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You almost touched photon mapping there but as long as rays start only from the screen, there is nothing wrong calling anything varying as ray tracing. Limiting
by leowoo91 7y ago
You almost touched photon mapping there but as long as rays start only from the screen, there is nothing wrong calling anything varying as ray tracing. Limiting reflection count or having multiple rays (monte-carlo) are often aligned with priciples you described.
- quickthrower2 7y agoPhoton mapping? As in can render diffraction?
- magicalhippo 7y agoSimplified, photon mapping is a technique where you shoot rays from the light sources and then record the hits on geometry. Name comes from pretending you're tracing a photon bouncing around. Then, when doing the regular ray/path tracing, at each intersection of the camera-ray, you see if the intersection location is near any of the light-ray hits. If so, add in some contribution from the light-ray hits. This avoids you having to explicitly check each light at each intersection point, saving you quite a number of visibility tests. Also, due to the smoothing kernel used when the "photon contributions" are added up, it leads to low-frequency noise rather than high-frequency noise that is normal in regular path tracing. This is especially noticeable when caustics are involved. A nice introduction to the technique can be found here: https://web.cs.wpi.edu/~emmanuel/courses/cs563/write_ups/zackw/photon_mapping/PhotonMapping.html https://web.cs.wpi.edu/~emmanuel/courses/cs563/write_ups/zac...