Abstract: Extracting wire frame from 3D models is a challenge. Existing methods are typically based on the analysis of local shape properties, such as surface curvatures and angles between faces, which are generally sensitive to small features in the model. In order to solve this problem, we proposed a wire frame extraction method based on geometric approximation of 3D shapes. This method employed a well-established variational geometric segmentation algorithm to derive a complete set of descriptive feature curves. Firstly, the model was divided into several patches based on the variational geometry approximation method. Secondly, the internal characteristic curves of all patches were extracted, and the short characteristic curves were filtered. Then, the boundary curves of patches were smoothed. Finally, the patch boundary curves and characteristic curves were merged, and the closed wireframe network was obtained by extending the curves. The advantage of the proposed method was that descriptive wire frames can capture the global structures of the 3D shapes using a reliable feature filtering mechanism that was inherently incorporated in the geometric approximation step. Experiments on various kinds of meshes have been carried out and the results demonstrate that our method is superior to existing approaches in terms of correctness and completeness of the extracted wire frame. 

Key words: mesh model processing, variational shape approximation, geometric segmentation, wire frame extraction, feature extraction