Local Matching of 3D CAD Models Based on Subgraph Isomorphism

The 3D model retrieval methods considering only global shape features cannot compare models accurately at a local level of detail.A new approach to local matching of CAD models based on subgraph isomorphism is presented.First,an attribute adjacent graph(AAG)for the representation of CAD models is constructed.Then,by taking the local features provided by users as portions of the AAG,and the whole CAD model as the whole AAG,the problem of local feature matching is transformed into that of subgraph isomorphism.Subgraph isomorphism is a NP-complete problem.Rapid isomorphism matching can be realized through the effective classification of the vertices of the graph by using the face features of the CAD model and the dynamic pruning of the search space by using the adjacent relationship of the matched vertices.Experimental results show that this method supports the precise local matching and the matching efficiency can meet the requirement of the practical retrieval.