Interaction is probably the easiest of the four dimensions to describe. Simply stated, interaction is the effect that the characters have on their environment, and effect the environment has on the characters. Again in terms of the boxing scene, the sweat from the boxer’s face hitting the floor would both splash and cause the floor to become slightly more slippery. The boxer may be knocked off balance and run into the ropes around the ring, which in turn cause him to spring forward, back towards his opponent.

Sophistication then, is essentially the magnitude at which all of this can occur. The boxer will be built on a life-like skeletal frame rather than a series of boxes and spheres. The boxing glove will be a boxing glove instead of a sphere. In a game where you can shoot steel drums, the drum would deform from the bullet impact as expected, rather than a simple material change. In the event of an explosion causing this drum to be blasted away, the deformed part would slide with increased friction along the ground surface, whereas the non-deformed part would roll as expected, but be interrupted by the deformed part. Highly realistic, flexible, and unique models add to the physics effects and realism.

You may have noticed that these four dimensions seem to overlap quite significantly. That is the beauty of the whole thing. The effect of the full implementation of two or even three of these dimensions would be nothing compared with the realism and immersive effect that is created through the synergy of all four dimensions.

However, processing these four dimensions to their utmost degree is not an easy task. Not only would the chip need a highly parallel architecture to accommodate for the large amounts of information that need to be processed to produce the required scale, but the architecture itself would have to be custom tailored to physics calculations. A parallel architecture is more effective in this scenario because it can take these large chunks of data and compute them at once, as opposed to a more serial architecture that computes smaller bits of data simultaneously. Furthermore, the data required to process these four dimensions is traditionally placed in the system RAM before it is calculated by the CPU. Should this data be placed in a memory bank that is dedicated to the parallel processor discussed above, the speed at which this data could be processed increases, as does the efficiency of the system’s RAM, which is no longer having to store all of these bits of data.

More observant readers will note that there already exists a processor in gaming computers that acts in this manner, the GPU. However, a GPU is a highly specialized processor that is designed to render and display frames on the screen. Due to its parallel nature, it would likely be fairly effective at physics calculations, but just doing this would take away from the graphics processing capabilities of the card, and it would still not be as effective as a processor that is specifically designed to handle these physics calculations. That is where AGEIA’s PhysX PPU comes in.