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Related papers: Spiral Unfoldings of Convex Polyhedra

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We show that four of the five Platonic solids' surfaces may be cut open with a Hamiltonian path along edges and unfolded to a polygonal net each of which can "zipper-refold" to a flat doubly covered parallelogram, forming a rather compact…

Computational Geometry · Computer Science 2010-10-21 Joseph O'Rourke

We define a notion for unfolding smooth, ruled surfaces, and prove that every smooth prismatoid (the convex hull of two smooth curves lying in parallel planes), has a nonoverlapping "volcano unfolding." These unfoldings keep the base…

Computational Geometry · Computer Science 2015-03-12 Nadia Benbernou , Patricia Cahn , Joseph O'Rourke

An unfolding of a polyhedron is produced by cutting the surface and flattening to a single, connected, planar piece without overlap (except possibly at boundary points). It is a long unsolved problem to determine whether every polyhedron…

Computational Geometry · Computer Science 2007-05-23 Mirela Damian , Robin Flatland , Joseph O'Rourke

There exists a surface of a convex polyhedron P and a partition L of P into geodesic convex polygons such that there are no connected "edge" unfoldings of P without self-intersections (whose spanning tree is a subset of the edge skeleton of…

Computational Geometry · Computer Science 2008-10-06 Alexey S Tarasov

Using the orthogonal connectedness, we introduce the notion of orthogonal decomposability of convex polytopes and study it in the case of Platonic and Archimedean solids. While doing so, we also encounter polytopes which are not…

Combinatorics · Mathematics 2026-03-10 Julia Q. Du , Xuemei He , Xiaotian Song , Daniela Stiller , Liping Yuan , Tudor Zamfirescu

An unfolding of a polyhedron along its edges is called a vertex unfolding if adjacent faces are allowed to be connected at not only an edge but also a vertex. Demaine et al showed that every triangulated polyhedron has a vertex unfolding.…

Combinatorics · Mathematics 2013-02-19 Toshiki Endo , Yuki Suzuki

We define a new class of orthogonal polyhedra, called orthogrids, that can be unfolded without overlap with constant refinement of the gridded surface.

Computational Geometry · Computer Science 2013-10-18 Mirela Damian , Erik Demaine , Robin Flatland

We show that every orthogonal polyhedron homeomorphic to a sphere can be unfolded without overlap while using only polynomially many (orthogonal) cuts. By contrast, the best previous such result used exponentially many cuts. More precisely,…

Computational Geometry · Computer Science 2011-12-21 Mirela Damian , Erik Demaine , Robin Flatland

We address the unsolved problem of unfolding prismatoids in a new context, viewing a "topless prismatoid" as a convex patch---a polyhedral subset of the surface of a convex polyhedron homeomorphic to a disk. We show that several natural…

Computational Geometry · Computer Science 2012-05-10 Joseph O'Rourke

Over a decade ago, it was shown that every edge unfolding of the Platonic solids was without self-overlap, yielding a valid net. We consider this property for regular polytopes in arbitrary dimensions, notably the simplex, cube, and…

Computational Geometry · Computer Science 2021-11-03 Satyan L. Devadoss , Matthew Harvey

We extend the notion of a source unfolding of a convex polyhedron P to be based on a closed polygonal curve Q in a particular class rather than based on a point. The class requires that Q "lives on a cone" to both sides; it includes simple,…

Computational Geometry · Computer Science 2012-05-07 Jin-ichi Itoh , Joseph O'Rourke , Costin Vilcu

It is shown that there are examples of distinct polyhedra, each with a Hamiltonian path of edges, which when cut, unfolds the surfaces to a common net. In particular, it is established for infinite classes of triples of tetrahedra.

Computational Geometry · Computer Science 2011-06-09 Joseph O'Rourke

We present structures comprised of identical convex polyhedra which are interlocked geometrically. These sets cannot be disassembled by removing individual polyhedra by translations and/or rotations. The shapes that permit interlocking…

Metric Geometry · Mathematics 2017-12-05 A. J. Kanel-Belov , A. V. Dyskin , Y. Estrin , E. Pasternak , I. A. Ivanov-Pogodaev

It is shown that every orthogonal terrain, i.e., an orthogonal (right-angled) polyhedron based on a rectangle that meets every vertical line in a segment, has a grid unfolding: its surface may be unfolded to a single non-overlapping piece…

Computational Geometry · Computer Science 2007-07-12 Joseph O'Rourke

We investigate how to make the surface of a convex polyhedron (a polytope) by folding up a polygon and gluing its perimeter shut, and the reverse process of cutting open a polytope and unfolding it to a polygon. We explore basic enumeration…

Computational Geometry · Computer Science 2007-05-23 Erik D. Demaine , Martin L. Demaine , Anna Lubiw , Joseph O'Rourke

We extend the notion of a star unfolding to be based on a simple quasigeodesic loop Q rather than on a point. This gives a new general method to unfold the surface of any convex polyhedron P to a simple, planar polygon: shortest paths from…

Computational Geometry · Computer Science 2008-12-15 Jin-ichi Itoh , Joseph O'Rourke , Costin Vîlcu

We extend the notion of star unfolding to be based on a quasigeodesic loop Q rather than on a point. This gives a new general method to unfold the surface of any convex polyhedron P to a simple (non-overlapping), planar polygon: cut along…

Computational Geometry · Computer Science 2009-06-24 Jin-ichi Itoh , Joseph O'Rourke , Costin Vîlcu

We show how to edge-unfold a new class of convex polyhedra, specifically a new class of prismatoids (the convex hull of two parallel convex polygons, called the top and base), by constructing a nonoverlapping "petal unfolding" in two new…

Computational Geometry · Computer Science 2021-06-29 Vincent Bian , Erik Demaine , Rachana Madhukara

We present two algorithms for unfolding the surface of any polyhedron, all of whose faces are triangles, to a nonoverlapping, connected planar layout. The surface is cut only along polyhedron edges. The layout is connected, but it may have…

Computational Geometry · Computer Science 2010-01-21 Erik D. Demaine , David Eppstein , Jeff Erickson , George W. Hart , Joseph O'Rourke

A notion of "radially monotone" cut paths is introduced as an effective choice for finding a non-overlapping edge-unfolding of a convex polyhedron. These paths have the property that the two sides of the cut avoid overlap locally as the cut…

Computational Geometry · Computer Science 2016-08-01 Joseph O'Rourke
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