基于海量空间数据的实时地形视景仿真算法研究

随着数字地球和数字城市概念的提出，建立海量空间数据的实时地形视景仿真系统受到了越来越多的关注。建立了多分辨率空间数据的四叉树结构模型，提出了基于屏幕分割的LOD数据装载算法和基于相同地理空间大小的LOD数据分割方法，实现了任意方向和分辨率数据块之间的无缝拼接，融合了视相关和地表特征的地形简化方法，同时综合运用了可视区数据的各种预处理手段，提出了可视区数据小号更新算法．通过原型系统开冀。在微机平台上地形绘制速度可达每秒25帧.

Research on Algorithm for Real-Time Visual Simulation of Terrain Based on Mass Spatial Data

As the conception of Digital Earth and Digital City was put forward, a system of real-time visual simulation of terrain has been paid more and attention based on mass spatial data. A multi resolution model of spatial data with quad-tree structure was built. The algorithm for loading LOD data based on window-divided and the method of dividing LOD data based on the same spatial size in geography were proposed. They achieved seamless patching in the random direction and resolving capability, and syncretized the method of terrain simplification on view-dependent and hypsography. At the same time, they synthesized all kinds means of pretreating the visible data, and presented the algorithm for updating a jag of data in the visible area. Finally, an archetypal system was exploited, and the rendering soeed is about 25 frames per-second on PC.