Octane Scattering Medium
Descritption
The Scattering medium node is used to create the look of subsurface scattering. This is the phenomena where light rays enter a surface, are scattered within the material of surface, and then exit again. It is the key to creating the look of realistic human skin and other organic surfaces.
Node Inputs/Outputs
- Input/Output
Absorption: By default, the absorption attribute is controlled by a value slide ranging from 0 - 1 where 0 is no absorption and 1 is full absorption. A color or texture can be added to replace the value slider. The color's value and saturation can be used to further determine the absorption amount. Note: If the Invert Absorption attribute is active, these values will behave in the opposite fashion, for example: 0 will be full absorption and 1 will be no absorption.
Scattering: Determines how quickly light scatters as it moves through the surface. High values mean that light scatters sooner as it enters the surface, and low values mean that light passes deeper into the surface before it scatters. By default, the scattering attribute is controlled by a value slide ranging from 0 - 1 where 0 is no scattering and 1 is full scattering. A color or texture can be added to replace the value slider. The color's value and saturation can be used to further determine the scatter amount.
Density: Determines the density of the particles in the surface. The larger the density value, the more likely light will be absorbed when passing through the surface.
Phase: Controls the light's direction as it scatters in the surface. Use the Phase Function node as input.
Emission: - Accepts Octane Blackbody or Texture Emission nodes.
Volume Step Length: The default value is 4, but if the volume is smaller than this, you need to decrease the value. Decreasing this value decreases render speed, and increasing the value causes the ray marching algorithm to take longer steps. If this value exceeds the volume's dimensions, then the ray marching algorithm takes a single step through the whole volume. To get the most accurate results, keep this value as small as possible.
Shadow Step Length: Step length that is used by the shadow ray for marching through volumes
Displacement: Allows a texture to control a volume's sample positions displacement.
Node Parameters
Douible-clicking on the node will open the Parameters window. The settings are described below.
- Parameters
Absorption: As described above.
Scattering: As described above.
Density: As described above.
Volume Step Length: As described above.
Use Vol Step for Shadows: Toggle Volume Step Length for Shadows on/off.
Shadow Step Length: As described above.
Phase: As described above.
Invert Absorption: Toggle to invert the absorption value.