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Light is scattered when it strikes an object. It is either reflected off, absorbed, transmitted, or some combination of the three. In the LPE syntax we list two types of events:
- Reflected Light (R) is light that reflects off the object and back into the scene. This light carries information about the objects reflective properties like its diffuse color and what the object might reflect more sharply of other objects around it.
- Transmitted Light (T) is the light that transmits into and possibly through the object. Subsurface scattering is a very diffuse transmission of light. Refractive objects have a sharper specular transmission of light through the object.
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Scattering Events
A scattering event is a type of light scatteringlight scattered from a reflection or transmission. In RenderMan we provide two main events and one special User event:
- Diffuse (D) scattering events are the type we associate with diffuse surfaces like paper, rough wood, skin, dust, cardboard, etc.
- Specular (S) events are shiny or dielectric type scattering. This covers things like shiny car paint, metals, plastics, water, glass, etc.
- User (U) events are available to shader writers interested in using them to store some other information. While mentioned here, the documentation will cover the D and S events.
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