[jfrancis]

You never see a flat rollercoaster track go into a perfectly circular loop-the-loop because while that track is continuous in the first derivative, it is not continuous in the second derivative, and would make for a very jarring ride.



http://www.digitalartform.com/archives/ ... _no-s.html



http://www.core77.com/blog/featured_ite ... _12752.asp

[jfrancis]

DO you do anything special in order to get the smoothest light transition from floor to wall?

[raja]

in Rhinoceros, you can use extruded surface from a single 5 control-point curve:

[jfrancis]

That looks nice and smooth.

I was just noticing in the real world people use circles a lot because it's easier, and wondering if it mattered in practice.

It's probably actually more trouble to use a circle than not to use one in CG.