NVIDIA TXAA Brings Movie CGI Rendering To PC Games

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The following two videos give you an apples-to-apples comparison of how each anti-aliasing method looks in-game. We recommend viewing in full-screen and HD mode, as the smaller video player view can obscure some of the differences.




Texture shimmering in both of these cases is pretty bad. It's enough to be distracting during normal game play, particularly on the light poles and the streetcar rails. Thin, sharp lines flicker, and in a cityscape, those sorts of lines are everywhere.

So here's how TXAA resolves it.



If you're comparing to the first videos, check the streetcar rails, the light poles, and the red car.  As we move into the alley, check the bike stands on the right-hand side. 2x TXAA really looks good here; it eliminates most of the shimmering we noticed previously without significantly blurring the scene. The GeForce GTX 670 we tested on had no problem keeping the frame rate around 50fps at 1920X1080 resolution.

The blur that we've mentioned isn't just an byproduct of the AA method -- it's designed to mimic how Hollywood incorporates CGI with real-world footage. Timothy Lottes, one of the TXAA designers, has an extensive blog post on the topic, along with side-by-side shots of how the eye interprets subtle blurring as presenting a more realistic image.

The Not-So-Final Verdict:

With just one game to examine and no way to force TXAA in games that don't explicitly support it, it's hard to call whether the technology will catch or not. Historically, specialized graphics functionality that's only supported by Nvidia or AMD, but not both, hasn't done particularly well.

We suspect TXAA's long-term popularity will hinge on how easy it is to support and whether or not the upcoming crop of game engines are capable of using standard MSAA. Game developers are used to supporting Nvidia-specific AA modes like CSAA. If TXAA requires a similar level of optimization, it may catch on quickly.

We're optimistic about TXAA's long-term potential. Image output is superior to 4xMSAA and the temporal component works well. Nvidia has chosen to keep TXAA as a Kepler-only feature for now, which may slow its market growth, but The Secret World demonstrates that there's a place for this technology. Hopefully next time it appears, we'll be able to compare it directly against MSAA.

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Comments

Comments
Jaybk26 2 years ago

Ok, that's pretty sick. Does anyone know what the entry level video card with this costs?

RTietjens 2 years ago

If you have to ask, you can't afford it.

marco c 2 years ago

Check back tomorrow morning. The answer right now and the answer after tomorrow morning will be different...

CDeeter 2 years ago

Now if that isn't a teaser statement, I don't know what is. lol

Jaybk26 2 years ago

Lol, is this going to be one of the "slick deals?"

CDeeter 2 years ago

Ok it's the next morning, what's the answer? lol

marco c 2 years ago

Here's the answer: http://hothardware.com/Reviews/NVIDIA-GeForce-GTX-660-Ti-Round-Up-MSI-EVGA-Gigabyte-Zotac/

Joel H 2 years ago

While I appreciate the compliment, Marco does a good job handling GPU reviews. He's also got far more equipment on hand than I do and can offer a better sense of how different GPUs compare in any given product. 

I prefer to focus on narrower considerations or features; full-frontal deep dives aren't so much my thing. If there are features or games that you want to see tested, speak up -- you'll find us receptive to such things. :) 

mernerion 2 years ago

looks like its going to cost you but probably give you a run for your money.

CDeeter 2 years ago

It does appear to work very well, hopefully they can enable this for more of their cards.

shadizzle 2 years ago

Thats pretty slick for sure, I am curious to see how upcoming titles look with this and a little refinement.

nicoletoledo 2 years ago

Damn. Thats awsome. Imagine if all games are like that (ofcourse pc games) not like console games can. Drool

Erakith 2 years ago

got a 680 on its way.. can't wait to take advantage of this.

enprim22 2 years ago

It does appear to work very well

kidbest100 2 years ago

Anyone else see the "Tesselated toad" on the Crysis 3 Trailer? I bet it would look even cooler with TXAA ;) ( If it isnt already)

sarah.a180 2 years ago

Nice overview, but I'm afraid that you're mistaken when you claim that FXAA is somehow not "true" anti-aliasing. I would suggest you study up on the mathematics of frequency-space representations and filtering before you try to argue against the engineers at NVIDIA.

Aliasing is a patterning artifact caused by high-frequency signal components interacting with a low-frequency sampling space. Anti-aliasing is *any* technique that filters out these high-frequency artifacts. There is no such thing as perfect anti-aliasing: all real low-pass filters are approximations. (Even if a perfect low-pass filter were possible, you would not want to use it for graphics because its non-locality would cause undesirable ringing artifacts.)

All real anti-aliasing filters involve trade-offs between

* aliasing (failure to remove frequencies above the sampling cutoff),

* ringing (caused by frequency truncation),

* excessive blurring (failure to retain frequencies just below the frequency cutoff), and

* complexity (because compute time is finite)

Supersampling is an approximation. So is the box kernel that is typically used to down-sample from the supersampled representation to the traditional one. Coverage-sampling and z-buffer-only supersampling (MSAA) techniques are, in many ways, a bigger compromise than those of FXAA: traditional MSAA looks terrible if not combined with good texture filtering, which is another anti-aliasing technique. The linear texture projection used in texture filtering are another approximation of true texture transforms, and not that great an approximation. (Anisotropic texture filtering is still a linear interpolation technique.)

FXAA is just a different (and far more sophisticated) approximation to a low-pass filter. Because it is a full-screen technique, it outperforms MSAA in many ways. It has slightly more blurring and doesn't do a good job with temporal aliasing, but it is vastly superior at removing aliasing due to transparency or small features—all at a radically lower cost. Most people should probably be using FXAA instead of MSAA in many games unless they already hit 60 FPS with all the effects they want enabled, especially if you are running in 1080p where the extra blurring is negligible. The only real drawback to FXAA is its poor ability to handle temporal aliasing (thus we have TXAA).

Let's try to put a stop to the false dichotomy that FXAA is "blurring" and MSAA is "true anti-aliasing." It's completely false. If anybody is looking for a good introduction, Jim Blinn's "Dirty Pixels" is a great introduction. (And if you don't know who Jim Blinn is, you probably shouldn't claim to know much about computer graphics.)

Joel H 2 years ago

Sarah, 

A full explanation and comparison of FXAA / SSAA / MSAA was beyond the scope of this article. Nevertheless, I read Intel's original FXAA/MLAA whitepaper, spoke extensively with Timothy Lottes at Nvidia, and consulted additional research materials. FXAA is a different approach to the aliasing problem and it utilizes different GPU resources. It's also an approximation by the literal meaning of the acronym. 

Also? Let's avoid the e-peen. "If you don't know who Jim Blinn is, blah blah blah." That's like claiming you can't possibly understand Ron Paul if you haven't read John Locke. History and context give additional data points, they are not required for accurately processing the difference between various AA methods. 

FXAA/MLAA does no sub-pixel sampling. Later versions of FXAA at NV have attempted to reduce the pixel 'snapping' distraction. The advantage of FXAA is that it's fast and can be run on cards that can't handle standard antialiasing. 

Being able to extend AA capability to mobile devices or handheld gaming that wouldn't otherwise see any antialiasing capability at all is good. I daresay that games designed explicitly for FXAA can take steps to reduce the pixel snapping issues. There's evidence that FXAA works fabulously on a cell-shaded game like Borderlands, for example. 

But if you're a user who hates jaggies -- and I am -- FXAA is a joke. Every AA method is a balance of compute time, end visual quality, and speed. When I can afford to, I opt for 4x sparse grid supersampling, or 8xMSAA with supersampled transparencies. The only way most modern games can handle that is if you use SLI -- which again, I've often done.

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