Umm, why not physics on console GPU's?

[Rangers]

So, there's this fake valve interview running around, where the guy says they are running 93-95% on 360 and PS3's boundry is unknown. That one.

One of the things I was arguing on another forum to point out the article was fake, is this supposed Dev at one point says they are running HL2 physics on RSX.

So I mentioned this as a clue it's not a real dev. Because this isn't possible, I said.

But then I got to thinking..why not?

Shouldn't consoles be the ideal place for this sort of hackery?

We heard about physics on GPU in the PC space..why absolutely zero on consoles?

 

[Skrying]

Using GPUs for things besides graphics... is becoming very popular. Also, ATi and Nvidia have been talking about doing physics on the GPU for a good bit but nothing has materialized out of it. However, the RSX (being based around G70) isn't the hottest GPU for this type of work.

It probably comes down to that Cell is simply much better suited for the job over RSX, which I would say is already worked around in interesting ways. On the Xbox 360 side.. could be some other issue, I think using its GPU for some creative processing could be neat.

 

[Arwin]

Half-life 2 uses Havok for physics. And the Havok engine has been greatly optimised in the last year to make the best use of the SPEs in Cell, with some spectacular results (as Havok demonstrated on an IBM presentation). In a gaming environment, where the RSX will be already pushed to the limits for just taking care of spitting out vertices and shaders, combined with the SPEs being better suited for the job in almost all cases, I think it's very obvious that there's simply no good reason to want physics calculations on the RSX in the PS3. Matters may in rare cases be different on the 360, but not by that much. The demands for Hi-Def gaming graphics are pretty high, and satisfy the capacity of the GPUs on both processors quite well. That doesn't mean it will never happen, but there are good reasons why it will never become very popular.

As an aside, using PS3's Havok implementation, you have to keep in mind that obviously Valve is still using very clearly using the SPEs on the PS3, no matter what they are saying in any interviews. They probably just mean that they haven't developed any custom SPE routines for anything in Half-life 2, as opposed to the stuff that the SPEs do in Havok.

In that respect, I will be very interested to see whether you'll be able to see a difference in future games, but it may be some time yet before any games are visibly limited in terms of physics calculations in that regard. We'll see ... (or not).

 

[Kaotik]

Arwin, you've been playing too much Halo's or are waiting for Halo 3 too eagerly, this is Half-Life and Valve, not Halo

 

[Cheezdoodles]

As an aside, using PS3's Havok implementation, you have to keep in mind that obviously Valve is still using very clearly using the SPEs on the PS3, no matter what they are saying in any interviews. They probably just mean that they haven't developed any custom SPE routines for anything in Halo 2, as opposed to the stuff that the SPEs do in Havok.

You need new sources, or post links to them! Halo 2 is apparently coming to the PS3, using havoc middleware, AND being developed by Valve

 

[Rainbow Man]

I'd much rather seem y console GPU draw graphics with its clock cycles than waste them on rather gimmicky physics nonsense.

Alsmost zero games hjave used physics for anything even remotely useful in the big scheme. It just doens't add much to the experience at the moment. Whereas the not super duper drawing performance of today's console GPUs lead to sub-30 FPS and tearing in many games alreasdy WITHOUT any physics junk running on the GPU also.

It's a waste of resources.

Maybe in a future console but not today is my take on it.
Peace.

 

[Cryect]

Well one thing about that article that seems odd is EA is the ones porting Half Life 2 not Valve.

Also with physics till you are talking about fully destructible buildings etc there really isn't that big need for a hugely robust physics engine unless you want some physics gimmick puzzle (which was all the hype a few years ago but now unless its a major part of your game).

 

[joker454]

Games are still (for the most part) gpu bound. So you don't want to add more load to the gpu unless you absolutely have to.

 

[Rangers]

By saying "games are still GPU bound" and whatnot, you're just saying graphics are more important than any other part of gaming! Which certainly wouldn't fly in many other threads or, in threads about the Wii. Even John Carmack is saying we're getting close to all that can be done on presentation.

The Wii will play heavily in my argument hear, because clearly you could do Wii level graphics on PS3/360 even at 720P and still have tons of power leftover, right? In fact you could do much better than Wii and have GPU left over.

I'm not advocating it as a general solution. But what I've noticed is most games push one aspect of innovation particularly far. This game may focus on atmosphere, this game may focus on animation, this game may focus on physics..this game push new online uses. For example, I have read about a upcoming FPS (cant recall the name) that focuses on silky smooth animation from a FPS perspective. This is something that's just never been done before. What about that game where you deform the terrain as gameplay? And so on.

So, a game with less than state of the art graphics (but still good looking enough) and focusing on GPU physics would certainly seem viable. I can just imagine such a game being targeted at Xenos.

I wonder if the EDRAM would hinder this?

 

[joker454]

The Wii will play heavily in my argument hear, because clearly you could do Wii level graphics on PS3/360 even at 720P and still have tons of power leftover, right? In fact you could do much better than Wii and have GPU left over.

Sure, you could ship a 360/PS3 game with Wii graphics and their respective gpu's would mostly be sleeping. But you'd get crucified in ratings and sales would reflect it once word got out that the game looked "old gen". Maybe Katamari can get away with it, but most games can't.

 

[Rangers]

Sure, you could ship a 360/PS3 game with Wii graphics and their respective gpu's would mostly be sleeping. But you'd get crucified in ratings and sales would reflect it once word got out that the game looked "old gen". Maybe Katamari can get away with it, but most games can't.

I'm saying use the rest of the GPU for physics?

Because tha argument against was "you need all the GPU for graphic"

Anyways I think you could have a much better than Wii looking game and still leave room for physics.

On PC, GPU physics are said to be non-interactive only. Would that be the same case on comsoles? Or could they be programmed to even be real time interactive?

 

[AlphaWolf]

I'm saying use the rest of the GPU for physics?

Because tha argument against was "you need all the GPU for graphic"

Anyways I think you could have a much better than Wii looking game and still leave room for physics.

On PC, GPU physics are said to be non-interactive only. Would that be the same case on comsoles? Or could they be programmed to even be real time interactive?

I think thats a hard sell, I bet impressive graphics will move more boxes than impressive physics.

 

[Rainbow Man]

By saying "games are still GPU bound" and whatnot, you're just saying graphics are more important than any other part of gaming!

Not sure I agree wiyth that interpretation..

Fluid graphics updates is surely more important than pseudo-realistically breaking planks crates and barrels.

And when it comes down to it, saying games are still GPU bound is merely stating a fact. There's no value judgement in it at all.

Peace.

 

[Blade47167]

Not sure I agree wiyth that interpretation..

Fluid graphics updates is surely more important than pseudo-realistically breaking planks crates and barrels.

And when it comes down to it, saying games are still GPU bound is merely stating a fact. There's no value judgement in it at all.

Peace.

Personally I would sacrifice a certain level of graphical beauty for fully destructible environments and realistic explosions.

 

[Shifty Geezer]

I'm saying use the rest of the GPU for physics?

Why not use the CPU for that instead? It's not like these machines have tiddly little 500 MHz x86s that can't cope with complex physics and you'd need to use the GPU to help out.

IF a game is processor limited in its physics, with the devs wanting a certain level of physical gameplay which the CPU can't cope with, then the option of using the GPU could be considered, sacrificing graphical prowess. But given the potential of these processors, that's not a worry at the moment!

As for the technical limits about doing physics on GPU, I don't know. They'd probably serve an assist role rather than do the whole lot. Xenos ought to be better than RSX, being more versatile and supporting branching more effectively, but I don't know how well it could solo physics. It's unlikely we'll find out too, if devs are happy with the performance of the CPU. It'd be a darned sight easier to scale back your physics to less items and run it on a 200 GFlop CPU, then get a physics engine running in RSX!

 

[Rangers]

Not sure I agree wiyth that interpretation..

Fluid graphics updates is surely more important than pseudo-realistically breaking planks crates and barrels.

And when it comes down to it, saying games are still GPU bound is merely stating a fact. There's no value judgement in it at all.

Peace.

The wii is the bestselling console in America and the world by far.

It's graphics are far below the other contenders.

One would not be "GPU bound" if one did a Wii level graphics game on Xbox360, period. Far from it.

GPU bound is a matter of programming, not a statement of fact.

I'm not advocating ALL, even most, even 10%, games on 360/PS3 do this, but it would certainly be a viable avenue for one or more games to explore to set themselves apart. At least if "GPU bound" is the only consideration.

Hell, with the advent of Cell and Ageia's card, we were told physics would become more important than graphics, though that seems to have died off.

But I still dont know how TECHNICALLY feasible it would be. And nobody so far in this thread appears to either.

IF the physics were non-interactive, that would present another major drawback obviously.

 

[Titanio]

It's feasible, but I'm not sure if it's readily useable or desireable for console developers.

HavokFX, for example, supports SM3.0 class hardware and up. So the console GPUs would be capable. But on their product page they seem to be targeting PC developers, with no mention of availability on consoles. If it is available, then it's up to the developer to make the tradeoff between physics processings and 'pure' rendering processing. I say pure, because it's quite reasonable that you'd be doing physics processing in order to improve 'graphics'.

 

[Shifty Geezer]

The wii is the bestselling console in America and the world by far.
It's graphics are far below the other contenders.

One would not be "GPU bound" if one did a Wii level graphics game on Xbox360, period. Far from it.

The fact Wii level graphics work on Wii doesn't mean they'd work on XB360. In all probability people who bought an XB360 did so because of the graphics as much as anything.

I'm not advocating ALL, even most, even 10%, games on 360/PS3 do this, but it would certainly be a viable avenue for one or more games to explore to set themselves apart.

How so? Seriously, what physics are you thinking of that games will want to take signficant resources away from the graphics to drive them? We have advanced fluid dynamics possible now without dropping in visual fidelity (See Hydrophobia) and lots of busy rigid-body physics (see R:FoM). No-one's getting pinched in the physics at the moment, and the hardware isn't being fully tapped yet by any stretch.

Hell, with the advent of Cell and Ageia's card, we were told physics would become more important than graphics, though that seems to have died off.

Well, there's limits to these. Cell is still in early days. Aegia's PPU isn't going to be targeted by developers without a huge install base, which means it'll only be used to add extra eye-candy rather than create physics gameplay. And finally things like physics in animation techs are in their infancy. Behavioural physics in Euphoria and Havok have only recently been introduced.

But I still dont know how TECHNICALLY feasible it would be. And nobody so far in this thread appears to either.

The right place to ask this is in the GPGPU forum. They'll know more about how feasible physics on GPUs are. Though it's still not something most devs will give much serious regard for at the moment, because they have enough CPU power to drive the physics they are using. It could be that some devs are using Xenos to help with physics, but XB360 developers tend to keep mum on techniques. eg. Perhaps Hydrophobia makes use of Xenos? On PS3 it makes no sense as you have a monster CPU far better suited to the task.

 

[pjbliverpool]

Hell, with the advent of Cell and Ageia's card, we were told physics would become more important than graphics, though that seems to have died off.

Im not so sure of that. Just take a look at Farcry 2 and Crysis, both seem to be pushing physics quite hard and certainly well beyond the limits of previous generations. And all without Cell or an Ageia PPU!

I remember one of the selling points of the PPU originally was "imagine fields of grass that sways in the wind and gets pressed down as you move over it". Yup Farcry 2 has that.

 

[archangelmorph]

Im not so sure of that. Just take a look at Farcry 2 and Crysis, both seem to be pushing physics quite hard and certainly well beyond the limits of previous generations. And all without Cell or an Ageia PPU!

I remember one of the selling points of the PPU originally was "imagine fields of grass that sways in the wind and gets pressed down as you move over it". Yup Farcry 2 has that.

This doesn't make his point any less valid..

In both games you mentioned the vast majority of people care more about the graphics than the physics and both don't utilise physics to any particularly novel and important degree.. Wind and swaying grass is a nice asthetic touch but adds nothing to gameplay..