is a 3-dimensional version of visualization.
The colors may be an integer, color function, or the string "Random";
if fewer colors then points are specified, the last color in the list is used.
If color=-1, then Mathematica's standard Lighting functions are used. If
color="Random" then a random RGBColor is generated.
Implementation note: The convex hull of each cell in the boundedCellVoronoi
diagram is plotted using convexHullSurface.