Radiosity for Real-Time Simulations of Highly Tessellated Models

Abstract

The accurate simulation of light is one of the most important aspects of computer graphics. Radiosity is a physically-based method that can generate view-independent solutions of the light scattering in a scene. This thesis describes a radiosity system capable of generating high-quality global illumination solutions suitable for real-time simulations. State-of-the-art algorithms in hierarchical radiosity, such as face clustering and vector-based radiosity, are combined to efficiently handle scenes containing highly tessellated models. A new patch refinement method suitable for meshes with badly shaped triangles is also presented. A radiosity representation method is proposed, that combines vertex lighting and light mapping to allow real-time simulations of the radiosity solutions. The light map generation is based on the texture atlas approach, using a new segmentation scheme. To allow realistic rendering of materials that are not completely diffuse, the radiosity lighting is combined with specular lighting using OpenGL. The presented system supports quick visual feedback on how the radiosity calculation progresses. The preprocessing needed before the calculations can begin is very quick and the initial results can be displayed very fast. Even for large models, it is possible get a good idea of how the final result will look like in under a minute.