CompuServe Messages

Uh….caustics are reflective / refractive phenomena that occur when light interacts with a material with those properties, in particular water. Let's see…. have you ever noticed at a swimming pool, the shimmering light patterns on the concrete sides of the pool, or on the bottom ? Caustics are the patterns of light that appear due to light reflecting from a wind-peturbed curved specular surface OR refracting through a non-homogeneous material. Another example would be when light passes through a glass or chandelier, etc.. Besides seeing shadows and reflections possibly, you also see the light patterns produced which are caustics. They form because rays from a light source converge AND diverge when interacing with objects in a given environment. In rendering, can be considered a form of diffuse reflection, resulting in patterns of light AND darker areas. When formed on second-hit surfaces (such as the sides of the pool), are examples of specular-to-diffuse transport. Any additional light propagation from a second to third or greater hit is purely diffuse interaction. That's about all I can say on the subject. Hope it helped more than confused <g>. BILL