ref: 5dfb42dcc2a66f99de1f736ec12062417700a9c9 dir: /mdl/tribasis.obj/
mtllib basis.mtl v 0 0 0 v 1 0 0 v 0 1 0 v 0 0 1 usemtl x f 1 2 3 usemtl y f 1 3 4 usemtl z f 1 4 2