Marcus (giraffe.asd.sgi.com!sgi.sgi.com!uunet.uu.net!multigen!Marcus)
Thu, 23 Mar 1995 16:54:40 PST
I didn't find any response to this question back then ...
and it seems relevant again (still):
::Message-Id: <00581.2850143389.1269++at++multigenuunet.UU.NET>
::Organization: Software Systems
::X-Charset: MACINTOSH
::X-Umcp-To: INFO PERFORMER
::From: Marcus <uunet!multigenuunet.uu.net!Marcus>
::To: INFO PERFORMER <giraffe.asd.sgi.com!info-performer>
::Date: Mon, 25 Apr 1994 17:40:44 PST
::Subject: Re: >Flashing on and off of
::
:: Reply to: RE>>Flashing on and off of c
::>Hi
::>
::>I had a posting a few days ago about texture flashing on and
::>off. I have since investigated this further, and found out
::>that it isn't texture, but in fact appears to be the ambient
::>colour for some of the polygons either saturating at peak white
::>or peak black.
::
::<stuff deleted>
::
::>Thanks for your time
::>Richard Gallery
::
::I have seen similarly "flashing" geometry. It happens on machines
::without hardware z-buffer, when there is co-planer geometry in the
::data base. On an Indigo XS24 with 4 stencil planes and no z-buffer for
::instance.
::
::I suspect that Performer requires a z-buffer (and stencil planes) in
::order to render co-planer geometry correctly, although the Performer
::1.0 manual page for pfLayer says that only a "hardware stencil buffer"
::is required.
::
::The visual results imply [ ... quick check of the stencil(3g) manual page]
::that the FAIL and ZPASS cases are handled correctly by Performer, but
::perhaps not the PASS case? (Corrections welcome ;-)
::
::Note also the multi-sampling configurations can alter the *apparent*
::existance of both stencil and z buffers.
::
::Regards,
::Mark Barnes
::Member Technical Staff
::multigen!marcus++at++uunet.UU.NET
Regards,
Marcus Barnes, Member Technical Staff
MultiGen Inc., 1884 The Alameda, San Jose CA, 95126
PH: (408) 261 4118 FX: (408) 247 4329
EMAIL: multigen!marcus++at++uunet.UU.NET
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