What antialiasing is and why its so important

[LadyCrimson]

...if I look to the right screen with AA enabled, I see my character standing in the ebon hawk. Not to mention that it is highly annoying to see the aliased edges flicker as I move.

 

Actually, in either picture you posted I can't see your character...well ok, a slight shadow tells me he's there, but it's pretty dark. :D

 

Just for more comparison (and cause I'm bored...), here's mine at 1600x1200, 2xAA and 4x AF. I do not have the latest super-vid-card, it's a GeForce 6200. Click the pic if you want to see it full size (770kb .jpg). And of course, it looks better in-game & away from lossy .jpg's. In the full-size pic you can see a little jagged edges here and there but in-game it's not noticable...I don't see the flicker Kaftan is talking about in Kotor2 - I do know what he means tho, in some games I still see that even with everything on max (WoW....).

 

Edited December 31, 2005 by LadyCrimson

[Haitoku]

I don't like jaggies and I don't mind taking the FPS hit in order to use atleast x4 AA. I could stand them on my old monitor, but not on my new LCD. Clarity is really good, that means however, I can see all the jaggies a lot better.

[angshuman]

When it finds an edge, it blurs out the edge by painting it in different shades of gray, making the optical effect of having a slightly less jagged edge.

I don't mean to sound like a smartass, but that is completely incorrect.

 

In its simplest (and most inefficient) form, antialiasing is accomplished by Supersampling (SSAA). Here, the frame is rendered at a much larger resolution than the actual output resolution. Then, every target output pixel for the final image is generated by a weighted averaging of several pixels in that region in the larger image. This filtering operation is *very* different from a Blur operation. Blurring results in detail loss, as you correctly mentioned. There is *no* loss in detail due to antialiasing, mathematically or visually.

 

Most modern cards use multi-sampling (MSAA), which I don't understand completely, but I know that it involves rotating points along polygon edges according to a fixed grid, and supersampling only these points. But the basic principle is still the same -- rendering multiple pixels for the same point, and then filtering those into the final pixel.

 

Antialiasing always involves aggregating an *excess* of information (which is where the performance hit comes from) into a single unit, and there is no loss of detail in the process, not within polygons, not at polygon edges, not anywhere.

[LadyCrimson]

How the game feels when I'm playing (not the techie numbers) I notice a much bigger performance hit from upping resolution than from increasing the AA/AF. Going from 1024 to 1600 causes a large FPS loss, which I assume is a combo of older card+only 128vid memory + just the extra load.

 

If I then max out AAwhile in 1600, the loss to performance (lag, lowering of FPS) takes another minor hit but I really hardly notice it. if I max everything out in 1024, same thing - the performance loss isn't very significant vs. the resolution itself.

 

Anyway, if I had more video ram (my system RAM is 2gigs, that's not it) would that reduce the hit at 1600 by a lot? Because I swear every time I upgrade I see a tiny bit of FPS style improvement but nothing enough to have made it worthwhile to me. I don't care about another 3-5fps...maybe 15-20 would be worth it.

 

P.S. If you build your own PC it's only about $800-1000 for a decent (not uber) newer system, not including monitor. Not $2000...but still too much for some I know...just saying...

[alanschu]

Like I said, if I take the time to look for the aliasing in the left pic, I can still notice the aliasing (though blurred) in the right pic just as easily in most cases.

[angshuman]

Well, the fps hit my games take if go for too much AA is what kills the suspension of disbelief for me. It might make the game nearly unplayable, too.

Absolutely, FPS comes first and foremost. Aliasing might make the game look horrible, but a slideshow makes it unplayable. However, once you see that your system is maintaining your desired FPS (the comfort level varies from person to person, of course), that's when you can start bumping up the resolution/AA/AF while keeping the fps within your constraints.

 

... I notice a much bigger performance hit from upping resolution than from increasing the AA/AF. Going from 1024 to 1600 causes a large FPS loss, which I assume is a combo of older card+only 128vid memory + just the extra load.

That varies from game to game and scene to scene. I'm not completely sure about what factors exactly affect this, but I'll go out on a limb and say that with MSAA, if your scene has a lot of polygon edges, you'll probably see a more significant performance degradation due to MSAA than with resolution bumping.

[mkreku]

When it finds an edge, it blurs out the edge by painting it in different shades of gray, making the optical effect of having a slightly less jagged edge.

I don't mean to sound like a smartass, but that is completely incorrect.

You're not sounding like a smartass, but I just have to add that I do know the technical stuff behind antialiasing too (even if I would describe it slightly different than you), but that isn't the point of this thread (in my opinion). If you look at any screenshot and compare it without antialiasing and with antialiasing on, the difference you will notice is blurred, grayed out lines where the 'jaggies' used to be. The result of antialiasing is what I am discussing, because that is after all what we're seeing on the screen, even without knowing the methods behind those grey areas appearing.

 

A good example is the closeup of figure 3 in the following link:

 

http://en.wikipedia.org/wiki/Antialiasing

[EUIX]

 

The first image is crappy old Bilinear filtering, the second image is 16x Anisotropic filtering.

<{POST_SNAPBACK}>

 

 

Those two look exactly the same to me except the second one the wall is at a greater incline, there a greater sense of perspective. Is that it?

[Blodhemn]

Look at the brickwork right past the drainage gate. The pic on the left(bilinear) has it blurred.

[SamuraiGaijin]

How the game feels when I'm playing (not the techie numbers) I notice a much bigger performance hit from upping resolution than from increasing the AA/AF. Going from 1024 to 1600 causes a large FPS loss, which I assume is a combo of older card+only 128vid memory + just the extra load.

 

If I then max out AAwhile in 1600, the loss to performance (lag, lowering of FPS) takes another minor hit but I really hardly notice it. if I max everything out in 1024, same thing - the performance loss isn't very significant vs. the resolution itself.

 

Anyway, if I had more video ram (my system RAM is 2gigs, that's not it) would that reduce the hit at 1600 by a lot? Because I swear every time I upgrade I see a tiny bit of FPS style improvement but nothing enough to have made it worthwhile to me. I don't care about another 3-5fps...maybe 15-20 would be worth it. 

 

P.S. If you build your own PC it's only about $800-1000 for a decent  (not uber) newer system, not including monitor. Not $2000...but still too much for some I know...just saying...

<{POST_SNAPBACK}>

 

LadyCrimson - all that you mentioned is 100% correct - your Video RAM is most likely your bottleneck, not the GPU's ability to compute more AA or AF effects per frame. If you think about the minimum amount of memory required to store one frame of 800x600 resolution screen (800x600 pixels x 32-bits (color) =10,240,000 bits ~1.2 MB) versus a higher resolution (1600x1200, for example) ~7.32 MB (four times as much).

[SamuraiGaijin]

I typically play at 2x AA and 2x AF, with a 1280x1024 resolution (my LCD's native resolution) ... while I can tell the difference between different levels of AF, AA is not quite as obviious to me, especially during gameplay.

[angshuman]

You're not sounding like a smartass, but I just have to add that I do know the technical stuff behind antialiasing too (even if I would describe it slightly different than you), but that isn't the point of this thread (in my opinion). If you look at any screenshot and compare it without antialiasing and with antialiasing on, the difference you will notice is blurred, grayed out lines where the 'jaggies' used to be. The result of antialiasing is what I am discussing, because that is after all what we're seeing on the screen, even without knowing the methods behind those grey areas appearing.

 

A good example is the closeup of figure 3 in the following link:

 

http://en.wikipedia.org/wiki/Antialiasing

Aha! But Figure 3 is a zoomed-in image, and it is supposed to look that way, simply because there is not sufficient information available about the frame at that high a resolution. Given an ideal "picture" and a final target resolution, AA attempts to create the perfect digitization of said "picture" at that target resolution. If you blow it up, it will look weird. But at exactly the target resolution, an infinite-X antialiased image should look *exactly* as perfect as is possible for a continuous-space "picture" to look at that resolution, and 16x SSAA gets bloody close to that.

[Bokishi]

All games look horid without AA.

[Dhruin]

Aha! But Figure 3 is a zoomed-in image, and it is supposed to look that way, simply because there is not sufficient information available about the frame at that high a resolution. Given an ideal "picture" and a final target resolution, AA attempts to create the perfect digitization of said "picture" at that target resolution. If you blow it up, it will look weird. But at exactly the target resolution, an infinite-X antialiased image should look *exactly* as perfect as is possible for a continuous-space "picture" to look at that resolution, and 16x SSAA gets bloody close to that.

<{POST_SNAPBACK}>

 

I simply don't understand any of that but as far as I can see (regardless of the process itself), at any given resolution the "jaggy steps" are "filled in" with some gray (or whatever) pixels to hide them - which is what I think Matthias is saying.

 

Anyway, on the topic itself I occasionally enable 2x AA when I think of it. It rarely bothers me. And if the gameplay works, I don't care too much about the graphics.

Edited January 1, 2006 by Dhruin

[@\NightandtheShape/@]

How the game feels when I'm playing (not the techie numbers) I notice a much bigger performance hit from upping resolution than from increasing the AA/AF. Going from 1024 to 1600 causes a large FPS loss, which I assume is a combo of older card+only 128vid memory + just the extra load.

 

If I then max out AAwhile in 1600, the loss to performance (lag, lowering of FPS) takes another minor hit but I really hardly notice it. if I max everything out in 1024, same thing - the performance loss isn't very significant vs. the resolution itself.

 

Anyway, if I had more video ram (my system RAM is 2gigs, that's not it) would that reduce the hit at 1600 by a lot? Because I swear every time I upgrade I see a tiny bit of FPS style improvement but nothing enough to have made it worthwhile to me. I don't care about another 3-5fps...maybe 15-20 would be worth it. 

 

P.S. If you build your own PC it's only about $800-1000 for a decent  (not uber) newer system, not including monitor. Not $2000...but still too much for some I know...just saying...

<{POST_SNAPBACK}>

 

The reason you take a performace hit is the screen buffers alone are flooding the VRAM, so it's likely most things such as textures are being stored in your system RAM.

 

Now depending upon the speed of your system ram and if the programs memory management is quality or not, bundled with the fact that it takes a life age to fetch everything from the system ram in general then it is expected you'd have a HUGE performance hit.

 

The main reason to upgrade GFX cards at the moment is due to shader technology, which makes a huge differance to how things look.

[LadyCrimson]

Supposedly my system RAM is fairly fast - tho I suspect sometimes that it's not as fast as it claims to be.

 

My performance at 1600 is acceptable/smooth enough to me personally, in general, tho there's sometimes graphic slowdowns when a lot is going on. If more vid RAM would help that aspect then I guess I'll try it. I hate shopping for video & sound cards. Meh.

[alanschu]

LadyCrimson - all that you mentioned is 100% correct - your Video RAM is most likely your bottleneck, not the GPU's ability to compute more AA or AF effects per frame.  If you think about the minimum amount of memory required to store one frame of 800x600 resolution screen (800x600 pixels x 32-bits (color) =10,240,000 bits ~1.2 MB) versus a higher resolution (1600x1200, for example) ~7.32 MB (four times as much).

<{POST_SNAPBACK}>

 

 

Or you could just go 1600 is 2x800 and 1200 is 2x600 and go 2x2=4 times as much?

 

I'm just being a smartass though "

[Marka Ragnos]

Also, as most of you already pointed out, antialiasing is not worth it if you can play the game in 1280x1024 or higher. By that resolution the pixels are so small that any jagged edges look smooth by default.

<{POST_SNAPBACK}>

bah, it can still look bloody jaggy. kotor is one of the jaggiest games I've ever seen. without aa I'd go crazy.

[Lyric Suite]

I like AA a lot, it makes even older games look pretty by giving them a sort of visual cleansiness, making them look more like animated cartoons then video games.

 

That said, frames rates are still king, no matter what.

 

BTW, has anybody ever played Tron 2.0? That games makes the best case for AA i ever seen...

[@\NightandtheShape/@]

Supposedly my system RAM is fairly fast - tho I suspect sometimes that it's not as fast as it claims to be.

 

My performance at 1600  is acceptable/smooth enough to me personally, in general,  tho there's sometimes graphic slowdowns when a lot is going on. If more vid RAM would help that aspect then I guess I'll try it. I hate shopping for video & sound cards. Meh.

<{POST_SNAPBACK}>

 

Doesn't matter how fast your RAM is, still takes a lifetime to get from A to B, in computing terms atleast.

 

128meg is kinda tiny... But nothing worth worrying about, depends what games you play etc... TBH I've never bothered playing anything in 1600x1024x32 there isnt much point to doing so.

 

as for buying a video card it is simple.

 

Get the latest NVIDIA card you can afford that is compatible with your system, be it AGP or PCI-E, and buy a brand name such as PNY or ASUS.

 

That way you never go wrong .

 

Some folks like ATI, personally I think they're unreliable. As for the brand name well, just because it says Geforce whatnot on the tin doesn't mean that'll it'll have been made with gaming in mind, or performance, or general compatibility.

[Mondo]

higher resolutions have knocked jaggies down a little

 

but AA is still the ****

[LadyCrimson]

128meg is kinda tiny... But nothing worth worrying about, depends what games you play etc... TBH I've never bothered playing anything in 1600x1024x32 there isnt much point to doing so.

 

Yeah, I don't play FPS's much so I don't generally worry about it. But a lot of games these days are more and more demanding, even so.

 

Get the latest NVIDIA card you can afford that is compatible with your system, be it AGP or PCI-E, and buy a brand name such as PNY or ASUS.

 

I do that...I just don't neccesarily like the 'latest' one because I have no need for the bells and whistles...and it always seems like on the shelf, there's 20 different options...each one having a different number in their 'name.'

 

Some folks like ATI, personally I think they're unreliable.

 

I tend to notice a lot more tech/bug complaints on myriad forums with ATI over Ge, so I agree.

Tho I don't think it's unreliable so much as perhaps games not supporting ATI as well, or something. Dunno.

Edited January 2, 2006 by LadyCrimson

[@\NightandtheShape/@]

Yeah, I don't play FPS's much so I don't generally worry about it. But a lot of games these days are more and more demanding, even so.

 

May I ask what games your playing at the moment?

 

 

I do that...I just don't neccesarily like the 'latest' one because I have no need for the bells and whistles...and it always seems like on the shelf, there's 20 different options...each one having a different number in their 'name.'

 

Depends what you want from your card, in terms of the Geforce series the first number is the generation, we're currently on generation 7 for example, the number after that is usually more to do with the chip the higher the better, anything after that GT or ULTRA is generally good news, any L's pop up expect it to be a trimmed down version of the standard card.

 

From what I can tell, I don't know if you're running an AGP based or PCI-E based motherboard, but series 6 cards are generally produced for both and you can usually find them cheap.

 

Geforce 6200 with 256mb of ram shouldn't be too expensive.

 

 

I tend to notice a lot more tech/bug complaints on myriad forums with ATI over Ge, so I agree.

Tho I don't think it's unreliable so much as perhaps games not supporting ATI as well, or something. Dunno.

 

Nah, it's just ATI generally has poor driver implementation, hence the drivers are unreliable. NVIDIA patch the drivers way way more often than ATI.

 

ATI's are generally that little bit faster.

Edited January 2, 2006 by @\NightandtheShape/@

[LadyCrimson]

@ @\NightandtheShape/@ -

 

I use AGP. If I can find a GeF 6200 w/256 I'd buy it. I've been pretty happy with the 128 one. I don't like buying on-line tho and sometimes the stores don't have much of the older stuff because they like to reserve the shelf space for the $500 new things.

 

As to games...well to be honest I haven't played too many lately, especially when there's so few in the genres that I like, new release wise. WoW/ DungeonSiege2 are probably the most current. WoW, digital photo manipulation and some older RTS games like Stronghold/Majesty NE/RCT with their huge 'chug-chug' map sizes is why I bought another gig of RAM...didn't absoultely need it but it helped quite a bit.

 

I was waiting for Majesty2 but apparently it's kaput. In short, I like RPG's, action-RPG's, and RTS that have something different from AoE like gameplay.

 

Edit - sometimes even 3 smileys seem like too many...

Edited January 2, 2006 by LadyCrimson

[@\NightandtheShape/@]

@ @\NightandtheShape/@ -

 

I use AGP. If I can find a GeF 6200 w/256 I'd buy it. I've been pretty happy with the 128 one. I don't like buying on-line tho and sometimes the stores don't have much of the older stuff because they like to reserve the shelf space for the $500 new things.

 

As to games...well to be honest I haven't played too many lately, especially when there's so few in the genres that I like, new release wise. WoW/ DungeonSiege2 are probably the most current. WoW, digital photo manipulation and some older RTS games like Stronghold/Majesty NE/RCT with their huge 'chug-chug' map sizes is why I bought another gig of RAM...didn't absoultely need it but it helped quite a bit.

 

I was waiting for Majesty2 but apparently it's kaput.   In short, I like RPG's, action-RPG's, and RTS that have something different from AoE like gameplay.

 

Edit - sometimes even 3 smileys seem like too many...

<{POST_SNAPBACK}>

 

Okay, well if you are going to upgrade your card I'd do it pretty sharpish, AGP is old hat - PCI-E is pretty much the standard now. If like me you didn't like the idea of a mobo upgrade as well I hope you can see it's good advice.

 

WoW will just look better, you'll probably see some speed improvements on DSII, been playing that myself of late inbetween coding it's loads better than DSI IMHO.

 

Seems your setup is great for digital photographic manipulation, that stuff is all about RAM, but you knew that .

 

The thing about the latest cards is the shader technology, I'm gunna take a guess at the likes of NWN2 needing shader tech 2.0 or greater, based upon the whole graphical improvements they've been harping on about.