This contains "interesting" POV (raytracing) images and studies, including some older works.
Perverse Constructive Solid GeometryCreated 26-June-1994 PCSG.GIF is a study in "perverse constructive solid geometry" in POV 2.2. The techniques being developed are general, and may be used to create Escher-like effects as demonstrated here. I can move the viewpoint around (as long as it is still viewing the object from the same general direction) and preserve the effect. That makes it easy to reuse "twisted" objects, fine-tune the views, or apply to animations or stereo viewing.
For the source code and a "behind the scenes" look to see how the illusion works, click here.