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View Full Version : Nvidia graphics cards will have a bug in Half-Life 2


rsalonen
07-21-2003, 05:07 PM
http://www.xbitlabs.com/news/video/display/20030718155730.html

Half Life 2 will have some bugs when playing it on a Nvidia based graphics card.
This shouldn't be accepted really, even if the bug only occurs when using AA mode. Is ATI about to buy valve :scream:

Well, just thought I'd share this news for yah, if you haven't seen already.

Neil
07-21-2003, 05:39 PM
So who's at fault? Valve or MS for direct x 9?

Either way, they still got lots of time till the game comes out, i'm sure they'll patch that up.

Array
07-21-2003, 05:55 PM
I think this is just a marketing stunt. Im sure that Nvidia would be MORE than happy to help valve with any bugs they may be experiencing. :shame:

jipe
07-21-2003, 10:37 PM
It's a problem with DX9 and the hardware - currently only the ATI 9500-9800 series has the potential to be able to render hl2 correctly with AA.. and you can bet ATI is going to be working with Valve to fix the bug.

Gazortus
07-22-2003, 01:50 AM
More like ATI is paying us a shitload of money to hawk their hardware. Good marketting promotion I'd say :)

GRMac13
07-22-2003, 02:14 AM
Lame!

Like I'm really going to base my decision on what video card to buy on how well it runs one game. It's stupid if you ask me, even if Valve is getting a bunch of cash from ATI, they may potentially be losing a good percentage of their consumer base who own nVidia cards (doesn't nVidia lead the industry in sales of gfx cards?). The smart thing to do is to do some sort of cross-promotion with ATI, like offering discounts on HL2 with the purchase of a Radeon or vice versa. I just don't see how sabotaging your product is going to help sales. If anything, it's going to give you a bad rap with consumers who will opt to purchase other games (such as Quake 4, Doom 3, or Unreal 2004) that they know will run well on thier system. Nobody but the most hardcore of gamers is going to upgrade thier system based on the specs of a single title (no matter how great it may be).

Dargon
07-22-2003, 02:17 AM
From what I heard, Valve was sorking directly with ati to create the technologies in HL2. Basically, if ATI added a new feature, Valve would have been the first to find out, and if Valve wanted a new feature, ATI likely would of accomodated.

It's a marketing scheme, both parties doing well out of the deal. Hopefully for those of us with GeForce cards, they fix the problems... ...but I'm sure ATI hopes they don't.

Neil
07-22-2003, 03:39 AM
This is odd b/c with the updates they had for HL and CS in the past, there were times when people with ATI's couldn't play until the repatched it again.
So i figured Valve loved Nvidia, and that ATI was just behind Doom3.

jipe
07-22-2003, 03:58 AM
Please do your research before making baseless accusations. It is *NOT* some marketing scheme by ATI, although they are pretty close with Valve.

This is a side effect of hardware design based on an invalid assumption. The people who implemented the FSAA assumed that each physical texture contained the texture data for a single physical surface. Apparently this assumption is invalid for Half Life 2. It is definitely invalid for Call of Duty, though a cvar change will make it true once again for CoD.

There is an optimization to put the textures for several pieces of geometry together onto a single giant texture so that you can draw all of that geometry in a single call instead of multiple calls. Video cards tend to take the same amount of time to draw 1 triangle as they do to draw 100 or 200 triangles; it's not until you are drawing hundreds of triangles that the time to draw is proportional to the amount of geometry drawn. So, if you have to draw 8 pieces of geometry with unique textures that all have 32 triangles, it will typically take 8 times as long to draw them individually as it would if you combined their individual textures into a single large texture so that you can draw them all at once.

This is an optimization ATI and nVidia both recommend. Anyway, it appears that the FSAA hardware implementation uses pixels from neighboring images when several images are combined into one bigger texture, since it assumes that the whole big texture is a single image and not several independent images. This is what causes the visual errors Valve mentioned.

GRMac13
07-22-2003, 04:15 AM
Well I think most of us are reading between the lines here.

The developers of the legendary Half-Life game said that drivers are not likely to solve the problem, however, it still can be solved for graphics cards based on VPUs from ATI Technologies, such as RADEON 9500-, 9600-, 9700- and 9800-series. As for NVIDIA GeForce and GeForce FX-series, there are practically no chances to find a workaround, according to Valve.

"No chances?" Looks like Valve is making little attempt to solve the issue when it concerns nVidia products. Like Array said, nVidia would be more than happy to work with them on resolving the issue. Unfortunately, nVidia doesn't have the same relationship with Valve as ATI does. It may not be a traditional "marketing scheme" but rather a convienient by-product of ATI's relationship with Valve.

It's just bad business on Valve's part because they are potentially alienating customers. Of course, the issue may not be such a huge deal, but it's not wise to narrow your market (espcially in the PC arena). Doom 3 may very well bomb at the end of the year due to it's absurd system specs. People want games they can load up and run without having to make changes to their hardware.

jipe
07-22-2003, 04:41 AM
Well I think most of us are reading between the lines here.

.. and missing the point of the lines themselves. There is no possible software fix for current nVidia hardware. There is a chance of a software fix with the 9500-9800 series. By now, nVidia already knows of this problem, but they most likely can't fix it with the drivers - since it is a general problem with FSAA and that particular texture-combination technique, if there's a way to fix it, nVidia will be able to by themselves, and release it with new Detonator drivers.

The next-generation cards from both companies will not have this issue, by the way.

raz-0
07-22-2003, 07:14 PM
jeez people, put the torches and pitchforks away.

A lot of people will be upgrading for HL2. Believe it. Just like doom2 was a killer app for a bunch of ahrdware back when.

Second, at the moment, neither nvidia's or ATI's cards will be able to run half-life 2 with anti-aliasing turned on. Neither of them currently has support for centroid type AA that would be needed to not corrupt the graphics while playing.

The difference is that ATI claims to have hardware support (but no way to access it through the API, and no evidence that it is even usable), and that NVIDIA hasn't mentioned having any support for it.

The AA is not a required part of DX9 to be dx9 compliant. However, it is in the spec for DX9. IIRC from reading up oin the discussions, PS2.0 is required, but the centroid sampling is PS 3.0 functionality.

The upshot is basically that vlalve decided that better textures handled efficiently was the priority, and they didn't think it would break cards as badly as it has with AA. Perhaps they figured DX9 cards would be a bit more along than they are by this point so they wouldn't have to worry.

Goon
07-22-2003, 07:40 PM
It is quite possible that Nvidia does not really want to fix this so they can give extra incentive for people to purchase their next line. Its a disadvantage alright but if they can land a release near HL2's it could play well.

(that was said in pure ignorance. i have no knowledge whatsoever about what Nvidia is scheduling)

Array
07-22-2003, 08:21 PM
Originally posted by jipe
.. and missing the point of the lines themselves. There is no possible software fix for current nVidia hardware. There is a chance of a software fix with the 9500-9800 series. By now, nVidia already knows of this problem, but they most likely can't fix it with the drivers - since it is a general problem with FSAA and that particular texture-combination technique, if there's a way to fix it, nVidia will be able to by themselves, and release it with new Detonator drivers.

The next-generation cards from both companies will not have this issue, by the way.

But what is stopping a few talented Nvidia employees from heading over to valve and helping them adress the issue by modifying the halflife2 engine itself so that it works equally well on both platforms?

raz-0
07-22-2003, 10:30 PM
because it can't be fixed. It is an incompatibility between the source engine, and several anti-aliasing algorithms.

THe problem is that they have more than one piece of texture "art" on a single texture in order to save bandwidth. both NVIDIA and ATIs cards are cool with that. However, supersampling and multisampling AA algorithms are not cool with that as they can sample bits of texture that don't belong to the object being anti-aliased. This results in badness.

The centroid style of AA avoids this issue. I don't know how, I am completely unfamilliar with the algorithm for it. Hwoever, that is what valve says would work with it.

Centroid AA according to valve is part of the DX9 spec, but not part of what is mandatory for DX9 compliance. (don't ask me, I've not gottena good look at DX9 because I don't have a DX9 card to motivate me to do such after my 5800 destroyed itself, that's what the guy from valve said).

ATI claims that they support centroid AA. However, it can't actually be accessed in their api, or via DX9. So nobody knows if it actually works for ATI, or if it doesnt, or if it works, but works at an unacceptably slow speed.

Nvidia never claimed to support centroid AA, and hasn't spoken up. So it is unlikely that they will magically produce centroid AA. If they do it will be software, and thus likely slow.

The only way NVIDIA could help them "fix" it is to convince them to lose texturing efficiency in the source engine. This would seriously impede the engines ability to look decent on slower cards and not require massive ammounts of ram and lots of bus hogging transfers from main memory to video memory. It may even seriously impact their ability to use the pixel shaders they ahve implimented for the game.

With a due date of 9-30, that is not very likely. However, who the hell knows when nv40 will hit? Or ATI's part. ATI should be sneaking up on a release cycle for christmas, so should nvidia if they have managed recovery from nv30 sliding so much. However, ATI doesn't have competition to motivate it to put out their next chip, and NVIDIA may have scheduling issues, or have to suck up some serious fiscal damage fromt he nv30/31/34/35 line to roll out nv40.

Personally I'm wagering on HL2 having jaggies or corrupted smothed edges no matter what hardware you play it on. I mean splinter cell survived being incompatible with AA, why couldn't HL2? From both the vid card companies persepective and vlaves.

leuey
07-22-2003, 10:35 PM
Originally posted by Array
But what is stopping a few talented Nvidia employees from heading over to valve and helping them adress the issue by modifying the halflife2 engine itself so that it works equally well on both platforms?

Guys - read the words. It's a HARDWARE PROBLEM. Let me repeat that for those of you who aren't getting this.

IT'S A HARDWARE PROBLEM!
IT'S A HARDWARE PROBLEM!
IT'S A HARDWARE PROBLEM!
IT'S A HARDWARE PROBLEM!
IT'S A HARDWARE PROBLEM!
IT'S A HARDWARE PROBLEM!

Get it? New cards with new chips that fix the bug will have to be made. ATI claims a workaround due to some of their HARDWARE FEATURES which may or may not work and has NOTHING TO DO WITH ANY CONSPIRACY!

Remember when the PIV (or PIII) had a bug in it? Did anybody ask microsoft to release a patch to fix the bug? NO! why? b/c IT'S A HARDWARE PROBLEM! Likewise it's not Valve's fault or within Valve's ability to fix. Unless the redo their texturing.

later,

Greg

(all caps were tongue in cheek for those of you lacking a humor unit)

Array
07-22-2003, 11:00 PM
Originally posted by leuey
Guys - read the words. It's a HARDWARE PROBLEM. Let me repeat that for those of you who aren't getting this.

IT'S A HARDWARE PROBLEM!
IT'S A HARDWARE PROBLEM!
IT'S A HARDWARE PROBLEM!
IT'S A HARDWARE PROBLEM!
IT'S A HARDWARE PROBLEM!
IT'S A HARDWARE PROBLEM!

Get it? New cards with new chips that fix the bug will have to be made. ATI claims a workaround due to some of their HARDWARE FEATURES which may or may not work and has NOTHING TO DO WITH ANY CONSPIRACY!

Remember when the PIV (or PIII) had a bug in it? Did anybody ask microsoft to release a patch to fix the bug? NO! why? b/c IT'S A HARDWARE PROBLEM! Likewise it's not Valve's fault or within Valve's ability to fix. Unless the redo their texturing.

later,

Greg

(all caps were tongue in cheek for those of you lacking a humor unit)

ugh....YOU'RE the one who didnt read my post well. If this game engine is having so much trouble running on consumer level cards, why not change the game??

leuey
07-22-2003, 11:59 PM
Originally posted by Array
ugh....YOU'RE the one who didnt read my post well. If this game engine is having so much trouble running on consumer level cards, why not change the game??

Array - maybe I didn't follow you. What I was trying to say was that there is presumably nothing an Nvidia engineer could do software wise for Valve to fix the game.

Every game developer who is using the technique described earlier (packing textures for multiple objects into 1 image) will have the same problem Valve has.

Seeing as how much time and money it takes to make a game I would think that Valve will simply tell people to

1. Don't use FSAA in the game (a lot of people don't anyway)
2. Try the ATI trick/hack if it works
3. Wait a couple of months for new cards to come out w/ fixed hardware.

The ATI proposed workaround only works b/c of a Hardware feature in the ATI card (that Nvidia's seem to lack)

I really don't see Valve delaying the release of the game for god knows how long to go back in and change the way they've been texturing the objects for the last 5 years. (plus it will slow the game down, they did it that way b/c it's a performance issue, they just got burned w/ the bug b/c of DX9 first gen. hardware was buggy.)

later,

Greg

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