Ninja Theory on HDR

[Siraris]

For all of you tech heads, and people just interested in reading about the Playstation 3, there is a great interview (http://psinext.e-mpire.com/index.php?categoryid=3&m_articles_articleid=599) over at PSINext. The interview is conducted with an engine programmer from Heavenly Sword Developer Ninja Theory (http://www.ninjatheory.com) who has developed a new HDR solution that is being used in Heavenly Sword.

Marco: Correct. The main idea behind NAO32 is that we want to trade shading power to regain memory space and bandwidth (very precious resources on a console). So instead of encoding our HDR colors into a FP16 or FP32 frame buffer, we devised a scheme to use RSX pixel shading units to convert an RGB color in a CIE Luv color that only requires a common RGBA8 frame buffer (4 bytes per pixel, half the space of a FP16 pixel) to be fully stored.

The quality of this format is really outstanding. Even if it uses half the space/bandwidth of common HDR rendering solutions, it really makes no compromises at all in image quality.

It's nice to see a very nice, unbiased, information article every once in a while

[Reanimated]

So PS3 can't handle real HDR, so they came up with this rigged solution? Nice.

[DanAmerson]

No, I'm sure PS3 can handle full HDR with floating point buffers. His point is that he can do a good enough HDR with half the memory and a few more shader instructions. Since memory bandwidth is usually at more of a premium than shader ALU cycles, it's a good tradeoff.

dba

[Mike Jones]

So PS3 can't handle real HDR, so they came up with this rigged solution? Nice.


Trolling at it's best :D

[Yeti2005]

It's not exciting news but it's good news for Heavenly Sword. That game looks damn nice from the videos. It's just too bad it's probably not coming out till 2007.

[51|RandoM]

Quick, file a patent.

[51|RandoM]

Trolling at it's best :D

Might want to change his name to Regurgitated, since that is all we get.

[Reanimated]

Hey now, it's not my fault that the PS3 has a gimped memory system that forces developers to rig solutions for otherwise easily implemented effects. :)

[saran_js]

Might want to change his name to Regurgitated, since that is all we get.

No, no. He's the cause of all the problems with the whole world. Might want to do something about that.
:D ;)

[mulligan]

No, I'm sure PS3 can handle full HDR with floating point buffers. His point is that he can do a good enough HDR with half the memory and a few more shader instructions. Since memory bandwidth is usually at more of a premium than shader ALU cycles, it's a good tradeoff.

dba


I think is close to what Valvle did with Half Life 2, instead of relying on floating point buffers, wich at the time was only supported by NV4X (and does not support AA) they decided to store HDR's floating point values using PS 2.0, thus giving a wider set of video cards pretty much the same hdr effects while keeping HDR intact, it seems a lot of people are underestimating the RSX chipset, while somewhat behind Ati's Unified Shaders, still pack quite a punch in shader Ops.

edit: looks kinda god of warish (wich for me its s plus)

[Kelegacy]

When I saw this game at E3, I was wowed. I've also read some of the developer diaries and these guys are putting a tremendous amount of work into making this game stellar. I'm usually not a fan of the genre, but I'd still like to try it out eventually.

[Citizen Philip]

I truly wonder if he (Reanimated) believes himself to be a crusader. An armchair crusader under the mighty banner of the Xbox! He travels the wilds of the interweb a keyboard under one arm and an xbox under the other: he smashes his keys attacking the Evil Sony, a solider of good, fighting the good fight!

Or a middle aged man with nothing to live for, attaching himself to whatever belief he can find, as the general apathy of his real life is boring tedium... but at night.. and sometimes at work if the boss isn't looking he is: the Sony Crusader! Smiting! Crushing! Killing! Fuding! Spiteing!

...

Anyways. With most new tech (ie. HDR), I'm sure different companies/developers are going to find more efficient ways of implementing the protocals, getting the most performance and ideal user experience with the smallest footprint possible in system resources. Good for everyone.

[J3DI]

This all sounds amazing... HDR lighting techniques, unified shaders, and blah blah blah... For most people like myself I'm just happy that the game looks good. How they got there... doesn't matter to me. There could be a squirel running on a wheel inside the thing, but as long as it looks good I'm happy.

Yet, how is this article considered to be nice and unbiased? Its from a PS3 site, from an exclusive in house PS3 developer, who incidentally told me (in an email during early development) to pay up the extra money for a PS3 if I wanted to play the game...

More like this is the nicest "biased" article. Yet I'm glad that they are doing good things with the game and I cannot wait to play it.

[DanAmerson]

I think is close to what Valvle did with Half Life 2, instead of relying on floating point buffers, wich at the time was only supported by NV4X (and does not support AA) they decided to store HDR's floating point values using PS 2.0, thus giving a wider set of video cards pretty much the same hdr effects while keeping HDR intact, it seems a lot of people are underestimating the RSX chipset, while somewhat behind Ati's Unified Shaders, still pack quite a punch in shader Ops.

edit: looks kinda god of warish (wich for me its s plus)

Technically, support for shader model 2.0 and support for floating point buffers with blending and AA are separate. For example, (and if I recall correctly) Radeon 9000 series cards support floating point buffers and shader model 2.0, but they don't support post pixel shader blending which makes it difficult to do HDR effects with them.

The cool thing about the format that these guys are talking about is that it separates luminance(brightness) and chrominance(color). It can encode those formats at different accuracies. So, you can use 8 bits per channel for your two normalized chrominance components, but you can let your luminance consume 16 bits allowing you to record large variations in brightness.

These types of decompositions work well for visual data because brightness varies a lot more and a lot more frequently than color. A lot of video codecs use this fact to record chrominance at half the rate of luminance as a data compression technique. Theoretically, you could use a format like this on a shader model 1.0 card although you might quickly run into limitations in terms of pixel processing power.

dba

[Reanimated]

I truly wonder if he (Reanimated) believes himself to be a crusader.




I see myself as a fisherman and you ass the fish. The great thing is that you tools get baited every. single. time.

[Kelegacy]

I see myself as a fisherman and you ass the fish. The great thing is that you tools get baited every. single. time.
And that is the nature of a troll.

I could probably say a trollish remark in every thread as well, but I'd feel adolescent and absurd. Apparently that doesn't bother you.

[01010]

I see myself as a fisherman and you ass the fish. The great thing is that you tools get baited every. single. time.

Unfortunately for you I'm sure that you hold more emotional stock in your actions than anyone that "bites".

Personally it's annoying to see idiots on any "side" in this console "war" posting stupid shit all over the goddamn place.

[EGO]

I'm truly amazed by this type of attitude.

The "I have to start a fight, because I have nothing better to do" attitude. Or the "I'm going to argue with you, just to prove how much smarter than you I am, even though you're not really fighting and didn't solicit my OPINION".

WTF is wrong with the world?!?

[mulligan]

Technically, support for shader model 2.0 and support for floating point buffers with blending and AA are separate. For example, (and if I recall correctly) Radeon 9000 series cards support floating point buffers and shader model 2.0, but they don't support post pixel shader blending which makes it difficult to do HDR effects with them.

The cool thing about the format that these guys are talking about is that it separates luminance(brightness) and chrominance(color). It can encode those formats at different accuracies. So, you can use 8 bits per channel for your two normalized chrominance components, but you can let your luminance consume 16 bits allowing you to record large variations in brightness.

These types of decompositions work well for visual data because brightness varies a lot more and a lot more frequently than color. A lot of video codecs use this fact to record chrominance at half the rate of luminance as a data compression technique. Theoretically, you could use a format like this on a shader model 1.0 card although you might quickly run into limitations in terms of pixel processing power.

dba



Radeon 9000 Series only have PS 1.4, an update from 1.3, wich allowed for single pass shader ops, maybe you're refering to the 9600 series?.

That sounds awesome, choosing separate luminance and chrominance values, and it seems there isn't a huge trade off on 8 bits per channel for chrominance norms, (maybe some color precision lost?) as the full blown 16 bit luminance will take care of HDR light variations.

Also the limited shader instructions set up would gimp the whole thing.

[devicelimit]

It's not exciting news but it's good news for Heavenly Sword. That game looks damn nice from the videos. It's just too bad it's probably not coming out till 2007.

And it's coming out for the PS3.

[Serapth]

And that is the nature of a troll.

I could probably say a trollish remark in every thread as well, but I'd feel adolescent and absurd. Apparently that doesn't bother you.

You don't already feel like an adolescent? :D

[Kelegacy]

You don't already feel like an adolescent? :D
Only when I'm in the shower.

[51|RandoM]

As a fisherman, he is a master of baiting.

[Mr.Condescension]

So PS3 can't handle real HDR, so they came up with this rigged solution? Nice.

Actually, if you hang out in the beyond3d.com forums where nAo and other devs talk about all the video card architectures, it appears to be alleviating a problem on all current video cards. They all have difficulty doing HDR and 4xMSAA at the same time. Add AF on top of that and you're in trouble on any game. For instance, you'll probably note that Oblivion can't run HDR and AA at the same time. This new tech is allowing PS3 developers (it's not applicable to the 360 card) to use 4xMSAA, AF, and HDR all at the same time, which no 360 title yet shown can do. I hope the 360 devs come up with a similar solution for their system.

[DanAmerson]

Radeon 9000 Series only have PS 1.4, an update from 1.3, wich allowed for single pass shader ops, maybe you're refering to the 9600 series?.


Yeah. I meant the 9700 and 9800. My bad.

dba