基于几何方法的地形点坐标的拾取

摘要

Aiming at the problem of interactive pickup of terrain point’s accurate coordinate,the pickup strategy of terrain point coordinate based on geometric method was proposed. The strategy used the intersec-ting geometric ray and sphere,and designed the dichotomy of spherical center’s angle which searched the accurate terrain point’s coordinate according to DEM spatial information. The experimental results showed that the strategy not only got the accurate coordinates of the intersection of terrain,but also increasesd inter-active operating fluency in virtual reality geographic system,and it provided a new approach for studying the theory of generating interactively curve on Earth.%针对无法交互式拾取地形点精确坐标的问题，提出了一种基于几何方法的地形点坐标拾取策略：利用几何射线与球体求交，根据 DEM 数据空间信息，设计了球心角二分法，并利用其查找地形点的精确坐标。实验结果表明，该策略不仅得到的地形交点的坐标较精确，且增加了虚拟现实地理系统中交互式操作的流畅性，为研究交互式生成地球上的曲线提供了一种新的方法。