• Linear interpolation of shape operators for umbilical points via local parameterization

    Subjects: Computer Science >> Computer Application Technology submitted time 2017-03-10

    Abstract:Principal curvatures and principal directions are exploited ubiquitously in shape analysis. On one hand, umbilical points severely hinder the analysis as the singularities in the vector field of principal directions; on the other hand, providing shape-intrinsic qualitative information about a surface, they are desirable quantities in some applications. Umbilical points are fundamental for geometric analysis, but their accurate computation on a discrete surface is still challenging. In this paper, we develop a simple and effective method to detect umbilical points on a triangle mesh, in which any parametrization works. In particular, we propose two practical processes for local parametrization by orthogonally projecting or conformally transforming the matrix onto a specified parametric plane. Furthermore, we make a systematic analysis on our method and demonstrate its convergence behavior. The algorithm of our approach is flexible and easy to implement for a triangular mesh of arbitrary topology.