domain decompostion

doubtsingrid

hello all, does anyone know domain decomposition algorithms which generate arbitrary convex polyhedra given the boundary? For example, in 2D, if I was given the Brep for inner and outer boundary, i would want the domain to be decomposed into arbitrary polygons which could be any combination of triangles, quads, pentagons etc. I would want to know the 3D counterpart rather than 2d. For 2d, I am doing the delaunay triangulation and generating the voronoi polygons. What can I do for 3D? Delaunay triangulation is very very complex in 3d. Any suggestions? Thanks