【作者】 潘胜玲；

【导师】 刘学军；

【作者基本信息】 南京师范大学 ， 地图学与地理信息系统， 2007， 硕士

【摘要】 表面重建是GIS、逆向工程等领域的研究重点，也是地学领域的研究热点之一。地形表面重建有直接重建和间接重建两种。直接重建是指由地形数据，通过一定的数据结构和表面重建方法来表达研究区域的地形表面。间接重建是指某些格式的数据如STL数据在转换成TIN时，由于其拓扑关系的丢失而需要建立TIN的拓扑关系。本文讨论了当前基于TIN的地形表面重建的两个基本问题：剖分准则和拓扑重建。在TIN的剖分准则中，论文分析了当前主流剖分原则，指出了其不足，并针对这一点，论文提出了顾及高程信息的空间三角形剖分准则：标准差准则。在该准则下的TIN能较好地处理一些特殊地形。标准差准则在剖分时即使用了点的x，y，z坐标，通过计算选出的是空间上形状较好的三角形，即剖分结果三角形是空间上形状较好的，因此建立的TIN地形表面在空间上更符合实际地形表面，也更符合人们的思维逻辑。本文详细研究了标准差准则的含义、计算、描述、简化等，以及用新设计的标准差准则来重建地形表面。最后，通过一个具体的实例和算法的对比分析来说明标准差准则的优越性。在拓扑重建中，论文针对STL数据结构特点，通过Hash函数实现了STL数据结构的拓扑显式表达，提高了拓扑重建速度。将HASH函数的思想引入到拓扑关系重建中分别建立TIN的点拓扑和面拓扑关系，并通过实验证明该算法具有较高的效率和良好的发展前景。该算法主要将点坐标文件和用点号表示的三角形文件通过HASH函数来快速地表示TIN的显式拓扑关系，即生成无重复的点坐标文件和用点号表示的三角形文件，并找出具有公共边的相邻三角形，从而建立三角形的拓扑关系。论文对相应算法开发了原型验证系统，研究成果对3DGIS，计算机图形学，逆向工程等领域有一定的理论意义和应用价值。今后可对距离标准差准则的唯一性及Hash函数在GIS矢量拓扑结构中的应用方面展开进一步的研究。更多还原

【Abstract】 Surface reconstruction has broad application prospects in geography information system CAD and converse project. There are two methods in terrain surface reconstruction, which are indirect and direct reconstruction. Direct reconstruction is that using some data structure and surface reconstruction method to express the whole terrain surface by terrain data. Indirect reconstruction is that consummate terrain surface, construct the topology relationship of TIN (Irregular Triangular Network) .This paper discusses two basic problems. There are triangulation rule and topology reconstructruction. In the TIN triangulation rule, we analysis the existing triangulation rule and then give a new triangulation algorithm which considering the elevation information. The algorithm is called standard deviation rule.This paper describes standard deviation rule which uses x, y and z coordinate in triangulation. So it chooses the good shape triangles in space after computing. The result of triangulation is triangles which having good shapes in space. The TIN terrain surface is more near to real terrain surface and thinking logic. We explain the standard deviation, how to compute and why use it. Then provide the algorithm steps based on it. Finally, through an example and comparison analyse of algorithms we show the advantages of standard deviation rule.In the topology reconstructruction, it takes the idea of hash function into topology relationship to reconstruct the point topology and surface topology. Then through an experiement, we validate the algorithm. First, use hash function to express the obvious topology relationship of TIN fastly from point coordinate file and triangle file. That is, create the exclusive point coordinate file and triangle file which showed by point number, and find out adjacent triangles which having same side, so we build the topology relationship of triangles.The paper designs programme of the algorithms, it has some theory value and application value to 3DGIS, computer graphics and converse project. We will have some research on the exclusion of standard deviation rule and the application of hash function in GIS vector topology structure.更多还原