Appendix B - Radiosity Visualization

At the conclusion of the radiosity process the final luminous exitance of each element is known in RGB color. Using a Flat Shading graphics technique were each element area is assigned its computed Spectral Radiant Exitance (RGB), we can visualize the environment.

 

 

The flat shading technique appears blotchy as each entire element is assigned one color. To improve the image, ElumTools uses a more refined technique known as Gouraud Shading (credit to Henri Gouraud). Gouraud shading requires that we know the exitance value at each element vertex. To achieve this, ElumTools computes the average exitance value of all elements sharing the common vertex and assigns this value.

 

Once each vertex exitance is known, Gouraud shading linearly interpolates from vertex to vertex to arrive at the shading for each element. Applying Gouraud shading to the same image we can see a dramatic difference.