v 0.0 0.0 0.0
vn 1.0 0.0 0.0
vt 0.0 0.0
v 1.0 0.0 0.0
vn 1.0 0.0 0.0
vt 1.0 0.0
v 1.0 1.0 0.0
vn 1.0 0.0 0.0
vt 1.0 1.0
v 0.0 1.0 0.0
vn 1.0 0.0 0.0
vt 0.0 1.0
usemtl Glass
f 1/1 2/2 3/3
usemtl Air
f 3/3 2/2 4/4
