ply
format ascii 1.0
element vertex 5           { define "vertex" element, 8 of them in file }
property float x           { vertex contains float "x" coordinate }
property float y           { y coordinate is also a vertex property }
property float z           { z coordinate, too }
property float nx
property float ny
property float nz

element edge 4            { there are 6 "face" elements in the file }
property int vertex1
property int vertex2
property list uchar float beam_dimensions
property list uchar float beam_material {poissons ratio , young's modulus in GPascal}
end_header

0 0 0 0 0 1
1 0 0 0 0 1
2 0 0 0 0 1
3 0 0 0 0 1
4 0 0 0 0 1

0 1 2 0.03 0.026 2 0.3 200
1 2 2 0.03 0.026 2 0.3 200
2 3 2 0.03 0.026 2 0.3 200
3 4 2 0.03 0.026 2 0.3 200