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Posted 17 December 2012 - 04:25 PM
Posted 17 December 2012 - 04:32 PM
Posted 17 December 2012 - 05:24 PM
Posted 17 December 2012 - 05:46 PM
Correct me if I'm wrong, but isn't it hundreds of times faster to do raytracing operations through the GPU? I haven't gone that low level yet with graphics stuff, but from other stuff I've seen that utilizes GPU, it seems like it'd be the optimal choice.
Edited by ic0de, 17 December 2012 - 05:47 PM.
you know you program too much when you start ending sentences with semicolons;
Posted 17 December 2012 - 07:19 PM
Yeah, pretty much every feature for which people use ray tracing in the first place will multiply the work. Just doing simple shadows generates one shadow ray per ordinary ray for each light in the scene, so if you have 10 lights, it'll be almost 10x the work. (Shadow rays are not as expensive as normal rays, but still.) Want soft shadows? More work, say 3x. Want reflection and refraction with a moderate 3 bounces? If there's a lot of reflective and refractive objects in the scene, that might quadruple the entire workload again. Now we are already at 120x the original workload. If we then add AA, motion blur, DOF etc., for a difficult scene we'll be doing hundreds of rays per pixel, billions of rays for the entire image.
Doing almost anything 2 million times takes a lot of time. If you want to get improvements like anti-aliasing, motion blur and field-of-depth effects, you'll have to launch many (100?) rays per pixel.
Posted 17 December 2012 - 11:25 PM
Edited by Bacterius, 18 December 2012 - 03:48 AM.
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