Study On Critical Technologies In Real-time Graphics

The two-dimension polyline set, triangle mesh and point sampled model are primary methods of geometric model representation and are widely employed to represent the vector map and three-dimension geometric model corresponsively. How to transmit and operate these geometric models is the important task of real-time graphics. Basing on the principle and methodologies of geometric compression, we analyzed the properties of the topological and geometric data contained in vector map and proposed new strategies for saving, transmitting and rendering these data as well as triangle mesh and point sampled model. The first strategies presented in this dissertation is the multiresolution representation and progressive transmission of vector map based on polyline simplification and Simplicial Multi-Complex by which the volume of coarser level data can generally be reduced to one tenth of that of the finest level while preserving the visual consistency between them and the progressive transmission of vector map data is speeded up. The second is the fan strip based topological data representation for simple triangle mesh by which the connectivity between vertice can be encoded less than log 2 (274) bit/vertex when the split vertex and merge vertex is ignored. The third is the generalized triangle strip based data compression and multiresolution representation for simple triangle mesh. The single and multi resolution representations have same codec strategies in this method which is appropriate to the architecture of modern graphic process unit in personal computer. At last, KD-tree based anisotropic quantization was developed to reduce the volume of geometric data, i.e. coordinates of point sample, for a 2-manifold point sampled model. The breadth-first traversal of KD-tree was used to construct the multiresolution presentation. In this method, the hybrid point and polygon rendering surmounts the obstacle of large flat surface representation by point sample set. All these strategies increase the efficiency of realtime graphics processing.