GPU Image Quality

[evolucion8]

Originally posted by: BFG10K

Originally posted by: josh6079

Although, there is one area I've seen so far that, even under those settings, still some shimmering. That said, it isn't much at all and you really have to look for it.

Yes, and I'll bet I know exactly which one: the metallic walls of the red buildings where you first get the buggy? There's some pretty bad shader aliasing there that takes a lot of super-sampling to squash, even with nVidia?s AF.

If you're feeling brave you can try some of the pure super-sampling modes (e.g. 3x3), though I personally avoid them due to their lacking edge strength.

This is why I advocate nVida implementing combined modes that have RGSS/SGSS with more than four samples. 4xOGSS is good, but it?s not good enough sometimes, especially with (near) horizontal & (near) vertical lines.

But shader aliasing is something that cannot be eliminated with normal anti aliasing since it only targets the z-buffer, in other words, the polygon edges. Super sampling may help a little but shader aliasing has a lot to do with the algorythm and precision used, in ATi the Narrow and Wide Tent helps greatly to reduce that kind of shader aliasing, but there are some games which it blurrs all the screen and looks terrible, like in Crysis, but in other games like Tomb Raider Legend or Half Life 2 is not noticeable at all. I'm not sure if nVidia has some kind of filter that blurrs the screen slighly like ATi does, but any nVidia user may want to clear that out for me,

 

[BFG10K]

Originally posted by: evolucion8

But shader aliasing is something that cannot be eliminated with normal anti aliasing since it only targets the z-buffer, in other words, the polygon edges.

Right, I?m well aware of this. Who do you think wrote the article Thilan linked to on page 1 of this thread?

Super sampling may help a little

Actually it helps a lot because the shader is being rendered at a larger target and then sampled down. Check the Doom 3 screenshots I posted in that review.

in ATi the Narrow and Wide Tent helps greatly to reduce that kind of shader aliasing, but there are some games which it blurrs all the screen and looks terrible,

Narrow & wide tent isn?t anti-aliasing, it?s a blur filter. It takes existing samples and averages them out.

Super-sampling makes new samples by rendering the scene higher, then averaging them down. Also super-sampling stacks with AF so if you?re doing 2xSSAA with 16xAF, you actually end up getting 32xAF.

I'm not sure if nVidia has some kind of filter that blurrs the screen slighly like ATi does, but any nVidia user may want to clear that out for me,

Yes, unofficially they have 2xQ (2xMSAA + quincunx) and 4x9T (4xMSAA + blur).

 

[josh6079]

Originally posted by: evolucion8
But shader aliasing is something that cannot be eliminated with normal anti aliasing...

Yeah, that's why we were talking about super-sampling modes. Skewed Grid, Rotated Grid, and Ordered Grid super-sampling are all methods of eliminating that.

I'm not sure if nVidia has some kind of filter that blurrs the screen slighly like ATi does, but any nVidia user may want to clear that out for me,

Only features that cause some blur are the super-sampling modes themselves. It's pretty incremental though compared to the huge reduction of aliasing in my opinion.

edit:

Originally posted by: BFG10K
Yes, unofficially they have 2xQ (2xMSAA + quincunx) and 4x9T (4xMSAA + blur).

Not that I'd use them, but I haven't seen those in nHancer. Where do you go to enable them?