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Introduction to Radiosity. The 'radiosity' method of
computer image generation has its basis in the field of thermal heat
transfer. Heat transfer theory describes radiation as the transfer of
energy from a surface when that surface has been thermally excited. This
encompasses both surfaces which are basic emitters of energy, as with
light sources, and surfaces which receive energy from other surfaces and
thus have energy to transfer.
This 'thermal radiation' theory can be used to describe the transfer of
many kinds of energy between surfaces, including light energy.
As in thermal heat transfer, the basic radiosity method for computer
image generation assumes that surfaces are diffuse emitters and reflectors
of energy, emitting and reflecting energy uniformly over their entire
area. It also assumes that an equilibrium solution can be reached, such
that all of the energy in an environment is accounted for, through
absorption and reflection.
The basic radiosity method is viewpoint independent. The distribution
of energy in the scene is the same regardless of the viewpoint of the
image. |