Is the GFFX AA gamma correct?

[Bigus Dickus]

I read a couple of the reviews, and didn't notice any statements about that. I was kind of expecting this to be an included feature. I also haven't noticed any statements on the forums about it, but they could have easily been lost in "FX Art" and "Dustbuster" threads.

Did I just miss that, or is it still unknown?

 

[Bambers]

Assuming the screenshots are correct then it doesn't look like it.

 

[THe_KELRaTH]

Probably too busy trying to correct everything else

 

[MuFu]

I think (not 100% sure) gamma correction when implementing FSAA is one of the "features" of Intellisample. Might be a good idea to call up a whitepaper and see what it says. The others are colour compression, adaptive texture filtering blah blah...

MuFu.

 

[Dave Baumann]

Dynamic Gamma Correction
Contrary to what a computer monitor shows or how the human eye perceives it, computer graphics programs generally assume a linear color space. And, with most artwork created in some form of gamma space, operations done in the shaders should take place in gamma space as well, but this is not really convenient. Instead, the correct approach should bring color values back into linear space, perform the math, and corrects back into gamma space. Many previous shaders did not take gamma into consideration, resulting in color inaccuracies. However, with built-in gamma correction capabilities, NVIDIA GPUs free developers from the burden of changing gamma spaces. Users see a truer representation of each rendered image’s luminance (or brightness).

As I said in the other thread, it only talks about Shaders, not FSAA specifically, so I never have been sure on this point. Reading one of ram's translations the German GFFX reviewer said it didn't.

 

[Bigus Dickus]

As I said in the other thread, it only talks about Shaders, not FSAA specifically, so I never have been sure on this point. Reading one of ram's translations the German GFFX reviewer said it didn't.

Yeah, it does sound like the shaders certainly do it, but I was really counting on AA being gamma correct as well. After seeing the direct comparisons, this seems to have nearly as big of an impact as the number of samples taken, or the pattern of the samples.

:?

 

[3dcgi]

My understanding of Ati's gamma corrected antialiasing is that it's actually gamma corrected rendering and antialiasing is just part of that. Discussions on the web indicated that they stored the frame buffer in sRGB (gamma corrected) format so the subpixel values that are ultimately filtered maintain more effective precision.

If my understanding is correct then Nvidia's hardware also supports gamma correct antialiasing. Whether the drivers do is another question.

Is my interpretation off base or do others agree?

 

[Bigus Dickus]

I suppose we'll have to wait for either B3D to get a card to "properly" review, or for some member here to be a guinea pig and sink the money into one so that he/she can do some more exhaustive screenshots for us.

 

[Humus]

My understanding of Ati's gamma corrected antialiasing is that it's actually gamma corrected rendering and antialiasing is just part of that. Discussions on the web indicated that they stored the frame buffer in sRGB (gamma corrected) format so the subpixel values that are ultimately filtered maintain more effective precision.

If my understanding is correct then Nvidia's hardware also supports gamma correct antialiasing. Whether the drivers do is another question.

Is my interpretation off base or do others agree?

There's two things going on here. Gamma correct AA and gamma correction on texture reads. The 9700 supports both these. The gamma correct AA is automatic while gamma correction on texture reads must be done by the application.

 

[Ostsol]

The big problem I noted with the GeforceFX screenshots in HardOCP's review was the lack of fog. . .