# a simple OFF file
OFF                # header keyword 
4 4 6                # NVertices Nfaces (Nedges)
# vertices
1.0 0.0 0.0
0.0 1.0 0.0
0.0 0.0 1.0
0.0 0.0 0.0
# faces 
3 0 1 2
3 0 3 1
3 0 2 3
3 1 3 2