Ok, Ill try to explain Anisotropic filtering as I understand it.
Im sure someone will correct me if Im wrong on something.
Ok, distant objects in 3d games are drawn with less detailed textures called mip maps, since they are too far away to see clearly anyhow.
The further away the object, the smaller & less detailed the texture(mip map) has to be.
Now with standard bilinear mip map filtering , the textures are smoothed out to give a better appearance, but you can see a slight but definate "change"
in the texture resolution where the smaller mip maps begin to appear & meet the higher rez mip maps. (ie: theres a noticeable drop in texture quality where the the less detailed textures meet the higher rez textures)
Trilinear filtering elimates the sudden change where the high rez textures & the low rez textures meet by "blending" the textures (mip maps) together to make the texture resolution change less noticable.
But with bilinear & trilinear filtering turned on, textures on objects that are at an angle to the camera tend to lose detail & look "blurry".
Thats where anisotropic filtering comes in.
Anisotropic filtering takes the angle of a texture into account & redraws the textures with appropriate changes to eliminate the "blurriness".
Anistropic filtering can also eliminate texture "shimmering" where distant objects seem to have a "noisy" appearence. (i hope that describes it right, its tough to describe without pics or actually seeing the "shimmering" effect in motion.
As far as the different settings for anistropic filtering. 2x, 4x, 8x
Im gonna speak from my experience experimenting with these settings in Nascar2002.
From what ive seen, the numbers indicate how far from the player the anistropic filtering takes place. (in front & to the sides of the players view)
At 2x anisotropic I can see a noticeable drop in texture resolution 2 rows of cars ahead & in the grandstands. (3 rows of cars ahead are blurry as are the grandstands especially when a car is viewed from an angle IE: youre in the bottom groove & the other car is in the high groove)
At 4x anisotropic filtering the drop in texture resolution is like 6 rows ahead & the grandstands are alot less blurry.
This looks alot more realistic in Nascar2002 as it seems to stop drawing the high rez textures at a normal distance from the players view.
Cuz like in real life, distant objects are not as sharp as objects directly in front of you.
At 8x anisotropic filtering, all distant oblects & grandstands have a nice "sharp" detail to them, but it does look a bit unrealistic due to the fact that in real life
distant objects are'nt as clear & sharp as objects right in front of you.
To be honest I have Anisotropic filtering disabled in Nascar2002 & I use Mip Map LOD bias settings to eliminate the blurriness cuz theres just to much of a performance hit in N2k2 with anisotropic filtering enabled. (I use rivatuner to adjust the mip map LOD)
As far as FSAA, I currently only use 4x FSAA in Nascar2002 at 1600x1200 cuz even at that resolution, the tops of the walls on the track tend to have jaggies.
2x barely improves the jaggies at all.
And quincunx seems to "blur" everthing on the screen, even the text in the game menus.
Other games Im currently playing like MOHAA & Jedi KnightII at 1600x1200 there seems to be no need for any FSAA whatsoever cuz the games look much better without any
"blurriness" that FSAA causes.
So, YES I use FSAA, but only in certain games cuz it helps some games look better, yet it "filters" the texture details to much in other games for my liking.
BTW: Im using a Visiontek GF4 Ti4600.