Design Intent Preserved Reuse of 3D CAD Models

The retrieved models are difficult to reuse in the current 3D model search.To solve this problem,a new method is proposed to reuse the CAD models represented by B-rep.An algorithm for automatically detecting the symmetry of B-rep model is first defined to reduce the feature interaction.The faces of the B-rep model are permuted based on their attributes.The identical faces are classified into different groups and groups are merged to produce symmetric features while the symmetric constraints are also obtained.Then the rest of features of the B-rep model are specified interactively.This makes all the faces of the B-rep model belong to a feature,primary feature or subsidiary feature.Finally the primary feature is taken as the root of feature tree.The dependent relationships between the features are detected and all the features are added to the feature tree iteratively.This feature tree,as the high level of design knowledge,is a robust way of reusing the existing CAD models.In the experiments,the method presented in this paper is compared with NXTM synchronous modeling method.Our method preserving the original design intent is better than the synchronous modeling in the process of reusing the retrieved model.