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Sykora
03-09-03, 03:32 PM
This is my biggest problem. In EVERY 3d game, whether it is D3D or OpenGL there are always distant artifacts. The artifacts kinda look like static (poping polys/snow). However, these artifacts don't appear on a constant basis; they only appear if I move a game's camera angle or if I start moving around in general. In other words, the artifacts pop up while a 3d surface is being rendered.
This problem is not apparent in programs that support a W-Buffer; however, very few games are designed around the W-buffer.

So here are my questions:
1. Is there anyway to force all programs to use a 24 or 32-bit W- buffer instead of the Z-Buffer?
2. if not, is there any tweak or fix that can disable these distant artifacts?

Here's my specs...
Pent. 4 @ 2.53 GHz
512 DDR Ram
Win XP
Geforce TI 4600 128 DDR using the 41.09 dets.

Here's a pic that shows the symptoms of my problem...
http://www.evl.uic.edu/pape/CAVE/linux/nVidia/harlem-24bit.jpg
(the distorted texels in the distance flicker as the scene is being rendered)

I can tell that all of my applications are using a 16 bit Z-buffer. I think that my GF4 TI 4600 is defaulting to a 16 bit Z-buffer as well. Does anyone know of any driver versions that can correct this problem and default a 24 or 32 bit Z-buffer? Or perhaps there is a line or registry setting I could tweak

Bambers
03-10-03, 03:12 AM
Z buffer inaccuracy will cause polygons that are close together at long range to 'fight' and usually get shown alternatly in strips.

It won't cause texture shimmering. If you're getting that then your mipmap LOD bais is presumably at a negative value. Try raising it a bit.

Falkentyne
03-10-03, 07:47 AM
I don't think it's possible to force any program to "use" a 24 bit Z buffer, or a W buffer, unless the program either defaults to it, or has an option for it. Unreal uses the W-buffer, for instance, if it's available. The most you can usually do is tell the driver that it "supports" W buffer, or 24 bit z-buffer.

You might mess around with the Z and W buffer settings, in Rivatuner, but besides that, there isn't much you can do, if the game doesn't have any options for changing these.

You can try switching the color depth, also (maybe in combination with the above settings).

Sykora
03-15-03, 09:24 PM
What's the best value then for the LOD bias?