Can anyone tell me the way to generate a 3D Voronoi Diagram like the one given at http://mathworld.wolfram.com/VoronoiDiagram.html. I need to draw the 4th diagram on this page (Second row, last plot).

In that plot the points are only on the top of the structures. I need to have points in-between the structures also (some of them needs to be visible). There needs to be two sets of points with two different colours. The ratio of density for the two sets of points should be 2-3 times.