Realistic Lighting Technology Research And Implementation

The photorealistic rendering technology is one of the core technology for computer graphics all along , and the truely light and shadow effects is the soul of photorealistc. today rendering Realistic lighting tech is widely used in video games, virtual reality, computer-aided design and many other fields.In the light model, global illumination model can present lighting effects closer with real-world than the local illumination. global illumination is based on indirect illumination. It does not only need to calculate the direct source ,but also need to concern about all the light-react contributions from the other objects. We can devide the global illumination with Ray tracing method and radiosity method, which are based on ray's straight line transmission. Ray tracing method work good on specular reflection and Radiosity method can simulate diffusion. both of the two method can give us real-like lighting effects, but it will take so enormous computing that we can't use it in interactive real-time projects. Many optimization of global illumination algorithms are derived from the two kinds of methods in order to get balance between rendering speed and quality.The spherical harmonics lighting tech what we studied in the paper is that tech: we can separate a part of calculation from the rendering and it will reduce the workload of sence rending. This paper summarized the calculation of spherical harmonics for the superiority of light. and we how to get spherical harmonics function applied to specific scenes, analyzed with advantages and disadvantages. Spherical harmonic lighting technology has some real-time performance and good realistic effect result.At the of this paper describes the real-time applications, Mainly use variety of lighting technology which applied in games, Mainly tech for the illumination-Mapping , normal-mapping, dump-mapping, environment texture-mapping and so on. today's game engine will not use global illumination tech to perform lighting only, they use mapping technology with some of the global or local illumination model to perform lighting, because in these kind of applications we need performance more than the quality. In this paper we used a typical game engine with some photorealistic illumination technology, analysis it and give my result.The paper's theme is research for Photorealistic illumination technology. It follows realistic illumination and real-time performance, from only use more realistic non- realtime global illumination technology, then some real-time performance can only be applied to a static scene precomputed spherical harmonic lighting technology, finally completely use real-time for dynamic scene illumination technology, research some of the typical realistic lighting technology, and make my arguments for it.