视点相关实时LoD地形模型动态构网算法

A Dynamic Triangulation Algorithm for the View-depentent and Real-time LoD Model of Terrain

论述了一种视点相关实时LoD地形模型动态构网算法。基于GRID数据,以直角三角形为基本单元,利用二叉树构建地形的层次结构,兼具GRID与不规则三角网(TIN)的优点;并且解决了模型带来的"裂缝"问题。视景体可见区域多分辨率地形生成时,通过地形面片自身复杂程度、地形面片与视点距离以及地形面片与视线间的方向关系三方面确定该面片的绘制分辨率。实验结果表明,该算法在保持地形场景逼真的情况下,极大地提高了绘制速度,满足了实时交互的要求。

This paper presents a dynamic triangulation algorithm for the viewdependent and realtime LoD model of terrain. The algorithm is based on GRID Data and rightangled triangles, uses bintree to construct the terrain hierarchy, has the advantages of GRID and TIN. The 'crack' caused by bintree structure is covered as well. The multiresolution terrain patch is generated in the visible filed of view volume and the resolution of its compositive terrain tile is determined with three criterion: the complexity of terrain tile, the distance from terrain tile to view point and the orientation relation between terrain tile and the line of sight. The experiment results show that this algorithm can achieve good performance on the quality of landscape and the speed of rendering.