# a box without the front face

v 0 0 0 
v 0 1 0
v 0 1 -1
v 0 0 -1

v 1 0 0 
v 1 1 0
v 1 1 -1
v 1 0 -1

v 0 0 -2

f 1 2 3 4
f 8 7 6 5
f 4 3 7 8

f 2 6 7 3
f 1 5 8 4
f 9 9 9