What IS AA?

[pjwinkler]

what is this AA x4 or x8 stuff in games. What does it do, why turn it on/off?

 

[Viper96720]

Get rid of the jaggies. 3-d games is mostly just a bunch of triangles stuck together to make a picture. The more triangles in the picture the more smooth the edges will look.

 

[pjwinkler]

ehat do you mean, if you turn it off it gets a more jagged picture. and when its on it looks cleaner but you get less FPS?

 

[naruto1988]

exactly

 

[Goi]

AA doesn't produce "more triangles", it simply uses an algorithm(different manufacturers implement this differently) to blur adjacent pixels so that the transition is smoother and less jagged. Try it in Photoshop on sharp edges, near vertical/horizontal lines and text to have a clearer view of what it does.

 

[Mrvile]

You can really tell the difference if you run Filtering and AA test in 3DMark05. It lets you play with the different AA and AF levels.

 

[dullard]

A quick search gave this. Look at the zoomed in picture. Notice that the picutre is jagged without AA, and it is semi smooth with AA.

Essentially if you have a good enough resolution, you won't really see the jagged lines. But many times you can't have a high enough resolution, so instead AA was born. The edges of objects are blurred to make the jaggedness appear less noticible.

However you (1) now have a blurry image and (2) introduce a very complex time consuming step. Thus you will get fewer frames per second and more skips in playing games.