基于约束Delaunay三角剖分的道路三维建模方法

3D-modelling for roads based on constrained delaunay triangulation

深入研究了一种建立道路三维模型的方法.首先依据道路设计成果计算出道路模型与地形模型的拼合交线,然后用设计点(特征线)数据替换拼合交线内的地形点(特征线)数据,形成建模所需的原始点集和约束边集.针对原始点集采用逐点插入算法进行Delaunay三角剖分,再依据约束边将初始三角网调整为约束Delaunay三角网,由此得到外观与内部拓扑关系均为整体的道路三维模型.此外,还研制了三角形的快速定位算法,加速了建模过程.实践表明,该方法具有整体性好、网形优、速度快的优点.

One of methods for building 3D road model was presented. According to the design fruits, the merging intersection lines between the road model and the terrain model were worker out. The terrain points and feature lines located in the area covered by the merging intersection lines were replaced by the design feature points and feature lines. Collective of points and constraining edges needed by modeling were formed. The incremental insertion algorithm was applied to make the points to form standard Delaunay triangular net. Then the previous triangular net with constraining edges were adjusted and constrained by Delaunay triangular net made. The 3D model of road, whose appearance and inner topological relationship were both integrated, was created successfully. The applications showed that the method had such advantages as good integrality, nice shape and high speed.