全球地形可视化方案的设计和实践

Design & Realization of Earth-based Terrain Visualization

地形数据是地理环境中的基础数据,也是地理环境中数据量比较大的部分。实现海量地形数据的实时交互显示是构建虚拟地理环境的关键技术之一。本文以全球地形数据为研究对象,探讨解决全球地形数据的实时显示方案。通过对全球地形数据进行分层和分块预处理,在实时显示的过程中运用动态数据页和多线程技术,对海量地形数据实现快速提取;同时采取与视点相关的细节层次控制方法对地形数据进行进一步简化,实现在微机环境下全球多分辨率地形三维场景的实时漫游和缩放。在图形加速卡的支持下,三维场景实时交互的效果将更好。

Data of terrain is the base of digital geographical environment and it is also very vast. Its one of the key techniques for constructing virtual geographic environments that achieving real-time rendering for huge terrain data. In this paper, a new method is designed to make it come true though the terrain data is earth-based. With the pre-processing to make terrain data into multiple resolutions and a set of small patches, terrain data paging and multi-thread function can support rapid culling of polygons not within the field of view. Furthermore, view-dependent levels of detail controls of terrain are also presented to simplify the data efficiently. With the help of above techniques, real-time rendering for earth-based terrain data is realized on PC and higher rates will get if supported by an accelerated graphic card.