I don't believe sparse sampling does quite that much for you. This is definitely falling into the region where the angles at which 6x sparse looks poor should be more noticeable than those where 16x ordered looks poor.Ailuros said:Even with 16xOGMS you fall behind in terms of edge quality compared to a 6x sparse sampled grid.
That's very true, thanks a lot for remembering me of that! It's so simple I'm ashamed I didn't realize it myself...Chalnoth said:One quick note. If I remember correctly, a logarithm is always taken of the result anyway. This means, to me, that the square root is a trivial operation: if done after the logarithm, it becomes a simple division by two. It's just an aside, but worth thinking about if one is interested in how hard it is to actually implement the above operations. The most expensive thing about doing the full operation is squaring the partials (Another aside: I suspect that a large portion of the performance problems associated with nVidia's anisotropic come down to this selection issue).
I don't believe sparse sampling does quite that much for you. This is definitely falling into the region where the angles at which 6x sparse looks poor should be more noticeable than those where 16x ordered looks poor.
Yes, that does make sense. But the resolution difference would be much, much more significant.Ailuros said:Yeah I missed to mention little important details like bandwidth and resolution. Inevitably a 6 sparse grid MSAA allows you much higher resolutions than 16xOGMS will (all concentrated on the Z units/bandwidth current high end hardware has).
(1024*4) * (768*4)
vs
(1280*6) * (960*6)
Just a simple example.
Anyway, I would like to say that when somebody says, "when looking at so and so," I tend to just consider that effect, not any secondary effects (in this case, texture AA and performance).
All effects are relevant in the end result.Ailuros said:I'm not so sure what you really mean with "secondary effects" especially when it comes to performance.
Performance has all the relevance in the world when it comes to comparing different kind of implementations, especially if there's supersampling involved.
It is that irrelevant in reality
I think in this case it's probably due to the use of 8xS, which makes use of supersampling, and therefore will increase texture clarity across the entire scene.Randell said:just a small question.
Why do the guns in nVidia screenshots always look better than the ATI screenshots?
Totally irrelevant to the perfromance trade off comparison here, but its been noticed a lot. Its not down to LOD bias is it?
Randell said:just a small question.
Why do the guns in nVidia screenshots always look better than the ATI screenshots?
Totally irrelevant to the perfromance trade off comparison here, but its been noticed a lot. Its not down to LOD bias is it?
I think in this case it's probably due to the use of 8xS, which makes use of supersampling, and therefore will increase texture clarity across the entire scene.
A. 16-degree anisotropic filtering will only have an effect on surfaces that are angled at greater than an 8:1 ratio in some direction. The vast majority of surfaces are not. Supersampling affects all surfaces, allowing for more aggressive LOD without aliasing.Ailuros said:I think in this case it's probably due to the use of 8xS, which makes use of supersampling, and therefore will increase texture clarity across the entire scene.
Niet
The 2nd shot has 16xAF.
Aliasing is notoriously difficult to pick out in static screenshots. You typically need regular patterns to pick out aliasing. So, in essence, you may be right, but I wouldn't bet on it.Eolirin said:Is it just me or is the nVidia shot *more* aliased on certain angles than the ATi one?
I would bet on it.Chalnoth said:Aliasing is notoriously difficult to pick out in static screenshots. You typically need regular patterns to pick out aliasing. So, in essence, you may be right, but I wouldn't bet on it.
Eolirin said:Is it just me or is the nVidia shot *more* aliased on certain angles than the ATi one?
Supersampling affects all surfaces, allowing for more aggressive LOD without aliasing.
4x supersampling (as is used with 8xS) achieves essentially the same effect, for high-angle surfaces, as doubling the degree of anisotropy. Thus, for surfaces that would use 16-degree anisotropy on the Radeon, the GeForce FX's 8-degree anisotropy + 4x supersampling achieves similar results.
Anyway, look closely at the rough part at the top of the gun. I get the impression that the FX picture is very slightly more clear, which would be in line with what is expected from supersampling.
I don't feel supersampling is a good use of computational resources.
Sorry, for some reason, I was thinking of texture aliasing.Althornin said:I would bet on it.
Static screenshots like the pinwheel type that we have seen in several reviews show that ATI's 6x has better edge quality than nVidias 8x
Sorry, didn't notice that. Yes, on any surface at higher than 2-degree, the ATI card should be showing better texture clarity (except for those angles which the ATI card's aniso algorithm is poor...). I don't know what degree that part of the gun I pointed out is, but chances are it's under 2-degree...Ailuros said:A= 8xS/ no aniso
B= 4x MSAA/16x AF