Basic Anti-Aliasing Questions

Discussion in 'Video Cards and Graphics' started by Sleepingforest, Jan 7, 2013.

  1. Sleepingforest

    Sleepingforest Platinum Member

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    I'm a complete graphics newcomer, so I have only really, really basic questions. I don't need perfect, technical definitions (though a dumbed-down explanation could be helpful).
    • What are the different kinds of AA (TXAA, MSAA, etc)?
    • What's the difference in quality/hardware requirements between them?
    • How much of a difference can it make between the different kinds?
    I'm sure that I'll have even more questions about your answers, so thanks in advance (you may find yourself frustrated with my lack of knowledge).
     
  2. blackened23

    blackened23 Diamond Member

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    MSAA: High quality with the most flexibility, appreciable performance hit
    MSAA can also be converted to SSAA through GPU drivers

    SSAA: Do not use unless playing a very old game, it will destroy performance. Highest quality by a large margin.

    MLAA/FXAA: Fast approximate AA or MLAA (AMD version). Lower quality than MSAA, cannot be converted to SSAA. Compatible with nearly everything and not a very large performance penalty. Use it when the game does not support MSAA, or MSAA incurs too big of a performance hit

    TXAA: You'll have to form your own opinion here. Personally I don't like it too much, but some really like it. Pretty big performance hit, requires native application support. Works in AC3 and The Secret World.

    TLDR. For the most part you'll want to use MSAA. If MSAA lowers performance, try FXAA/MLAA. If game does not support MSAA, FXAA/MLAA by default is the only choice. TXAA requires native application support.
     
    #2 blackened23, Jan 7, 2013
    Last edited: Jan 7, 2013
  3. Sleepingforest

    Sleepingforest Platinum Member

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    So basically, in terms of quality (and reverse performance hit):
    FXAA<MSAA<SSAA
    and TXAA floats around somewhere, depending on personal preference.
     
  4. blackened23

    blackened23 Diamond Member

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    Pretty much. As far as the last question, TXAA was really designed to eliminate the "crawling" appearance that happens on edges while in motion. Quality wise it's probably higher than MSAA but more of a performance hit as well, and quite blurry (at least, in TSW)
     
  5. Sleepingforest

    Sleepingforest Platinum Member

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    So, in theory, TXAA would be better than MSAA, but the blurriness may be unappealing?
     
  6. SirPauly

    SirPauly Diamond Member

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    Imho,


    From a nVidia performance point:

    -FXAA
    -MSAA
    -TXAA
    -SGSSAA

    From a nVidia quality while moving point:

    -SGSSAA
    -TXAA
    -MSAA
    -FXAA

    TXAA may soften the screen and designed/engineered to be cinematic but if one desires more clarity though, there is the LumaSharpen ability in SweetFX for advanced IQ tweakers, FWIW!

    Here is an illustration of Sweet fx:

    http://international.download.nvidi...l-of-duty-black-ops-2-sweetfx-comparison.html
     
  7. Gryz

    Gryz Golden Member

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    And then there is SMAA.
    http://mrhaandi.blogspot.nl/p/injectsmaa.html

    There are several ways to look at it:
    Picture quality in screenshots.
    Picture quality with moving camera.
    Performance.
    Compatibility.

    SSAA is the oldest form of AA. It gives nice screenshot-quality images. But when you play the game, you will see "pixel creep". Also called "temporal aliasing". Basically you will see (white) flickering around the edges of objects. But the biggest drawback is the loss of framerate. SSAA just renders 4x (or more) the amount of pixels that your screen has. And then averages out 4 virtual pixels -> 1 pixel on your screen. This will give you 4x more to do, and thus a ~75% framerate loss.

    MSAA is the 2nd oldest. It only does work on pixels that are close to the border of objects on your screen. Again, nice picture quality in screen-shots. But suffers from temporal aliasing too. Performance his is a lot less, because the game is rendered in native resolution, and only work is done on a subset of pixels.

    SSAA and MSAA are done somewhere "early, or in the middle of the rendering". Nowadays a lot of engines do "deferred rendering". That means they do a lot of "post-processing". Basically alter the picture after the real 3D rendering has been done. Things like HDR (lighting), motion blur, etc. There is a new family of anti-aliasing that works as a post-processing effect. These are FXAA, MLAA, TXAA and SMAA. FXAA and TXAA are nvidia-only, MLAA is AMD-only. And SMAA is 3rd party, and works on both cards. All these 4 types of AA are relatively light on processing power. And they all are much better at getting rid of temporal aliasing than MSAA and SSAA. But they will also make the screen (particularly the textures) more blurry.

    The differences.
    FXAA and MLAA are the base of deferred AA technologies. AFAIK they are the same thing, FXAA for nVidia, MLAA for AMD.

    TXAA has its focus on 1) even less processing power required, 2) even better at getting rid of jaggies, 3) tries even harder to get rid of temporal aliasing. The big downside is: a) it gives the most blurry picture of all methods of AA. b) it needs native support in each game. There are only a handful of games supporting TXAA.

    SMAA was made by people other than nVidia or AMD. It works by dropping 4 files (including one dll) into the directory where your game's executable is. It requires very little processing power. And imho it is the least blurry of the 4 deferred AA methods. And it works pretty well getting rid of temporal aliasing. On top of that, you can enable it together with MSAA (or SSAA).

    My preferred way of doing AA in games is now.
    1) Enable 4xMSAA. (Or even 8xMSAA if the game is not too demanding).
    2) Enable Transparency MSAA.
    3) Drop SMAA in the game folder (keeping settings at the default High).
    I do this with nVidia inspector. I also set LoDBias to -1. And I prefer SSAO (which has nothing to do with anti-aliasing).
    This gives the best picture quality, for a reasonable performance price.
    Note, I have a pretty decent system (gtx680 + i5-3570K). But even on my old gtx260 I would run 4xMSAA in most games. (I hadn't heard of SMAA back then).

    And then there is SGSSAA. Sparse Grid Super Sampling.
    There used to be a bug in the nVidia drivers, where, if you enabled Transparency SSAA, it would actually do some form of SSAA over the whole picture (and not only the transparent parts). People liked this, and nVidia kept it in their drivers. If you enable SGSSAA you will get something that looks like SSAA. Very nice picture. But very very heavy on the framerates (>50% framerate loss). And I don't think it does anything against temporal aliasing.

    There are all kinds of 3rd party tools to mess with settings.
    ENB Series and SweetFX seem to be the most popular.
    The problem with those 2 tools is that they change so much in the picture, it might take days to find the settings you like best.
     
    #7 Gryz, Jan 8, 2013
    Last edited: Jan 8, 2013
  8. boxleitnerb

    boxleitnerb Platinum Member

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    SGSSAA combats temporal aliasing, of course. But it can only work as well as the underlying MSAA. In Max Payne 3 or BF3, the MSAA implementation is bad, so SGSSAA won't do wonders there because it isn't applied to everything.
     
  9. Black Octagon

    Black Octagon Golden Member

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    This is a little strong IMHO. I sometimes find that slight (2x) SSAA looks superior to 4x or 8x MSAA/FXAA/WHATEVERAA for about the same performance hit...at least at high resolutions like 2560x1440

    SSAA is 'real' AA. Other forms are like a flurry of (mostly half-assed) attempts to be real AA without...being real AA, and that's why they come with less of a performance hit
    (ok maybe I'm coming on a little strong now, but the OP should be aware that AA is the original still the best AA, and not do be avoided)
     
  10. blackened23

    blackened23 Diamond Member

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    Do you use SSAA in a "real" game such as Witcher 2 through the use of uber sampling? Metro 2033? etc? I play at 2560 resolution as well and you can get away with SSAA in old games (2008-2009?), but for the most demanding ones....well, that really depends. I don't disagree about the quality, Supersampled is by far the best.

    I would say a 50% framerate loss isn't uncommon with supersampled, depending on game of course.
     
    #10 blackened23, Jan 8, 2013
    Last edited: Jan 8, 2013
  11. Black Octagon

    Black Octagon Golden Member

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    Yes, I play Metro 2033, Crysis 1, etc. at 2560x1440 and either use 2x SSAA or no AA at all. I think FXAA looks crap in pretty much all games except Deus Ex: Human Revolution (which is not very demanding anyway).

    This is on a 120Hz monitor where I need to maintain a solid 90-120fps too...
     
  12. boxleitnerb

    boxleitnerb Platinum Member

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    Please use proper terms, SSAA and SGSSAA and OGSSAA aren't the same thing. It get's difficult to follow the discussion this way.

    In my experience, SGSSAA is best if MSAA works well. Usually 4xSGSSAA halves framerate, but on newer cards you might get away with "only" 30-40% performance hit.
     
  13. Black Octagon

    Black Octagon Golden Member

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    Yes I know but the OP wants clear answers to disarmingly simple questions. It doesn't really help him/her to get into the different sub-categories of the 'SSAA family'

    Also, for AMD users, 'SSAA' is the only setting you actually see in CCC. I know that he has a 670 and that more advanced users of tools like NVIDIA Inspector can choose from a nice variety of specific forms of AA, but the OP wants some basic guidance, and other readers who are on AMD may want to simply know what the 'SSAA thingy' in CCC will do...
     
  14. Ibra

    Ibra Member

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  15. BFG10K

    BFG10K Lifer

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    Eh? All forms of AA combat temporal AA, but to differing degrees. Temporal AA is basically just a buzzword being thrown around by nVidia when promoting TXAA, as if their method is somehow special. It isn’t.

    SSAA - when properly implemented with a high enough sample count - offers perfect image quality and eliminates all forms of aliasing, temporal and spatial.

    That's not normal.

    The performance loss is not a linear proportion to sample count, not even in 100% GPU limited situations. 2xSSA is usually about the same performance hit as 8xMSAA, and neither are 50%, except maybe when being externally forced into a deferred renderer by drivers.

    Less processing power than what? TXAA is basically MSAA + temporal blur, which means it'll be slower (or at best equal) to regular MSAA in terms of performance.
     
  16. f1sherman

    f1sherman Platinum Member

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    I wanted to say something, but then I remembered I'm in war with NV over locking TXAA on Kepler :mad:

    I'll still leave this link for OP
     
  17. f1sherman

    f1sherman Platinum Member

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    Also, it's nice to have general knowledge about AA methods, but in practice you are always limited with specifics of the game you play.

    I.e. it's better to ask what's best(looking) AA in particular game, than to follow single recipe.
     
  18. Black Octagon

    Black Octagon Golden Member

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    I was not talking about using FXAA injectors because, AGAIN, the OP just wants the basics. I'm talking about those games that let you simply turn FXAA 'on' or 'off' from the settings menu. Nothing more than that. So your second link, while fascinating, goes beyond FXAA in the sense that the OP is likely to be asking about.

    As to your first link, I'm not sure why exactly you posted it. So a guy compared FXAA and SMAA screenshots in a game. He noticed the FXAA blurriness I referred to and...what?

    EDIT: Oh yeah, and you presumably intended to write "it does when you have NO idea what you are doing," which I'm going to write off this time as mild banter à la the forum guidelines. If you disagree with me, please post an actual rebuttal instead of a disparaging one liner backed up by links to forum threads that say little without some accompanying explanation as to why they support your point of view. Thank you
     
    #18 Black Octagon, Jan 8, 2013
    Last edited: Jan 8, 2013
  19. Elcs

    Elcs Diamond Member

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    I've started using RadeonPro's SMAA injector for almost everything I'm playing right now. It definitely improves the looks of things to my eyes.

    I'm very glad I stumbled across this thread as I've been trying to decide what kind of AA options to use for what games and in what situations. This thread will become very useful :)
     
  20. railven

    railven Diamond Member

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    Something important to note is that TXAA has to be supported by the game, and I believe there are about 4 or 5 that support it at this point.

    I actually like how AC3 looks with TXAA, possibly because that game benefits from no crawlies (so many trees!) and the experience is already more cinematic than an FPS (to me at least.)