From: Angus Dorbie (dorbie++at++sgi.com)
Date: 05/15/2001 10:14:52
Well I'd have said this was z fighting, BUT since it pops instead of
seeing pixel noise I reckon you're not sorting for transparency. The
OpenGL path should be OK reproducing z fragment values textured on most
platforms although it's not quaranteed since only one pass is blended
transparent.
Turn sorting on for the channel to ensure that the transparent pass
get's drawn after the opaque one and that should stop the popping.
Cheers,ANgus.
Alex Hill wrote:
>
> Dear colleagues;
> I wish to morph between two geometries; each with a different texture.
> The vertex morphing is straight forward, but I am NOT using a pfFlux, yet.
> I am drawing the first geometry normally, and then blending the second
> geometry texture using setMode(PFSTATE_TRANSPARENCY,PF_ON).
> This appears to give the right result, yet at times the geometry rendered
> first "pops" out in front of the second pass render and subsequently is not
> blended. The best explaination I have gotten is that when rendering
> geometry a second time "performer must decide if a point is in front or
> behind". The advise I've been given is to make the second render slightly
> larger than the first to make sure that it does not end up behind the first.
> This makes no sense to me. Certainly I should be able to render the
> second pass into the same depth in the Z-buffer and blend it with the first.
> Am I wrong? Will all of this resolved if I move to using fluxed memory?
> Why?
>
> Thank you in advance,
> Alex Hill
> ahill.evl.uic.edu
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This archive was generated by hypermail 2b29 : Tue May 15 2001 - 10:15:15 PDT