Realistic Image Rendering System Based On The Photon Mapping And Application Research In Participating Media

Calculation of global illumination is an important method for realistic imagerendering which requires extremely complicated computation. Generally, Monte Carloalgorithm is adopted to solve the problem. However, it'll bring on much noise due to itsrandomized sampling operation. Photon mapping is an effective way to cope with thedilemma and it also can be applied to the modeling of participating Media and imitationof natural texture. Nowadays, the increasingly enhanced computation capability ofhardware provides an ideal foundation for the implementation of this algorithm.In this paper, all the content aims at the implementation of global illumination basedon photon mapping and its application in participating Media rendering. Such field astheory of global illumination, global illumination method based on photon mapping andpolicy of participating Media rendering are discussed thoroughly and comprehensively.Firstly, a general mathematical model of global illumination and related equation arepresented and analyzed. Then we dig into the rendering equation of Monte Carlorandomization method for global illumination problem and propose a criterion forthe scene making of global illumination and texture rendering.Secondly, we discussed the whole process and rendering equation of globalillumination based on photon mapping method and the detailed computation work in eachstep. Partial operation was improved to the algorithm after analysis in order to optimizethe storage and searching of photon. The experiment result proves the advantage of thenew algorithm compared to the old one.Finally, based on the profound analysis of photon mapping's advantage in solvingglobal illumination and participating texture feature, and also based on the analysis ofdispersion and phase function of Media, we come up with a new participating texturerendering algorithm based on photon mapping: Ray Marching algorithm. We alsoproposed and realized the improved version of the volume rendering equation. Wepresented the result of typical texture scene in terms of participating Media's uniquefeature. The analysis of the result can provide the possibility of further improvementregarding the participating Media's global illumination based on photon mapping.