Feature request: tetrahedron

[rth238]

This is impressive! You said that you were open to feature requests, so I hope this will be OK to suggest: It would be great to have a tetrahedron primitive. Even better would be per Vertex colors… And, blue sky dreaming, a 10-nosed tet with side nodes (vertices) giving quadratic sides to the tetrahedron edges, with many such tetrahedrons (for example finite element visualization).