Question: Can't plot proc - why?

Hi, I have a proc that generates a "piston" plot in 2-D. I generate this with a procedure. Calling the procedure works, but calling it from Plot3d doesn't. I'm really not sure why. I'd appreciate the help. My stuff is below: Diameter := 46; Shape := proc (x,y) if((x^2+y^2)^(0.5) <>
Please Wait...