From: sewell++at++dramail.com
Date: 10/18/2001 06:19:04
If I disable my second channel, and its OpenGL calls, then the clipmap works
correctly. The solution I've found for now is to not use the glPushAttrib.
I've gone through all of my OpenGL code and made sure that before I change
an attribute, I call glGet, save it, call the opengl, and then set the
setting to whatever I saved. Not exactly the most elegant solution, but its
working now. Thanks to everyone that replied.
Dorosky, Christopher G writes:
> I have had problems with this before. Down this road lies madness.......
>
> It seems that either performer or GL behaves COMPLETELY differently when a
> cliptexture is on one channel,
> verses when it is on two (or more).
>
> Try cutting down to one channel, and see what happens.
> If this temporarily fixes it, then this is not an easy problem to solve. I
> would investigate throwing out this
> approach and trying something different.
>
>
>
> Christopher Dorosky
> Lead Electronic Systems Engineer - Real Time Simulation
> Lockheed Martin Missiles and Fire Control - Dallas
> christopher.g.dorosky++at++lmco.com
> 972-603-2349
>
>
> -----Original Message-----
> From: Ken Sewell [mailto:sewell++at++donet.com]
> Sent: Wednesday, October 17, 2001 1:06 PM
> To: Performer Mailing list
> Subject: Problem with clipmaps and glPushAttrib
>
>
> I have an application that draws terrain w/clipmap
> in one channel and some OpenGL geometry in the other. In
> the OpenGL draw callback, I call glPushAttrib with the
> texture bit set. When I do this I get a strange effect on
> the clipmap. At the border of every cliplevel, there
> is a stripe of imagery than does not belong. The imagery
> is from elsewhere in the clipmap. After about a second the
> stripe is replaced by the correct imagery. About a second
> later it repeats. My best guess is that the clipcenter is
> being updated but its being drawn before the cliptexture is
> updated. If I don't call glPushAttrib, my terrain shows up,
> but no cliptexture.
> Right now I've stripped down the callback for the
> OpenGL channel, all it does is glPushAttrib, glClear, and
> glPopAttrib and I get this effect. Has anyone encountered
> this problem before? Attached is a screenshot showing the
> cliptexture problem. Thanks.
>
> Ken.
>
> --
> Ken Sewell Defense Research Associates
> Project Engineer 1430 Oak Ct., Suite 303
> sewell++at++dramail.com Beavercreek, Ohio 45430
> 937-255-2811 x4377 (voice) 937-255-6663 (fax)
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