Ray Tracing for Gaming Explored
Vigile brings us a follow-up to a discussion we had recently about efforts to make ray tracing a reality for video games. Daniel Pohl, a research scientist at Intel, takes us through the nuts and bolts of how ray tracing works, and he talks about how games such as Portal can benefit from this technology. Pohl also touches on the difficulty in mixing ray tracing with current methods of rendering. Quoting:
"How will ray tracing for games hit the market? Many people expect it to be a smooth transition - raster only to raster plus ray tracing combined, transitioning to completely ray traced eventually. They think that in the early stages, most of the image would be still rasterized and ray tracing would be used sparingly, only in some small areas such as on a reflecting sphere. It is a nice thought and reflects what has happened so far in the development of graphics cards. The only problem is: Technically it makes no sense."
I guess one has to state the obvious in that by moving to a process which is not implemented in silicon, as with current graphics cards, the work must necessarily be done in software. That means it runs on CPUs and that's something Intel is involved in where as when you look at the computational share of bringing a game to your senses right now, NVIDIA and ATI/AMD are far more likely to be providing the horsepower than Intel.
But really, even if this wasn't a vested interest case (and it may not be, no harm exploring it after all) - the fact remains that we don't actually need this for games. Graphics hardware has gone down an entirely different route whereby you write little shader programs which create surface visual effects on top of the bread and butter polygons and textures. This is a well established system by now and has a naturally compressive effect. It's like making all your visual effects procedural in nature rather than giving objects simple real-world textures and then doing a load of crazy maths to simulate reality. It works very well. Rememeber a lot of the time you want things to look fantastical and not ultra-realistic so lighting is some of the challenge.
Games aren't having a problem looking great. They're having a problem looking great and doing it fast enough and game developers are having a problem creating the content to fill these luscious realistic-looking worlds. That's actually what's more useful, really. Ways to aid game developers create content in parallel rather than throwing out the current rendering strategy adopted world wide by the games industry.
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