More than 16 tap anisotropic filtering?

[RejZoR]

I've been wondering this for a while, how come we are still stuck at 16x (16 tap) Anisotropic filter even today when we could already have 24x, 32x or even 64x sampling.

I've started wondering this even more when I've noticed a setting in Unreal Engine games where you could input a number of taps beyond 16 without game crashing or anything.

Which makes me wonder, are for example 64 taps actually used and you can't actually see any difference beyond 16x or is the game simply ignoring higher values and still only using 16x filtering.
I was unable to make a comparison because of how that game works so maybe someone who knows Unreal Engine 3x

 

[spectatorx]

The only game which i know is possible to be forced to use more than 16x af samples is brothers a tale of two sons and it can use up to x32 samples of anisotropy filtering. This i know from this site:
http://pcgamingwiki.com/wiki/Brothers:_A_Tale_of_Two_Sons

I have no idea how it is with other ue3 games. Brothers is made with ue3 so natural assumption would be "other ue3 games can do the same" but from my experience it is not so obvious. For example let's take borderlands series. Whole series is made with ue3, in first game you can enable msaa up to 16x samples but in borderlands 2 and pre-sequel it is simply not working anymore even if such setting is available in .ini files like in any other ue3 game.

 

[RejZoR]

Hm, I'll have to check this out. Gotta find a map that has an open spawn area so I can make consistent comparisons when map loads.

Mostly because 16x Aniso is so freaking cheap, so why not use something higher.

 

[spectatorx]

Agree, in most games x16 samples is not taking fps at all so i do not understand why not to extend it with more samples. I've heard in assetto corsa af drops fps a lot but personally i didn't find it to be the case on my hardware (fx-8320+r9 380).

Anyway, currently a lot companies prefer to give to players sick options of aa (for example ssaa x16) instead of providing more options for anisotropy filtering. BTW, current hardware and software, both, are limited and can't render 4K with 16x ssaa.

 

[vega22]

i think nv tested it upto 128 in beta drivers a few years back and it wasn't noticeable.

but res ftw.

 

[Aquinus]

The question isn't if a graphics card can do more than 16 samples, the question is if there is really any reason to do more than 16 taps of AF. Consider for a moment that AF is supposed to improve the quality of textures as weird angles in relation to the camera, add some distance and it gets worse. There does come a point where there are only so many pixels you can work with on the screen and you can only improve the quality of a texture so much before extra samples are wasted (no improvement.) I would argue that there are a lot of cases where scenes don't even need 16 tap AF and would look just as good with 8.

My point is that higher than 16 in most cases probably will have incredibly limited benefits where even 16 doesn't benefit every scene. You would probably get better benefit from higher resolution textures than you would from higher AF levels because AF only is as good as the textures that are getting filtered.

 

[Vayra86]

The question isn't if a graphics card can do more than 16 samples, the question is if there is really any reason to do more than 16 taps of AF. Consider for a moment that AF is supposed to improve the quality of textures as weird angles in relation to the camera, add some distance and it gets worse. There does come a point where there are only so many pixels you can work with on the screen and you can only improve the quality of a texture so much before extra samples are wasted (no improvement.) I would argue that there are a lot of cases where scenes don't even need 16 tap AF and would look just as good with 8.

My point is that higher than 16 in most cases probably will have incredibly limited benefits where even 16 doesn't benefit every scene. You would probably get better benefit from higher resolution textures than you would from higher AF levels because AF only is as good as the textures that are getting filtered.

This, and only this. If someone can provide me screenies of the difference between 8 and 16x AF, I'll happily spend a few days gazing at them to find those differences.

Higher AF is about as relevant as the x64 tesselation factor Nvidia pulled in TW3.

 

[newtekie1]

Higher AF is about as relevant as the x64 tesselation factor Nvidia pulled in TW3.

That wasn't nVidia, that was the developer of the game.

 

[Vayra86]

That wasn't nVidia, that was the developer of the game.

No it was a Hairworks 'optimization' that is side-coded by Nvidia teams that come visit devs.

The tesselation factor was chosen on the basis of Maxwell Tesselation performance, and as can be clearly seen, anything pre-Maxwell struggles. Turn it off and you've got playable frames on Kepler.

On release, GTX 770 @ 1080p with hairworks on managed about 18 fps. With it off, you'd jump to 25-30 on ultra. Later they added several quality levels to Hairworks. They really wanted everyone to buy a 970.