ref: 470b40da76046fdd1ea0de2c0f020aac99d9a9d4 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