I've a long-standing fascination with donut-shapes, toroids.
They're so convenient because they map nicely onto a rectangle,
and they're inherently soothing to look at. I'm not sure what this says about me, but now it's said.

Here is a series of programs titled "the final donut".
The first two require directX 7, i believe, and the last one needs dx9.
The Final Donut 1.zip 15KB 200202 ScreenShots finaldonut1_110.wmv 7.4MB
This one is not very interactive (ok, it's not interactive at all) but it is nice to look at. The strange lighting effect on the "fins" was a bug in the rendering engine, which i decided to leave in for a while. It's fixed in the next version tho.
The Final Donut 2.zip 26KB 200204 ScreenShots finaldonut2_110.wmv 5.4MB
This one lets you play with the number of lobes, the number of twists, the material, etc. Also lets you load & save your settings.
The Final Donut 3.zip 444KB 200301 ScreenShots finaldonut3_111.wmv 4.0MB
This version didn't start life as another incarnation of the final donut. I was actually starting on a 2D bubble-simulator, but obviously got sidetracked.
Again, not very interactive, but cycles thru its own internal settings on by itself.
This requires directX 9.