# 1 4--6
# |\ \ |
# | \ \|
# 2--3 5
o First
v -1  1 0
v -1 -1 0
v  1 -1 0
f 1 2 3
o Second
v -1  1 0
v  1 -1 0
v  1  1 0
f 4 5 6