Pretty cool and well done, I like the idea of using a simple plane and pixel clipping.

However, see the following:



When you try to create a full torus (or even before that) there are small lighting differences (huge black circles) and you can see where both ends of the ring connect (esp. in motion).

Btw. I suggest to deliver the next demo with a png/ tga screenshot function, not the default jpg format with bad compression.

EDIT: Oh and as mentioned by the previous poster it crashed when I made the torus infinitely small.