here
p	-0.5	0.25	0
p	0.5	0.25	0
p	0.5	-0.25	0
p	-0.5	-0.25	0

p	-1	0.5	1
p	1	0.5	1
p	1	-0.5	1
p	-1	-0.5	1

mtl metal_yellow
f 0 1 2 3
f 0 4 5 1
f 1 5 6 2
f 2 6 7 3
f 3 7 4 0