去LoD层级约束的海量三维地形裂缝实时消除算法  

A Level Constraints Removed Algorithm for Avoiding Crack in Massive 3D Terrain

作　　者：刘振东 李成名[1] 武鹏达 刘坡[1] LIU Zhendong;LI Chengming;WU Pengda;LIU Po(Chinese Academy of Surveying and Mapping,Beijing 100830,China)

机构地区：[1]中国测绘科学研究院,北京100830

出　　处：《测绘通报》2018年第7期48-52,共5页Bulletin of Surveying and Mapping

基　　金：中国测绘科学研究院基本科研业务费(7771720)

摘　　要：海量三维地形的实时渲染技术是三维可视化领域的核心技术和难点之一。针对传统地形裂缝消除方法中存在的瓦片层次约束强、渲染效率低的问题,本文提出了一种去Lo D层级约束的海量三维地形裂缝实时消除算法。在分析地形四叉树组织方式及地形可视化Lo D控制规则的基础上,首先建立包含地形瓦片角点及边邻居关系的四叉树地形多分辨率表示结构;然后根据视点相关的Lo D控制规则,动态地改变地形四叉树节点的分裂或合并状态,更新四叉树;最后根据线性插值算法修正四叉树中互为邻居关系的瓦片高程以消除地形裂缝。通过海量山区地形数据的试验,验证了本文算法的可行性与高效性。Massive three-dimensional（ 3 D） terrain real-time rendering technology is one of the core technology and difficulties for 3 D visualization system. Aiming at the problems of strong tile level constraint and low rendering efficiency which exist in traditional methods,this paper presents a new level constraints removed algorithm to avoid the crack in massive 3 D terrain. Firstly,it builds a multi resolution representation structure of quad-tree terrain including terrain tile corner and edge neighbor relationship. Then the split or merged state for the nodes of quad-tree is updated dynamicly on the basis of Lo D control rule. Finally,the linear interpolation algorithm is used to modify the tile elevation of neighbor relations in quad-tree to eliminate terrain cracks. The experiment on massive mountainous terrain data shows that the algorithms we proposed are effective and efficient.

关 键 词：地形可视化 四叉树 去层次约束 裂缝消除 

分 类 号：P208[天文地球—地图制图学与地理信息工程]