OctaneRender™ has two types of mediums: AbsorptionDefines how fast light is absorbed while passing through a medium. and ScatteringDefines how fast light gets scattered when traveling through the medium.. These medium can only be connected to “DiffuseAmount of diffusion, or the reflection of light photons at different angles from an uneven or granular surface. Used for dull, non-reflecting materials or mesh emitters.” and “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 (ie. they cannot be connected to “GlossyThe measure of how well light is reflected from a surface in the specular direction, the amount and way in which the light is spread around the specular direction, and the change in specular reflection as the specular angle changes. Used for shiny materials such as plastics or metals.” materials).