Of course, how a programmer exploits these features can lead to some interesting approaches. One game uses the cloth approach to simulate deformable car fenders. It only required setting the parameters of the item as a shiny silver cloth.
Fidelity, sophistication, interaction, and scaling show the importance of physics to a game. For example, fidelity with hardware support could show a boat floating on the water, while a simplistic approach would keep the water flat and the boat movement severely restricted. The boat example also shows sophistication.
Meanwhile, hardware acceleration permits true muscular and skeletal-based movement. Or, say, it could allow for a broken windshield that shatters into hundreds of pieces based on the impact details of another object—including its size, direction, and velocity. In a typical non-accelerated game, a canned sequence would be used whenever a windshield breaks, regardless of the object that hit the windshield.
Such interaction is key as the number of interactions increases. Imagine walking under a waterfall. The water that splashes off a person walking through the waterfall interacts with the rest of the water. These kinds of interactions are readily noticed by the observer, but game play before physics hardware severely restricted such a level of interaction.
Like 3D graphics chip vendors, Ageia keeps its internal architecture secret. The company only provides general details about data flow and the number and type of processors contained within its chip. The company indicates that any game performance bottleneck tends to occur on the graphics side, rather than with the PCI interface between the host and the PhysX chip.
The PhysX chip consists of on-chip memory with a memory bandwidth on the order of 1 Tbit/s. Its massively parallel set of processors is optimized for physics-oriented computation. Each thread of execution handles data depending on the type of interaction. For example, a tennis ball may consist of thousands of triangles on screen, but it will be detailed as a deformable body with the physics world. Fluids are interpreted using meshes.
Ageia delivered a standard API for its hardware and its free software implementation. Of course, the differences between these are usually two orders of magnitude. Software-only implementations then must limit the fidelity, sophistication, interaction, and scale to achieve reasonable game performance.
Most of the gaming technology developed over the years still targets gaming applications. But desktop applications and operating environments are starting to take advantage of features like hardware 3D graphic support and alpha blending.
Microsoft's forthcoming Windows Vista has a version of the user interface that requires 3D video hardware. No 3D hardware. Then your are stuck with the more conventional Windows XP-style interface. Don't be surprised to see 3D showing up in other places, like GPS navigation systems.
Gaming is only going to get better if you can afford the latest console or PC upgrade. The only limits are money, power consumption, and the ingenuity of developers.
For a complete list of companies mentioned in this report, see Drill Deeper 12540.
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