What does Anti-Aliasing Do?

[HFS+]

I see this term used a lot for people that run on max settings. Just wondering what does it do as a setting / why is it used / (etc)..

 

[n7]

It smooths out the jaggies.

 

[irishScott]

The higher the anti-aliasing, the smoother things look. I could attempt a technical explanation but there are others more qualified on this board.

 

[Cerb]

http://en.wikipedia.org/wiki/Anti-aliasing

The best visual there is by far these, viewed in order:
http://en.wikipedia.org/wiki/File:Mandelbrot-spiral-original.png
http://en.wikipedia.org/wiki/File:Mandelbrot-spiral-antialiased-4-samples.png
http://en.wikipedia.org/wiki/File:Mandelbrot-spiral-antialiased-25-samples.png
http://en.wikipedia.org/wiki/File:Mandelbrot-spiral-antialiased-400-samples.png

 

[Sulaco]

A picture is worth a thousand words:

Here's an article that might help explain it.

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

 

[TakeNoPrisoners]

It is a setting where the video card attempts to get more information about the edges of polygons and ends up smoothing out the edges using that information.

Instead of seeing jagged lines, you see a smoother picture.

The most common type of AA only works on polygons, to smooth out things like fences you need a different type of AA.

 

[wuliheron]

Antialiasing is a way of compensating for pixelation, the Lego-like look of low resolution digital pictures. In modern video games pixelation is often noticeable as the "jaggies" where what are supposed to be smooth straight lines look more like saw teeth. At resolutions about 4 times higher then high definition the jaggies and pixelation become too small to see, but then you need a computer powerful enough to process all those extra pixels.

 

[imaheadcase]

Its a setting that is based on personal appearance, most people don't notice jaggies, others just look for them in the game all the time so they can enable AA and praise how great it is.

 

[PrincessFrosty]

Anti-Aliasing is a function to reduce the effects of Aliasing.

Aliasing is a side effect of rendering a 3D scene on to a 2D monitor which is built up from many small square pixels. What happens when you draw diagonal lines on a grid is you get a sort of stepping effect, often referred to as "jaggies" because edges are jagged rather than smooth.

Pixel colour on the screen is decided by sampling the appropriate surface in the 3D scene like for example a brick wall, with a normal render only 1 sample of the wall is taken to decide each pixels colour, with increased levels of anti-aliasing more and more samples are taken for each pixel and the result is an average of those samples.

Other methods of AA exist such as simple blur filters which consoles tend to use and the newer post-processing methods of AA used today like MLAA. Also Super Sample Anti-Aliasing which essentially renders the scene at twice the resolution and then downscales the result.

 

[Lonbjerg]

Its a setting that is based on personal appearance, most people don't notice jaggies, others just look for them in the game all the time so they can enable AA and praise how great it is.

[citation needed]

 

[BFG10K]

Moved to video forum, Super Moderator BFG10K.

 

[d3fu5i0n]

In short, but slightly descriptive, the displayed image [game output - each frame] has pixes generated - many of which noticeably seem to be "jagged". Due to the desired representation of smooth lines having to run across pixels, when in a diagonal manner [not on a direct horizontal or vertical line], they will seem jagged. A colour is generated that blends inbetween both of the colours that produced the aliased image. When this is applied on several pixels by these lines, it produces a smoother and softer image to the eye. This is then anti-aliasing.

I could go more into depth, but you appear to be looking for a basic description. That's what it is, and slightly as to how it works [I don't think I said anything incorrect].

 

[lavaheadache]

Its a setting that is based on personal appearance, most people don't notice jaggies, others just look for them in the game all the time so they can enable AA and praise how great it is.

not sure if you are serious of if this is a trolling post.

Either way your comment is going to start a huge debate.

I don't know how you say most peope don't notice it but even people who only have played pong know what the "jaggies" are.

AA is one of the greatest things to ever grace video gaming.

 

[ArchAngel777]

Its a setting that is based on personal appearance, most people don't notice jaggies, others just look for them in the game all the time so they can enable AA and praise how great it is.

Well, I agree with you that it is based on personal preference. However, the majority of people [not just enthusiests] would notice the difference. I think Anti Aliasing was one of the greatest features ever added. Vsync is also another feature that is a must in my opinion.

 

[imaheadcase]

I don't know many people who play with AA on, since most people don't have huge fancy setups..aka the majority of people they don't have it enabled, in fact most games default to it OFF, including vsync.

When i had my "old" gtx 460..still a decent card, used by a lot of people, games did not use AA simply because it took a HUGE hit.

I don't notice Jaggies in the game at all, most people don't simply because the mind filters them out when you play a game.

That is the citation you need.

 

[lavaheadache]

ok, well my mind doesn't filter them out. I'm not saying that I need to have 8X AA on at all times but I have to atleast use some token 2X AA, but I like to run 4X AA if I can manage it.

 

[lavaheadache]

Well, I agree with you that it is based on personal preference. However, the majority of people [not just enthusiests] would notice the difference. I think Anti Aliasing was one of the greatest features ever added. Vsync is also another feature that is a must in my opinion.

I too am a huge fan of vsync. Getting a 120hz monitor was good because even without vsync the image has far less tearing than normal.

 

[lavaheadache]

I don't know many people who play with AA on, since most people don't have huge fancy setups..aka the majority of people they don't have it enabled, in fact most games default to it OFF, including vsync.

When i had my "old" gtx 460..still a decent card, used by a lot of people, games did not use AA simply because it took a HUGE hit.

I don't notice Jaggies in the game at all, most people don't simply because the mind filters them out when you play a game.

That is the citation you need.

You know, I just thought of something. I'm a car guy. I can pick cars off from great distances. I notice fender gaps of cars going by on the other side of the highway and think damn, that car needs to be lowered or those are some sweet rims.

I point stuff like that all the time yet other people could have a line of Lambo's cross in front of them like a funeral procession and not even know it happend.

I coined the term as ATD. Attention to Details syndrome

 

[SlowSpyder]

I don't know many people who play with AA on, since most people don't have huge fancy setups..aka the majority of people they don't have it enabled, in fact most games default to it OFF, including vsync.

When i had my "old" gtx 460..still a decent card, used by a lot of people, games did not use AA simply because it took a HUGE hit.

I don't notice Jaggies in the game at all, most people don't simply because the mind filters them out when you play a game.

That is the citation you need.

I used to be a lot like you in this regard, I never used AA because of the performance hit, and to me things looked ok. Then I got a 5870 and had enough horsepower and video memory to start turning on AA. Once I got used to it I could not go back, it was so much more noticeable than before.

I was the same way with DVD and VHS. DVD was clearly better, but not a night and day difference (I just liked that I didn't have to rewind anymore ). But than after being used to DVD I tried a VHS movie I had, it was hard to watch, the difference was huge. Once I got used to having AA, it was a lot like that, the jaggies stood out quite noticeably.

 

[Pia]

I'd say most people who don't know what aliasing is will not notice it in the sense that they'd stop while playing and say, "hey, there's totally a pixel staircase along that line there". Certainly they'll see it if they are specifically asked about it or presented with a comparison.

Type of content matters a ton.
Half-Life 2 is full of transparent objects with small detail, chain link fences, trees, tree leaves, electric lines. It's also slow-moving and has vistas which the player stops to look at. Same goes for Starcraft 2, stuff often stays put on the screen and there's small detail, therefore AA matters. Visuals in something like Painkiller do not improve much at all with AA.

 

[arredondo]

Since the original question has been fully answered, this won't be a thread hijack. What is the best way to turn on AA for Dead Space 1 (Steam dload) with my card? I know it is not built in, and I already have Radeon Pro which I use for other titles. For some reason I am unclear of how DS1 on Steam should be handled with my 6970 card.

 

[taltamir]

Sulaco's pictures really sell it. Those pictures, that is what AA does.

If you want to know about the different TYPES of AA and how they differ check
http://forums.anandtech.com/showthread.php?p=30995870

 

[Lonbjerg]

Since the original question has been fully answered, this won't be a thread hijack. What is the best way to turn on AA for Dead Space 1 (Steam dload) with my card? I know it is not built in, and I already have Radeon Pro which I use for other titles. For some reason I am unclear of how DS1 on Steam should be handled with my 6970 card.

This thread might educate you a bit
http://forums.anandtech.com/showthread.php?t=2217769

 

[lavaheadache]

Since the original question has been fully answered, this won't be a thread hijack. What is the best way to turn on AA for Dead Space 1 (Steam dload) with my card? I know it is not built in, and I already have Radeon Pro which I use for other titles. For some reason I am unclear of how DS1 on Steam should be handled with my 6970 card.

I know there was a way you could do it with nvidia inspector, dunno if that even works for AMD cards though.

 

[imaheadcase]

I used to be a lot like you in this regard, I never used AA because of the performance hit, and to me things looked ok. Then I got a 5870 and had enough horsepower and video memory to start turning on AA. Once I got used to it I could not go back, it was so much more noticeable than before.

I was the same way with DVD and VHS. DVD was clearly better, but not a night and day difference (I just liked that I didn't have to rewind anymore ). But than after being used to DVD I tried a VHS movie I had, it was hard to watch, the difference was huge. Once I got used to having AA, it was a lot like that, the jaggies stood out quite noticeably.

Well i have SLI GTX 580 at 1900x1200 and don't use AA at all, because like I mentioned i don't notice jaggies.

The DVD vs VHS is different, because that was years leap in picture quality. AA really did not change anything visually to games, since its not a forced thing in games just a option. You could choose between VHS and DVD for a long time