Radiosity is the function to precisely trace the energy emitted from light sources which reflects between objects and diffuses within three-dimensional scene, then, to calculate shading of the objects based on the energy distribution resulted from the trace. Radiosity can simulate the effect of indirect light by placing only the realistic light sources in the scene, therefore placing virtual light sources is unnecessary. Only placing the actually existing light sources is enough. Rendering soft shades is enabled by accurate calculations of the effect of the indirect light with Radiosity. It can also render similar image to a photograph of the real scene by the combination with Ray Tracing method. The result of Radiosity calculation is saved as three-dimensional data. Therefore, the walk-through in the scene is possible.

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1. What is Radiosity ?
2. The Radiosity calculation result doesn't become brighter even though light sources are increased in the scene.
3. What is an important reminder to generate model data for Radiosity calculation ?
4. Why is it a problem, whether front or back of the surface, in Radiosity calculations ?
5. Why some surfaces were displayed as black after Radiosity calculation ?
6. When is the completion point of Radiosity calculation ?
7. How to deal with the texture-mapping or the bump-mapping in Radiosity calculations.
8. What is the relation between Radiosity and Ray Tracing when using them together ?