论文标题
普遍的光谱粗化
Generalized Spectral Coarsening
论文作者
论文摘要
用于几何形状的许多计算算法以形状的离散表示作用。有时有必要先简化现代数据集中的表示或更粗糙的表示形式,以实现可行或加快处理。粗化算法的效用取决于同时选择的代表以及特定的处理算法或操作员。例如使用有限元方法,计算贝蒂数字等的仿真。我们提出了一种新的方法,该方法可以使三角形,四面体网格和简单复合物进行擦拭。我们的方法允许从高分辨率几何形状中控制显着特征,因此可以对不同的应用进行自定义。 显着特性通常是由局部形状描述符通过线性差分运算符(Laplacians的变体)捕获的。其离散矩阵的特征向量产生了用于几何处理的有用光谱域(类似于使用衍生物操作员的特征函数的著名傅立叶光谱)。现有的保留频谱变厚的方法使用拉普拉斯运算符(顶点定义)的零维离散化。我们提出了一种广义的光谱粗化方法,该方法考虑了在串联不同维度中定义的多个拉普拉斯运算符。我们的简单算法贪婪地决定了基于每个单纯质量功能的简单收缩顺序。质量函数量化了由于在所选的几何形状范围内选择的单纯形上去除该单纯形引起的误差。
Many computational algorithms applied to geometry operate on discrete representations of shape. It is sometimes necessary to first simplify, or coarsen, representations found in modern datasets for practicable or expedited processing. The utility of a coarsening algorithm depends on both, the choice of representation as well as the specific processing algorithm or operator. e.g. simulation using the Finite Element Method, calculating Betti numbers, etc. We propose a novel method that can coarsen triangle meshes, tetrahedral meshes and simplicial complexes. Our method allows controllable preservation of salient features from the high-resolution geometry and can therefore be customized to different applications. Salient properties are typically captured by local shape descriptors via linear differential operators -- variants of Laplacians. Eigenvectors of their discretized matrices yield a useful spectral domain for geometry processing (akin to the famous Fourier spectrum which uses eigenfunctions of the derivative operator). Existing methods for spectrum-preserving coarsening use zero-dimensional discretizations of Laplacian operators (defined on vertices). We propose a generalized spectral coarsening method that considers multiple Laplacian operators defined in different dimensionalities in tandem. Our simple algorithm greedily decides the order of contractions of simplices based on a quality function per simplex. The quality function quantifies the error due to removal of that simplex on a chosen band within the spectrum of the coarsened geometry.