuseTextureMatrix, Matrix3::scaling({0.5f, 1.0f})},
         {MaterialAttribute::DiffuseTextureCoordinates, 2u},
+        {MaterialAttribute::DiffuseTextureLayer, 8u},
         {MaterialAttribute::SpecularColor, 0x33556600_rgbaf},
         {MaterialAttribute::SpecularTexture, 1u},
         {MaterialAttribute::SpecularTextureSwizzle, MaterialTextureSwizzle::RGBA},
         {MaterialAttribute::SpecularTextureMatrix, Matrix3::scaling({0.5f, 0.5f})},
         {MaterialAttribute::SpecularTextureCoordinates, 3u},
+        {MaterialAttribute::SpecularTextureLayer, 9u},
         {MaterialAttribute::Glossiness, 0.79f},
         {MaterialAttribute::GlossinessTexture, 2u},
         {MaterialAttribute::GlossinessTextureSwizzle, MaterialTextureSwizzle::A},
         {MaterialAttribute::GlossinessTextureMatrix, Matrix3::scaling({1.0f, 1.0f})},
         {MaterialAttribute::GlossinessTextureCoordinates, 4u},
+        {MaterialAttribute::GlossinessTextureLayer, 10u},
         {MaterialAttribute::NormalTexture, 3u},
         {MaterialAttribute::NormalTextureScale, 0.35f},
         {MaterialAttribute::NormalTextureSwizzle, MaterialTextureSwizzle::BA},
         {MaterialAttribute::NormalTextureMatrix, Matrix3::scaling({1.0f, 0.5f})},
         {MaterialAttribute::NormalTextureCoordinates, 5u},
+        {MaterialAttribute::NormalTextureLayer, 11u},
         {MaterialAttribute::OcclusionTexture, 4u},
         {MaterialAttribute::OcclusionTextureStrength, 0.66f},
         {MaterialAttribute::OcclusionTextureSwizzle, MaterialTextureSwizzle::B},
         {MaterialAttribute::OcclusionTextureMatrix, Matrix3::scaling({1.0f, 0.75f})},
         {MaterialAttribute::OcclusionTextureCoordinates, 6u},
+        {MaterialAttribute::OcclusionTextureLayer, 12u},
         {MaterialAttribute::EmissiveColor, 0x111111_rgbf},
         {MaterialAttribute::EmissiveTexture, 5u},
         {MaterialAttribute::EmissiveTextureMatrix, Matrix3::scaling({0.75f, 0.5f})},
-        {MaterialAttribute::EmissiveTextureCoordinates, 7u}
+        {MaterialAttribute::EmissiveTextureCoordinates, 7u},
+        {MaterialAttribute::EmissiveTextureLayer, 13u},
     }};
 
     CORRADE_VERIFY(data.hasSpecularTexture());
@@ -159,34 +167,41 @@ void PbrSpecularGlossinessMaterialDataTest::textured() {
     CORRADE_VERIFY(!data.hasSpecularGlossinessTexture());
     CORRADE_VERIFY(data.hasTextureTransformation());
     CORRADE_VERIFY(data.hasTextureCoordinates());
+    CORRADE_VERIFY(data.hasTextureLayer());
     CORRADE_COMPARE(data.diffuseColor(), 0xccffbbff_rgbaf);
     CORRADE_COMPARE(data.diffuseTexture(), 0);
     CORRADE_COMPARE(data.diffuseTextureMatrix(), Matrix3::scaling({0.5f, 1.0f}));
     CORRADE_COMPARE(data.diffuseTextureCoordinates(), 2);
+    CORRADE_COMPARE(data.diffuseTextureLayer(), 8);
     CORRADE_COMPARE(data.specularColor(), 0x33556600_rgbaf);
     CORRADE_COMPARE(data.specularTexture(), 1);
     CORRADE_COMPARE(data.specularTextureSwizzle(), MaterialTextureSwizzle::RGBA);
     CORRADE_COMPARE(data.specularTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
     CORRADE_COMPARE(data.specularTextureCoordinates(), 3);
+    CORRADE_COMPARE(data.specularTextureLayer(), 9);
     CORRADE_COMPARE(data.glossiness(), 0.79f);
     CORRADE_COMPARE(data.glossinessTexture(), 2);
     CORRADE_COMPARE(data.glossinessTextureSwizzle(), MaterialTextureSwizzle::A);
     CORRADE_COMPARE(data.glossinessTextureMatrix(), Matrix3::scaling({1.0f, 1.0f}));
     CORRADE_COMPARE(data.glossinessTextureCoordinates(), 4);
+    CORRADE_COMPARE(data.glossinessTextureLayer(), 10);
     CORRADE_COMPARE(data.normalTexture(), 3);
     CORRADE_COMPARE(data.normalTextureScale(), 0.35f);
     CORRADE_COMPARE(data.normalTextureSwizzle(), MaterialTextureSwizzle::BA);
     CORRADE_COMPARE(data.normalTextureMatrix(), Matrix3::scaling({1.0f, 0.5f}));
     CORRADE_COMPARE(data.normalTextureCoordinates(), 5);
+    CORRADE_COMPARE(data.normalTextureLayer(), 11);
     CORRADE_COMPARE(data.occlusionTexture(), 4);
     CORRADE_COMPARE(data.occlusionTextureStrength(), 0.66f);
     CORRADE_COMPARE(data.occlusionTextureMatrix(), Matrix3::scaling({1.0f, 0.75f}));
     CORRADE_COMPARE(data.occlusionTextureSwizzle(), MaterialTextureSwizzle::B);
     CORRADE_COMPARE(data.occlusionTextureCoordinates(), 6);
+    CORRADE_COMPARE(data.occlusionTextureLayer(), 12);
     CORRADE_COMPARE(data.emissiveColor(), 0x111111_rgbf);
     CORRADE_COMPARE(data.emissiveTextureMatrix(), Matrix3::scaling({0.75f, 0.5f}));
     CORRADE_COMPARE(data.emissiveTexture(), 5);
     CORRADE_COMPARE(data.emissiveTextureCoordinates(), 7);
+    CORRADE_COMPARE(data.emissiveTextureLayer(), 13);
 }
 
 void PbrSpecularGlossinessMaterialDataTest::texturedDefaults() {
@@ -204,37 +219,44 @@ void PbrSpecularGlossinessMaterialDataTest::texturedDefaults() {
     CORRADE_VERIFY(!data.hasSpecularGlossinessTexture());
     CORRADE_VERIFY(!data.hasTextureTransformation());
     CORRADE_VERIFY(!data.hasTextureCoordinates());
+    CORRADE_VERIFY(!data.hasTextureLayer());
     CORRADE_COMPARE(data.diffuseColor(), 0xffffffff_rgbaf);
     CORRADE_COMPARE(data.diffuseTexture(), 1);
     CORRADE_COMPARE(data.diffuseTextureMatrix(), Matrix3{});
     CORRADE_COMPARE(data.diffuseTextureCoordinates(), 0);
+    CORRADE_COMPARE(data.diffuseTextureLayer(), 0);
     CORRADE_COMPARE(data.specularColor(), 0xffffff00_rgbaf);
     CORRADE_COMPARE(data.specularTexture(), 2);
     CORRADE_COMPARE(data.specularTextureSwizzle(), MaterialTextureSwizzle::RGB);
     CORRADE_COMPARE(data.specularTextureMatrix(), Matrix3{});
     CORRADE_COMPARE(data.specularTextureCoordinates(), 0);
+    CORRADE_COMPARE(data.specularTextureLayer(), 0);
     CORRADE_COMPARE(data.glossiness(), 1.0f);
     CORRADE_COMPARE(data.glossinessTexture(), 3);
     CORRADE_COMPARE(data.glossinessTextureSwizzle(), MaterialTextureSwizzle::R);
     CORRADE_COMPARE(data.glossinessTextureMatrix(), Matrix3{});
     CORRADE_COMPARE(data.glossinessTextureCoordinates(), 0);
+    CORRADE_COMPARE(data.glossinessTextureLayer(), 0);
     CORRADE_COMPARE(data.normalTexture(), 4);
     CORRADE_COMPARE(data.normalTextureScale(), 1.0f);
     CORRADE_COMPARE(data.normalTextureSwizzle(), MaterialTextureSwizzle::RGB);
     CORRADE_COMPARE(data.normalTextureMatrix(), Matrix3{});
     CORRADE_COMPARE(data.normalTextureCoordinates(), 0);
+    CORRADE_COMPARE(data.normalTextureLayer(), 0);
     CORRADE_COMPARE(data.occlusionTexture(), 5);
     CORRADE_COMPARE(data.occlusionTextureStrength(), 1.0f);
     CORRADE_COMPARE(data.occlusionTextureMatrix(), Matrix3{});
     CORRADE_COMPARE(data.occlusionTextureSwizzle(), MaterialTextureSwizzle::R);
     CORRADE_COMPARE(data.occlusionTextureCoordinates(), 0);
+    CORRADE_COMPARE(data.occlusionTextureLayer(), 0);
     CORRADE_COMPARE(data.emissiveColor(), 0x000000_rgbf);
     CORRADE_COMPARE(data.emissiveTextureMatrix(), Matrix3{});
     CORRADE_COMPARE(data.emissiveTexture(), 6);
     CORRADE_COMPARE(data.emissiveTextureCoordinates(), 0);
+    CORRADE_COMPARE(data.emissiveTextureLayer(), 0);
 }
 
-void PbrSpecularGlossinessMaterialDataTest::texturedSingleMatrixCoordinates() {
+void PbrSpecularGlossinessMaterialDataTest::texturedSingleMatrixCoordinatesLayer() {
     PbrSpecularGlossinessMaterialData data{{}, {
         {MaterialAttribute::DiffuseTexture, 1u},
         {MaterialAttribute::SpecularTexture, 2u},
@@ -243,23 +265,31 @@ void PbrSpecularGlossinessMaterialDataTest::texturedSingleMatrixCoordinates() {
         {MaterialAttribute::OcclusionTexture, 5u},
         {MaterialAttribute::EmissiveTexture, 6u},
         {MaterialAttribute::TextureMatrix, Matrix3::scaling({0.5f, 0.5f})},
-        {MaterialAttribute::TextureCoordinates, 7u}
+        {MaterialAttribute::TextureCoordinates, 7u},
+        {MaterialAttribute::TextureLayer, 22u},
     }};
 
     CORRADE_VERIFY(data.hasTextureTransformation());
     CORRADE_VERIFY(data.hasTextureCoordinates());
+    CORRADE_VERIFY(data.hasTextureLayer());
     CORRADE_COMPARE(data.diffuseTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
     CORRADE_COMPARE(data.diffuseTextureCoordinates(), 7);
+    CORRADE_COMPARE(data.diffuseTextureLayer(), 22);
     CORRADE_COMPARE(data.specularTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
     CORRADE_COMPARE(data.specularTextureCoordinates(), 7);
+    CORRADE_COMPARE(data.specularTextureLayer(), 22);
     CORRADE_COMPARE(data.glossinessTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
     CORRADE_COMPARE(data.glossinessTextureCoordinates(), 7);
+    CORRADE_COMPARE(data.glossinessTextureLayer(), 22);
     CORRADE_COMPARE(data.normalTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
     CORRADE_COMPARE(data.normalTextureCoordinates(), 7);
+    CORRADE_COMPARE(data.normalTextureLayer(), 22);
     CORRADE_COMPARE(data.occlusionTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
     CORRADE_COMPARE(data.occlusionTextureCoordinates(), 7);
+    CORRADE_COMPARE(data.occlusionTextureLayer(), 22);
     CORRADE_COMPARE(data.emissiveTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
     CORRADE_COMPARE(data.emissiveTextureCoordinates(), 7);
+    CORRADE_COMPARE(data.emissiveTextureLayer(), 22);
 }
 
 void PbrSpecularGlossinessMaterialDataTest::texturedImplicitPackedSpecularGlossiness() {
@@ -273,10 +303,12 @@ void PbrSpecularGlossinessMaterialDataTest::texturedImplicitPackedSpecularGlossi
         CORRADE_COMPARE(data.specularTextureSwizzle(), MaterialTextureSwizzle::RGB);
         CORRADE_COMPARE(data.specularTextureMatrix(), Matrix3{});
         CORRADE_COMPARE(data.specularTextureCoordinates(), 0);
+        CORRADE_COMPARE(data.specularTextureLayer(), 0);
         CORRADE_COMPARE(data.glossinessTexture(), 2);
         CORRADE_COMPARE(data.glossinessTextureSwizzle(), MaterialTextureSwizzle::A);
         CORRADE_COMPARE(data.glossinessTextureMatrix(), Matrix3{});
         CORRADE_COMPARE(data.glossinessTextureCoordinates(), 0);
+        CORRADE_COMPARE(data.glossinessTextureLayer(), 0);
 
     /* Explicit parameters for everything, but all the same */
     } {
@@ -285,19 +317,23 @@ void PbrSpecularGlossinessMaterialDataTest::texturedImplicitPackedSpecularGlossi
             {MaterialAttribute::SpecularTextureSwizzle, MaterialTextureSwizzle::RGB},
             {MaterialAttribute::SpecularTextureMatrix, Matrix3::scaling({0.5f, 0.5f})},
             {MaterialAttribute::SpecularTextureCoordinates, 3u},
+            {MaterialAttribute::SpecularTextureLayer, 17u},
             {MaterialAttribute::GlossinessTextureSwizzle, MaterialTextureSwizzle::A},
             {MaterialAttribute::GlossinessTextureMatrix, Matrix3::scaling({0.5f, 0.5f})},
-            {MaterialAttribute::GlossinessTextureCoordinates, 3u}
+            {MaterialAttribute::GlossinessTextureCoordinates, 3u},
+            {MaterialAttribute::GlossinessTextureLayer, 17u}
         }};
         CORRADE_VERIFY(data.hasSpecularGlossinessTexture());
         CORRADE_COMPARE(data.specularTexture(), 2);
         CORRADE_COMPARE(data.specularTextureSwizzle(), MaterialTextureSwizzle::RGB);
         CORRADE_COMPARE(data.specularTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
         CORRADE_COMPARE(data.specularTextureCoordinates(), 3);
+        CORRADE_COMPARE(data.specularTextureLayer(), 17);
         CORRADE_COMPARE(data.glossinessTexture(), 2);
         CORRADE_COMPARE(data.glossinessTextureSwizzle(), MaterialTextureSwizzle::A);
         CORRADE_COMPARE(data.glossinessTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
         CORRADE_COMPARE(data.glossinessTextureCoordinates(), 3);
+        CORRADE_COMPARE(data.glossinessTextureLayer(), 17);
 
     /* Swizzle is ignored when the combined texture is specified, so this is
        fine. */
@@ -323,6 +359,14 @@ void PbrSpecularGlossinessMaterialDataTest::texturedImplicitPackedSpecularGlossi
             {MaterialAttribute::GlossinessTextureCoordinates, 1u},
         }};
         CORRADE_VERIFY(!data.hasSpecularGlossinessTexture());
+
+    /* Unexpected array texture layer */
+    } {
+        PbrSpecularGlossinessMaterialData data{{}, {
+            {MaterialAttribute::SpecularGlossinessTexture, 2u},
+            {MaterialAttribute::SpecularTextureLayer, 1u},
+        }};
+        CORRADE_VERIFY(!data.hasSpecularGlossinessTexture());
     }
 }
 
@@ -339,10 +383,12 @@ void PbrSpecularGlossinessMaterialDataTest::texturedExplicitPackedSpecularGlossi
         CORRADE_COMPARE(data.specularTextureSwizzle(), MaterialTextureSwizzle::RGB);
         CORRADE_COMPARE(data.specularTextureMatrix(), Matrix3{});
         CORRADE_COMPARE(data.specularTextureCoordinates(), 0);
+        CORRADE_COMPARE(data.specularTextureLayer(), 0);
         CORRADE_COMPARE(data.glossinessTexture(), 2);
         CORRADE_COMPARE(data.glossinessTextureSwizzle(), MaterialTextureSwizzle::A);
         CORRADE_COMPARE(data.glossinessTextureMatrix(), Matrix3{});
         CORRADE_COMPARE(data.glossinessTextureCoordinates(), 0);
+        CORRADE_COMPARE(data.glossinessTextureLayer(), 0);
 
     /* Explicit parameters for everything, but all the same */
     } {
@@ -351,20 +397,24 @@ void PbrSpecularGlossinessMaterialDataTest::texturedExplicitPackedSpecularGlossi
             {MaterialAttribute::SpecularTextureSwizzle, MaterialTextureSwizzle::RGB},
             {MaterialAttribute::SpecularTextureMatrix, Matrix3::scaling({0.5f, 0.5f})},
             {MaterialAttribute::SpecularTextureCoordinates, 3u},
+            {MaterialAttribute::SpecularTextureLayer, 17u},
             {MaterialAttribute::GlossinessTexture, 2u},
             {MaterialAttribute::GlossinessTextureSwizzle, MaterialTextureSwizzle::A},
             {MaterialAttribute::GlossinessTextureMatrix, Matrix3::scaling({0.5f, 0.5f})},
-            {MaterialAttribute::GlossinessTextureCoordinates, 3u}
+            {MaterialAttribute::GlossinessTextureCoordinates, 3u},
+            {MaterialAttribute::GlossinessTextureLayer, 17u}
         }};
         CORRADE_VERIFY(data.hasSpecularGlossinessTexture());
         CORRADE_COMPARE(data.specularTexture(), 2);
         CORRADE_COMPARE(data.specularTextureSwizzle(), MaterialTextureSwizzle::RGB);
         CORRADE_COMPARE(data.specularTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
         CORRADE_COMPARE(data.specularTextureCoordinates(), 3);
+        CORRADE_COMPARE(data.specularTextureLayer(), 17);
         CORRADE_COMPARE(data.glossinessTexture(), 2);
         CORRADE_COMPARE(data.glossinessTextureSwizzle(), MaterialTextureSwizzle::A);
         CORRADE_COMPARE(data.glossinessTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
         CORRADE_COMPARE(data.glossinessTextureCoordinates(), 3);
+        CORRADE_COMPARE(data.glossinessTextureLayer(), 17);
 
     /* Different texture ID */
     } {
@@ -413,6 +463,16 @@ void PbrSpecularGlossinessMaterialDataTest::texturedExplicitPackedSpecularGlossi
             {MaterialAttribute::GlossinessTextureCoordinates, 1u}
         }};
         CORRADE_VERIFY(!data.hasSpecularGlossinessTexture());
+
+    /* Unexpected array texture layer */
+    } {
+        PbrSpecularGlossinessMaterialData data{{}, {
+            {MaterialAttribute::SpecularTexture, 2u},
+            {MaterialAttribute::SpecularTextureLayer, 1u},
+            {MaterialAttribute::GlossinessTexture, 2u},
+            {MaterialAttribute::GlossinessTextureSwizzle, MaterialTextureSwizzle::A},
+        }};
+        CORRADE_VERIFY(!data.hasSpecularGlossinessTexture());
     }
 }
 
@@ -428,72 +488,89 @@ void PbrSpecularGlossinessMaterialDataTest::invalidTextures() {
     data.diffuseTexture();
     data.diffuseTextureMatrix();
     data.diffuseTextureCoordinates();
+    data.diffuseTextureLayer();
     data.specularTexture();
     data.specularTextureSwizzle();
     data.specularTextureMatrix();
     data.specularTextureCoordinates();
+    data.specularTextureLayer();
     data.glossinessTexture();
     data.glossinessTextureSwizzle();
     data.glossinessTextureMatrix();
     data.glossinessTextureCoordinates();
+    data.glossinessTextureLayer();
     data.normalTexture();
     data.normalTextureScale();
     data.normalTextureSwizzle();
     data.normalTextureMatrix();
     data.normalTextureCoordinates();
+    data.normalTextureLayer();
     data.occlusionTexture();
     data.occlusionTextureStrength();
     data.occlusionTextureSwizzle();
     data.occlusionTextureMatrix();
     data.occlusionTextureCoordinates();
+    data.occlusionTextureLayer();
     data.emissiveTexture();
     data.emissiveTextureMatrix();
     data.emissiveTextureCoordinates();
+    data.emissiveTextureLayer();
     CORRADE_COMPARE(out.str(),
         "Trade::MaterialData::attribute(): attribute DiffuseTexture not found in layer 0\n"
         "Trade::PbrSpecularGlossinessMaterialData::diffuseTextureMatrix(): the material doesn't have a diffuse texture\n"
         "Trade::PbrSpecularGlossinessMaterialData::diffuseTextureCoordinates(): the material doesn't have a diffuse texture\n"
+        "Trade::PbrSpecularGlossinessMaterialData::diffuseTextureLayer(): the material doesn't have a diffuse texture\n"
         "Trade::PbrSpecularGlossinessMaterialData::specularTexture(): the material doesn't have a specular texture\n"
         "Trade::PbrSpecularGlossinessMaterialData::specularTextureSwizzle(): the material doesn't have a specular texture\n"
         "Trade::PbrSpecularGlossinessMaterialData::specularTextureMatrix(): the material doesn't have a specular texture\n"
         "Trade::PbrSpecularGlossinessMaterialData::specularTextureCoordinates(): the material doesn't have a specular texture\n"
+        "Trade::PbrSpecularGlossinessMaterialData::specularTextureLayer(): the material doesn't have a specular texture\n"
         "Trade::PbrSpecularGlossinessMaterialData::glossinessTexture(): the material doesn't have a glossiness texture\n"
         "Trade::PbrSpecularGlossinessMaterialData::glossinessTextureSwizzle(): the material doesn't have a glossiness texture\n"
         "Trade::PbrSpecularGlossinessMaterialData::glossinessTextureMatrix(): the material doesn't have a glossiness texture\n"
         "Trade::PbrSpecularGlossinessMaterialData::glossinessTextureCoordinates(): the material doesn't have a glossiness texture\n"
+        "Trade::PbrSpecularGlossinessMaterialData::glossinessTextureLayer(): the material doesn't have a glossiness texture\n"
         "Trade::MaterialData::attribute(): attribute NormalTexture not found in layer 0\n"
         "Trade::PbrSpecularGlossinessMaterialData::normalTextureScale(): the material doesn't have a normal texture\n"
         "Trade::PbrSpecularGlossinessMaterialData::normalTextureSwizzle(): the material doesn't have a normal texture\n"
         "Trade::PbrSpecularGlossinessMaterialData::normalTextureMatrix(): the material doesn't have a normal texture\n"
         "Trade::PbrSpecularGlossinessMaterialData::normalTextureCoordinates(): the material doesn't have a normal texture\n"
+        "Trade::PbrSpecularGlossinessMaterialData::normalTextureLayer(): the material doesn't have a normal texture\n"
         "Trade::MaterialData::attribute(): attribute OcclusionTexture not found in layer 0\n"
         "Trade::PbrSpecularGlossinessMaterialData::occlusionTextureStrength(): the material doesn't have an occlusion texture\n"
         "Trade::PbrSpecularGlossinessMaterialData::occlusionTextureSwizzle(): the material doesn't have an occlusion texture\n"
         "Trade::PbrSpecularGlossinessMaterialData::occlusionTextureMatrix(): the material doesn't have an occlusion texture\n"
         "Trade::PbrSpecularGlossinessMaterialData::occlusionTextureCoordinates(): the material doesn't have an occlusion texture\n"
+        "Trade::PbrSpecularGlossinessMaterialData::occlusionTextureLayer(): the material doesn't have an occlusion texture\n"
         "Trade::MaterialData::attribute(): attribute EmissiveTexture not found in layer 0\n"
         "Trade::PbrSpecularGlossinessMaterialData::emissiveTextureMatrix(): the material doesn't have an emissive texture\n"
-        "Trade::PbrSpecularGlossinessMaterialData::emissiveTextureCoordinates(): the material doesn't have an emissive texture\n");
+        "Trade::PbrSpecularGlossinessMaterialData::emissiveTextureCoordinates(): the material doesn't have an emissive texture\n"
+        "Trade::PbrSpecularGlossinessMaterialData::emissiveTextureLayer(): the material doesn't have an emissive texture\n");
 }
 
-void PbrSpecularGlossinessMaterialDataTest::commonTransformationCoordinatesNoTextures() {
+void PbrSpecularGlossinessMaterialDataTest::commonTransformationCoordinatesLayerNoTextures() {
     PbrSpecularGlossinessMaterialData a{{}, {}};
     CORRADE_VERIFY(a.hasCommonTextureTransformation());
     CORRADE_VERIFY(a.hasCommonTextureCoordinates());
+    CORRADE_VERIFY(a.hasCommonTextureLayer());
     CORRADE_COMPARE(a.commonTextureMatrix(), Matrix3{});
     CORRADE_COMPARE(a.commonTextureCoordinates(), 0);
+    CORRADE_COMPARE(a.commonTextureLayer(), 0);
 
     PbrSpecularGlossinessMaterialData b{{}, {
         {MaterialAttribute::TextureMatrix, Matrix3::scaling({0.5f, 0.5f})},
-        {MaterialAttribute::TextureCoordinates, 7u}
+        {MaterialAttribute::TextureCoordinates, 7u},
+        {MaterialAttribute::TextureLayer, 22u}
     }};
     CORRADE_VERIFY(b.hasCommonTextureTransformation());
     CORRADE_VERIFY(b.hasCommonTextureCoordinates());
+    CORRADE_VERIFY(b.hasCommonTextureLayer());
     CORRADE_COMPARE(b.commonTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
     CORRADE_COMPARE(b.commonTextureCoordinates(), 7);
+    CORRADE_COMPARE(b.commonTextureLayer(), 22);
 }
 
-void PbrSpecularGlossinessMaterialDataTest::commonTransformationCoordinatesOneTexture() {
+void PbrSpecularGlossinessMaterialDataTest::commonTransformationCoordinatesLayerOneTexture() {
     Containers::StringView textureName = PbrSpecularGlossinessTextureData[testCaseInstanceId()];
     setTestCaseDescription(textureName);
 
@@ -501,19 +578,23 @@ void PbrSpecularGlossinessMaterialDataTest::commonTransformationCoordinatesOneTe
         {textureName, 5u},
         {textureName + "Matrix", Matrix3::scaling({0.5f, 1.0f})},
         {textureName + "Coordinates", 17u},
+        {textureName + "Layer", 22u},
 
         /* These shouldn't affect the above */
         {MaterialAttribute::TextureMatrix, Matrix3::translation({0.5f, 0.0f})},
-        {MaterialAttribute::TextureCoordinates, 3u}
+        {MaterialAttribute::TextureCoordinates, 3u},
+        {MaterialAttribute::TextureLayer, 66u},
     }};
 
     CORRADE_VERIFY(data.hasCommonTextureTransformation());
     CORRADE_COMPARE(data.commonTextureMatrix(), Matrix3::scaling({0.5f, 1.0f}));
     CORRADE_VERIFY(data.hasCommonTextureCoordinates());
     CORRADE_COMPARE(data.commonTextureCoordinates(), 17u);
+    CORRADE_VERIFY(data.hasCommonTextureLayer());
+    CORRADE_COMPARE(data.commonTextureLayer(), 22u);
 }
 
-void PbrSpecularGlossinessMaterialDataTest::commonTransformationCoordinatesOneDifferentTexture() {
+void PbrSpecularGlossinessMaterialDataTest::commonTransformationCoordinatesLayerOneDifferentTexture() {
     Containers::StringView textureName = PbrSpecularGlossinessTextureData[testCaseInstanceId()];
     setTestCaseDescription(textureName);
 
@@ -526,18 +607,21 @@ void PbrSpecularGlossinessMaterialDataTest::commonTransformationCoordinatesOneDi
         {MaterialAttribute::EmissiveTexture, 7u},
         {textureName + "Matrix", Matrix3::scaling({0.5f, 1.0f})},
         {textureName + "Coordinates", 17u},
+        {textureName + "Layer", 22u},
 
         /* These are used by all textures except the one above, failing the
            check */
         {MaterialAttribute::TextureMatrix, Matrix3::translation({0.5f, 0.0f})},
-        {MaterialAttribute::TextureCoordinates, 3u}
+        {MaterialAttribute::TextureCoordinates, 3u},
+        {MaterialAttribute::TextureLayer, 66u},
     }};
 
     CORRADE_VERIFY(!data.hasCommonTextureTransformation());
     CORRADE_VERIFY(!data.hasCommonTextureCoordinates());
+    CORRADE_VERIFY(!data.hasCommonTextureLayer());
 }
 
-void PbrSpecularGlossinessMaterialDataTest::commonCoordinatesImplicit() {
+void PbrSpecularGlossinessMaterialDataTest::commonCoordinatesLayerImplicit() {
     Containers::StringView textureName = PbrSpecularGlossinessTextureData[testCaseInstanceId()];
     setTestCaseDescription(textureName);
 
@@ -546,16 +630,20 @@ void PbrSpecularGlossinessMaterialDataTest::commonCoordinatesImplicit() {
 
     PbrSpecularGlossinessMaterialData data{{}, {
         {textureName, 5u},
-        {textureName + "Coordinates", 0u}
+        {textureName + "Coordinates", 0u},
+        {textureName + "Layer", 0u},
     }};
 
     /* Zero is treated same as if there would be no attribute at all */
     CORRADE_VERIFY(!data.hasTextureCoordinates());
+    CORRADE_VERIFY(!data.hasTextureLayer());
     CORRADE_VERIFY(data.hasCommonTextureCoordinates());
+    CORRADE_VERIFY(data.hasCommonTextureLayer());
     CORRADE_COMPARE(data.commonTextureCoordinates(), 0u);
+    CORRADE_COMPARE(data.commonTextureLayer(), 0u);
 }
 
-void PbrSpecularGlossinessMaterialDataTest::noCommonTransformationCoordinates() {
+void PbrSpecularGlossinessMaterialDataTest::noCommonTransformationCoordinatesLayer() {
     #ifdef CORRADE_NO_ASSERT
     CORRADE_SKIP("CORRADE_NO_ASSERT defined, can't test assertions");
     #endif
@@ -566,20 +654,24 @@ void PbrSpecularGlossinessMaterialDataTest::noCommonTransformationCoordinates()
         {MaterialAttribute::DiffuseTextureCoordinates, 3u},
         {MaterialAttribute::SpecularTexture, 4u},
         {MaterialAttribute::SpecularTextureMatrix, Matrix3::scaling({0.5f, 1.0f})},
+        {MaterialAttribute::SpecularTextureLayer, 22u},
         {MaterialAttribute::OcclusionTexture, 5u},
         {MaterialAttribute::OcclusionTextureCoordinates, 17u}
     }};
 
     CORRADE_VERIFY(!data.hasCommonTextureTransformation());
     CORRADE_VERIFY(!data.hasCommonTextureCoordinates());
+    CORRADE_VERIFY(!data.hasCommonTextureLayer());
 
     std::ostringstream out;
     Error redirectError{&out};
     data.commonTextureMatrix();
     data.commonTextureCoordinates();
+    data.commonTextureLayer();
     CORRADE_COMPARE(out.str(),
         "Trade::PbrSpecularGlossinessMaterialData::commonTextureMatrix(): the material doesn't have a common texture coordinate transformation\n"
-        "Trade::PbrSpecularGlossinessMaterialData::commonTextureCoordinates(): the material doesn't have a common texture coordinate set\n");
+        "Trade::PbrSpecularGlossinessMaterialData::commonTextureCoordinates(): the material doesn't have a common texture coordinate set\n"
+        "Trade::PbrSpecularGlossinessMaterialData::commonTextureLayer(): the material doesn't have a common array texture layer\n");
 }
 
 }}}}

src/Magnum/Trade/Test/PhongMaterialDataTest.cpp

@@ -52,14 +52,14 @@ class PhongMaterialDataTest: public TestSuite::Tester {
         void defaults();
         void textured();
         void texturedDefaults();
-        void texturedSingleMatrixCoordinates();
+        void texturedSingleMatrixCoordinatesLayer();
         void texturedImplicitPackedSpecularGlossiness();
         void invalidTextures();
-        void commonTransformationCoordinatesNoTextures();
-        void commonTransformationCoordinatesOneTexture();
-        void commonTransformationCoordinatesOneDifferentTexture();
-        void commonCoordinatesImplicit();
-        void noCommonTransformationCoordinates();
+        void commonTransformationCoordinatesLayerNoTextures();
+        void commonTransformationCoordinatesLayerOneTexture();
+        void commonTransformationCoordinatesLayerOneDifferentTexture();
+        void commonCoordinatesLayerImplicit();
+        void noCommonTransformationCoordinatesLayer();
 
         #ifdef MAGNUM_BUILD_DEPRECATED
         void debugFlag();
@@ -90,19 +90,20 @@ PhongMaterialDataTest::PhongMaterialDataTest() {
         &PhongMaterialDataTest::defaults,
         &PhongMaterialDataTest::textured,
         &PhongMaterialDataTest::texturedDefaults,
-        &PhongMaterialDataTest::texturedSingleMatrixCoordinates,
+        &PhongMaterialDataTest::texturedSingleMatrixCoordinatesLayer,
         &PhongMaterialDataTest::texturedImplicitPackedSpecularGlossiness,
         &PhongMaterialDataTest::invalidTextures,
-        &PhongMaterialDataTest::commonTransformationCoordinatesNoTextures});
+        &PhongMaterialDataTest::commonTransformationCoordinatesLayerNoTextures});
 
     addInstancedTests({
-        &PhongMaterialDataTest::commonTransformationCoordinatesOneTexture,
-        &PhongMaterialDataTest::commonTransformationCoordinatesOneDifferentTexture,
-        &PhongMaterialDataTest::commonCoordinatesImplicit},
+        &PhongMaterialDataTest::commonTransformationCoordinatesLayerOneTexture,
+        &PhongMaterialDataTest::commonTransformationCoordinatesLayerOneDifferentTexture,
+        &PhongMaterialDataTest::commonCoordinatesLayerImplicit},
         Containers::arraySize(PhongTextureData));
 
     addTests({
-        &PhongMaterialDataTest::noCommonTransformationCoordinates,
+        &PhongMaterialDataTest::noCommonTransformationCoordinatesLayer,
+
         #ifdef MAGNUM_BUILD_DEPRECATED
         &PhongMaterialDataTest::debugFlag,
         &PhongMaterialDataTest::debugFlags
@@ -310,6 +311,7 @@ void PhongMaterialDataTest::basics() {
     CORRADE_VERIFY(!data.hasSpecularTexture());
     CORRADE_VERIFY(!data.hasTextureTransformation());
     CORRADE_VERIFY(!data.hasTextureCoordinates());
+    CORRADE_VERIFY(!data.hasTextureLayer());
     CORRADE_COMPARE(data.ambientColor(), 0xccffbb_rgbf);
     CORRADE_COMPARE(data.diffuseColor(), 0xebefbf_rgbf);
     CORRADE_COMPARE(data.specularColor(), 0xacabad_rgbf);
@@ -325,6 +327,7 @@ void PhongMaterialDataTest::defaults() {
 
     CORRADE_VERIFY(!data.hasTextureTransformation());
     CORRADE_VERIFY(!data.hasTextureCoordinates());
+    CORRADE_VERIFY(!data.hasTextureLayer());
     CORRADE_COMPARE(data.ambientColor(), 0x000000_rgbf);
     CORRADE_COMPARE(data.diffuseColor(), 0xffffff_rgbf);
     CORRADE_COMPARE(data.specularColor(), 0xffffff00_rgbaf);
@@ -337,43 +340,52 @@ void PhongMaterialDataTest::textured() {
         {MaterialAttribute::AmbientTexture, 42u},
         {MaterialAttribute::AmbientTextureMatrix, Matrix3::scaling({0.5f, 1.0f})},
         {MaterialAttribute::AmbientTextureCoordinates, 2u},
+        {MaterialAttribute::AmbientTextureLayer, 6u},
         {MaterialAttribute::DiffuseTexture, 33u},
         {MaterialAttribute::DiffuseColor, 0xeebbffff_rgbaf},
         {MaterialAttribute::DiffuseTextureMatrix, Matrix3::scaling({0.5f, 0.5f})},
         {MaterialAttribute::DiffuseTextureCoordinates, 3u},
+        {MaterialAttribute::DiffuseTextureLayer, 7u},
         {MaterialAttribute::SpecularColor, 0xacabadff_rgbaf},
         {MaterialAttribute::SpecularTexture, 17u},
         {MaterialAttribute::SpecularTextureSwizzle, MaterialTextureSwizzle::RGBA},
         {MaterialAttribute::SpecularTextureMatrix, Matrix3::scaling({1.0f, 1.0f})},
         {MaterialAttribute::SpecularTextureCoordinates, 4u},
+        {MaterialAttribute::SpecularTextureLayer, 8u},
         {MaterialAttribute::NormalTexture, 0u},
         {MaterialAttribute::NormalTextureScale, 0.5f},
         {MaterialAttribute::NormalTextureSwizzle, MaterialTextureSwizzle::GB},
         {MaterialAttribute::NormalTextureMatrix, Matrix3::scaling({1.0f, 0.5f})},
-        {MaterialAttribute::NormalTextureCoordinates, 5u}
+        {MaterialAttribute::NormalTextureCoordinates, 5u},
+        {MaterialAttribute::NormalTextureLayer, 9u},
     }};
 
     CORRADE_VERIFY(data.hasSpecularTexture());
     CORRADE_VERIFY(data.hasTextureTransformation());
     CORRADE_VERIFY(data.hasTextureCoordinates());
+    CORRADE_VERIFY(data.hasTextureLayer());
     CORRADE_COMPARE(data.ambientColor(), 0x111111_rgbf);
     CORRADE_COMPARE(data.ambientTexture(), 42);
     CORRADE_COMPARE(data.ambientTextureMatrix(), Matrix3::scaling({0.5f, 1.0f}));
     CORRADE_COMPARE(data.ambientTextureCoordinates(), 2);
+    CORRADE_COMPARE(data.ambientTextureLayer(), 6);
     CORRADE_COMPARE(data.diffuseColor(), 0xeebbff_rgbf);
     CORRADE_COMPARE(data.diffuseTexture(), 33);
     CORRADE_COMPARE(data.diffuseTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
     CORRADE_COMPARE(data.diffuseTextureCoordinates(), 3);
+    CORRADE_COMPARE(data.diffuseTextureLayer(), 7);
     CORRADE_COMPARE(data.specularColor(), 0xacabad_rgbf);
     CORRADE_COMPARE(data.specularTexture(), 17);
     CORRADE_COMPARE(data.specularTextureSwizzle(), MaterialTextureSwizzle::RGBA);
     CORRADE_COMPARE(data.specularTextureMatrix(), Matrix3::scaling({1.0f, 1.0f}));
     CORRADE_COMPARE(data.specularTextureCoordinates(), 4);
+    CORRADE_COMPARE(data.specularTextureLayer(), 8);
     CORRADE_COMPARE(data.normalTexture(), 0);
     CORRADE_COMPARE(data.normalTextureScale(), 0.5f);
     CORRADE_COMPARE(data.normalTextureSwizzle(), MaterialTextureSwizzle::GB);
     CORRADE_COMPARE(data.normalTextureMatrix(), Matrix3::scaling({1.0f, 0.5f}));
     CORRADE_COMPARE(data.normalTextureCoordinates(), 5);
+    CORRADE_COMPARE(data.normalTextureLayer(), 9);
 }
 
 void PhongMaterialDataTest::texturedDefaults() {
@@ -387,46 +399,57 @@ void PhongMaterialDataTest::texturedDefaults() {
     CORRADE_VERIFY(data.hasSpecularTexture());
     CORRADE_VERIFY(!data.hasTextureTransformation());
     CORRADE_VERIFY(!data.hasTextureCoordinates());
+    CORRADE_VERIFY(!data.hasTextureLayer());
     CORRADE_COMPARE(data.ambientColor(), 0xffffffff_rgbaf);
     CORRADE_COMPARE(data.ambientTexture(), 42);
     CORRADE_COMPARE(data.ambientTextureMatrix(), Matrix3{});
     CORRADE_COMPARE(data.ambientTextureCoordinates(), 0);
+    CORRADE_COMPARE(data.ambientTextureLayer(), 0);
     CORRADE_COMPARE(data.diffuseColor(), 0xffffffff_rgbaf);
     CORRADE_COMPARE(data.diffuseTexture(), 33);
     CORRADE_COMPARE(data.diffuseTextureMatrix(), Matrix3{});
     CORRADE_COMPARE(data.diffuseTextureCoordinates(), 0);
+    CORRADE_COMPARE(data.diffuseTextureLayer(), 0);
     CORRADE_COMPARE(data.specularColor(), 0xffffff00_rgbaf);
     CORRADE_COMPARE(data.specularTexture(), 17);
     CORRADE_COMPARE(data.specularTextureSwizzle(), MaterialTextureSwizzle::RGB);
     CORRADE_COMPARE(data.specularTextureMatrix(), Matrix3{});
     CORRADE_COMPARE(data.specularTextureCoordinates(), 0);
+    CORRADE_COMPARE(data.specularTextureLayer(), 0);
     CORRADE_COMPARE(data.normalTexture(), 1);
     CORRADE_COMPARE(data.normalTextureScale(), 1.0f);
     CORRADE_COMPARE(data.normalTextureSwizzle(), MaterialTextureSwizzle::RGB);
     CORRADE_COMPARE(data.normalTextureMatrix(), Matrix3{});
     CORRADE_COMPARE(data.normalTextureCoordinates(), 0);
+    CORRADE_COMPARE(data.normalTextureLayer(), 0);
 }
 
-void PhongMaterialDataTest::texturedSingleMatrixCoordinates() {
+void PhongMaterialDataTest::texturedSingleMatrixCoordinatesLayer() {
     PhongMaterialData data{{}, {
         {MaterialAttribute::AmbientTexture, 42u},
         {MaterialAttribute::DiffuseTexture, 33u},
         {MaterialAttribute::SpecularTexture, 17u},
         {MaterialAttribute::NormalTexture, 0u},
         {MaterialAttribute::TextureMatrix, Matrix3::translation({0.5f, 1.0f})},
-        {MaterialAttribute::TextureCoordinates, 2u}
+        {MaterialAttribute::TextureCoordinates, 2u},
+        {MaterialAttribute::TextureLayer, 17u},
     }};
 
     CORRADE_VERIFY(data.hasTextureTransformation());
     CORRADE_VERIFY(data.hasTextureCoordinates());
+    CORRADE_VERIFY(data.hasTextureLayer());
     CORRADE_COMPARE(data.ambientTextureMatrix(), Matrix3::translation({0.5f, 1.0f}));
     CORRADE_COMPARE(data.ambientTextureCoordinates(), 2);
+    CORRADE_COMPARE(data.ambientTextureLayer(), 17);
     CORRADE_COMPARE(data.diffuseTextureMatrix(), Matrix3::translation({0.5f, 1.0f}));
     CORRADE_COMPARE(data.diffuseTextureCoordinates(), 2);
+    CORRADE_COMPARE(data.diffuseTextureLayer(), 17);
     CORRADE_COMPARE(data.specularTextureMatrix(), Matrix3::translation({0.5f, 1.0f}));
     CORRADE_COMPARE(data.specularTextureCoordinates(), 2);
+    CORRADE_COMPARE(data.specularTextureLayer(), 17);
     CORRADE_COMPARE(data.normalTextureMatrix(), Matrix3::translation({0.5f, 1.0f}));
     CORRADE_COMPARE(data.normalTextureCoordinates(), 2);
+    CORRADE_COMPARE(data.normalTextureLayer(), 17);
 }
 
 void PhongMaterialDataTest::texturedImplicitPackedSpecularGlossiness() {
@@ -435,6 +458,7 @@ void PhongMaterialDataTest::texturedImplicitPackedSpecularGlossiness() {
         {MaterialAttribute::SpecularGlossinessTexture, 17u},
         {MaterialAttribute::SpecularTextureMatrix, Matrix3::scaling({1.0f, 1.0f})},
         {MaterialAttribute::SpecularTextureCoordinates, 4u},
+        {MaterialAttribute::SpecularTextureLayer, 22u},
     }};
 
     #ifdef MAGNUM_BUILD_DEPRECATED
@@ -445,11 +469,13 @@ void PhongMaterialDataTest::texturedImplicitPackedSpecularGlossiness() {
     CORRADE_VERIFY(data.hasSpecularTexture());
     CORRADE_VERIFY(data.hasTextureTransformation());
     CORRADE_VERIFY(data.hasTextureCoordinates());
+    CORRADE_VERIFY(data.hasTextureLayer());
     CORRADE_COMPARE(data.specularColor(), 0xacabad_rgbf);
     CORRADE_COMPARE(data.specularTexture(), 17);
     CORRADE_COMPARE(data.specularTextureSwizzle(), MaterialTextureSwizzle::RGB);
     CORRADE_COMPARE(data.specularTextureMatrix(), Matrix3::scaling({1.0f, 1.0f}));
     CORRADE_COMPARE(data.specularTextureCoordinates(), 4);
+    CORRADE_COMPARE(data.specularTextureLayer(), 22);
 }
 
 void PhongMaterialDataTest::invalidTextures() {
@@ -464,42 +490,52 @@ void PhongMaterialDataTest::invalidTextures() {
     data.ambientTexture();
     data.ambientTextureMatrix();
     data.ambientTextureCoordinates();
+    data.ambientTextureLayer();
     data.diffuseTexture();
     data.diffuseTextureMatrix();
     data.diffuseTextureCoordinates();
+    data.diffuseTextureLayer();
     data.specularTexture();
     data.specularTextureSwizzle();
     data.specularTextureMatrix();
     data.specularTextureCoordinates();
+    data.specularTextureLayer();
     data.normalTexture();
     data.normalTextureScale();
     data.normalTextureSwizzle();
     data.normalTextureMatrix();
     data.normalTextureCoordinates();
+    data.normalTextureLayer();
     CORRADE_COMPARE(out.str(),
         "Trade::MaterialData::attribute(): attribute AmbientTexture not found in layer 0\n"
         "Trade::PhongMaterialData::ambientTextureMatrix(): the material doesn't have an ambient texture\n"
         "Trade::PhongMaterialData::ambientTextureCoordinates(): the material doesn't have an ambient texture\n"
+        "Trade::PhongMaterialData::ambientTextureLayer(): the material doesn't have an ambient texture\n"
         "Trade::MaterialData::attribute(): attribute DiffuseTexture not found in layer 0\n"
         "Trade::PhongMaterialData::diffuseTextureMatrix(): the material doesn't have a diffuse texture\n"
         "Trade::PhongMaterialData::diffuseTextureCoordinates(): the material doesn't have a diffuse texture\n"
+        "Trade::PhongMaterialData::diffuseTextureLayer(): the material doesn't have a diffuse texture\n"
         "Trade::PhongMaterialData::specularTexture(): the material doesn't have a specular texture\n"
         "Trade::PhongMaterialData::specularTextureSwizzle(): the material doesn't have a specular texture\n"
         "Trade::PhongMaterialData::specularTextureMatrix(): the material doesn't have a specular texture\n"
         "Trade::PhongMaterialData::specularTextureCoordinates(): the material doesn't have a specular texture\n"
+        "Trade::PhongMaterialData::specularTextureLayer(): the material doesn't have a specular texture\n"
         "Trade::MaterialData::attribute(): attribute NormalTexture not found in layer 0\n"
         "Trade::PhongMaterialData::normalTextureScale(): the material doesn't have a normal texture\n"
         "Trade::PhongMaterialData::normalTextureSwizzle(): the material doesn't have a normal texture\n"
         "Trade::PhongMaterialData::normalTextureMatrix(): the material doesn't have a normal texture\n"
-        "Trade::PhongMaterialData::normalTextureCoordinates(): the material doesn't have a normal texture\n");
+        "Trade::PhongMaterialData::normalTextureCoordinates(): the material doesn't have a normal texture\n"
+        "Trade::PhongMaterialData::normalTextureLayer(): the material doesn't have a normal texture\n");
 }
 
-void PhongMaterialDataTest::commonTransformationCoordinatesNoTextures() {
+void PhongMaterialDataTest::commonTransformationCoordinatesLayerNoTextures() {
     PhongMaterialData a{{}, {}};
     CORRADE_VERIFY(a.hasCommonTextureTransformation());
     CORRADE_VERIFY(a.hasCommonTextureCoordinates());
+    CORRADE_VERIFY(a.hasCommonTextureLayer());
     CORRADE_COMPARE(a.commonTextureMatrix(), Matrix3{});
     CORRADE_COMPARE(a.commonTextureCoordinates(), 0);
+    CORRADE_COMPARE(a.commonTextureLayer(), 0);
 
     #ifdef MAGNUM_BUILD_DEPRECATED
     /* textureMatrix() should return the common matrix, if possible, and
@@ -511,12 +547,15 @@ void PhongMaterialDataTest::commonTransformationCoordinatesNoTextures() {
 
     PhongMaterialData b{{}, {
         {MaterialAttribute::TextureMatrix, Matrix3::scaling({0.5f, 0.5f})},
-        {MaterialAttribute::TextureCoordinates, 7u}
+        {MaterialAttribute::TextureCoordinates, 7u},
+        {MaterialAttribute::TextureLayer, 22u},
     }};
     CORRADE_VERIFY(b.hasCommonTextureTransformation());
     CORRADE_VERIFY(b.hasCommonTextureCoordinates());
+    CORRADE_VERIFY(b.hasCommonTextureLayer());
     CORRADE_COMPARE(b.commonTextureMatrix(), Matrix3::scaling({0.5f, 0.5f}));
     CORRADE_COMPARE(b.commonTextureCoordinates(), 7);
+    CORRADE_COMPARE(b.commonTextureLayer(), 22);
 
     #ifdef MAGNUM_BUILD_DEPRECATED
     /* textureMatrix() should return the common matrix, if possible, and
@@ -527,7 +566,7 @@ void PhongMaterialDataTest::commonTransformationCoordinatesNoTextures() {
     #endif
 }
 
-void PhongMaterialDataTest::commonTransformationCoordinatesOneTexture() {
+void PhongMaterialDataTest::commonTransformationCoordinatesLayerOneTexture() {
     Containers::StringView textureName = PhongTextureData[testCaseInstanceId()];
     setTestCaseDescription(textureName);
 
@@ -535,16 +574,20 @@ void PhongMaterialDataTest::commonTransformationCoordinatesOneTexture() {
         {textureName, 5u},
         {textureName + "Matrix", Matrix3::scaling({0.5f, 1.0f})},
         {textureName + "Coordinates", 17u},
+        {textureName + "Layer", 22u},
 
         /* These shouldn't affect the above */
         {MaterialAttribute::TextureMatrix, Matrix3::translation({0.5f, 0.0f})},
-        {MaterialAttribute::TextureCoordinates, 3u}
+        {MaterialAttribute::TextureCoordinates, 3u},
+        {MaterialAttribute::TextureLayer, 66u},
     }};
 
     CORRADE_VERIFY(data.hasCommonTextureTransformation());
     CORRADE_COMPARE(data.commonTextureMatrix(), Matrix3::scaling({0.5f, 1.0f}));
     CORRADE_VERIFY(data.hasCommonTextureCoordinates());
     CORRADE_COMPARE(data.commonTextureCoordinates(), 17u);
+    CORRADE_VERIFY(data.hasCommonTextureLayer());
+    CORRADE_COMPARE(data.commonTextureLayer(), 22u);
 
     #ifdef MAGNUM_BUILD_DEPRECATED
     /* textureMatrix() should return the common matrix, if possible, and
@@ -555,7 +598,7 @@ void PhongMaterialDataTest::commonTransformationCoordinatesOneTexture() {
     #endif
 }
 
-void PhongMaterialDataTest::commonTransformationCoordinatesOneDifferentTexture() {
+void PhongMaterialDataTest::commonTransformationCoordinatesLayerOneDifferentTexture() {
     Containers::StringView textureName = PhongTextureData[testCaseInstanceId()];
     setTestCaseDescription(textureName);
 
@@ -566,15 +609,18 @@ void PhongMaterialDataTest::commonTransformationCoordinatesOneDifferentTexture()
         {MaterialAttribute::NormalTexture, 5u},
         {textureName + "Matrix", Matrix3::scaling({0.5f, 1.0f})},
         {textureName + "Coordinates", 17u},
+        {textureName + "Layer", 22u},
 
         /* These are used by all textures except the one above, failing the
            check */
         {MaterialAttribute::TextureMatrix, Matrix3::translation({0.5f, 0.0f})},
-        {MaterialAttribute::TextureCoordinates, 3u}
+        {MaterialAttribute::TextureCoordinates, 3u},
+        {MaterialAttribute::TextureLayer, 66u},
     }};
 
     CORRADE_VERIFY(!data.hasCommonTextureTransformation());
     CORRADE_VERIFY(!data.hasCommonTextureCoordinates());
+    CORRADE_VERIFY(!data.hasCommonTextureLayer());
 
     #ifdef MAGNUM_BUILD_DEPRECATED
     /* textureMatrix() should return the common matrix, if possible, and
@@ -585,7 +631,7 @@ void PhongMaterialDataTest::commonTransformationCoordinatesOneDifferentTexture()
     #endif
 }
 
-void PhongMaterialDataTest::commonCoordinatesImplicit() {
+void PhongMaterialDataTest::commonCoordinatesLayerImplicit() {
     Containers::StringView textureName = PhongTextureData[testCaseInstanceId()];
     setTestCaseDescription(textureName);
 
@@ -594,16 +640,20 @@ void PhongMaterialDataTest::commonCoordinatesImplicit() {
 
     PhongMaterialData data{{}, {
         {textureName, 5u},
-        {textureName + "Coordinates", 0u}
+        {textureName + "Coordinates", 0u},
+        {textureName + "Layer", 0u}
     }};
 
     /* Zero is treated same as if there would be no attribute at all */
     CORRADE_VERIFY(!data.hasTextureCoordinates());
+    CORRADE_VERIFY(!data.hasTextureLayer());
     CORRADE_VERIFY(data.hasCommonTextureCoordinates());
+    CORRADE_VERIFY(data.hasCommonTextureLayer());
     CORRADE_COMPARE(data.commonTextureCoordinates(), 0u);
+    CORRADE_COMPARE(data.commonTextureLayer(), 0u);
 }
 
-void PhongMaterialDataTest::noCommonTransformationCoordinates() {
+void PhongMaterialDataTest::noCommonTransformationCoordinatesLayer() {
     #ifdef CORRADE_NO_ASSERT
     CORRADE_SKIP("CORRADE_NO_ASSERT defined, can't test assertions");
     #endif
@@ -614,20 +664,24 @@ void PhongMaterialDataTest::noCommonTransformationCoordinates() {
         {MaterialAttribute::DiffuseTextureCoordinates, 3u},
         {MaterialAttribute::SpecularTexture, 4u},
         {MaterialAttribute::SpecularTextureMatrix, Matrix3::scaling({0.5f, 1.0f})},
+        {MaterialAttribute::SpecularTextureLayer, 22u},
         {MaterialAttribute::NormalTexture, 5u},
         {MaterialAttribute::NormalTextureCoordinates, 17u}
     }};
 
     CORRADE_VERIFY(!data.hasCommonTextureTransformation());
     CORRADE_VERIFY(!data.hasCommonTextureCoordinates());
+    CORRADE_VERIFY(!data.hasCommonTextureLayer());
 
     std::ostringstream out;
     Error redirectError{&out};
     data.commonTextureMatrix();
     data.commonTextureCoordinates();
+    data.commonTextureLayer();
     CORRADE_COMPARE(out.str(),
         "Trade::PhongMaterialData::commonTextureMatrix(): the material doesn't have a common texture coordinate transformation\n"
-        "Trade::PhongMaterialData::commonTextureCoordinates(): the material doesn't have a common texture coordinate set\n");
+        "Trade::PhongMaterialData::commonTextureCoordinates(): the material doesn't have a common texture coordinate set\n"
+        "Trade::PhongMaterialData::commonTextureLayer(): the material doesn't have a common array texture layer\n");
 }
 
 #ifdef MAGNUM_BUILD_DEPRECATED