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NVIDIA To Showcase PhysX Content
Early next week, NVIDIA will release the GeForce Experience Pack to demonstrate the 'PhysX' engine it bought from AGEIA earlier this year. The pack is free, and it will contain a stand-alone action game, maps for Unreal Tournament 3, and various demos. Gamasutra notes that the UT3 maps are "designed to 'fundamentally change' the game's mechanics."
The pack will feature NetDevil's Warmonger (pictured), a complete action game allowing players to use destructive powers to destroy walls, floors, and whole buildings to open new paths or close existing ones.
Any 8000, 9000, or 200 series is supported, so you can get something a bit cheaper.
(Consider the -X ending, implying DirectX, rather than something like PhysicsGL, or PhysL, implying OpenGL -- you know, the actually portable industry standard for graphics.)
...Or maybe PhysX just sounds a hell of a lot better than PhysL?
PhysX is actually not connected to DirectX at all; the PhysX SDK is even available for the Playstation 3 and Linux.
How can I believe you when you tell me what I don't want to hear?
Both player super powers and quite a bit of Paragon City and the Rogue Isles have been designed or retrofitted for PhysX capabilities in mind.
For example, when a fire blaster sends a bad guy to the burn ward, bits of flame and whatnot fly around, catching on nearby terrain or even other players or enemies. The same things happen with electric and other blasters that have a big visual 'splash'.
My earth controller leaves lots of stones and pebbles lying around. Enemies, players, and my stone golem have to wade through these and kick them out of the way to get to where they're going. When her wind powers kick up, the rocks frequently roll around in the gusts.
Anyone who uses firearms in Paragon, Rhode Island or in the Rogue Isles generates LOTS of brass. If you're not careful, they'll pile up around your feet and go scattering when you walk around. If a flier-type happens to go around them, they'll be blown around by his wake.
Perhaps the most dramatic use of PhysX in player powers is the 'Propel' power. This allows some telekinetics and gravity control types to throw bits of the terrain around (summoned out of pocket-space, of course). It's frequently possible to litter a zone with 'Propel Junk', that you have to shove out of the way to get anywhere. It's quite a fantastic thing to knock out a gangster with a ballistic fork lift. Gravity control just does bad things to physics particles in general, such as spraying piles of the forementioned casing brass all over the place.
A flier who tears through a tree will see lots of leaves and maybe a branch or two swirl behind in his wake.
The real bonus to PhysX is ragdoll model physics. When you punt someone hard enough to send them flying, they often land... awkwardly. It takes a few seconds for a mook who's just been skipping along the pavement by his teeth to pull himself back together. A favorite bonus is to knock an enemy into a railing. You can often leave them helpless, hanging by their feet or even their head in some rare cases.
PhysX in City of Heroes uses the CPU-only dll by default, but will also work with an add on Aegia card or with the newer CUDA drivers from nVidia.
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Except that Nvidia is having, or at least helping get PhysX on ATi cards as well. http://www.engadget.com/2008/07/08/physx-on-ati-effort-gets-helping-hand-from-nvidia/
Feeding advanced physics back into gameplay creates a compatibility barrier.
True. But there's also a parallelism problem and a lag problem. Particle systems where the particles don't interact with each other parallelize easily. In other words, blowing stuff into little bits is easy to make run fast. Big-object collisions don't parallelize well; you need intercommunication between adjacent objects. This is transitive, which turns a parallel problem into a sequential one. Worst case: "Now let us all join hands around the world", or, "Everybody take hold of the rope and pull". Very few games do physics well enough that two players could pick up an object, one lifting each end, and move it realistically. I'd like to see a game where a raid team has to cooperate to pick up a boat, carry it to the water, and get it launched in the surf zone, timing the launch so they don't get pushed back onto the beach by a wave. That would be a good feature in any "special ops" game; SEALs train for weeks to get that particular skill nailed.
The lag problem is that the graphics pipeline normally runs behind the game engine, and the game engine doesn't wait for it. If some physics out in the graphics pipeline has to feed back into the game engine, either the game engine has to wait, which slows it down, or the effect has to be introduced into the game engine a few cycles late. In some cases that works; you could have a game where snow was falling and snowdrifts affected skiing or driving. That would work fine if the snowdrift updates reached the game engine a few cycles late. But large-object collision detection and response can't be processed late, or the results not only look awful, you get fly-throughs and instability.
(I used to do physics engines. I'm responsible for the "ragdoll falling downstairs" cliche (1997)).
I wouldn't call myself an expert by a long shot, but I myself made a [url=http://img.photobucket.com/albums/v438/neoKushan/Random%20Program%20creations/newtexts.png]simple app[/url] that had "lots of boxes falling" around the place and it worked fine without PhysX hardware or other. It was completely unoptimised as well, yet on a fairly limited machine I could have hundreds of boxes colliding all over the shop without much of a frame drop.
I'm not bragging or trying to sound "kewel", I'm just saying that it's not exactly difficult to do this stuff and every game I've seen so far that supposedly has "super realistic physics" has always disappointed me on so many levels.
Perhaps with some hardware acceleration, we'll see some really destructible environments in games.
One can only hope...
+1 IDisagreeSoHeMustBeATrollOrAnAstroturferOrAShill
For those that already have a Geforce 8 or 9 card and don't want to wait for Nvidia's demo.
Head on over to http://www.warmongergame.com/ and grab the game. I'd also recommend heading over to Guru3d and finding some BETA drivers that enable PhysX support for the 8 series cards and newer PhysX drivers.
the cake is a lie