[ODE] Not cylinders, but discs?

[Jon Watte (ODE)]

Cylinders aren't yet fully working. From what I understand, the main 
reason to get cylinders is for car wheels that don't "stick out" on the 
side of the car, with oil drum objects being a distant second.

Thinking about what you'll get out of car wheels, and how rays for 
wheels work just fine, wouldn't it be feasible to do an infinitely thin 
disc primitive? The hardest primitive to test against is usually 
trimesh, but disc-triangle is just a line segment-circle in the plane of 
the disc (assuming early rejection cases based on the disc plane have 
all passed).

You'd model car wheels as a disc where the outer edge of your tires 
would be; the inner edge, or even rolling surface, just aren't as 
important for simulation.

I certainly don't have time to write this primitive, but is it something 
to think about?

Cheers,

          / h+