v -3 1 -1
vn 1 0 0
vn 0 1 0
sp -1 -1 -2

v -1 1 -1
vn 1 0 0
vn 0 1 0
sp -1 -1 -2

v 1 1 -1
vn 1 0 0
vn 0 1 0
sp -1 -1 -2

v 3 1 -1
vn 1 0 0
vn 0 1 0
sp -1 -1 -2

#camera
v  0 0 0
v  0 0 -1
vn  0 1 0

g Camera
c -2 -1 -1