1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
v -1 -1 -1 v 1 -1 -1 v 1 -1 1 v -1 -1 1 vt 0 0 vt 1 0 vt 1 1 vt 0 1 vn 0 1 0 f 3/3/1 2/2/1 1/1/1 f 4/4/1 3/3/1 1/1/1
