A Mesh Emitter is a polygon object that emits light into a scene. This is possible by applying a 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. material to the Mesh object, and then connecting a Black BodyAn opaque object that emits thermal radiation. In Octane, this is used to designate illumination properties for mesh emitters. or Texture emission node to the Diffuse materialUsed for dull, non-reflecting materials or mesh emitters.'s Emission channel.
Figure 1: A light-emitting Diffuse material
To use a Mesh as a light source, apply a Diffuse material to the surface, then connect an Emission node to the Emission pin. There are two types of EmissionsThe process by which a Black body or Texture is used to emit light from a surface.:
Toon shading uses its own light sources, independent from any Mesh emitters in the scene. This is done because with area lights you can never render sharp boundaries between different colors in the toon shader. Toon lights are not visible in the rendered image. There are two kinds of toon lights:
Figure 2: Point lights behave similar to small mesh lights
Figure 3: Directional lights behave similar to sunlight