Trilinear Filtering Comparison(R420 vs R360 vs NV40 vs NV38)

Hellbinder said:
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The new method gives The same results as full trilinear. You would be accurate if they were noticably reducing Quality.

They are not.
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I'm not sure that this has been independently proven True of False yet. That really isn't the point. They should have an option to enable "Legacy Trilnear" (using thier words not mine). There obviously is a difference or else they wouldn't make a point like they have that thier method is different.

It still remains to be seen if thier method is better, I'm not going to just take thier word for it. :!:
 
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Raja/Andy says alp:

is this http://www.ixbt.com/video2/images/r420xt/r420-anis0x.jpg (copy and past it) bilinear or bri/trillinear as is is supposed to be...i heard it is possilby a bug in cod causing it to set filtering to bi rather than a really bad trillinear filtering method, is this true?



Andy/Raja:

This we believe is test error and the X800 images appear to be obtained using only a bilinear filter. We have been unable to reproduce this internally. Also, note that the game defaults to bilinear when a new card is installed and this may explain the tester error
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Evildeus said:
Fight, introducing the fight of the year, the century....
Nvidiots vs Fanatics 8) :rolleyes:
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Yep. I dont't think I've seen this much pointless messages in B3D's thread ever before. And this is only 10 pages long..
 
More Chat

Raja/Andy says question from Singer:

why did ATI say to the general public that they were using trilinear by default, when in fact it was something else? (quality is ok, i agree, but you did deceive, by claiming it to be a trilinear)



Our Answer:

We understand that there was confusion due to the recent reports otherwise. We provide trilinear filtering in all cases where trilinear filtering was asked for. As has been demonstrated many times by several people - almost every hardware has a different implementation of lod calculation and filtering calculations. If we start calling all the existing filtering implementations with different names - we will end up with many names for trilinear
Raja/Andy says question from Wer:

is bit comparison difference images can highlight IQ differences surely there must be some - why do you say there are no IQ differences when these comparisons show otherwise?



Our Answer:

The bit comparision differences between implementations occur due to many reasons. We constantly make improvements to our hardware algorithms. Bit comparisions just say they are different - not necessarily that one is better than the other. We always on the lookout for cases where we can find IQ problems with our algorithms. We can guarantee you that there will be bit-wise mis-matches withour future generation hardware too and the future generation hardware will be better. Our algorithms are exercized by the stringent MS WHQL tests for mipmap filtering and trilinear and we pass all these tests. These tests do not look for exact bit matches but have a reasonable tolerance for algorthmic and numeric variance.
Raja/Andy says question from crushinator:

Is this Algorythm implemented in hardware? who's analysing texture maps, is it just the driver doing that or is it the chip?



Our Answer:

The image analysis is performed by the driver to chose the appropriate hardware algorithm. This allows us to continually improve the quality and performance with future drivers.
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Hellbinder said:
The new method gives The same results as full trilinear. You would be accurate if they were noticably reducing Quality.

They are not.
Click to expand...

Ignore my last and let me ask this. Since the Drivers won't allow full-time enabled "legacy Trilinear". How is it that anyone else can confirm that thier method is better on an X800? True you can do some comparisons to a 9800 or Nv card but that is not the same. So how could anyone possibly prove to ATI that they should enable it when they can't even see the alternative on that hardware?
 
More...

Raja/Andy says question from Wer:

is bit comparison difference images can highlight IQ differences surely there must be some - why do you say there are no IQ differences when these comparisons show otherwise?



Our Answer:

The bit comparision differences between implementations occur due to many reasons. We constantly make improvements to our hardware algorithms. Bit comparisions just say they are different - not necessarily that one is better than the other. We always on the lookout for cases where we can find IQ problems with our algorithms. We can guarantee you that there will be bit-wise mis-matches withour future generation hardware too and the future generation hardware will be better. Our algorithms are exercized by the stringent MS WHQL tests for mipmap filtering and trilinear and we pass all these tests. These tests do not look for exact bit matches but have a reasonable tolerance for algorthmic and numeric variance.
Raja/Andy says question from crushinator:

Is this Algorythm implemented in hardware? who's analysing texture maps, is it just the driver doing that or is it the chip?



Our Answer:

The image analysis is performed by the driver to chose the appropriate hardware algorithm. This allows us to continually improve the quality and performance with future drivers.
Raja/Andy says question from Bouncing Zabaglione Brothers:

If its so good, why has it remained hidden from the public and not marketed as "ATI SmartFilter" or somesuch? Surely if its as good as you say (better quality, faster speed), ATI marketing should be crowing about it? One of the issue here is that it *looks* like ATI is trying to hide things, even if what you have is a genuine improvement for the customer.



Our Answer:

The engineering team at ATI is constantly improving our drivers by finding ways to take better advantage of the hardware. These improvements happen during all the catalyst releases. We might have missed an oppurtunity to attach a marketing buzzword to this optimization!
Raja/Andy says question from Hanners79:

can you give a more detailed explanation as to why the use of coloured mipmaps shows the use of full trilinear, which doesnt correspond to what seems to occur in a normal, real-world situation?



Our Answer:

Coloured mipmaps naturally show full trilinear as our image quality analysis reveals that there could be visible differences in the image. It should be noted that trilinear was originally invented to smooth transitions between mip-levels, and in the original definition mip-levels should be filtered versions of each other, as coloured mip-levels clearly are not. Despite this, we understand that people often make use of hardware for purposes beyond that originally envisioned, so we try to make sure that everything always functions exactly as expected.
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Coloured mipmaps naturally show full trilinear as our image quality analysis reveals that there could be visible differences in the image. It should be noted that trilinear was originally invented to smooth transitions between mip-levels, and in the original definition mip-levels should be filtered versions of each other, as coloured mip-levels clearly are not. Despite this, we understand that people often make use of hardware for purposes beyond that originally envisioned, so we try to make sure that everything always functions exactly as expected.
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what's this supposed to mean ? i really don't get it.... , can someone translate please ? :?
 
People have way too much time on their hands, 80 pages of nothing. Go grab a beer, take the wife out for dinner or something. The internet was just waiting for some smell of a ATI conspiracy, then it is like a pack of wolves smelling a wounded animal. :?
 
pino said:
Coloured mipmaps naturally show full trilinear as our image quality analysis reveals that there could be visible differences in the image. It should be noted that trilinear was originally invented to smooth transitions between mip-levels, and in the original definition mip-levels should be filtered versions of each other, as coloured mip-levels clearly are not. Despite this, we understand that people often make use of hardware for purposes beyond that originally envisioned, so we try to make sure that everything always functions exactly as expected.
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what's this supposed to mean ? i really don't get it.... , can someone translate please ? :?
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Since I am seriously techically impared, unless I'm missing to notice something very important, it looks to me as the guy is trying to avoid a clear answer.
 
bGeek said:
Ignore my last and let me ask this. Since the Drivers won't allow full-time enabled "legacy Trilinear". How is it that anyone else can confirm that thier method is better on an X800? True you can do some comparisons to a 9800 or Nv card but that is not the same. So how could anyone possibly prove to ATI that they should enable it when they can't even see the alternative on that hardware?
Click to expand...

Why would you think it might be worse? Think they'd want to decrease IQ, which is one of their big advantages over nVidia, simply to garner a bit higher frame-rates in benchmarks? I don't think it's likely, and that instead what they've done is to optimize their drivers to provide what they consider to be acceptable IQ in line with "legacy trilinear," while running faster at the same time. In short, this is what all legitimate optimizations are supposed to do. Maybe they should have called it "extra-trilinear" or "super-trilinear" or "faster trilinear" for the folks hung up on the terminology...;)

I mean, I think you've got it backwards: the first thing they looked at was "legacy trilinear" and what's come of it is an optimization congruent with the R4x0 hardware which employs optimized trilinear in certain cases only where the algorithm tells them it will work without IQ degradation. From what I understand of what they've said, in cases where the IQ requires legacy tri, the optimization switches off. The goal of the optimization seems to be, therefore, to only employ the optimization where it does not affect IQ adversely. That's a perfectly reasonable thing for an optimization to do. A "cheat" on the other hand would deliver demonstrably worse IQ while providing better performance, which is why it would be a "cheat" as opposed to an optimization.

The problem I think is that as ususal the idea of "cheating" is being confused with "optimization"--and we all know who to thank for that bit of throwback propaganda, don't we?...:D
 
Quote:

Coloured mipmaps naturally show full trilinear - statement

our image quality analysis reveals that there could be visible differences in the image. - issue

It should be noted that trilinear was originally invented to smooth transitions between mip-levels, and in the original definition mip-levels should be filtered versions of each other, as coloured mip-levels clearly are not. - statement

Despite this, we understand that people often make use of hardware for purposes beyond that originally envisioned, so we try to make sure that everything always functions exactly as expected. - issue

:?
 
WaltC said:
Why would you think it might be worse? Think they'd want to decrease IQ, which is one of their big advantages over nVidia, simply to garner a bit higher frame-rates in benchmarks? I don't think it's likely, and that instead what they've done is to optimize their drivers to provide what they consider to be acceptable IQ in line with "legacy trilinear," while running faster at the same time.
Click to expand...

I may have missed it but have we determined the reason for filtering differences between R360 and R420 or have such differences even been confirmed? Outside of the COD screenshots is there any evidence which points to reduced filtering quality of the R420 vs the previous generation ATI products?
 
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