OFF
5 3 0
# yo
# |\
# | \
# |f3\
# vo---ox
# |\f2|
# | \ |
# |f1\|
# uo---ow
0 0 0
1 0 0
0 1 0
1 1 0
2 0 0
# faces
3 0 2 1
3 1 2 3
3 1 3 4