基于区域分割的零件三维模型检索方法

3D Part Model Retrieval Method Based on Surface Region Decomposition

为了满足大规模零件库的实时检索要求和零件模型以结构单元重用特点,提出一种基于区域分割的零件三维模型检索方法.该方法将平面划分为边界凸平面、边界凹平面和混合边界平面;利用边界邻域曲率、垂直边界曲率和沿边界曲率定义曲面在该边界的表面边界凹凸性,提出了马鞍面在区域凹凸性分析时计为凹、凸和平表面的约定条件.根据两表面合并后区域凹凸性是否保持不变,提出了边分类规范;通过外部边闭合规范、待定边转换规范和表面平区域合并规范,实现零件三维模型的区域分割.通过表面区域编码规范对分割区域编码,利用区域结构码实现相似结构零件的检索.实验结果表明,区域分割后零件整体相似结构检索更加有效,局部相似结构检索可以通过二元邻接区域结构求交集实现.

In order to meet the requirements of real-time retrieval of large-scale part library and reusing structural unit of part models,a3D part model retrieval method based on surface region decomposition is presented.The planes are divided into convex boundary plane,concave boundary plane and mixed boundary plane.The curvatures of boundary neighbor domain,perpendicular boundary and border boundary are introduced to define the boundary concavity of the surface.The condition that saddle surfaces are regarded as convex,concave or flat surfaces in analyzing region concavity is presented.Based on whether or not the region concavity is changed after merging two surfaces,the edge classification specification is presented.By outer edge closing specification,undetermined edge transformation specification and flat region merging specification,surface region decomposition of3D part models is realized.Surface region code specification is used to code the decomposition region.By use of region structure codes,the retrieval mechanism of the similar parts is presented.Experimental results show that global structure retrieval is more effective after region decomposition,partial structure retrieval can be realized by intersecting operation of dual adjacent regions.