High Quality Real-Time Direct Volume Rendering

Volume rendering is an important research topic in the field of VISC. With the rapid development of GPU in recent years, real-time rendering based on GPU comes up as a hot topic for research in computer graphics. In this thesis, We focus on the techniques of GPU (Graphics Processing Unit) based volume rendering and propose to seek for a tradeoff between the realistic effects and interactive performance.This paper gives an overview of the visualization of 3D and GPU. Then, analysis the main flow of visualization and the GPU-based graphics pipeline. Several real-time and high quality volume rendering algorithms based on the brand new programmable Graphic Processing Unit were sumerized. The complete implements and comparative results were also described. The strong point and the weak point of the GPU-based 3D texture volume rendering algorithms were also analysed,the improved algorithms about rendering quality and speed were put forward.As the GPU has the parallel and computation-specified architecture, its float point operation speed is much higher than CPU. During 3D texture hardware volume rendering, only very little workload is assigned to the vertex processor. Put forward a vertex program which efficiently computes the slicing for textured-based volume rendering to handle the limited of graphic card. This technique enables us to balance the workload between vertex processor, fragment processor and memory bus. With space leaping and VBO (vertex buffer object) technique in the OpenGL, the speed is further accelerated .The traditional 3D texture based algorithm can't fully implement the shading model due to the fixed pipeline. The presented algorithm is able to define lighting algorithm, and make up the lackness of no pixel-level shading in the fixed pipeline. Moreover, the local lighting effect was enhanced, the Phong lighting model was realized and the realistic feeling of the effect was improved.In the pursuit of a higher quality of the rendering results and ensure interactive, considering scattering in 3D texture hardware volume rendering. Taking into account aspects of visual perception by means of real-time high dynamic range tone mapping in the results of high dynamic volume rendering. Experiments demonstrated that these techniques can improve the rendering quality greatly.