Specular Material


SpecularAmount of specular reflection, or the mirror-like reflection of light photons at the same angle. Used for transparent materials such as glass and water. materials have the following parameters to adjust:


The Reflection value determines the glossiness of the mesh.

TransmissionA surface characteristic that determines if light may pass through a surface volume.

The Transmission value gives the base color to the mesh.


The Index represents the Index of Refraction of the material. Standard values of Index of Refraction (IOR) can be readily found via searching the internet. Glass typically has a value of 1.53 and water 1.33.

Film Width (filmwidth)

This controls the thickness of a optical, thin film on the material. This is useful in creating rainbow or oil slick effects.

Film Index (filmindex)

This controls the Index of Refraction of the thin film.

Bump / Normal

Both the Bump and Normal channels can load images to control the amount of bump mapping and normal mapping (respectively). The Bump channel should be set to floatimage to load a bump map. The Normal channel should be set to the image data type to load a full color normal map.


Opacity sets the transparency of the material. Set the data type to alphaimage(if the image has an alpha channel) or floatimage(for black/white images) to load an image to set the transparency (use the Invert checkbox if necessary to adjust whether black or white regions are considered transparent.


Smooth is a Boolean value that sets whether to smooth the normals of all meshes sharing that material. When off, the materials can be faceted and polygonal.

Dispersion Coefficient (dispersion_coefficient_B)

The dispersion in OctaneRender™ is based on Cauchy’s equation which has two terms: A which is the index of refraction and B which is the dispersion coefficient. Increasing the value increases the amount of coloration and dispersion in the object and in caustics.

AbsorptionDefines how fast light is absorbed while passing through a medium.

Absorption means that the material slightly absorbs light while passing through. The color resulting from this 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 get more saturated.

Absorption Color (absorption_color)

The absorption color gives the spectrum remaining from white light after traveling through the material for a certain distance. Only constant colors are supported correctly.

Depth of Absorption (depth_of_absorption)

The Depth of Absorption specifies the aforementioned distance (in meters). The smaller this distance, the stronger the absorption will be.