一种任意三维实体网格模型的体积特征提取算法

Extracting Volumetric Features from Arbitrary Geometric Models

体积在不同轴向上的分布是三维网格模型的重要几何特征。在分析三维模型数据结构的基础上,提出一种提取任意三维实体网格模型体积分布特征的算法。算法首先应用主元分析法确定模型的主轴方向,并将模型按主轴方向旋转至特定姿态,再以一组等距的平行平面从三个坐标轴方向对模型进行剖分处理,并利用平面简单多边形的带符号面积公式求取相应的截面面积,进而求得模型的沿不同轴向的体积分布特征。模型在三个坐标轴向上的体积分布描述了模型的几何特征。实验表明,算法程序运行稳定、快速,可用于提取具有任意几何和拓扑复杂性的各类实体模型的体积分布特征。

Distribution of volume along certain direction in 3D space is one of the most important features for a geometric object, in this paper, based on an analysis of data structure of 3D manifold meshes, an algorithm to extract volumetric characters from arbitrary given models is presented. The algorithm first rotates the mesh model to coordinateaxis-align position by employing Principal Component Analysis （PCA） methods, and then uses a set of parallel planes to slice the model into several high-equal segments along three principal axes, respectively. From cross section in each plane, a polygon set composed of one or more polygons can be obtained and absolute value of its area can be consequently computed by using the signed area formula of planar simple polygon, By normalizing the area, volume distribu- tions of the model along the principal axes can be plotted by three characteristic curves and the curves give the model a description of the shape. Experiments show that our algorithm is fast and stable, and can process various 3D models with arbitrary geometry and topology.