Re: Flimmering

New Message Reply Date view Thread view Subject view Author view

Marcus Barnes (marcus++at++multigen.com)
Mon, 12 Aug 1996 14:46:13 -0700

On Aug 5, 11:07am, Jude Anthony wrote:
> Subject: Flimmering
> I've got a model of a hotel with a parapet. The parapet is made out
> of quads, and it has triangular polygons of a different color on top
> to represent windows. The windows are flimmering. (Not _my_ term;
> found it in the Perfomer programming guide.)
>
> I've tried moving the windows away from the quads, I've changed the
> "Rel Priority" field of the window's polygon attributes in MultiGen
> to 100 (as compared to the quads' 0), and I've tried making each
> window a subface of its quad, all without noticeable results.

The subface approach is supported by the OpenFlight loader, but not the
"relative Priority" approach. There have been bugs in the support for
pfLayer/pfDecal in Performer 2.0, pfdBuilder and pfdLoadFile_flt. The
Performer 2.0.2 patch from SGI fixes such problems. The only decaling
mechanisim that always renders correctly is PFDECAL_BASE_STENCIL.
 Unfortunately it is costly on RE2 (but not on iR). You can tell the
OpenFlight loader to use this mode:

% perfly -y flt,9,6 file.flt

or:

{
        pfdConverterMode ( "flt", PFFLT_LAYER, PFDECAL_BASE_STENCIL );
        pfdLoadFile ( "file.flt" );
}

> Do I have to triangulate everything before subfacing works, or is
> there something else I should be doing here? I don't want to cut the
> window out of the parapet, as that would increase my polygon count
> unacceptably for this realtime application.

Cutting out the subfaces can give good performance, especially on iR. Don't
rule it out without doing a benchmark first. MultiGen has tools, to
triangulate and cut out subfaces, that work pretty well.

Regards.

--
   ____ ___  ____  _    Marcus Barnes, Member Technical Staff
  / __ `__ \/ __ `( )   MultiGen Inc. 550 S. Winchester Blvd. STE 500
 / / / / / / /_/ / /    San Jose CA 95128 WEB: http://www.multigen.com
/_/ /_/ /_/\__, /_/     PH:1-408-556-2654 FX:1-408-261-4102
          /____/        EMAIL: marcus++at++multigen.com
=======================================================================
List Archives, FAQ, FTP:  http://www.sgi.com/Technology/Performer/
            Submissions:  info-performer++at++sgi.com
        Admin. requests:  info-performer-request++at++sgi.com

New Message Reply Date view Thread view Subject view Author view

This archive was generated by hypermail 2.0b2 on Mon Aug 10 1998 - 17:53:21 PDT

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