Realistic 3D Terrain Mapping And Real-time Roaming

The rapid development of the Geographic Information System (GIS) provides people a deeper, broader vision in world's understanding, also gives strong support for the development of the national economy. The Virtual Reality (also known as the Virtual Environment) is always hot spot in the fields of research, development and application of the information technology. As the basis of GIS and virtual reality, realistic 3D terrain becomes hot spot in recent years.This paper focus on discussions of 3D terrain modeling, visualization, realistic expression, and other related technologies. The multi-resolution digital terrain modeling, mesh simplification, error control, data scheduling algorithm, photorealistic rendering, and other core technologies were studied in the paper. First, data structure and storage structure of the binary triangular tree in the real-time adaptive mesh modeling method were improved and optimized to increase the speed of modeling. Secondly, in view of the characteristics of the data structure of ROAM modeling process, an effective segmentation algorithm was proposed for the purpose of elimination of the terrain cracks phenomenon in the process of mesh simplifying. Then, the algorithm of data blocking and dispatching based on the viewpoint was designed to solve dispatching problem of the large-scale terrain data. Finally, the bottlenecks of roaming speed was analyzed, and a evaluation system was given. After that, parallel processing of the CPU and GPU which is taken full advantage of the GPU was realized to improve the speed of the real-time roaming and a realistic real-time 3D terrain roaming was achieved.