PS3 hypotheticals thread

[Npl]

.... with a traditional CPU like PS2 EE. ...

I think you`re the first person on this earth calling the EE a traditional CPU. It wouldve been known to the devs by now, but that doesnt mean its traditional, I`d say say Cell is a logical evolution of the EE.. and easier to handle too.


But on hypothetical what-if scenarios: I said it way before launch and still think the PS3 would`ve been better served with an additional 256 MB Ram (XDR preferably) instead of a required HDD. (of course with the optional HDD-Bundle and the ability to use plain SATA-Drives intact)
Cost shouldve been roughly the same, Multiplatform games would have better textures than the XBox and thats wouldve been an obvious improvement for Users. Noone cares if a year later you`d need a (bigger) HDD anyway, its the initial expense that shocks people most - Whos really gonna believe a 20GB HDD will last through this gen, its just a useless doorstop you HAVE to pay for)

And theres no reason for not allowing games that require HDD, even if a SKU without was sold. (Im sure soon MS will prove that point)

 

[patsu]

theres a pdf about the tech behind uncharted where the describe what they use the SPUs for
*/Scene traversal
*/Geometry processing
*/Spherical Harmonics to cube maps
*/Particle simulation
*/Water
*/Animations
*/Decompression
*/Collisions
*/Physics
*/Path Finding

ie far more than basic polygon clipping/culling , though they do mention they are doing most pervertex work on the SPUs instead of the card

Do we know how they did their shadow ? In animation, I believe the SPUs were used for multilayer blending (and animating facial expressions). Beyond graphics, the SPUs are also used for audio processing. Uncharted has great sound.

Insomniac also uses SPUs to great effect. We can probably glean some details from Mike Acton's and his colleagues' slides.

 

[Mintmaster]

theres a pdf about the tech behind uncharted where the describe what they use the SPUs for
*/Scene traversal
*/Geometry processing
*/Spherical Harmonics to cube maps
*/Particle simulation
*/Water
*/Animations
*/Decompression
*/Collisions
*/Physics
*/Path Finding

ie far more than basic polygon clipping/culling , though they do mention they are doing most pervertex work on the SPUs instead of the card

Aside from geometry processing, none of that qualifies as being a "graphical co-processing element", as stated in the post I replied to. Maybe there's a little stuff beyond clipping/culling in the geometry work like patsu mentioned, but it's still only done by Cell because RSX is based on a chip designed for low poly workloads.

All of that is stuff every game on every platform does on the CPU. There's nothing special about Uncharted in terms of Cell usage other than maybe being written better. Even "SH to cube map" is just a form of data decompression.

Uncharted looks good because they wrote good shaders and have great art/content.

 

[Mobius1aic]

Nothing I've read suggests that Cell had anything to do with the graphics of Uncharted beyond basic polygon clipping/culling (which is only helpful to aid a GPU originally designed for low poly PC workloads).

They're just good coders and artists. Don't underestimate the impact of the latter. Artistic talent (both in the content and from the coders themselves) is what really sets apart titles like Uncharted, Gran Turismo, and Gear of War.

Oh I'm well aware of their artistic prowess. All their character textures are hand done, no pre-made skin textures. Actually I think the whole game was hand done, nothing pre-made. And considering this was their first PS3 title, it's very impressive.

 

[BoardBonobo]

theres a pdf about the tech behind uncharted where the describe what they use the SPUs for
*/Scene traversal
*/Geometry processing
*/Spherical Harmonics to cube maps
*/Particle simulation
*/Water
*/Animations
*/Decompression
*/Collisions
*/Physics
*/Path Finding

ie far more than basic polygon clipping/culling , though they do mention they are doing most pervertex work on the SPUs instead of the card

All that and they said "As far as the Cell processor and the SPU's are concerned we were only using about 1/3 to 1/2 of the SPU's at one time and so there is still quite a bit more we can do."

As a ceratin dark lord once said... Impressive.

 

[patsu]

Aside from geometry processing, none of that qualifies as being a "graphical co-processing element", as stated in the post I replied to. Maybe there's a little stuff beyond clipping/culling in the geometry work like patsu mentioned, but it's still only done by Cell because RSX is based on a chip designed for low poly workloads.

I think I forgot muscle emulation (probably also geometry processing to prevent collapsing chest/torso and flattened elbows).

We will likely see more attempts in subsequent games. The original physics-based water was pulled because they couldn't make it work in the context of a roaring river. They said they want to try again. I am looking for advances that help both graphics and gameplay at the same time.

The deferred rendering (and post processing) in KZ2 is something to look out for. The weather system (and its rendering) is another good possibility.

We may see new examples in LBP, R2, Heavy Rain and other upcoming PS3 titles.


EDIT: Mintmaster, do you have any idea how ND did their shadow ? Do you see SPUs assisting in streaming after reading Insomniac's texture streaming slides ? (Okay, the extra capacity in decompression will help but what else ?)

 

[Mintmaster]

I think I forgot muscle emulation (probably also geometry processing to prevent collapsing chest/torso and flattened elbows).

Muscle emulation is just a deformation tied to a constant, like elbow angle (or maybe something fancier that knows when a muscle is being exerted). More of an artistic achievement than a technical one, like all animation.

The deferred rendering (and post processing) in KZ2 is something to look out for. The weather system (and its rendering) is another good possibility.

We may see new examples in LBP, R2, Heavy Rain and other upcoming PS3 titles.

Don't get me wrong. I'm not saying we won't have some cool stuff coming soon from these CPUs. I'm just saying that Uncharted isn't relying on Cell at all to get its look.

EDIT: Mintmaster, do you have any idea how ND did their shadow ? Do you see SPUs assisting in streaming after reading Insomniac's texture streaming slides ? (Okay, the extra capacity in decompression will help but what else ?)

I think it's just cascaded shadow maps, like everyone is using. There are just little things that make the difference, like aligning texels to avoid swimming, and using just the right amount of softness for the sample count that you can afford. Streaming doesn't really use many CPU cycles.

 

[patsu]

I see.

Don't get me wrong. I'm not saying we won't have some cool stuff coming soon from these CPUs. I'm just saying that Uncharted isn't relying on Cell at all to get its look.

Don't worry. I am just doing a mental dump of what to expect in the coming months. Yeah, I believe Uncharted's look is all in the art, attention to details and their willingness to push the PS3 limit (The RSX water effect is nice).

I think it's just cascaded shadow maps, like everyone is using. There are just little things that make the difference, like aligning texels to avoid swimming, and using just the right amount of softness for the sample count that you can afford.

WTH, if it's only a small thing, every developers should do it. It makes a big difference to the final quality.

Streaming doesn't really use many CPU cycles.

The texture streaming slides is this one:
http://www.insomniacgames.com/tech/articles/1107/files/texture_streaming.pdf
It talks mainly about RSX, HDD and Blu-ray; and does not mention Cell. So you are probably correct to say that it does not play a big part (I was wondering).

But I have been trying to fit "Everything Insomniac" into the software architecture proposed here:
http://forum.beyond3d.com/showthread.php?t=47057
Unfortunately, I don't have enough background to do so. e.g., I can't really appreciate the amount of improvements described in the "SPU Programming Best Practices" slide.

Does the slide describe a formal deferred rendering process ? Or does it describe the general approach of SPU parallelism (i.e., we can still use the proposed architecture to implement a forward rendering system) ? My guess is it's the latter.

Now back to the OP, all those hardware options will need to be evaluated in the context of the software run-time. In a way, I'm trying to figure out, if we are using Insomniac's proposed framework, which of those hardware options would show the best improvement.

 

[Arwin]

Muscle emulation is just a deformation tied to a constant, like elbow angle (or maybe something fancier that knows when a muscle is being exerted). More of an artistic achievement than a technical one, like all animation.

Don't get me wrong. I'm not saying we won't have some cool stuff coming soon from these CPUs. I'm just saying that Uncharted isn't relying on Cell at all to get its look.

Not in that it is 80% Cell, 20% RSX, but the Cell is definitely quite involved in the graphics pipeline in Uncharted, doing some culling, animation and such. Did you read the Uncharted post-mortem / GDC presentation? Almost the exact tech is all explained there, including the geometry involvement, the shadows, the animation layering using the Cell, etc.

Reading upwards it seems I'm not the first to mention the pdf, but you should really check it out, it's very interesting. Anyway, surely it's partly shaders, but partly also loads of high-res and very different textures with many texture layers and very many different environments. The game is big and has a lot of high-quality textures and a lot of geometry. At the very least I'm quite convinced it would have been very tough to pull off this quality in combination with this quantity without using the BD.

 

[Cheezdoodles]

Beyond graphics, the SPUs are also used for audio processing. Uncharted has great sound..

I love how i often see people mention this and it sounds like its a big deal (not saying you think so). Like "Woow, they are using SPU's for the sound man!!! its gonna be great!"

OF COURSE SPUs ARE GOING TO PROCESS THE AUDIO. There is no soundcard, the GPU cannot do audio processing, so the only thing left, is the cpu. Now the PPU core is probably the bizziest one, so the only logical solution is to process audio on one of the other cores. Im willing to bet that 99,9% of all games released this year will process audio on the SPU's. Its no big deal.

Tons of X360 games uses one core for audio (amongst other things) again, no big deal.

 

[patsu]

I love how i often see people mention this and it sounds like its a big deal (not saying you think so). Like "Woow, they are using SPU's for the sound man!!! its gonna be great!"

OF COURSE SPUs ARE GOING TO PROCESS THE AUDIO. There is no soundcard, the GPU cannot do audio processing, so the only thing left, is the cpu. Now the PPU core is probably the bizziest one, so the only logical solution is to process audio on one of the other cores. Im willing to bet that 99,9% of all games released this year will process audio on the SPU's. Its no big deal.

Tons of X360 games uses one core for audio (amongst other things) again, no big deal.

It was just a one liner reminder (that SPUs are used for audio processing to great results). Many high profile PS3 games have excellent sound. In the case of Uncharted, they have DTS Surround by default. I was told all US first party games like MotorStorm, Lair have 7.1 LPCM, DMC4 has 5.1 LPCM, and Dirt has 7.1 LPCM.

 

[Mintmaster]

Sound is 99% content and 1% format (i.e. DD5.1, DTS 7.1, etc). When you look at the data rates involved its clear that processing power isn't an issue there no matter how much fiddling you want to do.

Not in that it is 80% Cell, 20% RSX, but the Cell is definitely quite involved in the graphics pipeline in Uncharted, doing some culling, animation and such.

You're still just repeating stuff that I've already acknowledged in earlier posts. This is stuff that the CPU does in all games on all platforms, except for maybe the 360 when it comes to geometry related stuff since Xenos is almost at G80 speed for that stuff.

BD may well be necessary for Uncharted, but I personally don't think that reducing the texture variety a bit would have any noticeable impact in its enjoyability. It's not like you keep a texture database in you head and say "Hey, I saw that texture before!"

In any case, my comments were solely directed at that statement about Cell being "a graphical co-processor" in Uncharted and more games needing to do that.

 

[patsu]

Sound is 99% content and 1% format (i.e. DD5.1, DTS 7.1, etc). When you look at the data rates involved its clear that processing power isn't an issue there no matter how much fiddling you want to do.

Agreed ! It's just that the PS3 devs have more consistently taken advantage of the SPUs to spoil users in the audio department. In the light of the entire game load, perhaps having unused core(s) give them the peace of mind to handle pristine audio without being "wasteful" or affecting other subsystems ?

BD may well be necessary for Uncharted, but I personally don't think that reducing the texture variety a bit would have any noticeable impact in its enjoyability. It's not like you keep a texture database in you head and say "Hey, I saw that texture before!"

It's the other way round. You won't notice missing texture because they are not there. But you will notice them when the variety is there.

In any case, my comments were solely directed at that statement about Cell being "a graphical co-processor" in Uncharted and more games needing to do that.

Understand. The reason I brought up Insomniac's framework is I am trying to see if the way they arrange their work/modules would give the SPUs and RSXs more time to process the work. And how much is that extra time ?

 

[Arwin]

In any case, my comments were solely directed at that statement about Cell being "a graphical co-processor" in Uncharted and more games needing to do that.

For the scene traversal, they did visibility frustum culling, PVS lookup, and mesh processing setup on the SPUs (and sorting and the render setup on the PPU), as well as decompression, skinning, back-face culling and rendered geometry collision (decals, IK and some gameplay collisions). Then there is all the particle work for which simulation and setup is done on SPU. I'm not sure if I understand the presentation correctly at this point, but I think these are partly used in some of the many post-processing effects that the game has (depth of field, blur, tonemap, bloom, saturate, tint, distortion, motion blur and blend).

Whether or not you think that's important in the graphics pipeline, it clearly was on the PS3 because it allowed Uncharted to be shader bound. Combined with excellent shaders and the texture streaming from the HDD, that allowed the game to look as good as it does.

Here's the presentation, which I think should probably be required reading for many PS3 devs? Very nice presentation anyway. The way they did the shadows is also explained, and the whole rendering pipeline including dealing with opaque, FP16 (and using something called logluv which apparently renders two RGBA8 scenes to combine for HDR for some aspects of the pipeline, which goes beyond my full comprehension of rendering pipelines right now )

http://www.naughtydog.com/corporate/press/GDC 2008/UnchartedTechGDC2008.pdf

 

[AlNom]

Has NAO32 been forgotten already

 

[gongo]

Pristine audio is that not because of BRD streaming uncompressed PCM signals? Playing a PS3 game in DD5.1 makes no different from the original Xbox in audio fidelity.

So it still seems what uses of Cell are, are for the graphics. What then be the point of making a new CPU when a more powerful Nvidia GPU would be better and easier for programmers. I thought the whole point of a powerful CPU is to create better playing worlds that are alive and react to your actions?

I have a feeling a NVForce GPU+media chipset will turn out a better machine.

 

[patsu]

Pristine audio is that not because of BRD streaming uncompressed PCM signals? Playing a PS3 game in DD5.1 makes no different from the original Xbox in audio fidelity.

Somewhere on the net, ND mentioned that they are streaming up to 12 streams of audio from BD. I do not know what format was streamed but Uncharted does DTS Surround processing. And yes, it should not take much CPU power alone.

So it still seems what uses of Cell are, are for the graphics. What then be the point of making a new CPU when a more powerful Nvidia GPU would be better and easier for programmers. I thought the whole point of a powerful CPU is to create better playing worlds that are alive and react to your actions?

I have a feeling a NVForce GPU+media chipset will turn out a better machine.

I think the worlds of GPU and CPU are evolving and will continue to change. As long as the combined system meets the developers' demand, and the right tools are available, it should be fine. I do not know whether it is meaningful to shoehorn them into their current molds/roles in the future.

Furthermore, Cell was created to address specific issues in price, performance and power consumption. Having an all powerful GPU does not necessarily address any points in these areas overall.

As for powerful CPU reacting to you... have you tried PS Eye ?