Abstract
The radiosity method for simulating global illumination has been used to produce some of the most realistic synthetic image to date. However, the computation time required by its traditional algorithm is too long to be applicable to dynamic environments. In this thesis, we propose two approaches to extend the traditional radiosity algorithm to dynamic environments, that is, virtual scene whose objects are subject to be modified interactively.Our first approach is to devise a hierarchical link indexing scheme and a hierarchical visibility testing algorithm, so that those changed links in hierarchical radiosity due to scene modification can be identified rapidly. Then, instead of computing the illumination of the entire changed environment, only those changed links are required updating. In the second approach, we propose light buffer data structure to localize the computation of energy exchange. The basic notion of light buffer is to store light distribution around dynamic object in a light field liked structure. Then, the computation due to global illumination of the scene change is confine to the interaction between light buffer and enclosed local scene.Finally, some empirical tests are given to show that our proposed approaches are not only feasible but also achieve interactive frame rate.