VistaPro
John,
The idea is that the two seperate surfaces intersect each other. Each one is
itself smoothly shaded. I do not rely on the renderer to smooth between the
seperate objects. Since they are the same shape (except for the very small
bend near the edges which causes the intersection of the two surfaces) they
should be shaded similarly. The question is, how many polygons need to
overlap? Exactly how a loose end is shaded is arbitrarily chosen by the
rendering program. If one or two polygons of overlap is not enough I can go to
three or four — however many is required for the shading algorithm.
John.