*Sub-Thread* Dithering in GTA4

Discussion in 'Console Technology' started by Laa-Yosh, Apr 28, 2008.

  1. Mintmaster

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    Oh really? I suppose it was some imposter that said all this:
    The textures are the same. The AF is the same level. The difference is shadows and this bug.

    Because, like I said, Rockstar just didn't care much about 360 image quality. There is no other explanation for them using different colour tone with the PS3. There's no other explanation for them having a texturing bug that none of the other thousand XBox 360 games have.

    It has nothing to do with power. 360 is executing 25% more shader instructions and writing 2.5 times the samples per frame, and by most accounts it's at a slightly higher framerate too. If that's not a statement of power then I don't know what is.

    Nope, PS3 is doing nothing. The 360 version is just doing something that hurts texture quality.
     
    #121 Mintmaster, May 3, 2008
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  2. btdvox

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    It happens when you enter the restaurant and then goes away when you go closer or if you move - It seems when its a static image it gives that effect. Any thoughts on why?

    Also I Alot of you may not be able to do this but just because you see a bunch of screen shots and are jduging that is much different than playing. For those that have both consoles and if you want - rent the other version to see the difference, Its quite different on my TV. With the exact same settings the main thing that strikes out is that the PS3 is quite a bit blurrier, I should also state that if PS3 has no AA and 360 has 2 XAA i still think ps3 has less ailasing simply because its alot blurrier.
     
    #122 btdvox, May 3, 2008
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  3. betan

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    So it's not a smooth transition from noisy version to "correct" one?
    Noise just pops out?
    Probably not a mipmap error if so.
     
  4. Juan Panson

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    looks like it doesnt affect every texture on 360. these look the same to me.

    [​IMG]

    [​IMG]
     
  5. speedsix

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    My screen in particular has been calibrated with the coloured, clear plastic cards you get with the Avia calibration disc, including the internal service menu decoder settings so I would say it's going to be fairly close to what the developer was looking at. Maybe :)

    You are right about the indoor scenes thought, they defintiely have a different tint to them.
     
  6. B1663r

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    Another wild conspiracy theory....

    Is it possible that the intent of the post effects processing is to make the hd game look like the sd game? On my setup at least, I can't get over how much more similar the sd game is to the box art than the hd game. Also, overall, I would say the sd game has a much more consistent look to it...
     
  7. grandmaster

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    The forthcoming Eurogamer piece should be up on Wednesday I think, but in the meantime, here are some preview shots. Lossless 24-bit full-range RGB, as usual. Left is 360, right PS3. Click to expand.

    Indoors shot first. Yes there does appear to be a small variance in the palette. It's very rare to actually come across a cross-platform game where the colour balance is identical on both formats.

    [​IMG] [​IMG]

    Outdoors shot. The weather cheat was engaged to make sure that lighting was as close as possible.

    [​IMG] [​IMG]
     
  8. grandmaster

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    Here's a shot straight after the intro sequence has completed. You'd expect them to be identical, but again there are minor differences.

    [​IMG] [​IMG]

    This is a tough game to compare. I'm running them side by side but even with judicious use of the pause button it's very tough to capture the same scene at the same in-game time. The capture unit does allow for capture from two HDMI sources simultaneously, but I'd need to use lossy compression to do so and drop from 24-bit RGB to YPrPb 4:2:2, which I'd rather not.

    Lighting appears to be pretty much constant between the two versions, but even a change of a couple of minutes of in-game time shows small differences.

    It's also very, very tough to keep the games in sync as the change in weather appears to be arbitrary.

    With regards the 'which is better-looking debate', I'm not a fan of the blur effect of sub-HD resolutions in general, so normally I'd plump for 360. But the dithering effect seems to magnify a shimmering effect seen in both versions and occasionally looks very unattractive. But you get an ugly moire pattern on PS3 too, which combined with the blur doesn't look great.

    [​IMG] [​IMG]

    I can't help but think that the texture dithering is not a bug though. I really find it hard to think that such a prominent 'bug' would be left in a game with a $100m budget. That said, a patch to turn this effect off would be very, very welcome.
     
    #128 grandmaster, May 3, 2008
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  9. Mintmaster

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    Unfortunately those shots are downscaled instead of cropped, so we can't say for sure whether the originals had the problem or not. Also, it only affects textures when they're being minimified.

    Any argument about significantly different lighting should be put to rest, though, as the time of day is identical. A very slight colour tweak is all there is.
     
    #129 Mintmaster, May 3, 2008
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  10. grandmaster

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    You think? Look at the memory lanes texture in the bottom left quadrant.

    [​IMG] [​IMG]
     
    #130 grandmaster, May 3, 2008
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  11. Mintmaster

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    Thanks for the screenshots, grandmaster.

    That laundromat shot has the same washer control face texture repeated, and you can gradually see it getting messed up in a way that I think fits my theory. Can you give me one screenshot where you get at close to the machine as possible, preferably with you facing it head on? If it's magnified enough, I can recreate part of that texture, screw up the first mipmap, and see if it gives the same symptoms in a 3D app.

    EDIT: Took out my banding comment, as it was a wierd display problem on my end.
     
    #131 Mintmaster, May 3, 2008
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  12. Mintmaster

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    Yup, I noticed the same thing in Dot50Cal's screenshots. When you're close enough that the trilinear filter only uses the top level mipmap, it's artifact free. Check the other "Memory Lanes" decals on the bar.
    I would think the same thing. However, I'm not about to accuse Rockstar of intentionally sabotaging the 360 version to fuzz up the textures, so I'll just chalk it up to apathy.
     
    #132 Mintmaster, May 3, 2008
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  13. _phil_

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    i don't see any banding on my screen.That's normal ,banding can appear on someone screen and not on another ,or not in the same hue range.

    But jumping back and forth on both links , i see a shadow poping.
     
  14. Mintmaster

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    You know what, I think it was some Internet Explorer problem. I don't see it anymore either. I'll edit the post.

    I don't know why you call that "a shadow popping". There's no shadows in the PS3 image and there is at least one in the 360 image.
     
  15. btdvox

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    I find the dithering to be a little annoying - The main thing is I can tell both versions have it- but the 360 is much mroe prone to it, And i beleive it has also to do with the fact that its also much sharper and doesnt have a blurry image to begin with.

    That being said- On the PS3 text and signs/banners are clean of the dithering effect but on 360 you can see them when your standing still, if you move though the banner becomes clean, fact is i dont know if thats better or worse as if you stop you can notice again and then it'll go away when you move lol.

    But Shadows are the main culprit, Indoor scenes are fine but when its dawn or sunset, and your near fences or anyhting like that you'll see more of the dithering from shadows on the 360 than the ps3, But its still somewhat noticeable on the ps3 and I think that is a given, as alot of console games I play have that same effect on shadows. Correct me if im wrong.

    I highly doubt its a MipMap error. And it seems that its not caused from Alpha Textures- as fences as such portray the Dithering much less.
     
  16. Philip42

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    Does anyone know what's causing the blur effect on the PS3?

    Is it some sort of filtering effect?

    It seems like whatever that is, it may be the reason why the PS3 version is less dithered but also more blurry.

    This reminds me of the days when the Voodoo 5 would do 4X FSAA, but with the cost of bluring textures.
     
  17. Philip42

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    You can easily read the 'take a roll down' letters of the PS3 version, while the 360's are too dithered to make out.

    This is a great example of what is happening in many textures in this game, for some reason the 360 version is more dithered, and it really effects the smaller signs/textures.

    Of course the 360 version is cleaner/sharper on the flip side.

    I'm sure if you got 100 gamers to look at both versions in action, it would be split 50/50(give or take +1 or +2) as to which they prefer.

    I'm not sure why there was not an in between here, it's eithier too much on the blurry side or too much on the dithered(sharper) side.

    I still would opt for the PS3 style because it's a sandbox game and everything on it's map matters, but if this was a FPS, i'd easily opt for the 360's style.

    And thanks for posting those great pics.
     
  18. aaronspink

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    anyone else noticing all the missing shadows on the PS3 shots?

    Aaron spink
    speaking for myself inc.
     
  19. aaronspink

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    what strikes me the most is it looks like the 360 and PS3 are using totally different lighting systems.
     
  20. Pete

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    I must be missing those missing shadows. What's not shadowed that should be in those bowling shots? All I see is the ceiling shadows or whatever shifted (and the usual warmer red/yellow tint).

    And I thought SSAA didn't blur textures, but actually was equivalent to a small amount of AF? I can't remember if it seemed blurry b/c some games unnecessarily let text and the HUD be SSAA'ed as well. Though the 360's texture problem doesn't seem to be one of blurring, but of poor sampling (or MIP-map creation, as Mint says).
     
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