Pre-Computed Lighting - Adobe ATMOSPHERE User Manual

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CHAPTER 13
Any Solid Object or Surface Object in the scene can be an emissive surface. The fl uorescent lights on the ceiling are
cylinders set to be emissive surfaces.

Pre-Computed Lighting

Computers calculate light by tracing the path of light rays from each light source to objects in the scene and back
to the observer. The angle of incidence, the refl ective properties of the object and dozens of other properties must
be considered and calculated to show lighting that appears realistic to the human eye. Atmosphere uses advanced
Radiosity lighting algorithms that produce cinematic lighting quality by calculating the myriad ways that real light
bounces through a scene.
This is a huge computing job, even for the most powerful modern PC, and can take hours or even days for complex
scenes. Since that wouldn't be practical for a real-time experiences, the work-around is to compute the lighting and
then save the information in fi les called Light Maps that are savedwith the scene. This process is referred to as pre-
computed lighting, and is distinct from real-time or dynamic lighting.
Light maps have the advantage that they can quickly be read during scene playback.
Atmosphere uses the Lighting Controls palette to set parameters that affect the lighting.