ChaosGroup >Photon Maps in VRay
for VRay 1.09.02e and Max 3.1
level: all
A Basic Guide to Photon Maps in VRay
General concept
The basic idea behind photon mapping is to try and recreate the indirect illumination in a scene by tracing rays (called photons, although they have nothing to do with the actual physical photons in the real world) from the lights in a scene and bouncing them around, storing the points at which they intersect the scene geometry. This is advantageous in several situations. First, the lights may be in a place that is difficult to reach with camera raytracing. Second, there may be many lights in the scene and evaluating the direct light contribution from each light source at every point may become extremely slow. A third advantage of photon maps (although not currently used in VRay) is to guide the raytracer to the more important parts of the scene.
