表面模型缓冲区分析方法

摘要

三维缓冲区分析是三维空间分析的基本功能之一, 也是三维地理信息系统的重要组成部分. 针对目前空间对象表面模型的缓冲区分析算法尚不完善的问题, 提出基于空间填充思想的三维缓冲区分析方法. 首先将表面模型离散化; 然后基于带符号的欧氏距离算法和缓冲距筛选体素; 再应用隐式曲面重构算法构建三维缓冲区参考曲面;最后从缓冲控制点和参考缓冲曲面出发, 计算得到光滑, 精确的缓冲区分析结果. 从方法复杂度、可视化效果、缓冲区等距性等方面将文中方法与栅格模型缓冲区方法进行对比的结果表明, 该方法具有较强的通用性与扩展性, 同时能够处理空间对象的内, 外缓冲区等复杂情况.%Three-dimensional Buffer Analysis is one of main functions of 3D spatial analysis, further, is one of important parts of 3D geographic information system (GIS). It should be improved for buffer analysis of bound-ary representation (B-rep) of spatial objects. This paper proposed a method of buffer analysis based on spatial tessellation. Today, buffers of B-rep always are presented by volumetric body, which are redundancy, lack of ac-curacy and poor visualization. For solving these problems, firstly, B-rep is voxelized to volume. Secondly, Signed Euclidean Distance is to select available voxels. Thirdly, Iso-surfaces are extracted by implicit algorithm. Fourthly, buffer surfaces are reconstructed by discrete smooth interpolation algorithm based on Buffer Points and Iso-surfaces. Finally, a group of tests were carried out for comparisons in aspects of time complexity, visualiza-tion and equidistance between paper's method and volume model. Furthermore, both inner and outer could be re-alized. As the above discussed, experiments show the method in this paper are universal and extended.