Abstract
We show that every orthogonal polyhedron of genus \(g \le 2\) can be unfolded without overlap while using only a linear number of orthogonal cuts (parallel to the polyhedron edges). This is the first result on unfolding general orthogonal polyhedra beyond genus-0. Our unfolding algorithm relies on the existence of at most 2 special leaves in what we call the “unfolding tree” (which ties back to the genus), so unfolding polyhedra of genus 3 and beyond requires new techniques.
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Notes
The \(\pm y\) faces are given the awkward names “forward” and “rearward” to avoid confusion with other uses of “front” and “back” introduced later.
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Acknowledgements
We thank all the participants of the 31st Bellairs Winter Workshop on Computational Geometry for a fruitful and collaborative environment. In particular, we thank Sebastian Morr for important discussions related to Theorem 1, and to the stitching of unfolding strips at the root node.
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Damian, M., Demaine, E., Flatland, R. et al. Unfolding Genus-2 Orthogonal Polyhedra with Linear Refinement. Graphs and Combinatorics 33, 1357–1379 (2017). https://doi.org/10.1007/s00373-017-1849-5
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DOI: https://doi.org/10.1007/s00373-017-1849-5