基于拓扑数据模型的三维宗地合并与分割算法

三维宗地是宗地在三维空间的扩展,其合并与分割是三维地籍最常用、最基本的功能。在给出数据结构基础上,提出基于拓扑数据模型的三维宗地合并与分割算法。其中,合并算法通过查找公共面,获取公共面集,设立拓扑取舍准则,删除舍弃的边与顶点,合并被删除的边和顶点所属的共平面的面与边,更新对应的体与面实现。分割算法通过边分裂,以新生成边替换原始边;面分裂,以新生成面替换原始面;体分裂,以新生成体替换原始体实现。为验证算法,建立了实验原型系统,实验结果表明:算法有效、可行。

Combining and cutting algorithms for 3D parcel based on topological data model

Using the given data structure,combining and cutting algorithms for 3D parcel based on topological data model were offered in the paper.Combining algorithm was implemented by following steps: finding common faces,obtaining common face set,establishing topological accepting and rejecting criterion,deleting abandon edges and vertices,combining coplanar faces and edges to which deleted edges and vertices is belonging,and updating corresponding volumes and faces.Cutting algorithm was implemented by following steps: dividing edges and replacing original edges with new generation edges,dividing faces and replacing original faces with new generation faces,dividing volume and replacing original volumes with new generation volumes.To test algorithms,experimental prototype system was established,and the results showed that the algorithms are feasible and effective.