programmable clipping

[Davros]

please explain how it looks like it uses a w buffer

 

[Tokelil]

That's JK 2 which uses the z-buffer due to the fact that opengl didn't use the w-buffer. Looks like it uses the w-buffer tho, but it don't.

What makes you think it looks like w-buffer is used? The "only" difference between the two shots seems to be texture filtering to me, which has little to do with the depth buffer.

 

[Johnny_Physics]

Tokelil: Exactly! Now look at the textures between Shadowman's puny draw distance, declared as great, compared to the Giants-shot enormous draw distance, declared as bad and containing z-artifacts or whatever.

I'm starting to think that these "z-buffer artifacts" is nothing more than normal use of mip-maps and texture filtering, and iq's ultimate w-buffered dreamboat would involve no fog, point filtering and no mip-maps.
Like a high resolution Quake 1 in software with mip-level 0 or whatever that command was. Using an extreme negative lod bias(like some do) will achieve a similar effect. It's like rubbing sand in your eyes, but some people see it as "high quality" and there is(or used to be) specially "tweaked" drivers to enforce that on a driver level.

 

[2008 IQ is unacceptable]

please explain how it looks like it uses a w buffer

The whole game does because of the huge draw distances and openness of the environments.

@tokelil:

I never said that the depth buffer had anything to do with the filtering. Try to refrain from putting words in my mouth, but I'm not mad at you. lol.

 

[2008 IQ is unacceptable]

Tokelil: Exactly! Now look at the textures between Shadowman's puny draw distance, declared as great, compared to the Giants-shot enormous draw distance, declared as bad and containing z-artifacts or whatever.

I'm starting to think that these "z-buffer artifacts" is nothing more than normal use of mip-maps and texture filtering, and iq's ultimate w-buffered dreamboat would involve no fog, point filtering and no mip-maps.
Like a high resolution Quake 1 in software with mip-level 0 or whatever that command was. Using an extreme negative lod bias(like some do) will achieve a similar effect. It's like rubbing sand in your eyes, but some people see it as "high quality" and there is(or used to be) specially "tweaked" drivers to enforce that on a driver level.

I've always preferred positive lod bias if I couldn't have neutral.

I can't stand the shimmering and over-sharpness of LOD's below zero.

 

[Davros]

im talking about the picture in question IQ

 

[Andrew Lauritzen]

The whole game does because of the huge draw distances and openness of the environments.

I think you're really mistaking bad LOD for depth buffer precision problems. The latter is a total non-issue nowadays, while doing good LOD is still hard. So while I can accept whining about LOD (although doing some research and coming up with a better scheme would be more productive!), absolutely none of the modern IQ problems with games have anything to do with depth buffer precision...

 

[2008 IQ is unacceptable]

I think you're really mistaking bad LOD for depth buffer precision problems. The latter is a total non-issue nowadays, while doing good LOD is still hard. So while I can accept whining about LOD (although doing some research and coming up with a better scheme would be more productive!), absolutely none of the modern IQ problems with games have anything to do with depth buffer precision...

I never said that.

The 2 are totally unrelated; the depth buffer has to with depth precision, LOD has to do with sharpening or blurring textures.

 

[Johnny_Physics]

No, he's talking about the kind of LOD that deals with changing the complexity of the geometry depending on their distance from the virtual camera/viewport, not textures.

 

[Davros]

lod also has to do with polygons
an object far away will be drawn will fewer polys than one close up
it would be a huge waste to draw an object with 10,000 polys if it only occupies a dozen pixels on screen

ps: i finally got around the timelimit in dxtweaker and selected NONPOW2CONDITIONAL but the problem still remains with crimson skies
(ive only tried the demo cos it was quicker to download than find my cd and had to run in win98 compatability mode could that be why dxtweaker doesnt work ?)

 

[kyetech]

I cringed all the way through this thread.

 

[MDolenc]

I never said that.

The 2 are totally unrelated; the depth buffer has to with depth precision, LOD has to do with sharpening or blurring textures.

I don't think you have provided a single screenshot where there would be any artefacts caused by depth buffer precision.

 

[Andrew Lauritzen]

The 2 are totally unrelated; the depth buffer has to with depth precision, LOD has to do with sharpening or blurring textures.

This tells me that you are indeed muddling the concepts in your mind. I suggest you go do some reading on geometry LOD, progressive meshes, etc. If you have time, even go look at some micropolygon renderers like REYES.