Generation of Hierarchical Multi-resolution Medial Axis for CAD Models

Medial axis (MA) is widely used in many engineering fields. The difficulty of current methods for the generation of MA of CAD models is how to make balance between the efficiency and quality. In this study, an approach to iteratively generating hierarchical multi-resolution MA is proposed. In each iteration, only local MA needs to be refined, by which the time cost and the space cost are reduced greatly. First, the model is voxelized and its initial MA is generated by the distance dilation method. Meanwhile, the MA quality is computed and evaluated. Second, the MA level is upgraded and the details of the model is re-voxelized if the MA quality doesn´t satisfy the requirement. Third, the affected region is computed in which the local MA needs to be refined. Forth, the local MA is re-computed in the affected region, and it is combined to the MA in other regions. Several examples are given to demonstrate the outperformance of the proposed method in terms of time and space.