Re: Q: pfLayerModes

New Message Reply Date view Thread view Subject view Author view

Marcus Barnes (marcus++at++multigen.com)
Thu, 12 Jun 1997 18:46:15 -0700

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.

Regards.

--
+ Marcus Barnes, Technical Staff        mailto:marcus++at++multigen.com +
+ Multigen Inc.                         http://www.multigen.com    +
+ 550 S. Winchester Blvd.               phoneto:1-408-556-2654     +
+ Suite 500 San Jose CA 95128           faxto:1-408-261-4102       +
=======================================================================
List Archives, FAQ, FTP:  http://www.sgi.com/Technology/Performer/
            Submissions:  info-performer++at++sgi.com
        Admin. requests:  info-performer-request++at++sgi.com
   SGI DevForum 97 info:  http://www.sgi.com/Forum97/

New Message Reply Date view Thread view Subject view Author view

This archive was generated by hypermail 2.0b2 on Mon Aug 10 1998 - 17:55:26 PDT

This message has been cleansed for anti-spam protection. Replace '++at++' in any mail addresses with the '@' symbol.