-----> Octane Absorption Medium

Absorption is controlled with the absorption texture, which defines how fast light is absorbed while passing through a medium. A setting of 0.0 means no absorption. The higher the value the faster light is absorbed by the medium.

The Absorption node can be added to a material by clicking on the Add in the Material Node Editor and choosing Octane Medium.

Octane Absorption Medium Parameters

The Absorption parameter can be a color, value, or texture map and is multiplied by the Scale parameter. This allows setting a wide range of values more easily.

The color resulting from the absorption is dependent on the distance light travels through the material. With increased distance it will get darker and if the absorption is colored it will become more saturated. It works in a subtractive manner in that the scattered color is the compliment of the color designated in the parameter.

Rendering an absorption medium requires the Path Tracing or the PMC kernel. For media inside Diffuse transmitting materials the Direct Light kernel with Diffuse mode can be used as well.

Meshes

Participating media should only be added to meshes that define a closed volume, rather than planes. Using planes to model leaves of a plant with SSS will for instance not work. Using a single plane as a ground plane will work, however, it will be treated as an infinitely deep material. The mesh can have opaque objects nested inside, but nested participating media are not supported.