大数据量三维地形实时可视化的扩展算法  

Extended algorithm of real-time rendering for 3D terrain in the large volume of data

作　　者：沈利强[1] 都金康[1] 胡裕军[1] 

机构地区：[1]南京大学地理与海洋科学学院,南京210093

出　　处：《南京大学学报（自然科学版）》2008年第3期297-303,共7页Journal of Nanjing University（Natural Science）

基　　金：国家自然科学基金(49672102)

摘　　要：针对大数据量三维地形实时可视化问题,本文在传统实时优化自适应网络(real-time optimaladaptive mesh,ROAM)算法的基础上进行扩展,提出了一种视点相关的适合大数据量三维地形实时绘制的简单高效的算法.该算法是通过基于线性四叉树索引的数据管理模式进行管理和组织数据,并根据地形复杂度的不同对高程数据间隔提取然后渲染地形,从而大大降低了大范围三维地形的复杂度和计算量,同时该算法支持拓扑结构和多分辨率,有效地简化了地形模型的绘制,提高了三维地形实时渲染效率.并用微软基础类(Microsoft Foundation Classes,MFC),结合Open Graphics Library(OpenGL)开发了一个程序实例,进一步验证算法的有效性.An extended algorithm was put forward in this paper, for real-time visualization of 3D terrain in the large volume of data, based on the traditional real-time optimal adaptive mesh （ROAM） algorithm. The extended ROAM algorithm was a view-dependent, simple and efficient algorithm. It was appropriate for rendering 3D terrain in the large volume of data. In this algorithm, the mode of data management and organization was based on linear quadtree,and elevation data was abstracted to render terrain by interval calculated according to different terrain complexities. The complexity of 3D terrain and calculation were descended greatly through the extended ROAM algorithm, and topology structure and multi-resolution model were supported in this algorithm. The algorithm also simplifies the terrain rendering and improved the efficiency of terrain rendering. At last, an actual program example was developed based on Microsoft Foundation Classes （MFC） and Open Graphics Library （OpenGL）, which verified the validity of the algorithm further.

关 键 词：三维地形 可视化 线形四叉数 算法 

分 类 号：P285[天文地球—地图制图学与地理信息工程] TP391[天文地球—测绘科学与技术]