interesting idea for the PDL 3D graphics stuff, ive never used PDL before, and have been wanting to learn it, this could be a good time to learn some. ill try to come up with some sort of equations, perhaps like you suggested, and i think i have another idea for the 3D-ness of the image, something having to do with the concentration of points in a single area, ill try to post some code for comment/suggestion/flame/praise in the next few days
~michael