🚀 go-pugleaf

In article <alan.728007287@godzilla.cgl.citri.edu.au> alan@cgl.citri.edu.au (Alan Dorin) writes:
>When drawing polys on the Reality Engine using concave(TRUE)
>I get a few polys that appear to be missed out. (Ie. some
>convex polys become invisible) The polys _are_ visible on
>PI's and Indigo's though so the problem appears to be with
>the RE.
>
>If I turn concave polys off, obviously the RE (and other machines)
>screws up the truly concave polys. Anyone know of a bug that
>would cause this and how to overcome it? (apart from removing the
>concave polys)
>
>
>					Thanks,
>					Alan Dorin
>					(alan@godzilla.cgl.citri.edu.au)

Does your concave polygons have any shared vertices? The concave decomposition
code is very sensitive about illegal polygons and will abort early if any are 
detected. From the man page:

      Polygons whose edges intersect each other are never guaranteed to be
     drawn correctly.

this includes repeating vertices. Each architecture tends to implement slightly
different algorithms for concave polygons, and illegal polygons are good for
detecting these differences.

Erik
-- 
Of course I'm lying,  .....but I think I love you.       (Yello)

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