AA Bug Ever Fixed?

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Monkfish

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I've only just got around to playing the Orange Box. I thought I'd like to play HL2 again as a refresher. Since playing last I've changed my graphics card from a Radeon X1900 XTX to a GeForce 8800 GTX. I would like to run at 1280x1024 with 4X transparency AA. Unfortunately I'm getting those famous MSAA white line glitches (usually in the distance). I've read articles detailing centroid sampling and shader solutions, but did either NVIDIA or Valve get around to sorting this out? I hope all the other Orange Box games don't suffer from the same problem.
 
You'll have a hard time finding much more information than is in this thread, even if it doesn't contain much:
http://halflife2.net/forums/showthread.php?t=142636

Some different drivers might be worth a try; you won't eliminate the problem but some people say a change of drivers has made it less noticeable.

If all else fails disable AA and compensate for the jaggies by upping the res.
 
why o why do people by high end cards for such low res.........
 
giant384 said:
why o why do people by high end cards for such low res.........
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Cause some of us don't have the monitors capable of handling the higher res. My monitor only supports up to 1280x1024, and i'am more than happy with it.
 
Actually, my monitor can do 2048x1536 @ 70Hz, which is the setting I go for most often (without AA). However, HL2 uses all those annoying point-sampled transparent textures for telegraph wires and chain fences, which to my eye look awful even at the highest resolutions. I think this particular game looks better at 1280x1024 with 4X supersampled transparency antialiasing.

I've read that Episode 1 & 2 and the other Orange Box games don't suffer from the white line glitch under AA. If this is the case I won't bother to play HL2 through again and will simply jump straight into the OB. This would also seem to suggest that it was basically an oversight in Valve's level editor. Once the levels were created it was just too much work to go back and tweak them all to remove the lines. Despite what Gabe has stated, I haven't noticed this problem in any other game, apart from the occasional white line around alpha blended textures under AA. If it were a simple fix it would have been done.
 
I've had it for quite a time and over time got used to it (see my original thread here.). I'm usually playing with 1680x1050 @ 4x AA and it isn't really that noticeable unless you're in a dark corridor, if that's the case then you can clearly see it.
 
Here's an example image segment that flips between No AA and 4X TAA. Notice how the transparency AA improves the look of the tree and telegraph wires, but also how it introduces all those hideous vertical and horizontal white line glitches. This was taken from Valve & NVIDIA software and hardware circa May 2008. So much for having addressed the problem since 2004.

hl_aa_bug.gif
 
I can't help but get the impression that Valve are so tied up in new projects that they don't have the resources or the inclination to address longstanding, fundamental stuff like this. Look at what happened with the stutter-crash; Valve spent years directing people to a lame duck of a Steam support page for the issue, until some determined people in the community came across the pagedpoolsize fix.

Stuff like that makes me suspect that this might not be as much of a tough thing to fix as Valve's failure to do so makes it seem. I'm sure they have the expertise, and they respect their fans enough that it's not like it's a matter of laziness or anything, but with L4D, TF2 updates, Steam development, etc. all in the pipeline, who in management is going to say 'RIGHT, we REALLY need you guys to go back and fix that old HL2 antialiasing issue today...!'
 
I was hoping that centroid AA would be an option in a 3rd party GeForce driver, bios or tweak. But I guess that NVIDIA's AA just isn't as flexible as ATI's implementation with programmable sample points.

Turning gamma correction off reduces the brightness of the glitches slightly and leads to a marginal improvement. Here's a higher resolution comparison...

hl_aa_bug2.gif
 
diluted said:
Because 1280x1024 is the native resolution for many monitors, genius.
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i understand that....smartass.

my point was that its wasted power that wont be used for that low of a resolution.
 
Actually, sometimes I regret having relatively large, a high-res monitor, because in order to play some games at full resolution it usually requires a hell of a lot of resources. Obviously this isn't a problem with Source games, but in more hardware intensive titles I often have to sacrifice features such as AA in order to have a consistent playable framerate.
 
To reiterate, I still suspect that this problem was caused by a sloppy level editor that permitted small misalignment errors to go unnoticed in the underlying level mesh. Effectively, any game level should be a single coherent mesh with no discontinuities. MSAA simply revealed these errors, but by that time it was too late. Going back over all the levels to detect and then correct these tiny errors was simply not worth the trouble. Valve probably improved their level editor and design process to eliminate such errors in subsequent products.

example1.gif


Here’s a simple example. The square in the left image has vertex B, but the rectangle has no corresponding vertex B (along edge AC). Any small error in the position of vertex B will produce a misalignment in the abutting edges AC (side of rectangle) and BC (side of square). This will lead to slightly different alias stepping along each edge. This error is not so obvious when it causes the two shapes to overlap slightly, but can show up as AA sub-sample errors especially in the distance as the Z-buffer loses spatial accuracy. A good level editor will further subdivide the rectangle so that it does share the same vertex (E), as shown in the example on the right. In this case the mesh is consistent and has no discontinuities.
 
GreatBlackthorn said:
Actually, sometimes I regret having relatively large, a high-res monitor, because in order to play some games at full resolution it usually requires a hell of a lot of resources. Obviously this isn't a problem with Source games, but in more hardware intensive titles I often have to sacrifice features such as AA in order to have a consistent playable framerate.
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But with a high res monitor AA shouldn't be as necessary compared to a low res monitor.
 
Yes, apart from anything that's point-sampled, like those hideous chain fences in HL2.
 
Operational said:
But with a high res monitor AA shouldn't be as necessary compared to a low res monitor.
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This is true, but it depends on the game. Many modern games have complex geometry and lighting effects that hide aliasing very well. Gears of War and The Witcher are examples of games where I happily have AA disabled. I would of course enable AA if it didn't come at a performance hit, in the case of Gears of War, or irritating artifacts in the case of the Witcher, but the aliasing goes unnoticed enough for me to play without.

It would be interesting to see the ratio between resolution to FPS compared AA to FPS, to evaluate which is more beneficial to gamers on a budget.

Luckily Source runs so damn well I can have all features at their maximum and enjoy a constant 60FPS.

Edit: Monkfish, could you take a screenshot of these point sampled textures? I can't recall them.
 
Many modern games have complex geometry and lighting effects that hide aliasing very well.
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I totally agree, which is why I like to run at 2048x1536 @70Hz without AA in most games.

Could you take a screenshot of these point sampled textures? I can't recall them.
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They are used for tree foliage, telegraph wires and chain fencing. Higher resolutions are acceptable for the first two, but chain fencing produces a hideous moire effect that I find ugly. Only supersampled transparency AA improves those. Here's an image comparison that switches between no AA, 4x multisampled AA, and 4x supersampled transparency AA.

hl_aa_bug3.gif
 
Eesh you're right that is pretty ugly. Only becomes noticeable for me at relative distances, though I am playing at a lower resolution than you. Do they not change the resolution of point sampled textures to adapt to the resolution you play on?

Luckily I don't spend much time looking at chain link fences =D
 
Do they not change the resolution of point sampled textures to adapt to the resolution you play on?
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Well this is a product more of the texture resolution than the pixel resolution. Obviously, the finer the pixels the more accurate the fence will appear and serious break-up will occur at a greater viewing distance.

Here's a comparison between one resolution with 4X SSTAA and twice that resolution without AA. In most games the lower resolution would have the edge on performance, but in HL2 the performance is the same on high-end cards. You should view this image at twice the distance than you would normally to get the correct impression. The antialiased mode helps to smooth fence disintegration, and it also looks better in motion, something that an image can't show.

hl_aa_bug4.gif
 
I totally disagree. Some games make antialiasing virtually pointless unless SSTAA is enabled. Company of Heroes is a good example.
 
@ Monkfish: Strange you posted this. I've had the same problems with my GeForce card too. Awesome too how you did those screenshots. A very neat trick indeed.

Your not the only one to have this problem. I've discussed this with Loke and Asus in the past.
Prvmsg Asus (you'll find him in the Hardware & Software section of the forums) a link to this thread so he can show you my screenshot. I think he saved a copy of the screenshot I had. I'd post it myself, but I deleted my copy. I took it in the Anticitizen-One chapter of the game in the tunnel section after the player gets bombarded with manhacks and just before crossing the toxic sludge section of the tunnel.

It's true what Loke said that the glitch seems to be more noticable in darker areas. Strangely, not ALL dark areas though. Only certain sections of the game it seems to me.

TBH, I think GeForce owners are screwed. We need someone from the Source modding community to fix this as Valve or NVIDIA doesn't seem to give a rat's ass anymore.
 
Saturos said:
TBH, I think GeForce owners are screwed. We need someone from the Source modding community to fix this as Valve or NVIDIA doesn't seem to give a rat's ass anymore.
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Will it still be an issue when Valve releases the console Orange Box editions of HL2 for the PC?
 
Operational said:
Will it still be an issue when Valve releases the console Orange Box editions of HL2 for the PC?
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I don't have a clue there tbh. I'm not a next-gen console programmer working for Valve, nor do I own any next gen consoles. I'm just a PC guy.

However IIRC, both the PS3 and 360 have Nvidia GPUs, but since this is a closed box we're talking about, there's not the issue of a near infinite possibility of different hardware configurations that PCs have.
Console hardware for the most part remains constant until it's death and replacement of the next-gen successor . (Apart for the different PS3/360 HD capacity packages available)

It would be alot easier in this case for Valve's QA development teams to locate and correct glitches on a console port. Maybe the console port will force them to port a fix over to the PC version as well? Thus it's likely console games don't suffer nearly as many glitches as PC games do. That's also why PC gamers have to patch their games.
 
^ Well if we go on what Monkfish was talking about, that the problem comes from the maps themselves it's possible that it wouldn't be an issue with the latest versions of the HL2 maps from the console Orange Boxes.
 
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