| 1. | Quantity of vast discrete points are compressed to a appropriate number and these points are partitioned to different quadrangle for the reason of surface approximation using nurbs
四边域划分是实现了离散数据点的划分问题，将离散数据点进行分割，使每个区域适合于四边域的曲面拟合。 |
| 2. | Secondly , based on nurbs curves approximation algorithm , a nurbs surface approximation algorithm on discrete data sets is given . thirdly , a shape - preserving parametric surface interpolation to data set is given
2基于所给的nurbs曲线的逼近算法，建立了带插值条件的离散点集的nurbs曲面的逼近算法。 |
| 3. | Using local base surface parameterization , a parametric quadric surface approximation method is used to estimate the local surface curvature properties of scattered points based on propagating normal vector direction
首先，计算各点的邻近点集，选取合适的局部基础曲面，把邻近点集投影到相应的局部基础曲面。 |
| 4. | Making full use of the correlated space information of multi - beam bathymetric data , the author put forward a method of gaussian surface approximation to build the grid net of regular digital terrain model ( dtm ) of surveyed seafloor , which is more accurate than other approximation methods
本文充分利用了多波束数据的空间相关信息，提出了一种基于高斯地形曲面拟合的数字地理模型数据网格化方法，准确快速地得到标准等深线图。 |
| 5. | The nurbs curves and surfaces approximation to constrained data sets is discussed in this dissertation . the major works are as follows : firstly , based on simulated annealing algorithm and least square principle , a nurbs curves approximation algorithm to constrained discrete data sets is presented
本文讨论了带约束的离散点集的nurbs曲线、曲面的逼近问题，主要工作如下： 1基于模拟退火算法和最小二乘法，给出了带插值条件的离散点集的nurbs曲线逼近的算法。 |
| 6. | In the final chapter , we discuss interval polynomial approximation of rational surfaces . firstly , we briefly state the interval - surface approximation based on the taylor expansion , and later , we give out a better interval - surface approximation based on the optimization method , which is also the main work of this paper
第四章主要介绍了有理曲面的区间多项式的逼近，首先简单介绍了基于泰勒展开来做的区间曲面逼近，后面是本文的主要工作，我们基于优化方法得到了更好的区间曲面逼近，它也是本文的重要部分。 |
| 7. | Algorithms of curvature estimation and data simplification of scattered point cloud data are studied . local surface curvature properties on scattered - point data are estimated using a parametric quadric surface approximation , and the key step is local base surface parameteration method which resolves parameteration of scattered - point data . an algorithm is presented for simplifying the scattered point cloud data based on curvature restriction
实例表明,本文算法的简化结果既较好地保留了形状特征,同时使点的分布以点云密集的强制保留区为中心,在向附近扩散的过程中逐渐变稀,避免简化后点云的局部过密或局部过稀的情况。 |
