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#1 |
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Artist formely known as Vysez
Join Date: Mar 2004
Location: Paris, France
Posts: 3,899
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Image Quality and Framebuffer Discussion for Available Games - Part 1
Why a new thread: The purpose of yet another incarnation of this thread is to streamline the content that is discussed in these thread. AKA get rid of some of the noise that plagued the other versions of the thread. Basic rules and guidelines: I'll start right off with the TL;DR version: TL;DR:
Full Version:
How-To and other useful explanations: How to tell the resolution of a backbuffer based on the outputted image: Someone has yet to take the time to compile all the relative information in a single comprehensive post. So bear with us and track down some of that information in the following posts: http://forum.beyond3d.com/showpost.p...&postcount=273 http://forum.beyond3d.com/showpost.p...&postcount=282 http://forum.beyond3d.com/showpost.p...&postcount=284 http://forum.beyond3d.com/showpost.p...&postcount=292 http://forum.beyond3d.com/showpost.p...&postcount=225 http://forum.beyond3d.com/showpost.p...&postcount=222 http://forum.beyond3d.com/showpost.p...7&postcount=29 Frame Buffer Calculations & Memory Consumption Back-Buffer(s) = Pixels * FSAA Depth * Rendering Colour Depth (may include multiple render targets for deferred rendering techniques) Z-Buffer = Pixels * FSAA Depth * Z Depth (usually 32-bit depth) Front-Buffer(s) = Pixels * Output Colour Depth (this is what you see, almost always resolved to 8-bit per component rather than 10-bit or 16-bit) Total = Back-Buffer(s) + Z-Buffer + Front-Buffer(s) Note: For Xenos, the back buffer and z-buffer must fit within the 10 MiB (10*1024*1024 bits, 8 bits/byte) to avoid tiling. Frame buffer formats RGBA8 = 8 bits for Red, 8 bits for Green, 8 bits for Blue, 8 bits for alpha = 32 bits per pixel FP10 = 10 bits for RGB components, and 2 bits for alpha = 32 bits per pixel FP16 = 16 bits for each component = 64 bits per pixel (no support for hardware alpha blending on Xenos) NAO32 = LogLUV conversion, In-Depth explanation = 32 bits per pixel (no hardware alpha blending) Example: 1120x585, 2xMSAA, FP10, 32-bit Z-buffer back buffer + Z = 1120*585*2*(32/8 + 32/8) = 10483200 bytes = 9.9975... MiB Aspect Ratio Some of you might be wondering how games like Call of Duty 4 (1.71:1) , Halo 3(1.8:1) , Metal Gear Solid 4 (4:3) can have rendering resolutions that are not 16:9 aspect ratio. All you need to learn about is anamorphic widescreen. The image is squeezed into the rendered resolution but is then stretched to the proper 16:9 presentation. An example of this squeezing can easily be seen in any Doom 3 engine games (Quake 4/Prey/Quake Wars). If you have one of them handy on your PC (latest version will do), try setting your resolution to 960x720 and in the console type r_aspectratio 1 for 16:9 or 2 for 16:10. All you'll see is the in-game view being squeezed/stretched horizontally. On the flip side, if you render the game at 1280x720 while still in 4:3 mode, the Mancubus just might be the fattest enemy you'll ever see. You can help it lose some weight by setting the game to 16:9. And of course, the isomorphic 1280x720 rendition will offer more image clarity than the anamorphic 960x720. Multisample AA Multiple geometry/sub-sample (reddish squares in below images) points with a particular weighting (surrounding the texture sample point, green square in below images) are used to determine the colour of the pixel being rendered. Sample positions can differ between AMD/nVidia. As RSX is based on the G70 architecture, the following sample patterns should apply. In the case of Xenos, it would not be unreasonable to assume that it uses the same patterns as ATI has used in the past (R300+). The result for 2xMSAA is that there may be one intermediary shade in between polygon edge steps; one sample is found to be within one polygon (e.g. colour A), and the second sample is found in another polygon (e.g. colour B). If both sample points have equal weightings, the resultant pixel would be 50% colour A, 50% colour B. Obvious results are obtained when a polygon edge bisects the shortest imaginary line connecting the two geometry sample points. Hence, 2xMSAA for G70 will look slightly different to 2xMSAA for R520 (see sample positions below). For the case of 4xMSAA, there may be more shades in between polygon edge steps due to the higher number of geometry samples, resulting in a smoother transition between steps. With equal weightings to each sub-sample, there will be three intermediary shades. The easiest way to see MSAA level is to have a straight-edged object overlapping another object/background with a high contrast in colours between the two e.g. black object against a white background. Beware of JPG compressed screenshots where pixels near high frequency components (edges) can be distorted. G70 sample patterns 2xMSAA http://www.beyond3d.com/images/reviews/g70/2x.png 4xMSAA http://www.beyond3d.com/images/reviews/g70/4x.png R520 - sample patterns 2xMSAA http://www.beyond3d.com/images/revie...aa_samp_2x.gif 4xMSAA http://www.beyond3d.com/images/revie...aa_samp_4x.gif Quincunx AA on PS3 - two geometry sample points are used just like 2xMSAA (so the same storage cost), but it also uses 3 samples belonging to neighbouring pixels (regardless of a polygon edge) to the right and below of the original texture sampled point (see sample pattern image for clarity). The result is a blurring of the entire image, but higher perceived polygon AA. Consider a texture of higher frequency components, lots of different colour patterns. The current pixel's two geometry sample points indicate the pixel is entirely within one polygon. However, the three neighbouring sub-samples are still accounted for in the final pixel, hence the overall image blur. Quincunx sample pattern http://www.beyond3d.com/images/revie...plepattern.jpg Comparison between 2xMSAA/QAA/ & blur filters http://upsilandre.free.fr/images/Quincunx.jpg Temporal AA on PS3 (ala Quaz)- odd and even frames are rendered with a half-pixel shift. The current frame is blended with the previous frame to achieve a similar effect as super sample AA for static scenes. In a moving scene, the blending of the odd and even frames produces a persistent blurring of the image. However, this is also advantageous for the edges of alpha-to-coverage primitives, because traditional multisampling does not work*, only super sampling. *see transparency AA or adaptive AA settings on appropriate PC hardware. Black Levels & Output Xbox 360 Standard = 16-235 Intermediate Expanded = 0-255 PS3 Limited Range = 16-235 Full Range = 0-255 Wii Undocumented at the moment (feel free to address the issue) Current list of game rendering resolutions and IQ Archive of the older threads on the same topic: Thread 1: The Neverending Upscale Discussion Thread * Summary=#457 http://forum.beyond3d.com/showthread.php?t=43330 Thread 2: Neverending Upscaling/Resolutions/AA etc Thread #2 *Rules: post: #616 * http://forum.beyond3d.com/showthread.php?t=46242 Thread 3: Neverending Upscaling/Resolutions/AA etc Thread #3 (Rules Post #1!) http://forum.beyond3d.com/showthread.php?t=48252 Footnotes Thanks to all the people who contributed to the list, took captures and wrote large parts of the explanations. AlStrong, Quaz51/Upsilandre, grandmaster, dot50cal, etc.
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- Power corrupts and absolute power is kinda neat. - If at first you don't succeed, put it out for beta test. --Internets |
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#2 |
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Junior Member
Join Date: May 2008
Posts: 47
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Looks like Call of Duty: World at War defaults to 1080p on PS3, though it's a lot softer than 720p.
Does anyone have the ability to check the resolution at 1080p? |
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#3 |
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Senior Member
Join Date: Feb 2007
Posts: 1,159
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Here's Quantum of Solace:
Shot1: 360: http://img296.imageshack.us/img296/768/qos1360zw9.jpg PS3: http://img152.imageshack.us/img152/3728/qos1ps3st8.jpg Shot2: 360: http://img300.imageshack.us/img300/4317/qos2360bo2.jpg PS3: http://img397.imageshack.us/img397/9266/qos2ps3cp3.jpg Shot3: 360: http://img384.imageshack.us/img384/8740/qos3360sw6.jpg PS3: http://img152.imageshack.us/img152/9522/qos3ps3dx8.jpg Interesting differences in the graphics (plus 360 is v-locked, PS3 isn't). Shot3 indicates that the sub-720p resolution is identical on both systems. |
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#4 |
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rwaaaraararagh
Join Date: Feb 2004
Location: beaver
Posts: 14,050
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The second and third shots appear to exhibit a sort of ambient occlusion in the 360 edition.
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#5 |
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Senior Member
Join Date: Jan 2003
Posts: 1,657
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Quincunx AA also has the advantage (it's main selling point) to provide some filtering on alpha textures.
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#6 |
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hardly a Senior Member
Join Date: Jul 2008
Location: still camping with a mauler
Posts: 3,676
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Yes, it looks amost Crysisesque in that regard, especially in the second shot on Bond himself. SSAO?
Last edited by homerdog; 16-Nov-2008 at 20:09. |
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#7 |
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Senior Member
Join Date: May 2003
Location: Skirts of Vitosha
Posts: 1,377
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Yep, definitely. Very characteristic look, and once you see it, even with all its defects in motion, it's impossible to turn it off, because now you see how much worse the scene looks without it.
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#8 |
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Member
Join Date: Mar 2007
Location: Wroclaw, Poland
Posts: 578
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Are the extra texture details in 360 version higher resolution textures or extra layer of noise/detail textures?
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Shifty Geezer: I don't think the guy really understands the subject. PARANOiA: To be honest, Shifty, what you've described is 95% of Beyond3D - armchair experts spouting fact based on the low-level knowledge of a few. This posting is provided "AS IS" with no warranties, and confers no rights. |
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#9 |
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Junior Member
Join Date: Aug 2004
Posts: 83
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To me it doesn't look like extra textures, but extra shader detail.
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#10 | |
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rwaaaraararagh
Join Date: Feb 2004
Location: beaver
Posts: 14,050
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Quote:
On a side note, there is a fairly clear difference in filtering quality - bilinear filtering on the PS3 and some degree of anisotropy on the 360 as you can see that one "tile" of brick in the lower part of the third shot that clears up on 360, but the next area beyond it is equally as blurry as on PS3. ![]()
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#11 |
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Member
Join Date: Nov 2008
Posts: 207
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#12 |
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Senior Member
Join Date: May 2003
Location: Skirts of Vitosha
Posts: 1,377
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At least some of it is resolution: on the first shot, the bricks in the far left; on the second, the wall above Bond.
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#13 | |
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Junior Member
Join Date: Aug 2004
Posts: 83
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Quote:
Last edited by GarretASUS; 16-Nov-2008 at 23:52. |
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#14 |
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Junior Member
Join Date: Aug 2004
Posts: 83
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#15 | |
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Member
Join Date: Nov 2008
Posts: 207
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Quote:
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#16 |
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Member
Join Date: Nov 2008
Posts: 207
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Also grandmaster thinks that both games render(thats all that matters to what we are talking about) at the same res.
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#17 | ||
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rwaaaraararagh
Join Date: Feb 2004
Location: beaver
Posts: 14,050
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btw, I've edited my original post to show the difference in filtering.
Quote:
Quote:
I would agree with the 2xAA claim - the near vertical/horizontal edges show classic results.
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#18 |
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Member
Join Date: Mar 2007
Location: Wroclaw, Poland
Posts: 578
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@AlStrong: I don't think it's filtering:
![]() Left 1/5 is almost identical. If it was about filtering, similar difference would be visible there as it is on the rest of the pic, after all the angle is the same. However difference becomes very apparent moving more to the right side of the pic. In my opinion this indicates more agressive mipmapping and not filtering differences. But overal I think there are multiple techniques employed. ![]() Glow on the pipes is extra shader. "Deeper", sharper textures are either extra detail texture or some postprocessing in the shader. Differences on the rocky wall behind the pipes is lower res texture but once again I believe it's due to more agressive mipmapping.
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Shifty Geezer: I don't think the guy really understands the subject. PARANOiA: To be honest, Shifty, what you've described is 95% of Beyond3D - armchair experts spouting fact based on the low-level knowledge of a few. This posting is provided "AS IS" with no warranties, and confers no rights. |
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#19 |
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Junior Member
Join Date: Jun 2003
Posts: 37
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Replying to COD5 question. It's most likely sub 720p as the previous COD4 game. ie 1024x600p 2xaa.
I'm interested to know LBP iq/fb.On my set it appears to below 720p with no AA.It doesn't look sharp as a 720p game. |
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#20 |
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Senior Member
Join Date: Feb 2007
Posts: 1,159
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Eh? Both are outputting sub-720p and my PS3 had 1080p disabled when these shots were taken any way. It is the best method to ensure like-for-like shots.
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#21 |
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Junior Member
Join Date: May 2008
Posts: 47
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Thanks for the reply, but I'm mostly interested in the 1080p resolution for CoD. Jaggies are much worse in 1080p mode. In addition "waiting" text in multiplayer seems to be stretched wider, suggesting a non 16:9 resolution that wasn't properly accounted for.
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#22 |
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Senior Member
Join Date: May 2003
Location: Skirts of Vitosha
Posts: 1,377
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Why would they do more aggressive mipmapping (rather than smaller textures) on a machine which has, in general, more bandwidth, more texturing units, but less memory?
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#24 |
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Regular
Join Date: Oct 2005
Posts: 6,834
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I have the impression that the textures in the PS3 version are slightly more defined in some places than the 360 version. Then again I could be wrong
edit: here is a brief observation in the first shot The textures of the 2 characters in the foreground seem to depict slightly better textures on the PS3. Check particularly the standing soldier's hand. The shadow's are slightly crispier on the PS3 but on the 360 they are softer. Someone might say that they are a bit "jaggied" on the PS3. The right character in the background though seems to be missing some objects in the PS3. There is some difference in the lighting effects too. I am not sure if this is context dependable though. edit 2: I also noticed that the interior lighting effects are probably slightly better on the 360 on some places (see ceiling) Last edited by Nesh; 17-Nov-2008 at 10:31. |
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#25 |
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Senior Member
Join Date: Jan 2007
Posts: 2,601
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^ noticed the same things.
One other thing I noticed (in the third pic to be specific) some of things on the PS3 version seem to shine/have more reflection while the 360 version is a little flat in comparison. Do they both use 2xAA like CoD4? Hard to tell from those shots. edit: vines also seem to be absent on the PS3 version (4th pic). Last edited by djskribbles; 17-Nov-2008 at 11:42. |
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