Radeon 9700 gamma corrected AA

Looks like someone finally did antialiased sample weighting the right way! Has anyone used this, is there a second gamma factor or does it make an assumption about the monitor gamma response? How is the supsample gamma factor controlled?

"SmoothVision 2.0 - Now with gamma correction and Anisotropic Filtering for free

In addition, ATi has improved on their SmoothVision engine for Anti-Aliasing and Anisotropic Filtering. SmoothVision 2.0 utilizes a 2X, 4X or 6X Multi-Sample AA approach but also includes a new gamma correction technique. In addition to sampling jagged image pixels in a given scene, the Radeon 9700’s SmoothVision engine also adjusts gamma correction for those samples when they are applied and it determines the best color uniformity for each pixel. ATi claims this will produce superior AA image quality compared to anything on the market. "

thats sweet as well…:

… about the fsaa and anysotropic. how it looks, well, we’ll see (at least i, soon… someday ), but about the “for free”:
well, there is a drop, but its quite okay imho. if you think about how much more samples are done perpixel…

[This message has been edited by davepermen (edited 08-20-2002).]

I’m very impressed by the Radeon 9700. I have yet to find any weak spots on it. Massive performance lead, especially with AA and anisotropic. Not to talk about the quality of the AA.

I find these shots from the hothardware review quite telling:
GF4 4X

Parhelia 16X

Radeon 9700 6X

The difference really shows at the windows in the upper right corner which looks perfectly clean on the R9700 but kinda aliased on everything else. There’s a slight difference in viewing angle though between the shots, but it shouldn’t make that big difference.

Edit: Corrected 4x to 6x on the R9700 link.

[This message has been edited by Humus (edited 08-22-2002).]

haha, gf4 4x looks CRAPPPPPPPPPPPPP

I have yet to find any weak spots on it

Well, it’d be nice if the higher pixel precision lasted all the way through to the framebuffer. I’m pretty sure the it can only be 10 bits per component. I don’t know if this is true about the 9700 (correct me if I’m wrong, it was hard to get exact info out of the ATI guy I talked to at Siggraph…I have at least two conflicting reports about 9700’s precision from him) but I believe that sometimes cards with 10 bits per component do 10-10-10-2, so they skimp on alpha. I think Matrox Parhelia works like that.

Also, I think branches and loops in the programmable parts of the card would be nice.

Correct me if I’m wrong about any of this, though! I don’t have the patience to wait for ati.com to load so I haven’t spent much time reading anything official.

– Zeno

Originally posted by Zeno:
Well, it’d be nice if the higher pixel precision lasted all the way through to the framebuffer. I’m pretty sure the it can only be 10 bits per component.

Isn’t it only 10bits/Channel on the RAMDAC? (with the framebuffer being the full 32bit float/channel)

The floating point pixels don’t need to survive all the way to the framebuffer. All calculations can be done with floating point by rendering to offscreen buffers ( dithered to 10 bits per component when the final image is to be displayed ).

Regarding the AA - I really don’t see that big a difference in quality between the three cards. The GeForce4 has high quality AA and with moving images, who’s going to notice small artifacts.

haha, gf4 4x looks CRAPPPPPPPPPPPPP

I think you’re being a bit harsh. I cant find any significant differences at all.

I think the windows look better on the GF4. The AA on the new radeon is alot better, but we dont know what type of AA they used on each card.


Regarding the AA - I really don’t see that big a difference in quality between the three cards. The GeForce4 has high quality AA and with moving images, who’s going to notice small artifacts.

I agree. I think the whole anti-aliasing thing is overrated. I’ll take anisotropic filtering over anti-aliasing anyday, and I’ll even be able to notice it when I move around.

– Zeno

The only place I could really tell a difference is on the stairs. You get the classic example of aliasing on the other two cards, but the ATI looks better than I’ve ever seen. But, when somebody is coming after you with a gun like that, who has time to admire the stairs :slight_smile:

The underside of the gangway, where it contrasts with the sky, also shows rather worse for the GF4 than for the Parhelia or the 9700.

Also, the ceiling lights in the entranceway on the left look bad on both GF4 and Parhelia, but OK on the 9700.

On the other hand, what do you expect? The GF4 is a LAST generation card. I mean, you’ve been able to actually BUY it – for MONTHS!

[This message has been edited by jwatte (edited 08-20-2002).]

they have 96bits per pixel in the pixelshader => 24bits per component

they have a full 128bits per pixel framebuffer

and we could start the debate (==flamewar):

you’re BLIND if you don’t see the difference in the aa all over the image (edges )…

well, i see them, very good… the others just look so jaggy…

but i know of much people who haven’t even noticed ANTIALIASING at all…

its like the ones that can hear the difference between 320kbits mp3 and original cd … (i can hear the lost quality! i can HEAR IT! )

I had another look at the images and I can see the Radeon 9700 image looks far better that the others ( around the spherical base of the sculpture ).
Still, with animations I doubt anyone is going to notice the differences.

I can clearly see the difference between AA and no AA but I can’t see the difference between 2x, 4x, quincux, etc when moving around. Maybe others can ?

Anyway, I think the 9700 is one excellent GPU with a lot of great features ( and still able to perform well ).

Ok, I lined the images up in two different browser windows and flipped back and forth between them and I can tell now that the 9700 is much better at anti-aliasing.

I’m not sure if I could tell which card I was playing on, though, if I were to take a blind test without seeing the other one next to it.

One other interesting thing I noticed is that some of the coloration is different between the two pictures. For instance, if you look at the wall at the top right of the stairway, it is much darker in the 9700 image than in the gf4 image. Food for thought

– Zeno

FSAA sucks if you ask me. Each pixel gets the color from its neighbor, no matter what the algorithm is, and even if it gives the illusion of smoothness, the image is no longer what it was ment to be. It’s kind of like jpeg compression.

It’s much better to have higher resolution screens than FSAA. At the very least, they should attempt edge-AA

Try this if you don’t see the difference. Take snap shot of the upper right picture of the guy. Go into photoshop or whatever, and substract.

What we really need is smaller phospors on the screen, more video memory and higher resolution (say 4000x4000). More colors (12 bit per component perhaps)


well, vman, you’re just plain wrong… edges still get jaggy, and indepenend on resolution, the jaggyness is easily visible…

why does a dvd on the tv, like shrek, look far more detailed than any game on 800x600? its not the resolution… its just that there is more detail perpixel…

and they don’t get the pixels from the left, the right, etc… they DO render the screen in a higher res, and downsample it (directly, in hw, on my gf2mx its done in software => ultrahighresrendering, then sampled down with a box filter)…

so its the same…

the amount of pixels on the screen are enough.

I think the fact that people are having to line images up side by side in browsers and squint, speaks volumes about the value of fsaa. It’s an easy feature to implement, and is just something more to put on the box blurb.
The only time fsaa is valuable is when you’re operating at low resolutions, in say a VR headset, when the jaggies are actually apparent. Most people operate at 1024x768 or above, and do not notice jaggies.
FSSA would certainly not even be in my equation when choosing my next card.
And I have good eyesight

well if the images are animated, i normally see it even more…

scenes of quake are stupid to show it, take some modern scenes, with grass and trees with much leaves and everything. there you can see the aliasing even on high resolutions very much, if they are for example moving in the wind. (see the new cg demo of nvidia, without fsaa4x it looks terrible jaggy, even on 1024x768…)

thats why fsaa is here, to smooth edges. now q3 normally doesn’t have much edges, but a lot of huge flat polygons. they need anysotropic filtering…

Originally posted by knackered:
It’s an easy feature to implement, and is just something more to put on the box blurb.

I wouldn’t be so sure about that, as we have seen several different FSAA schemes from different vendors lately but all tend to have some kind of weakness, either not good enough quality, not good enough performance, compatibility problems or something else. The Radeon 8500 for instance has a serious performance hit by enabling FSAA, and the quality improvement isn’t good enough to justify it, thus I’ve always left it off. While I’ve been able to survive so far without a good FSAA scheme it does get increasingly annoying looking at aliasing artefacts at all resolutions (yes, even at 2048x1536!). I’ll certainly value a good FSAA scheme in my next video card purchase.

I don’t agree, so obviously it’s very subjective.