C4D Octane User Documentation

Post Process Volume Effects

Analytic/Post FX Fog is a quick way to add some apparent atmosphere into a scene, via the PostFX pipeline. As such, the fog will NOT be visible through any transparent materials, and Post FX fog doesn't contribute to motion blur since Post FX occurs after the rendering is complete. Use the Standard Fog and/or Volume Medium in cases where this is desired.

Fog — Enables Post FX fog.

Fog Extinction Distance — The distance where the primary ray's transmittance becomes 0 due to fog's density accumulation.

Fog Base Level — Base height in world space for post fog effects.

Fog Half Density Height — The height from the base level where post fog density halves.

Fog Environment Contribution — Controls how strong fog color is affected by the environment. 

Base Fog Color — The base color  for the fog contribution.

Medium Radius — Radius of the post volume. The post volume acts as a sphere around the camera position with the specified radius.

The illustration uses Post Processing Lens Effects and Post Processing Volume Effects (figure 4).