On Mon, 09 Aug 1999 00:45:58 +0200, Remco de Korte wrote:
>There is something weird though. The test-scene included renders fine, but I
>tested it with an orthographic camera and there are thin white lines on some
>objects which shouldn't be there. With a normal camera you can also see some,
>depending on the location of the camera. I have no idea what's causing this. It
>may well be a bug in the macro but I can't find it. Anyone any ideas?

This is a bug in POV.  I first reported it back in version 3.0, but I
have had no luck actually finding the problem.  It's similar to the bug
that Truetype fonts used to have, which Kochin Chang fixed.  I sent him
my code that duplicates the problem you see here and he never found a 
solution either, to my knowledge.  What's happening is that POV is 
counting crossings (the Jordan Curve Theorem) to see whether the ray/
object intersection point is inside or outside the object, but it's
accidentally counting a crossing twice due to numerical inaccuracies
or segment overlap or both, and thus thinking it's inside the object
when it shouldn't be.

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