English

Discrete Curvature and Torsion from Cross-Ratios

Differential Geometry 2020-09-01 v1 Graphics Numerical Analysis Numerical Analysis

Abstract

Motivated by a M\"obius invariant subdivision scheme for polygons, we study a curvature notion for discrete curves where the cross-ratio plays an important role in all our key definitions. Using a particular M\"obius invariant point-insertion-rule, comparable to the classical four-point-scheme, we construct circles along discrete curves. Asymptotic analysis shows that these circles defined on a sampled curve converge to the smooth curvature circles as the sampling density increases. We express our discrete torsion for space curves, which is not a M\"obius invariant notion, using the cross-ratio and show its asymptotic behavior in analogy to the curvature.

Keywords

Cite

@article{arxiv.2008.13236,
  title  = {Discrete Curvature and Torsion from Cross-Ratios},
  author = {Christian Müller and Amir Vaxman},
  journal= {arXiv preprint arXiv:2008.13236},
  year   = {2020}
}