The Research On Radiosity Of Global Illumination For Inline's Virtual Walkthrough

Illumination model has become the important research area of computer graphics in recent years, and has widely applied value. Lighting system is an important component of rendering photo-level virtual reality, it influence directly to the whole virtual reality system's emulational degree. With computer performance's doubling enhancement and increasing demands of show business, virtual realistic lighting techniques are widely used. That in turn furthers the development of relevant research.This thesis, target at establishing radiosity illumination model of indoor walkthrough, deeply studies several key issues in radiosity. Those include form factor calculation, analyzing hierarchical radiosity algorithm, computing octree scene and mesh simplification. During the research, we emphasis on comparing, analyzing the algorithms of those key issues. According to indoor walkthrough's feature, we improve existing global illumination model's algorithm and check improved results by experimental system. The experimental results show improved algorithm effectively reduced calculated complexity of radiosity and keeps original characteristics of illumination model well. It can be better applied in indoor virtual walkthrough system. The algorithm's proposal, improvement and check mainly expand as following three aspects.In scheme of calculating form factor, first we introduce form factor's geometrical concepts and describe its geometrical features by establish a unified model. When we mention how to calculate form factor from element to patch by projection method, we present approaches and ways of how to better apply this method into indoor illumination model. We check those in application system.In scheme of establishing radiosity illumination model's simplified calculational methods, we mention that logical meshed scene is important to radiosity calculation. By comparing and analyzing the flaws of traditional mesh simplified methods, we exploringly give a dual simplified method of mesh model. The experimental results show it didn't obviously reduce image's quality and can effectively decrease mesh patch's number in scene. So it can achieve the aim that shortens consuming time of scene rendering. In scheme of hierarchical radiosity, we discuss optimized method of how to reduce the number of calculate-necessary form factor in scene, which is under the precondition of maintaining its calculational precision. We present the flow design of this method and establish the mathematical model of hierarchical radiosity in theory. In scheme of establishing logical structure of scene, we...