Noob Question

I know what AA and AF stand for, I just have no idea what they do. Could someone explain this to mean, preferably with in game descriptions and examples?

 

AA= anti aliasing. It makes sure everthing in the game looks to detail.

If you examine it closely, since everything is made of pixels, it looks like a stair case. Anti aliasing helps close that, by tracing a line through it.

That's not a complete definition, but it's basic.

I'm not sure of AF though. I forgot, sorry. XD

 

AA stands for Anti-Aliasing. It helps reduce the appearance of "jaggies". If you have ever noticed the stepping on diagonal edges, this is what helps reduce them.

AF stands for Anisotropic Filtering. It makes textures that are a certain distance from the camera look better, instead of them being lowered in quality to raise performance.

Both of those links will do a better job explaining it than I can, and can show you pictures of what your asking about. Both options can also cause a considerable drop in your FPS during gameplay.

Edit: This page has some in-game shots that show the difference AA makes. You want to look at the edges of objects to see the difference.

 

This article does a very good job of explaining what AA and AF do (complete with comparison screenshots).

 

Both work in 3D,
AA - Anti-Aliasing basically blurs the edges of 3D objects, to reduce the staircase effect you commonly see in 3D games, especially on LCD's. From what I remember older AA used to draw an image 2x(or 4x - depends on how much you set the AA by) the size of your screen resolution so for 4x AA with a 1024x768 screen your card would actually draw a 2048x1536 and resize it to back, you get the same effect when you resize an image smaller in photoshop. This requires huge amounts of processing as not only are you drawing high resolutions, the gpu also has to calculate how to best blur 4 pixels into 1.

Basically AF - Anisotropic Filtering Sharpens Textures of planes in a 3D game facing away from you, its especially noticable in corridors, the floor moving away from you and curved objects.

 

awesome, thanks for the info and links

 

I never turn on AA, I think it just makes the game less sharp and more blurred. If you play at a high resolution you should leave it off anyway.

 

If you have a card that is powerful enough to use it, or are playing an old game, I think AA is one of the best things going to improve image quality. It's usually the first thing I turn off when settings have to be turned down though, simply because it can be such a phenomenal FPS hog. I'll post (very large) comparison screenshots later.

If I can ever leave the office

 

Without AA: With AA:


Look at the edges of the tree especially, and the difference shows on the buildings as well. The effect is much more noticeable in game because you can see the stepping effect moving back and forth along the edges.

Oddly enough, I got a slightly higher FPS with AA on, but I think thats just one of the many perks of SLI GeForce 7950 GTX's

Also of note is the fact that I had to lower the image quality a bit to get the file size down to something that ImageShack would host

If ImageShack changes the size of the picture to fit your screen, make sure you click on it to enlarge it to full size. Otherwise, JPG compression makes it hard to see the differences.

 

I'm with Amblin: AA offers a huge improvement to image quality. Just to add some more comparison shots (warning, images are 1MB+ to keep the quality up):

Also, once you open the image, be sure to click on it to make sure it's not re-sized.

This pair of screenshots is a good example of what Anti-aliasing can do:
<-- No AA or AF. Pay special attention to the jagged lines on my character's tail, and on the stair steps on the right.
<-- 4xAA and 16xAF. Notice that the jagged lines on my tail and the stairs are gone.


This next pair of screenshots really shows off what Anisotropic Filtering (AF) can do for image quality:
<-- No AA or AF. Notice the ground and the wooden porches get blurry as they go into the distance.
<-- 4xAA and 16xAF on. The textures on the ground now look much more detailed and clear.

Edit: It should also be noted that AA and AF can have significant impacts on your performance (depending on the particular scene). In the first pair of screenshots, my framerate dropped from 30 to 27 (not too bad), but in the second pair my framerate dropped from 33 to 24 (pretty significant).

 

awesome thanks for the screen shots. made everything alot clearer. sorry to ask you to do it again joga, but could you do one pic with nothing, then one with only AA 4x, then the next with only AF 16x and no AA, and then the last with both?