中文摘要：

产品三维CAD模型检索对实现产品设计信息的有效重用具有重要意义和作用.针对在工程应用中存在大量含有曲面的产品,提出一种基于距离-曲率形状分布的三维CAD曲面模型检索算法.首先在模型表面随机取点,计算出所取点的曲率以及该点到模型质心的距离;然后以模型质心为球心,统计处在不同半径球壳间所取随机点的曲率分布,分别以球壳半径和曲率为坐标轴构建距离-曲率平面网格,并统计每个网格中随机点出现的频次,从而形成距离-曲率矩阵;最后利用特定的规则计算矩阵的相似值,用该值衡量2个模型的相似程度,实现模型的相似性检索.实验结果表明,文中算法的检索性能比传统的形状分布算法有较大提高,尤其适用于自由曲面模型的检索.

英文摘要：

The retrieval for existing 3D CAD models has a great potential in efficient reuse of product design information.In engineering applications,a lot of products often contain some quadratic or freeform surfaces.This paper describes a 3D surface model retrieval approach based on the shape distribution of distance and curvature.First,a sufficiently large number of random points on surface of 3D model are sampled.The curvature and the Euclidean distance between each sample point and the 3D model＇s centroid are calculated.Secondly,a distance-curvature planar grid taking ball shell radius centered by the 3D model＇s centroid and curvatures respectively as two coordinate axes is constructed to express the distance-curvature distribution by obtaining a statistic data of the sample points and their curvatures existed in each mesh.Thus,a 3D model can be represented by a distance-curvature distribution matrix.Finally,an algorithm to compute the similarity between two distance-curvature distribution matrices is proposed and it can give the similar coefficient for two compared 3D CAD models.Experiment results showed that this approach can efficiently evaluate the similar degree of 3D surface models,especially for those models with freeform surfaces.