三维数字地形图及其地形、地物表达方式探讨

本文在深入研究三维数字地形图概念的基础上，对其地形和地物表达进行了初步地研究。三维数字地形图是基于抽象符号的三维空间数据显示和可视化表达技术，是用离散的三维特征点及特征线，表达地形或地貌以及地物空间立体形态的矢量地图。它以立体造型技术向用户展现地理空间，能够表达空间对象间的平面关系，也能描述和表达地面的高程和地物的高度，对客观世界的表达更完整准确，用户可以在上面进行三维空间量测和分析。研究三维数字地图将有力地推动虚拟现实或临境技术和三维GIS的发展。

Preliminary study of 3D digital topographic map

In view of the concept of 3D digital topographic map, the representations of surface features and landforms are studied carefully and seriously. The 3D digital topographic map is a technology of 3D spatial data vision and visualization representation based on abstract symbols. And it is the vector map to represent spatial stereo shape of relief and surface features by scattered 3D characteristic points and 3D characteristic lines. It represents the objective world more integrally and accurately. It can give unfold geographic landscape through stereo model technique. It can not only represent the plane geometry relation among spatial objects, but also, the elevation of earth surface and surface feature height. Therefore, users can do 3D spatial measuring and analyzing on it. The study of 3D digital topographic map will promote the development of VR and 3D GIS.