3^(1/2)细分模式的尖锐特征造型

Sharp Feature Modeling of 3^(1/2)-Subdivision Scheme

提出一种利用改进的3～(1/2)细分模式重建模型尖锐特征的算法。根据初始网格上标记的各种尖锐特征,通过修改3～(1/2)细分模式在不同特征处的几何规则,然后采用奇数次细分在尖锐边上插入两个新点、保持尖锐边不动,偶数次细分重新计算所有顶点坐标并连接两个新插入顶点的方法重建出初始网格上的各种尖锐特征。此外,还给出了算法的极限曲面在不同尖锐特征处的连续性分析。实验结果表明该算法具有较强的多分辨表达能力和较高的曲面拟合质量。

A method for sharp feature modeling using an improved √3-subdivision scheme was proposed. According to the different sharp features tagged on the initial control mesh, some geometric rules of original √3-subdivision scheme were modified to adapt to these features. Then, in odd refinement steps, feature edges were kept fixed and two new points were inserted onto each of them. In even steps, coordinates of all vertices were re-calculated and both new inserted points were connected to the mesh. Thus all sharp features on the initial control mesh could be reconstructed. In addition, continuity of the limit surface was analyzed for different features. Experimental results illustrate that this method allows more resolutions and good quality of fitting surfaces.