Research On Organization Model And Scheduling Strategy Of Massive Terrain Dataset

3D virtual terrain environment is widely used in economy,national defence and so on.It is a hot topic in the field of Cmputer Graphics,Visual Reality and Geographical Information Science. Both of the organization and scheduling of large-scale terrain dataset are key technique in building 3D virtual Terrain environment.After comprehensive study on the paper about organization and scheduling of very large-scale terrain dataset,we designed our own data organization model and data scheduling strategy.also conducted a comprehensive analysis from theory to practice.The main contents and contributions in this thesis can be summarized as follows:(1)Based on pyramid hierarchy model,this paper designed a data organization model of large-scale terrain dataset.In order to use map data conveniently,based on the pyramid hierarchy model,this paper used the idea of delaminating and tiling,organized the large-scale terrain dataset as tile pyramid,and built index for the data.(2)An algorithm about view frustum culling was designed,which uses the cross of view frustum and terrain. This algorithm solved the problem of real-time culling for terrain data in the process of data scheduling.(3)This thesis achieved data scheduling strategy of very large-scale terrain dataset and the multi-thread mechanism in data scheduling.Through dynamic scheduling between internal memory and hard disk,and parallelly working of rendering thread and data scheduling thread,the balance of loading and deleting data in the memory were kept.(4)This thesis designed a kind of hardware friendly real-time rendering algorithm. After discussing the influence of developing in graphics processing unit about terrain visualization algorithm,and summarizing the characteristic of terrain visualization algorithm in the new situation,this thesis designed a kind of hardware friendly real-time rendering algorithm of large-scale terrain,Furthermore,experiments were made to verify the feasibility and efficiency of this algorithm.(5)A data pre-procss system was developed,satisfying the pre-process demand of large-scale terrain data.A large-scale terrain real-time rendering system was also developed in this paper,achieving real-time rendering of large scale dataset.