3D CAD model retrieval based on the softassign quadratic assignment algorithm

A retrieval method for 3D CAD models based on the softassign quadratic assignment algorithm is presented in this paper. Firstly, retrieval models and target models are expressed as face adjacency graphs (FAGs) and thus 3D CAD model retrieval is turned to a graph matching problem. Secondly, vertex and edge compatibility matrices between the FAGs of a retrieval model and a target model are calculated. Then, an optimization objective function is created from compatibility matrices of a retrieval model and a target model, which serves as the similar metric for choosing vertex mapping matrix M of two models. Finally, the softassign quadratic assignment algorithm is introduced to find the optimal vertex mapping matrix M. Experimental results have shown that the proposed method supports 3D CAD model retrieval, and it is promising to meet the requirement of engineering applications.