矢量在全球规则格网地形上的叠加绘制方法  

A Method for Rendering Vector Data over Global 3D Regular Terrain Grid

作　　者：孙寅乐[1,2,3] 宋关福[1,3] 冯振华[3] 

机构地区：[1]中国科学院地理科学与资源研究所,北京100101 [2]中国科学院大学,北京100039 [3]北京超图软件股份有限公司,北京100015

出　　处：《地理与地理信息科学》2013年第6期14-17,25,共5页Geography and Geo-Information Science

基　　金：国家科技支撑计划项目"多尺度生态系统演变与未来情景模型模拟技术"(2013BAC03B03);国家发改委卫星应用专项"重庆市自主卫星技术综合应用服务示范"

摘　　要：为了精确、高效地将传统的且对地形有约束作用的二维矢量数据叠加绘制到多分辨率全球地形上,提出了一种基于矢量高程纹理矢量叠加绘制方法。首先将矢量高程渲染到矢量高程纹理金字塔中,然后在GPU中采用膨胀方法对高程纹理进行处理,在绘制地形网格时根据从矢量高程纹理中的采样值调整顶点高度,最后叠加绘制矢量网格。实验表明,该方法可与Clipmap等主流多分辨率规则格网地形模型结合,在地形上精确绘制矢量,并有效解决由于地形网格精度导致的矢量边缘被地形遮挡问题。To display traditional 2D vector data which constraints the terrain,on a 3D multi-resolution terrain model, a method based on elevation textures of vector data has been proposed in this paper. The elevation of vectors was saved in a dynamic pyra- mid of textures and the footprint of vectors in elevation texture was expanded in GPU. When rendering the terrain, the height of the vertex was modified according to the value read from vector elevation texture. Then meshes of vector data were constructed and rendered. The result of an experiment indicates that vector data and its edges could be rendered accurately and correctly. In addition, this method is suited to work with most of major terrain LOD algorithms.

关 键 词：矢量数据 三维地形 绘制 高程纹理 

分 类 号：P208[天文地球—地图制图学与地理信息工程]