Real-Time Dynamic Radiosity for High Quality Global Illumination

Abstract

The radiosity class of techniques is relatively underrepresented in the current studies towards real-time dynamic global illumination, while it provides unique advantages. This thesis builds upon the existing theory for the redistribution of radiosity and the existing progressive refinement adaptation for graphics hardware. The dynamic radiosity theory is expanded by this thesis to differentiate between types of redistribution based on the emitting or receiving role of the static and dynamic patches. The new theory grounds the proposed cross redistribution radiosity algorithm. The redistribution of radiosity originating from static patches is substituted by different types of redistribution. The advantage of this new technique is that the number of rendered hemicubes no longer depends on the number of static patches but only on the number of dynamic patches, which proves to be a significant performance increase. The novel cross projection function is essential for realizing the reduction of rendered hemicubes. Several hardware accelerated radiosity adaptations are developed for comparison. The hardware accelerated adaptation of the progressive refinement algorithm is improved significantly, focusing on quality and general applicability. Furthermore, a novel hardware accelerated adaptation of incremental radiosity is introduced, which introduces the concept of reshooting. Finally, the cross redistribution radiosity theory is supplemented with a fast hardware accelerated adaptation, with the cross projection adaptation as main innovation. A qualitative analysis demonstrates that all implementations are capable of delivering very high quality global illumination, although the scene properties are restricted. In certain situations cross redistribution radiosity generates artifacts due to undersampling. The execution time is benchmarked for all implementations, which proves that the cross redistribution radiosity adaptation performs well within real-time bounds. A comparative analysis of competing real-time high quality global illumination techniques is favorable to our cross redistribution radiosity method, within the imposed scene restrictions.