AMD's Roy Taylor: PhysX/Cuda doomed?

[Grooveriding]

I've seen one game, out of the 23 available that use GPU physx, that had effects that were worth the performance hit and didn't come off as overdone junk. Metro: LL's effects with fog and smoke were really something, as well the debris effects were not idiotically over-done and were kept in check.

There is a reason there have been an average of less than four games that use gpu physx a year in the past six years since the first game that offered it... Developers can do more using the CPU, along with not crushing the end-user's framerate experience. Games like BFBC2, BF3, BF4 all have done far more to actually impact game play and have physics across a much larger portion of the game world than any game that uses gpu physx has.

The only good effect I've seen it offer is what you get in Metro:LL with the interactive fog and smoke effects that look amazing. Otherwise stuff like massive debris fields from a single gun-shot, or water that looks like stiff wobbly gelatin are really not doing it for me at the cost of big frame rate spikes to enable the feature.

If someone can develop a gpu ran physics tech that is efficient and able to do as much as the CPU does in best-case examples like Battlefield 3 but improved on with the real-time calculations that gpu run physics brings that will be great. But it does not look to be happening any time soon. Can you imagine gpu physx in BF3 ? You'd get about 2 FPS at all times and the experience would be awful.

 

[cmdrdredd]

The latest iteration of OpenGL can do just about everything DirectX can, and is certainly a viable alternative. And I certainly would love to see DirectX ditched for an open API. MS loves to force people tp upgrade to the latest Windows to get the latest DirectX.

Just about everything but not everything and even John Carmack who has used OpenGL forever says DirectX is better these days than OGL. Plus none of the new consoles, which for better or worse are gaming's future are using OpenGL.

I see only a few people in this thread actually get it. It's this guy's job to say stuff like this, to downplay the strengths of Nvidia's tech. This is not surprising in the least.

 

[BallaTheFeared]

BF3 was awful canned pre rendered physics, lol. In fact it was a step backwards for most compared to BFBC2 which used Havok cpu based destruction.

Out of the 23 available games that use PhysX 23 of them are better than without.

Both consoles will have cpu based PhysX available to them, and possibly Havok on the GPU. That should be interesting, I welcome any and all contenders, just don't pretend pre rendered effects like BF3 or Crysis 3 are "Physics".

 

[DominionSeraph]

And for all those people complaining about how PhysX doesn't affect gameplay, look at Hawken's full destruction PhysX.

Oh God, that's horrible. Somebody needs to tell those programmers what "mass" is. "Tensile strength" as well.

 

[VirtualLarry]

Witcher 3 is going to be the pinnacle for PhysX games. There is so much potential for PhysX in that game, and the developers are aware of it for sure.

Hair and fur PhysX are already confirmed, and there will be fluid PhysX as well.. Destruction and particle PhysX for signs and spells will also assuredly be used in the game.

As long as you don't have to play "avoid the ropes" to get decent framerates while playing.

 

[cmdrdredd]

As long as you don't have to play "avoid the ropes" to get decent framerates while playing.

What does this mean?

 

[Keysplayr]

Just about everything but not everything and even John Carmack who has used OpenGL forever says DirectX is better these days than OGL. Plus none of the new consoles, which for better or worse are gaming's future are using OpenGL.

I see only a few people in this thread actually get it. It's this guy's job to say stuff like this, to downplay the strengths of Nvidia's tech. This is not surprising in the least.

Everybody gets it dredd. Though there are some who take this "info" and run with it.

 

[VirtualLarry]

What does this mean?

On one of the levels on one of the Crysis games, there are ropes, which are animated with physics (I don't think it's "PhysX"), and if you so much touch or shoot a rope, your framerate drops in like half.

 

[cmdrdredd]

On one of the levels on one of the Crysis games, there are ropes, which are animated with physics (I don't think it's "PhysX"), and if you so much touch or shoot a rope, your framerate drops in like half.

Hrm, you mean the first level on the ship in crysis 3 and honestly after having played through it again recently I don't see the problem with them. Maybe it is patched up now.

Yeah I think that was cause of CPU physics.

 

[Dankk]

On one of the levels on one of the Crysis games, there are ropes, which are animated with physics (I don't think it's "PhysX"), and if you so much touch or shoot a rope, your framerate drops in like half.

That was a bug in Crysis 3 level, I imagine they've probably fixed it by now.

 

[akugami]

Hawken full scale destruction physics.

And so what if it's been used for eye candy? Eye candy physics like cloth and smoke tend to be very compute intensive so running it on the CPU lowers your frame rate big time.

Would you rather developers use canned animations for these effects, rather than actual physics?

So one example of destructible environment...and not greatly done at that. Certainly not much better than "simulated" destructible environments.

I still stick by my opinions, after years of nVidia telling me how great PhysX is and how it'll change gaming, I'm underwhelmed. If anything, PhysX being artificially limited to only nVidia GPU's has limited PhysX adoption and has limited the usage of physics engines in games.

 

[Carfax83]

Red Faction Guerilla had more impressive destruction than Hawken, and that was back in 2009. PhysX is not necessary to make good looking physics interactions, neither is a GPU (remember how PhysX pre-3.0 crippled CPU performance to make GPUs look good?).

Thats just nuts. RFG's destruction physics is extremely basic, with the structures themselves comprised of only a few pieces; in the low hundreds it seems. Some of the debris is also a canned effect, as it disappears as soon as it hits the ground as you can see in the video.

The Hawken demo on the other hand (which was in beta I may add) uses THOUSANDS of particles. There is no comparison between them.

At any rate, rigid body physics is the least compute intensive, and the least impressive out of all the physics effects.

Cloth, smoke and fluid are far more intensive, which is why you typically don't see those effects with CPU generated physics; unless it's very limited in scope (like Batman's cape)

It's absolutely possible to achieve the exact same effects using OpenCL.

It certainly is, but I don't see OpenCL stepping up to the plate. Bullet is years behind PhysX enough as it is.

 

[SolMiester]

Wait, a competitor is downplaying their rival's tech? COLOR ME SURPRISED!

LOL, my thoughts exactly....

 

[Subyman]

PhysX will be around for awhile, Unity uses it.

 

[ShintaiDK]

PS4 uses PhysX and APEX.

 

[BallaTheFeared]

 

[Carfax83]

Who cares if there are canned effects as long as they look good?

Well from a developer perspective, canned animations take more time to implement which adds to development time and cost. Also, unless done VERY well, they don't look as good as computed physics generally speaking.

And that's rigid body physics, which is the easiest to implement..

With more complex physics like smoke, fluid and cloth, it's even harder to animate properly and I've personally never seen animated effects for these things that rival what PhysX offers.. There's a reason we never saw realistic looking cloth in computer games until Ageia came out with PhysX..

They are also repetitive. The first time you see it, you think awesome. But after seeing the same animation over and over again.....:whiste:

 

[SirPauly]

PhysX does not equal physics. PhysX is eye candy. Swirly particles, green goo, etc... They code some catchy special effects and insert them into the game, slap the TWIMTBP sticker, and pay the dev. Makes the game run faster on their hardware because it bottlenecks the CPU on their competitors. Win/Win for the Dev and nVidia.

Imho.

It may be logical to have robust, flexible physic software tools to take advantage of multi-platforms, the CPU and the GPU! Most PhysX titles are CPU based, Arma 3 takes advantages of the strengths of PhysX and the CPU!

It's not about just the GPU! PhysX' largest strength isn't just the GPU Component but its software for multi-platforms and hardware device

However, the developer is toying with the idea of bringing more advanced physX features to Arma3:

We would like to have advanced (PhysX) particles in the game, but we can't promise anything right now.

http://forums.bistudio.com/showthre...h-discussion&p=2416707&viewfull=1#post2416707

The Eye Candy Enigma!

Since when is having more effects and fidelity a negative? Fidelity is very important, one may imagine! To me, ideally, would like to see advanced physics raise the bar of realism, fidelity and the holy grail -- redefine game play itself.

 

[Carfax83]

Developers can do more using the CPU, along with not crushing the end-user's framerate experience.

Since you're so fond of the PhysX in Metro Last Light, try running it on your CPU, and see how far that gets you..

Games like BFBC2, BF3, BF4 all have done far more to actually impact game play and have physics across a much larger portion of the game world than any game that uses gpu physx has.

As has been mentioned, all of those games use canned animations in concert with computed physics. Using those games as a representation for what CPU physics is capable of is thus nonsensical, because it's not true physics.

If someone can develop a gpu ran physics tech that is efficient and able to do as much as the CPU does in best-case examples like Battlefield 3 but improved on with the real-time calculations that gpu run physics brings that will be great. But it does not look to be happening any time soon. Can you imagine gpu physx in BF3 ? You'd get about 2 FPS at all times and the experience would be awful.

GPU physics only runs slow if you're using your main rendering card to compute the physics, and the card is already heavily taxed from rendering and has no spare cycles.

In that case, you can either reduce your settings to alleviate the burden, or get a dedicated PhysX card.

 

[Carfax83]

So one example of destructible environment...and not greatly done at that. Certainly not much better than "simulated" destructible environments.

That's beta, and it's a lot more than any game so far has ever tried to do.

If anything, PhysX being artificially limited to only nVidia GPU's has limited PhysX adoption and has limited the usage of physics engines in games.

PhysX isn't artificially limited to NVidia GPUs.

PhysX runs on everything, and the only reason why it doesn't run on AMD video cards is because AMD refuses to support PhysX..

The license is apparently free, so there's no one but themselves stopping them from doing it.

 

[SirPauly]

PhysX runs on everything, and the only reason why it doesn't run on AMD video cards is because AMD refuses to support PhysX..

The license is apparently free, so there's no one but themselves stopping them from doing it.

The PhysX GPU component utilizes the Cuda API and AMD would have to license and support Cuda!

Speculation and conjecture hat on:

I believe AMD respects and likes the middleware PhysX but has issues with the proprietary API Cuda.

Back in 2008, AMD and Intel's Havok came to an agreement, which allowed AMD to port Havok to OpenCL.

I believe, that AMD asked nVidia, for permission or agreement changes to allow AMD to port PhysX to OpenCL, with their quiet conversations, AMD and nVidia had.

 

[Carfax83]

The PhysX GPU component utilizes the Cuda API and AMD would have to license and support Cuda!

AMD could port PhysX to OpenCl and bypass CUDA completely. Of course, they won't do that as they're too proud. It would be admitting that NVidia is their better..

 

[sontin]

AMD could port PhysX to OpenCl and bypass CUDA completely. Of course, they won't do that as they're too proud. It would be admitting that NVidia is their better..

You cant do it. The source is closed. They would need to catch the API calls and then send it to their OpenCL wrapper.
They did it with Havok but as we see that is not a usable solution.

 

[BFG10K]

Every single one of those games you mentioned uses a mixture of canned animations and computed effects. Do you honestly believe those games use 100% computed physics like PhysX games do?

The Red Faction games have been mentioned repeatedly, and they most certainly use computed physics: http://www.eurogamer.net/articles/digitalfoundry-red-faction-tech-part-one-interview?page=2

Digital Foundry: Can you take us through the basic principles of your destruction model?

Eric Arnold: What most games mean when they say "destruction" is "visual destruction" – things like tiles chipping off the wall, but the wall remains intact beneath it, or a destroyed version of the object swapping in when enough damage is done. Our goal was always to fully realise "physical destruction" – if a section of building looks like a main structural support it should behave as such and the building should realistically fall apart when it is taken out. That's where the stress system comes in to play. It is constantly evaluating the structural stability of objects in the game as they take damage. It doesn't care if the object is a knee high section of retaining wall or a bridge the size of a football field, it will run the same simulation on them so we get a consistent result.

The actual number crunching is done in a number of discrete steps so processing can be spread out over time. First we have to take in to account if there are objects being supported by the object being analysed, these could be anything from an enemy tank to a sky bridge connecting two towers. After that is done the stress code walks over the object from top to bottom adding up the force generated by the mass above (along with the mass of supported objects) and compares that to the strength of the material at that point. If the force is greater than the strength the material is broken which can result in a section completely breaking free and falling if that was the last connection.

As all of this is going on we also play audio and video cues to let the player know which areas are getting close to breaking. Beyond making the world more believable they serve as a warning system that the structure is unstable and could collapse on the player's head if they aren't careful and hang around too long. This small addition took the system from a neat tech demo to pulling the player in to the game world and generating very real chills as they flee from a creaking, groaning building while tendrils of dust and debris rain down around them.

The end result is a world that physically reacts to the player in the same way that real objects would – snap off two support legs of a tower and it will tip over sideways, if there happens to be building next to it the tower will crush the roof and tear a hole in the wall, if there happens to be enemy troops inside that building they will wake up with a splitting headache if they get up at all. And the best part of it all is that the engine is entirely player driven, they are given a set of tools, a list of goals to accomplish, and the freedom to solve them in any way they see fit. Rather than force premade solutions down their throats we wanted to liberate them to devise their own battle plan and succeed or fail on their own terms. Thankfully some of the most memorable moments can come from spectacular failures, so rather than being frustrating failure encourages the player to come back and try something new.

Heck, Red Faction 1 came out in 2001 and I've yet to see any PhysX game that can dig arbitrary tunnels like it did:

http://www.youtube.com/watch?v=o8KeFgzqsPQ
http://www.youtube.com/watch?v=lYJyzpZ-rP0

Minimum requirements for the game were a Pentium 2 @ 400 MHz, and the physics never bogged down machines back in the day.

No CPU is powerful enough to fully compute the destruction effects seen in those games..

There are several games that offer comparable (and even superior physics) to PhysX titles but run perfectly fine on the CPU. Somehow it seems like only PhysX is crippled on CPUs while Havok (et al.) isn't.

PhysX isn't artificially limited to NVidia GPUs.

Hardware PhysX most certainly is, which is what people are taking issue to. It's also locked if non-nVidia GPUs are in the system.

PhysX runs on everything, and the only reason why it doesn't run on AMD video cards is because AMD refuses to support PhysX..

No, the reason is because there's no license to run it on their GPUs.

The license is apparently free, so there's no one but themselves stopping them from doing it.

AMD could port PhysX to OpenCl and bypass CUDA completely. Of course, they won't do that as they're too proud. It would be admitting that NVidia is their better..

That's like saying "Windows is free because Linux can run DirectX through Wine".

You seem to have the mistaken notion that a wrapper/emulation is the same thing as a "free license".

 

[BallaTheFeared]

The problem with comparing games like Red Faction to PhysX enabled games is one has their gameplay routed in destructible environments and the other is applied after the fact.

Without PhysX in those games there would be no physics because the devs did not design their games around physics like effects, that's why PhysX suffers from being more akin to lipstick on a pig.

That said the effects in Red Faction is pretty awful, nothing compared to GPU enabled effects because of the huge difference in compute power between the two. And I'd rather have my pig get dolled up before I dive in, even if it's just dressing it helps.