ref: a6ea992058998552ad308a04261a53e5e2c2d523 dir: /mdl/window/window.obj/
mtllib window.mtl usemtl window v -1 -1 0 v 1 -1 0 v -1 1 0 v 1 1 0 vt 0 0 vt 1 0 vt 0 1 vt 1 1 f 1/1 2/2 3/3 f 4/4 3/3 2/2