Anti Aliasing

[Gamingphreek]

Well we all no the AA kills framerates. IIRC here is how it stands:

ATI: (Cant remember but i think it is MSAA)

Nvidia: SSAA

Matrox: Fragment AA

Recently i decided to refresh my mind and go retro and take a look at video card performance of the old days. I stumbled upon the Matrox article where fragment AA utterly stomped ATI and Nvidias solutions at the time. Im not sure if they use the same thing now but back then fragment AA seemed to be the best solution. What is the best nowadays?

-Kevin

 

[Schadenfroh]

nvidia now does FSAA the same as ATI
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[vshah]

Originally posted by: Schadenfroh
nvidia now does FSAA the same as ATI
Text

except in 8x which is supersampling

 

[Gamingphreek]

Well which AA solution works the best overal, entailing best quality and best performance?

-Kevin

 

[futuristicmonkey]

It used to be Ati's 2xAA. It was faster, and looked as good (if not better than) nVidia's 4xAA. Now, however, nVidia copied ATi's sampling patterns, so they both look good.

Now, if you have Ati, I guess you could use 2X or 4xTAA (temporal).

With nVidia, use 2x or 4x - they don't have 6x, and their 8x is too slow.

Oh, and you could you provide that link about Matrox's fragment AA ? - I've never heard of it.

 

[Matthias99]

Originally posted by: Gamingphreek
Well which AA solution works the best overal, entailing best quality and best performance?

-Kevin

SSAA (Supersampling) gives the best possible quality, because it resamples EVERY pixel. It is also the only way to filter transparent textures (in current implementations). However, it does a lot of unnecessary work (since many pixels will look exactly the same after the resampling), and is VERY slow. NVIDIA's "8X" AA on the 6800 cards uses 2x supersampling on TOP of 4x multisampling AA, and you can see how much it drops the framerates relative to just 4xMSAA.

MSAA (Multisampling) is not *quite* as good as SSAA, and cannot work on transparent textures (though few if any modern games use these), but is significantly faster. This is because it only works on edges and other high-contrast areas (the places where antialiasing is, presumably, needed the most). Thus, it does very little extra work. Both ATI and NVIDIA use MSAA in their modern cards (the NV30 and NV40, and R200 and up, I think).

FSAA (Full Scene antialiasing) is, AFAIK, just marketing BS. It's generally another name for MSAA.

There's no way to have the "best" quality AND performance at the same time, at least not with current hardware AA implementations. I would have to say that MSAA is the best overall, considering that it is very close in quality to SSAA and runs much faster.

 

[Gamingphreek]

Well i know there is one other. I remember that it is the one Matrox used and is supposed to be better than both of them. IIRC Fragment Anti Aliasing. That was way back when, but way back when it was the best of both worlds. Is SSAA better now?

-Kevin

 

[Schadenfroh]

3dfx had the best FSAA implementation in terms of IQ, if IIRC, it was the same method used by highend SGI workstations.

 

[Gamingphreek]

Thats best quality i assume then.

However what about fragment AA? Isn't that like top of the line, sort of best fo both worlds.

-Kevin

 

[Matthias99]

Originally posted by: Gamingphreek
Well i know there is one other. I remember that it is the one Matrox used and is supposed to be better than both of them. IIRC Fragment Anti Aliasing. That was way back when, but way back when it was the best of both worlds. Is SSAA better now?

-Kevin

Well, by definition you can't get any better quality than supersampling every pixel (which is what SSAA does), unless you step up to a higher sampling level. I don't know any technical details of 'Fragment AA', but it must have been doing something similar to MSAA on some level (that is, trying to ignore pixels that don't need AA). None of Matrox's hardware was really fast enough to do AA at reasonable resolutions...

Edit:

I found an old AT article on the Parhelia, which used Fragment AA. It talks about its performance and its limitations. Performance looks pretty good -- sounds like it's 16x edge-only AA. This would be quite fast, and would eliminate jaggies, but would not help at all with texture blending. They also said this in the conclusion:

Our favorite feature, by far, of the Parhelia was its Fragment Anti-Aliasing. The quality of the algorithm was incredible but in its current state it does have some limitations that must be addressed in future hardware from Matrox. Currently FAA will not work with any use of stencil in a game, which is one thing Epic had to disable in the UT2003 demo in order for FAA to properly work. Although the demand isn't necessarily great for UT2003 to support stencil right now, eventual support is necessary and if FAA doesn't properly work with it enabled then Parhelia will be forced into 4X supersampling mode which is no better than what the Radeon offers. Matrox should be working long and hard to make sure that they get as much support as possible from developers for their FAA. At the same time their engineers should be hard at work at making the system as seamless as ATI/NVIDIA's AA algorithms; the user should never have to worry about whether turning on AA will result in image artifacts.

(emphasis added)

That's a pretty bad restriction, and would render it essentially unusable on most new games.