What is AA?

WHat is AA, what does it do? I have seen Level 1-8 then 4x,8x and 16x... I dont get it...

 

Anti-Aliasing. it improves the quality of computer graphics by re-computing the way fine lines (or similar stuff) is displayed. see the image for what i mean. the top pic is without AA, the bottom is with AA.



oh yeah, the higher the number you choose (x2, x4, etc), the better the re-computing will be, but the harder your GPU will have to work.

 

Huh, I always thought it was Alcoholics Anonymous! Silly me... hehehe

 

hahaha, good one!!!

 

^ *cough*

http://www.tweakguides.com/Graphics_11.html

 

thanks again whizzo!

 

It reduces jagged lines. It really helps with image quality, but it's also quite demanding on you GPU.

Here are some comparison shots from NVIDIA's website:

 

huh, i'd've thought Nvidia could do better than that..

 

Yeah, very poor choice of screenshots lol.

 

yup. especially on the bottom pic - i can barely see a difference, i must admit.

 

AA is not really useful if your graphics card can barely render the game with recommended settings.

Generally I don't turn on AA unless I knew my graphics card can run the game on all high with perfect FPS.

 

When you can max out a game at max res and get 60+ FPS, you can get 2x or 4x AA. If you get over 100 FPS, use 16xAA.

 

i like how the first pic with the eggs you can definitely see the lines sharper on the bottom but the overall picture is blurrier than the above one lol

 

Unless you are running the source engine or you have a 256bit gpu, forget about AA, raise the resolution instead.

 

very true ....

 

Yeah, it looked more like Photoshop's Gaussian Blur rather than AA. Someone got lazy lol.

 

In practice, enabling AA in games essentially makes the game draw the image at a higher resolution than is being displayed, then has it shrink it down to the display resolution. By doing this, each pixel represents an average of a larger image rather than a single data point – which can lead to an increase in image quality (esp. noticeable on jagged linear objects.)

As everyone already said, though, you’d be better off just displaying the higher resolution in the first place. The only real reason to enable AA is if you have more headroom after reaching the maximum resolution that your monitor is capable of.

 

Actually, your a bit wrong. That is the old method of AA called Super sampling.

All new video cards since 2006 use MSAA, which does not use this method, and takes a far less hit than AA used to.

Here's some screenshots I took. There's a few things that you should note.




first picture is with no AA, second with 8xMSAA (ATI/AMD HD 4850)

Note that the reflections in the water still have jaggies because the methods of anti aliasing used today apply smoothing to the edges after the image is rendered. The resolution used was very low, when the resolution is higher, say something like 1680x1050, or greater, aliasing is far less noticable. None of this will really matter anyway in the next few years since 4xMSAA is mandatory in DX10.1 and thus is mandatory in DX11 and all future directX DX11 games.

 

Cool - thanks for the correction.

 

Some games need AA much more than others to look good. The low poly shooters seem to be the games notice the most where AA is needed since you have so may things like walls/guns/fence's ect that are jagged.

The game engine determines this a lot too Hallife 2 is going to be much worse than say Doom 4.

Also if your playing in a high resolution it doesn't seem to be needed as much. Playing 1280x800 and scaling it up is more of a candidate for AA than 1920x1080 is native.

I always crank AF up all the way, no texture filtering looks worse than "jaggies" and AF is easier to render. If the system allots for it without hurting performance I use 2x AA. I find no AA --> 2 AA makes a huge difference if the game needs it, while increasing the AA level higher from there is a very strong diminishing returns effect. It gets much harder on the system but the visuals hardly improve.

 

Assassin's Creed is a game that needs AA, and a lot of it, to look good.

 

Wait, so what's the difference between the standard AA and MSAA? Like in GRID there's MSAA 2x and Level 1 AA for example.

If I were to use the highest resolution in a game, then I wouldn't use AA but turn up the AF setting up high.