Feature-based Model Reconstruction Of Human Body Surface In Reverse Engineering

Traditional modeling method of reverse engineering (RE) technology is geometry-oriented. With this method of enormous working intensity, the designers are highly demanded, the geometric features and relations between them are not exactly expressed and the created models are hard to be edited, modified, creatively designed and are short of semantic information which is needed in manufacture and analysis. Feature technology is an effective way of integrating other information into CAD model. Thus it is significant to introduce feature technology into RE. Also feature and constraint based RE model reconstruction is the research focus in the field.Aiming at constructing the model of the upper part of male body, the feature and constraint based RE model reconstruction method is researched in this paper. A feature-based modeling method in RE is presented after the contents, current research and application state of RE technology and feature modeling method are summarized. In order to construct the freeform feature surface model of male body, firstly, the classification and parameterization of freeform feature and the freeform feature recognition from point cloud are researched, and a semantic feature language composed of vocabulary and grammar is presented. After the modeling method of this paper is confirmed and the male body surface feature is analyzed, the semantic feature model of male body that is composed of parameter, vertex vocabulary, edge vocabulary and grammar is constructed, which is the foundation of reconstructing the surface feature model of human body. Secondly, the key technology of how to align point cloud with surface feature model of human body, analyze error, adjust position are researched and the algorithms of calculating center of mass, inertia axis, and symmetry plane are successfully introduced. And then, for the aligned model, it is researched that how to project point cloud to the feature surfaces, recognize the surface features, assign the parameters to the point cloud and quickly construct smooth B-spline surface of different male body with G1 continuity based on constraint and energy optimization. Finally, the prototype system RE-FBMS is developed with the algorithms mentioned above.The reconstructed male body model can be used in 3D garment design and also in ergonomics, computer simulation, and animation.