ref: d0874baf0a5eccf203c9a06c99400adfc388d35d dir: /mdl/basis.obj/
mtllib basis.mtl v 0 0 0 v 1 0 0 v 0 1 0 v 0 0 1 usemtl x l 1 2 usemtl y l 1 3 usemtl z l 1 4