Research On Shader Real-time Refraction And Caustics Based On GPU

Since its naissance, the simulation of the virtual reality has been seriously regarded and used, and the simulation of the lighting effects in the real world is the important. The scene will be very rich by lighting. There are two methods in the simulation of the lighting, one is ray tracing, the other is texture processing. Early, The ray tracing was running on the CPU, but less efficient. As the implementation of GPU programmable, there have been many ray tracing based on GPU. Using this method, the simulation of the lighting have strong realistic. But as the limit of the GPU performance, the real-time was general poor., if applied to large scale virtual scene, the rendering of the scene would not seem smooth. This paper adopted texture processing, based on the GPU programmable, to simulate the refraction and caustics in the virtual scene, and render the simulation results real time.Firstly, this paper introduced the development of GPU and shader concepts, grasped the status of the lighting simulation at home and abroad, and as a theoretical basis for this study, in order to carry out this research work.Secondly, this essay researched the GPU graphics rendering pipeline, and done a thorough analysis for the all sections of the traditional pipeline, and researched the GPU vertex programmable unit and pixel programmable unit, and two computing architectures on GPU. The above was the basis of the program development.Thirdly, this essay discussed and researched the texture processing of the graphics rendering pipeline, include the technology of the texture mixed and cube mapped. Used it, the paper handled the rendering of background, the caustics effect, and the dynamic display in the scene simulation.Finally, based on VS2003, this paper realized the simulation rendering of the refraction and caustics effects in the virtual scene dynamically, using GPU programmable and technology of texture processing. The simulation scene had a good real-time, a certain interaction capacity, a high rendering frame rate and good realistic.