Physics acelleration: fixing the chicken-and-egg problem

[Zen[n00b]]

The problem is, developers don't want to make physics intensive games, because they know that people simply don't have the right hardware to run them and you can't enhance performance by lowering simulation complexity in "software mode" for anything else than pure eyecandy, because things like placement and movement of boulders which could kill players, have to be calculated in exactly the same way for everyone. To make it worse, people don't want to buy a physx card, because there's currently no benefit from having one of them, because there's few games that support it and most of those games add just some eyecandy without enhancing gameplay in any way, to stay compatible with the non-physx-accelerated versions - creating a vicious circle.

Would you rather have UT2007 with simplified graphics to make it possible to run in software rendered mode or UT2007 with insane graphics which couldn't be software emulated at all? The difference between visuals and physics is that you can change the graphics detail level/use a different render device and still have the same gameplay (or with slight changes, like: no FC glow = harder to spot FCs = theoretically easier caps), but you can't lower the physics complexity, because it's not just pure eyecandy and it would affect the gameplay (different boulder behaviour for players using different physics settings on the same server? = easier/harder to get killed/uneven gameplay). Of course, we could let the game do all the calculations using the CPU/GPU instead of a PPU, but it would probably cause drastic slowdowns in games like Cell Factor, which were designed with physics intensive gameplay (and dedicated hardware) in mind. It would be like playing UT'99 (or other 3D game) on a gfx card without 3D support, like Trident 9000i with 512kb of video RAM (ehehe, the memories ^^.

The Ageia PhysX card is probably the first PPU designed for gaming ever, so the lack of support is understandable at this point and we probably won't see many games running on first gen PPUs. Maybe in the future such processors will be integrated into CPUs, much like it happened with coprocessors evolving into floating-point units or maybe they'll become a part of graphics cards or simply become obsolete when IBM releases their godlike 0,3THz CPU. There just have to be some impressive games which would show the true power of a dedicated physics processing unit, in the same way there had to be impressive 3D games to popularize 3D accelerators.

Instead of playing safe all the time, somebody should release a game which would introduce completely new gameplay (cell factor is a good starting point), like completely destructible levels - for example, you would be a gigantic evil cybernetic entity and you could devastate some buildings using sophisticated pain delivery systems, throw a bus or a house or something at your enemy, block the entrances to your base with some debris, grab an aircraft trying to attack you and rip it apart, king kong style, etc. The point would be to make an epic game (user was banned for this pun) where it would be fun to completely obliterate the map, liero/worms style and use it to your advantage (probably frying your PC with no PPU in the meantime).

Making a physx-enabled game with nothing more than realistic smoke grenades and shell casings would be like creating the first 3D accelerator ever, opening the 3D screensaver in win95 or a 2D game with a special patch adding 3D particles, showing it to the world and screaming: "BEHOLD! THREE DEE REVOLUTIONZ OLOLOL!!!!!11111". What's the point if a normal CPU can do exactly the same thing?

 

[Kyllian]

There's a big difference between "support" and "dependance"

 

[Spiced Hammer]

~
Perhaps a better approach is to generalise the whole physics SDK so that it can operate using one of a number of different hardware options such as PPU, GPU, dual core, or just a single core if no other options available.

I agree with Cynic, Eggboy's got the right idea. I think it'll be kinda like video cards: I remember reading about Homeworld, one of the first games to require 3d accelaration. Before that you could do 3d w/o a card, but buying a card was a more cost-effective means of enabling the functionality since otherwise you'd need more CPU and RAM. Once that was firmly established, we accepted that we'd have to buy video cards to play games to the point that reading about UT2004 having a software render mode surprised me. It might be easier this time since the dual-core systems we'll all have next generation will make it easier to implement more advanced physics at first since games are still single-threaded...


Growler, I'm not holding my breath for Unreal Engine 7.0 optimised for quantum computing architecture.

 

[JaFO]

As soon as companies stop playing it safe there's tons of people screaming about lack of support for their ancient hardware.
Why'd you think even UT2k3 still had software-support in the end ?

Like it or not, but the UT-series is too much of a niche-genre already to risc alienating even more consumers by setting hardware-requirements like that.

 

[Spiced Hammer]

That's exactly why I think the cards won't be required at first; it's not safe. Even requiring more CPU juice and RAM for the latest games will still cause some whining from people who are out of touch with reality or something so it shouldn't be an issue. More advanced physics will probably be the first or one of the first ways games become more multithreaded to take advantage of the dual-core systems that are going to be mainstream soon for reasons applying to a wider consumer base than gamers. Eventually, like graphics, gamers will transition gradually to buying cards to do it.

There's a big difference between "support" and "dependance"

There's also a big difference between graphics and physics. You can still play UT in software mode with all options as low as they'll go but you can't play online with game-influencing physics stuff like collapsing towers disabled.

 

[-AEnubis-]

Yeah, but most of the UT series has always caused some whining in the department of hardware. It's always pushing the envelope.

Sierra puts out hardware surveys with their games, and designs them with gameplay in mind, and makes them to run well on the "average system." They do it to ensure sales.

Epic has never really done anything like this. Only high end systems have ever been able to run their games to the fullest the first 6 months of release. It's always effected their sales, but their content has stayed of a high enough quality, that they still have tons of dedicated followers.

Ever card in your machine that has it's own processor is designed to take some of the load of your CPU. Your GPU's didn't hit the market as a sudden necessity, APU's still aren't a necessity, and now we have NPU's and PPU's coming onto the market. Do you really think any software developers will make them as such? No. We all have CPU's, and all of this stuff will be scalable to lean on that. Easily too, considering prior Epic titles haven't been written with 64bit compatibility, or with multicore cpu's in mind. These too thing will get a lot more juice out of your current 64 bit processors, leaving you with hopefully some floating point crunch time to do some sick physics without your "specialty card."

In short: Don't worry about it

 

[Spiced Hammer]

Only high end systems have ever been able to run their games to the fullest the first 6 months of release. It's always effected their sales, but their content has stayed of a high enough quality, that they still have tons of dedicated followers.

As mid-range catches up with UT, though, sales probably pick up.
I read that Utech3 will support the newfangled PPU but will also allow those of us who don't go all out on flashy hardware to thread physics through the other CPU core and that it'll support SLI but not require such extravagant hardware to play. It's good news indeed for me since I plan on making the jump to dual-core architecture next time I build a PC and that alone will probably equip me to play UT w/o coughing up money for hardware physics or a second video device right away.

P.S. I love the Shock sig Anubis.

 

[gregori]

The solution to physic accleration is obvious: consoles!

Consoles are a standard hardware platform, so you can build games for them where physics are a central part of the gameplay, not just cosmetic. Really innovative games have to be made for Xbox360 and PS3, taking advantage of their multiple cores to do physics processing, games with ridiculous levels of enviroment interaction and totally new types of gameplay.

In order to compete with a wave of console games using amazing physics for gameplay and visuals, a range of solutions will have to be eveloped for PC's as i'm sure PC owners will want games just as their console counterparts, or even games far more advanced


Range of solutions to making physics part of the core gameplay include doing physics processing on Graphics card, on multithreaded multiple core pcs or on a physics accelator chip. What is crucial is that there are games that require physics acc. for gamplay reasons, and consoles are the best place to develop the first wave of those games!

 

[Spiced Hammer]

*slaps forehead*
Dag, Greg, it seems obvious now you said it. Consoles can do the dedicated physics thing, or any revolutionary technology, elegantly since developers can make real gameplay features with it not having to worry about support.

I'm a fan of consoles' performance/stability/price balance so I should have thought of that...

 

[MonsOlympus]

Im surprised no one mentioned that all this physics stuff would need to be sent from server to client and visa versa, so this begs the question will I need a 4mb connection for all this gameplay affecting physics?

Or the alternative get more lans going, see alot of people are hooking consoles together because most people have more than 1 tv these days but we'll see. Sometimes it easier to grab your pc and go round a friends house or to a lan party, if these events start picking up then we'll see alot more dedicated physics in gameplay.

Well just a few thoughts that I dont think were covered.

So Im hoping for the ps3/pc/xbox interoptabiliy that way we can have mega console/pc lans and no one will differentiate them anymore, it'll be purely games machines.

 

[JaFO]

I think in recent interviews Epic has pretty much said that PhysX-stuff was optimised for lan-play as that's where you're going to have the most bandwidth available.

Consoles definitely would get the PhysX-stuff into a playable state, because in a way they were responsible for the idea behind GPU's as well (they've always had specialised hardware for various features).

There's one massive hurdle ... up until now there hasn't been a good game that has a need for a PPU.
At best we've had Half-life 2 and only fanboys think the physics-based puzzles weren't more than a little far-fetched/boring after a while.
At worst we've had http://en.wikipedia.org/wiki/Trespasser_(game)]urassic park:Tresspasser.

Of course the 3d-graphics had to deal with loads of crap before 3Dfx & co arrived as well.

 

[-AEnubis-]

Spiced Hammer: ty

Yeah, we've discussed in multiple different threads, on multipe different subjects, why console are looking much yummier for gameing in general. Everything from maximizing hardware performance, to prioritized hardware capabilities, less likely hood of hax, less config tweaks unbalancing gameplay, more fair and consistant input for everyone to use, etc, etc.

My only gripe will be how they need be good about either keyboards, or n52 like devices for fps games, with a good selection of mouse drivers, and options.

F*ck a thumbstick.

 

[Kyllian]

There's also a big difference between graphics and physics. You can still play UT in software mode with all options as low as they'll go but you can't play online with game-influencing physics stuff like collapsing towers disabled.

Now, the way I've understood the PhysX chip is that it takes over for the processor in physics calculations when the card is present and the game supports it. So the game could have the same amount of physics whether or not the card is installed, it's just that the CPU would need to dedicate more cycles to physics

 

[DeathBooger]

Now, the way I've understood the PhysX chip is that it takes over for the processor in physics calculations when the card is present and the game supports it. So the game could have the same amount of physics whether or not the card is installed, it's just that the CPU would need to dedicate more cycles to physics

This is how it will work with any game that uses Ageia's physics SDK, but the developers may add extra things when the card is present. Still, all the physics will be calculated by the PhysX card when using the SDK. Unreal Engine 3 uses only Ageia physics. Other games, like the new Ghost Recon, uses Havok physics but they added extra stuff for the PhysX card.

 

[sinikk]

Im surprised no one mentioned that all this physics stuff would need to be sent from server to client and visa versa, so this begs the question will I need a 4mb connection for all this gameplay affecting physics?

If the sever and the client both have a physx card, the sever can just send the info 'this happend, here, with this force' and let the client work out where all the bits of debris actually go. If all clients have the same info, the same processing power and the same physics calculations, they should get the same result without having to be told by the sever exactly where things (like predictible bouncy objects) are and what they are doing.

This is how it will work with any game that uses Ageia's physics SDK, but the developers may add extra things when the card is present

And those extra thing can be incredibly CPU-intensive (enought to stop the game being playable) and could compleatly revolutionise computer gaming.

When I started this thread I was actually trying to argue all sides of the arguement. Yes, this could be awesome but needs a really cool game to get it off the ground. Also, I don't have 200USD and don't think I would ever pay that much to have better explosions. But if I do get a physx card I want it to actually do something. But I also want to be able to play new games coming out. And, although gregori's suggestion is blindingly obvious and would work really well, I like my keybord + mouse.

This is why I thingk that a really good game, like UT 2007, should have some 'revolutionary' content, but also have enough 'normal' maps that people dont feel left out. If Epic were willing to make, say, 40 normal maps and 12-15 truly awesome physx-only maps, they might just be ale to please everyone.

 

[-AEnubis-]

That's not really in tight accordance with now netcode for UT works. Though, this kind of physics will have a great impact on that, and it may be in for a serious overhaul.

 

[Wail of Suicide]

If the sever and the client both have a physx card, the sever can just send the info 'this happend, here, with this force' and let the client work out where all the bits of debris actually go. If all clients have the same info, the same processing power and the same physics calculations, they should get the same result without having to be told by the sever exactly where things (like predictible bouncy objects) are and what they are doing.

I think the same thing, but consider this: If we rely upon the macro-level physics to be deterministic (and, admittedly, in a perfect world they would be) across multiple clients, there's a huge potential for error. The more moving elements in a level the more of a chaotic system the game state would become and any error between clients or server could ultimately have dramatic effects (the butterfly effect) upon the gamestate represented on one client as compared to another, or the server. All it takes is a bit of rounding error and you're on your way ...

 

[DeathBooger]

I just found out that the BFG PhysX card comes with a demo that was made in Unreal Engine 3, I might pick one up just to see what the engine is like.

 

[Spiced Hammer]

My only gripe will be how they need be good about either keyboards, or n52 like devices for fps games, with a good selection of mouse drivers, and options.

F*ck a thumbstick.

Ty to you too. I'm looking up n52 today just to find out what it is. I'm glad the new xbox will have a VGA connector offered at all, my cruddy TV set has what I call poor man's AA: the picture's so fuzzy you can't even see jaggies. All I need to be converted completely is good support for PC pointers and keyboards and such PC connectibility that there can be a console mod community like with PC games instead of like with chipped Xboxes w/ voided warranties that can't play mods online.

I think thumbsticks are neat for some games; in Halo 2 it's handy for circle strafing since you just hold for a rate of rotation instead of picking up your mouse (or thumb if you're using a trackball) if you happen to be near the wrong edge of your range when you get ambushed. Also, it puts a cap on rotation speed so people don't turn around in like five frames; that creeps me out... Oh, yeah, and it means I don't need a "walk" key. I'd love the choice between gamepad and mouse/keyboard setup. I fear that there'd still be whining if both were offered, though; either thumbstickers would complain that mice offer unfairly fast response or mousers would complain that the max rotation speed's stoopid...