English

Conic Crease Patterns with Reflecting Rule Lines

Computational Geometry 2018-12-05 v1

Abstract

We characterize when two conic curved creases are compatible with each other, when the rule lines must converge to conic foci and reflect at the crease. Namely, two conics are compatible (can be connected by rule segments in a foldable curved crease pattern) if and only if they have equal or reciprocal eccentricity. Thus, circles (eccentricity 0) and parabolas (eccentricity 1) are compatible with only themselves (when scaled from a focus), and ellipses (eccentricity strictly between 0 and 1) and hyperbolas (eccentricity above 1) are compatible with themselves and each other (but only in specific pairings). The foundation of this result is a general condition relating any two curved creases connected by rule segments. We also use our characterization to analyze several curved crease designs.

Cite

@article{arxiv.1812.01167,
  title  = {Conic Crease Patterns with Reflecting Rule Lines},
  author = {Erik D. Demaine and Martin L. Demaine and David A. Huffman and Duks Koschitz and Tomohiro Tachi},
  journal= {arXiv preprint arXiv:1812.01167},
  year   = {2018}
}

Comments

17 pages, 12 figures. In Origami^7: Proceedings of the 7th International Meeting on Origami in Science, Mathematics and Education

R2 v1 2026-06-23T06:30:24.760Z