Dispersive Calculation of Global Illumination Based on Spherical Harmonics Method

The radiosity illumination model plays an important role in computer graphics. As the calculation in the traditional radiosity method is time consuming,it is not suitable for dynamic scenes.In the paper we present a system based on the radiosity approach to speedup the calculation of global illumination. The algorithm follows the thoughts of using point sampling to simulate global illumination,while the sampling process is special so that the radiosity solution could be more adaptive in a dynamic scene.To every object inside the scene in the method,reference points are setup just at the vertices of the bounding box. When the scene is only slightly changed,the sampling result can be reused to reduce computation. The direct light is computed by cube-mapping and the energy exchange between objects is simulated by a trilinea-r interpolation among the reference points. Experiments show that the method can accelerate rendering with less indirect illumination calculation required.