  Two important classes of three-dimensional elements in computational meshes
are hexahedra and tetrahedra. While several efficient methods exist that
convert a hexahedral element to a tetrahedral elements, the existing algorithm
for tetrahedralization of a hexahedral complex is the marching tetrahedron
algorithm which limits pre-selection of face divisions. We generalize a
procedure for tetrahedralizing triangular prisms to tetrahedralizing cubes, and
combine it with certain heuristics to design an algorithm that can triangulate
any hexahedra.
