Nvidia will this week show in-game physics code calculations being run on a graphics processor, the first time this has been done in public, the company claimed today. When the technique is implemented in future games, the benefit for players will be more realistic virtual worlds, Nvidia said.

The process uses code from physics and character animation middleware maker Havok. Its Havok FX software provides an API for the mathematics games need to perform to work out how objects physically interact with each other - the effect of gravity, friction, mass, elasticity and so on. Havok FX runs these calculations on the host computer's GPU rather the main processor. Havok's approach frees up the CPU to focus on ever more complex artificial intelligence calculations.

Nvidia likes the technique because it provides another job for its graphics chips to do. With high frame rates at high definition resolutions and the ability to do complex rendering effects all pretty much sorted out, the law of diminishing returns is kicking in, leaving the latest products providing less of a leap forward than previous generations of products achieved over their predecessors. Nvidia needs new tasks for its GPUs to perform if it's to continue to make the latest upgrade attractive to gamers.

Havok FX ties leverages the GPU using Shader Model 3.0 rendering instructions, so it's as applicable to ATI's latest GPUs as it is to Nvidia's, of course. That didn't stop Nvidia saying how well the code works on its GeForce 6- and 7-series GPUs, even in SLI mode.

Of course, mult-core processors and multi-threaded game code capable of using all of the CPU's processing engines may render Havok's technique redundant, which is why it's pitching the system at special effects rather than game-play physics. The company sees the code controlling, say, fountains of objects rather than what happens when the player shoots at something. ®