V-Ray EnvironmentFog is an atmospheric effect that allows the simulation of participating media like fog, atmospheric dust, and so forth. Volumetric properties can be determined by 3D texture maps. The atmospheric effect can also be confined with geometry objects.
V-Ray EnvironmentFogcan use either of two algorithms to calculate volumetric lighting. The first algorithm is a simple exponential sampling scheme, which is used when there are no texture maps specified. In this mode, V-Ray takes a number of random points inside the volume and calculates the volumetric lighting at those points. The second algorithm is a raymarching scheme, which is used when any of the volume properties are mapped with a texture. In that case, V-Ray traverses the fog volume in small steps, calculates the volume properties at each step, and computes the volume lighting accordingly.
