与二维电子地图互响应的虚拟三维场景生成

该文详细介绍了与二维电子地图互响应的虚拟三维场景中地形、地物的生成及场景组织等关键技术的解决方案。地形的生成是采用少量的可描述地形总体形状的DEM数据构建地形的总体框架，并应用分形技术来生成地形细部的方法。对与视点相近的树木用L系统分形生成，并将生成的描述树木的数据保存起来，以便在实时刷新时调用；与视点较远的树木用贴图的方法来表现。介绍了采用模块化与纹理贴图技术来简化桥梁生成的具体实现技术，从而减少桥梁描述的数据量。对实现互响应功能时需解决的视点位置确定问题给出了具体的解决方法。这些生成方法有效地减少了三维场景实时生成的延迟性，并保证了实时互响应的实现。

Research on Construction of 3D Virtual Scene and Interaction with 2D Digital Map

This paper presents the solutions for some key technologies that are needed to construct virtual scene, such as technique for terrain and terrain features generation and method of scene structure. Simplified DEM data are used to construct terrain frame at first, then fractal is used to generate the details of terrain. Trees close to viewer can be generated by L-system, and the data are stored to be transferred. Distant trees are generated by texture map. Also detailed methods are in troduced to simplify the generation of bridge and to reduce the mount of bridge's data. The detailed methods for evaluating current view position are puts forward in order to realize dynamic response between 2D digital map and 3 D virtual scene. All methods mentioned in this paper are used to decrease the delay of real-time generation and to ensure the realization of real-time interaction.