POV-Ray : Newsgroups : povray.advanced-users : Degenerate triangles mesh vs. union : Re: Degenerate triangles mesh vs. union Server Time
30 Jul 2024 10:24:11 EDT (-0400)
  Re: Degenerate triangles mesh vs. union  
From: Noah A
Date: 16 Aug 1999 16:22:40
Message: <37B87320.FB98329E@powersurfr.com>
i'm not worthey
i'm not worthey
i'm not worthey

if you get it good if you don't i don't wanna explain :)

Chris Colefax wrote:

> Ken <tyl### [at] pacbellnet> wrote:
> >  In the sample below we have an example of degenerate triangles. The
> > indented triangles are those that Pov reports as being degenerate.
> > When rendered as a union the degenerate warnings appear. When commented
> > out those warnings disappear. When rendered as a mesh however Pov fails
> > to report them as being degenerate. This has been true since the mesh
> > wrapper was added in Pov v3.0x. Why are they not being reported as
> > degenerate triangles when used in a mesh ?
> >
> > I have asked this before and have never received a response. Hopefully
> > someone has an idea now that I have provided an example to evaluate the
> > discrepancy with.
>
> It would seem to be the simple fact that when parsing meshes POV-Ray ignores
> degenerate triangles completely, whereas in the union each triangle is
> parsed as an individual object and so degenerate cases do get reported (a
> possibly dubious theory arrived at by the fact that creating a mesh composed
> entirely of degenerate triangles simply reports "no triangles in mesh").
>
> I can only imagine the rationale is that meshes are generally outputted by a
> program (conversion or otherwise), and might very well contain many
> triangles that POV-Ray can't use (in which case warnings would simply be
> annoying, rather than useful).  Non-mesh triangles, on the other hand, would
> usually be entered by hand, and as such a degenerate triangle is more likely
> to be a genuine user mistake....perhaps?!


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