Introducing Volumetric Fog Rendering
What exactly is Volumetric Fog Rendering? As the name suggests, it is the combination of Volumetric Rendering and the fog phenomena. We will now give some background on those components and see how they are combined in the final technique.
Let’s begin with Volumetric Rendering.
Volumetric Rendering
This rendering technique describes the visuals associated with what happens to light when it travels through a participating medium. A participating medium is a volume that contains local changes to density or albedo.
The following diagram summarizes what happens to photons in a participating medium:
Figure 10.2 – Light behavior in a participating medium
What we are trying to describe is how light changes when going through a participating medium, namely a fog volume (or clouds or atmospheric scattering).
There are three main phenomena that happen, as follows:
- Absorption: This happens...