Research On Real-time Lighting Technology Based On HDR

With the development of 3D graphics technology, real-time has been an important indicator of 3D graphics technology applications. And simulation of lighting is the core of real-time graphics system. The effect of realistic lighting can enhance user experience in such graphics systems as virtual reality and real-time simulation. So the research of real-time lighting has theory and practice significance.Real-time and realistic rendering are major difficulties of real-time lighting. This paper has used two methods to improve real-time and realistic rendering. First, using the technology of high dynamic range to convert the value of RGB in the virtual scene is into high dynamic range illumination, and the illumination value of top mapping high dynamic range shows in the low dynamic range illumination which can be displayed in the LCD. Second, using the real-time illumination model simulates the lighting effect and the graphics processor unit improves the speed and quality of graphics computing.First, the paper has analysed and researched global tone mapping algorithm and local tone mapping algorithm in tone mapping. Getting a algorithm which combines multi-resolution with global algorithm after operating in High Dynamic Range image. The algorithm has lower complexity, and the result can achieve requirements. Second, the paper has researched real-time lighting including global lighting, local illumination and real-time multi-lights lighting. In real-time of realistic scene, since the deferred lighting separates the geometry phase and lighting phase, the computational complexity and calculated amount are decreased. Thus Phong deferred lighting model is the most suitable for the calculating of multi-lights. Finally, High Dynamic Range which can enhance the effect of illumination has performanced the scene more realistically and the details more extensively. With the combination of HDR and the deferred lighting model, the paper has programmed corresponding operation on GPU shader, and achieved the deferred lighting algorithm based on HDR. The result shows that the algorithm which has achieved prospective targets can satisfy the request of real-time and realistic lighting.