One feature I really enjoyed using in #POVray that I haven't seen in other tools is the isosurfaces. They used some pretty complex math, and could make for some incredible images that you could never hope to create using more basic functions or constructive sold geometry. I would make animations in the parameter space, find an interesting camera position and angle, and then find stills that looked cool. Here are a couple that I found back in May of 2004.

