Large-scale Topographic Data Scheduling And Rendering Technology Research And Implementation

Since the progress of the technology in computer image processing and space shooting area, people have gained higher resolution data about the earth's elevation and texture, which makes the global aim called"digital earth"becoming true. The improvement of the resolution will cause huge scale data size, which brings many troubles in data processing and scene visualization. Academicians form all over the world have done a lot of researches in the area and invented excellent technologies, but there isn't any perfect solution. So this area has big value both in business and research.First of all, the thesis makes a simple summary about the huge scale terrain scene visualization area and analyzes its technology features. It introduces the features and history about two technologies called Out-of-core and Level-of-Detail. Out-of-core technology processes the huge scale terrain data while Level-of-Detail technology makes the scene visible. Chapter Two has introduced the particular implement way about the two technologies, which provides a theoretical basis for the thesis's ameliorations.Secondly, Chapter Three expands the thesis's solution and implement way. In the huge scale terrain scene visualization area, Out-of-core technology's core is pretreatment the terrain data and data scheduling. The thesis uses a familiar strategy called pyramid model to organize the terrain data and users other strategy called style box to do data prefetching, and also provides a simplified multi-thread patches clipping method and the memory manage strategy. Mean while, the thesis uses the restricted quad-tree model and provides a completed error evaluation criteria and cracks elimination way. In addition, the thesis implements a vision-based huge scale terrain simulation system. Chapter Four introduces the detail of the system.Finally, the thesis makes a summary about the huge scale terrain scene visualization area, and analyzes the computer graphics rendering technology's trends and research focus in the future.