Re: Q: pfLayerModes
Angus Dorbie (dorbie++at++multipass.asd.sgi.com)
Fri, 13 Jun 1997 15:33:40 -0700
On Jun 12, 6:46pm, Marcus Barnes wrote:
> Subject: Re: Q: pfLayerModes
> On Jun 12, 5:18pm, Angus Dorbie wrote:
> > On Jun 12, 1:15pm, Marcus Barnes wrote:
> >
> > > Coplanarity tolerance can be a problem for STENCIL. Performer 2.x
requires
> a
> > > much tighter (truer) tolerance than 1.x did.
> >
> > I don't understand why this should be.
> >
> > Can anyone furnish an explanation?
>
> I don't think it's strictly related to stencil usage. Decaling in 2.x uses a
> smaller displacement value or some such than 1.x did. Sharon mentioned this
to
> me awhile ago when we were debugging an apparent breakage in decal behavior
> introduced in Performer 2.0. The test case we were using involved subfaces
that
> were not quite coplanar and the deviation was outside the new tolerance. By
> making the test case truely coplanar (well it's floating point ;) the correct
> behavior was restored.
>
This has nothing to do with STENCIL decaling, it should only apply to the
polygon offset method.
Cheers,Angus.
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on Mon Aug 10 1998 - 17:55:26 PDT