ref: a3add1cdcbd30704a34d2876f556d0bff8694402
dir: /mdl/primtest.obj/
mtllib basis.mtl v 0 0 0 v 1 0 0 v 0 1 0 v 0 0 1 v 2 0 0 v 0 2 0 v 0 0 2 v 2.1 0 0 v 0 2.1 0 v 0 0 2.1 usemtl x f 1 2 3 l 1 5 p 8 usemtl y f 1 3 4 l 1 6 p 9 usemtl z f 1 4 2 l 1 7 p 10