Expected Count Light Transmission Light-by-pixel Rendering

Global illumination is an eternal topic of realistic computer image synthesis. It focuses on the behavior of light emission and transportation, and the so-called"photo realistic"imagery that is derived from these fundamental principals. But the traditional way of doing global illumination is costly, both in terms of storage and pre-computation complexity, and thus does not suite well with the graphics processing unit(GPU) as far as real-time rendering is concerned. Therefore, it is a crucial problem to be solved that we implement real-time diffuse and glossy global illumination lighting with the GPU power, while maintaining a low storage cost and high frame rates level.This thesis utilizes Pre-computed Radiance Transfer(PRT) technique, and Spherical Harmonics(SH) functions as the data base, to implement global illumination lighting effects in a high dynamic range(HDR) environment. First, with specific lighting conditions, we pre-compute the scene with spherical harmonics functions and encode it as low storage cost SH coefficients. Then at real-time rendering stage we compute the lighting using Spherical Harmonics with simple mathematic calculations. In addition, we use an encoding technique to lower the storage and bandwidth requirements, while maintaining almost the same precision details. Extending existing per-vertex PRT lighting techniques, together with bump mapping, we implement a global lighting effect with relatively low storage and computation costs.With the High Dynamic Range(HDR) rendering, we can render synthesized scene objects into real environments, with out method. And besides, as far as most real-time rendering applications are concerned, mid-dynamic range(MDR) rendering can gain fairly good results and can suffice most interactive and real-time application requirements.