“Those you wish should look farthest away you must make proportionately
bluer; thus, if one is to be five times as distant, make it five times bluer.”
—Leonardo Da Vinci
Participating media is the term used to describe volumes filled with particles. As we can tell by the name, they are media that participate in light transport, in other words they affect light that passes through them via scattering or absorption. When rendering virtual worlds, we usually focus on the solid surfaces, simple yet complex. These surfaces appear opaque because they are defined by light bouncing off of dense participating media, e.g., a dielectric or metal typically modeled using a BRDF. Less dense well-known ...