ply 
format   ascii   1.0
element   vertex   8 
property   float   x 
property   float   y 
property   float   z
element   face   12 
property   list   uchar   char   vertex_index
end_header 
0   0   0
1   0   0
1   1   0
0   1   0
0   0   1
1   0   1
1   1   1
0   1   1
3 0 1 2
3 0 2 3
3 1 5 2
3 5 6 2
3 4 5 6
3 4 6 7
3 0 4 7
3 0 3 7
3 6 2 3
3 6 3 7
3 1 5 4
3 1 4 0