一种基于三角网的地质体三维模型切割方法  

3D Geological Model Intersection Algorithm Based on Triangular Mesh

作　　者：万波[1,2] 尹芮芮 左泽均[1,2] 王润[1] 吴信才[1,2] 

机构地区：[1]中国地质大学信息工程学院,湖北武汉430074 [2]国家地理信息系统工程技术研究中心,湖北武汉430074

出　　处：《地球科学（中国地质大学学报）》2016年第11期1966-1976,共11页Earth Science-Journal of China University of Geosciences

基　　金：中国地质调查局油气资源调查中心项目(No.2013110069);国家自然科学基金项目(Nos.41301426;41301427;41371422);国家重点研发计划项目(No.2016YF0502304)

摘　　要：三维地质体模型相交元素之间构成的奇异空间关系与复杂的模型要素形态极大影响了切割算法稳健性及切割结果可靠性.提出一种几何运算与关系表达相统一的地质体三维模型切割算法.算法首先构建交点对象拓扑结构,存储交点与所在三角形单元及空间邻近要素的相对位置关系;然后结合精确谓词法设计完整的边-三角形相交类型分类图,记录27种相交情况与交点位置的对应关系,并在重三角化过程中建立交点调整机制,利用交点对象拓扑结构中关联的空间关系作为上下文约束,有效控制投影降维浮点误差带来的交点位置偏差的不良影响.实验结果表明,算法能够有效处理地质体模型中的三角网退化/近似退化、自相交及共面/近似共面等奇异空间关系,同时具有良好的运算效率.The complexity of 3D geological model and the singular spatial relationship among geological intersection objects greatly influenced the robustness and the reliability of intersection algorithm.An efficient and reliable intersection algorithm of complex geological model is proposed in this paper.Firstly,an intersection point topological structure is built to store the rela-tive position between intersection point and adjacent elements.Then combining the exact predicates method,a complete edge/triangle intersection classification figure is designed which records 27 kinds of intersection cases and corresponding intersection point positions;in the process of re-triangulation,the designed adjustment mechanisms make full use of associated spatial rela-tionship as the constraints,adding an additional level of reliability to the algorithm.The experimental results show that our al-gorithm efficiently handled the degenerate/self-intersection cases in triangular mesh and the tangency/co-planar/near co-planar triangles special cases in intersection process,and could provide a reference for 3D complex geological model intersection analysis.

关 键 词：地质体 三维空间分析 遥感 切割分析 可靠性 

分 类 号：P208[天文地球—地图制图学与地理信息工程]