George Reilly wrote:
To elaborate somewhat: Think of the rim of a wheel as a very thin, hollow cylinder. To draw a cylinder in two-point perspective, you draw an ellipse for the near end, the visible side of the cylinder wall, and a slightly different half-ellipse for the far end. Drawing one circle (drop shadow) and overlaying it with an offset circle in a different color approximates the two ends of a thin cylinder, but doesn't account for the wall of the cylinder. In a bitmap painting program, you could fake the cylinder wall by drawing a series of drop shadows, staggered one pixel apart, but that's not going to work very nicely in a vector drawing program.
You mean something like this? http://www.ark.in-berlin.de/rings.svg
This was done with Effect->Interpolation.
ralf