机械CAD三角网格模型的特征表面分割混合算法

针对机械CAD三角网格模型中普遍存在的网格稀疏性和非均匀性分布等特点，提出了一种特征的二次提取及表面分割混合算法。第一次分割采用基于边的方法，即在平面合并的基础上对相邻三角面片法矢夹角的方差进行判断和处理，从而实现平面与其他稀疏网格表面区域的分割和边界特征的提取；第二次分割采用基于顶点的方法，首先由顶点的估算曲率计算出各面片的近似曲率，然后通过区域生长实现其他表面区域的分割及特征提取。实验结果表明，该方法能较准确地实现机械CAD三角网格模型的特征提取和表面分割。

A Hybrid Approach to Feature Segmentation for Triangle Meshes of Mechanical CAD Model

Aiming at the characteristics of sparseness and non-uniformity of meshes that is popular in triangle meshes of mechanical CAD model, a new approach to feature segmentation was proposed. Firstly, by means of edge-based method, planar regions were merged and variances of the angles between normal vectors of the adjacent triangle meshes were calculated,on the basis of which the planar regions and other regions consisting of sparse meshes were segmented. Secondly, using vertex -based method, approximate curvatures of meshes were obtained according to the estimated curvatures of vertexes, and then segmentation of other regions was accomplished through region growing. The experimental results indicate that the feature segmentation for triangle meshes of mechanical CAD model by employing the new approach is satisfactory.