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Ray tracing for PCs-- a bad idea whose time has come
Dean Takahashi sent me an e-mail pointing to a piece he wrote on VentureBeat describing statements Wednesday by Intel's Chief Technical Officer Justin Rattner targeted at NVIDIA. CNET's own Brooke Crothers covered the same story and provides additional background here.
The technology at issue relates to 3D graphics for PCs. All current PC graphics chips use what's called polygon-order rendering. All of the polygons that make up the objects to be displayed are processed one at a time. The graphics chip figures out where each polygon should appear on the screen and how much of it will be visible or obstructed by other polygons.
Ray tracing achieves similar results by working through each pixel on the screen, firing off a "ray" (like a backward ray of light) that bounces off the polygons until it reaches a light source in the scene. Ray tracing produces natural lighting effects but takes a lot more work.
(That's the short version, anyway. For more details, you could dig up a copy of my 1997 book Beyond Conventional 3D. Alas, the book is long since out of print.)
Ray tracing is easily implemented in software on a general-purpose CPU, and indeed, most of the computer graphics you see in movies and TV commercials are generated this way, using rooms full of PCs or blade-server systems.
Naturally, Intel loves ray tracing, and there are people at Intel working to… Read more
