### 7.13.3 shapes2.inc

`Tetrahedron`
  4-sided regular polyhedron.
`Octahedron`
  8-sided regular polyhedron.
`Dodecahedron`
  12-sided regular polyhedron.
`Icosahedron`
  20-sided regular polyhedron.
`Rhomboid`
  Three dimensional 4-sided diamond, basically a sheared box.
`Hexagon`
  6-sided regular polygonal solid, axis along x.
`HalfCone_Y`
  Convenient finite cone primitive, pointing up in the Y axis.
`Pyramid`
  4-sided pyramid (union of triangles, can not be used in CSG).
`Pyramid2`
  4-sided pyramid (intersection of planes, can be used in CSG).
`Square_X, Square_Y, Square_Z`
  Finite planes stretching 1 unit along each axis. In other words, 2X2 unit squares.