Research Of Realistic Rendering In VR Based On Photon Mapping

Realistic rendering is always an important object of computer graphics. Based on current research, shadow generation, caustic and parallelized rendering are studied, several optimized algorithms are realized and particular experiments results are given.Based on photon mapping, accelerating of photons searching, optimize of caustic photon map and parallelization are emphasized. The concepts of realistic rendering are applied in real-time rendering of VR, in order to improve the performance of visual realistic. The main work of this dissertation is concentrated in following three aspects:1. In shadow generation, the shadow map algorithm is optimized based on projection distance, so the visual effects of traditional algorithm is improved. The blur degree and the light degree are related to the distance between the shadow and the object which cast it. Much more realistic shadow result can be generated while the rendering efficiency is kept. In order to generate the realistic shadow in nature, the concept of photon texture is proposed based on photon mapping algorithm. In photon texture algorithm, the photon collection process is completed in texture, so the rendering speed can be increased remarkably.2. In caustic rendering, photon clustering algorithm is proposed based on photon mapping, intending to decrease the caustic photons while the rendering quality can be maintained. In another word, photon clustering is a method to compromise the rendering quality and speed when doing the caustic rendering.3. Aim at the efficiency of graphics rendering, a parallelized photon mapping algorithm is realized on the share memory multi-processor cluster and satisfying speed-up can be achieved. Different assignment plans are compared and pilot studied.