Ray-Tracing

[freak67]

Ray-tracing, on the other hand, models a scene in terms of the rays of light that pass from each pixel into the eye of the viewer, rather than on the basis of triangles. The scene still contains many triangles, but this "geometry" is abstracted into data structures that resemble "trees". In other words, you can travel along the trunk of the tree, onto smaller and smaller branches, until finally arriving at the "leaves", which allows the overall complexity of the scene to be broken down into simpler and simpler pieces.

Daniel?s Quake IV demonstration required no video card interaction from the GPU, and instead only used the video card to send the image to the monitor. This is because Daniel?s demo system had eight x86 cores, a configuration that is destined to become mainstream in a few years. And, because the ray-tracing algorithm scales so well with CPU cores, it doesn't need the assistance of the GPU in order to get the same performance.

According to the PC Perspectives article, Daniel?s game reached almost 100 frames per second at 1024x1024 resolution. Note that as the resolution increases, the computation will spend more time tracing light rays for those additional pixels, and the frame rate will go down. To think that a PC with 8 cores can run a game like Quake IV without the use of a GPU, at high definition resolution and fluid frame rates, is impressive to say the least.

Source
Its a bit of reading, best to read it to understand it fully.

PC Perspective - Ray Tracing and Gaming - Quake 4: Ray Traced Project
This explains a little bit more of how it works.

 

[peterhuang913]

Umm.. yea... thanks for posting this.