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相关论文: Unfolding Restricted Convex Caps

200 篇论文

An edge-unfolding of a polyhedron is produced by cutting along edges and flattening the faces to a *net*, a connected planar piece with no overlaps. A *grid unfolding* allows additional cuts along grid edges induced by coordinate planes…

计算几何 · 计算机科学 2007-05-23 Mirela Damian , Robin Flatland , Joseph O'Rourke

This paper is a study of the interaction between the combinatorics of boundaries of convex polytopes in arbitrary dimension and their metric geometry. Let S be the boundary of a convex polytope of dimension d+1, or more generally let S be a…

度量几何 · 数学 2007-05-23 Ezra Miller , Igor Pak

This note shows that the hope expressed in [ADL+07]--that the new algorithm for edge-unfolding any polyhedral band without overlap might lead to an algorithm for unfolding any prismatoid without overlap--cannot be realized. A prismatoid is…

计算几何 · 计算机科学 2007-10-04 Joseph O'Rourke

We provide an algorithm for unfolding the surface of any orthogonal polyhedron that falls into a particular shape class we call Manhattan Towers, to a nonoverlapping planar orthogonal polygon. The algorithm cuts along edges of a 4x5x1…

计算几何 · 计算机科学 2007-05-23 Mirela Damian , Robin Flatland , Joseph O'Rourke

Starting with the unsolved "D\"urer's problem" of edge-unfolding a convex polyhedron to a net, we specialize and generalize (a) the types of cuts permitted, and (b) the polyhedra shapes, to highlight both advances established and which…

计算几何 · 计算机科学 2019-08-21 Joseph O'Rourke

Let C be a simple, closed, directed curve on the surface of a convex polyhedron P. We identify several classes of curves C that "live on a cone," in the sense that C and a neighborhood to one side may be isometrically embedded on the…

离散数学 · 计算机科学 2011-02-15 Joseph O'Rourke , Costin Vilcu

A well-known result in the study of convex polyhedra, due to Minkowski, is that a convex polyhedron is uniquely determined (up to translation) by the directions and areas of its faces. The theorem guarantees existence of the polyhedron…

计算几何 · 计算机科学 2017-12-06 Giuseppe Sellaroli

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…

计算几何 · 计算机科学 2015-03-12 Nadia Benbernou , Patricia Cahn , Joseph O'Rourke

We show that every orthogonal polyhedron of genus at most 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…

计算几何 · 计算机科学 2016-11-02 Mirela Damian , Erik Demaine , Robin Flatland , Joseph O'Rourke

A pseudo-edge graph of a convex polyhedron K is a 3-connected embedded graph in K whose vertices coincide with those of K, whose edges are distance minimizing geodesics, and whose faces are convex. We construct a convex polyhedron K in…

度量几何 · 数学 2019-03-01 Nicholas Barvinok , Mohammad Ghomi

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…

计算几何 · 计算机科学 2008-12-15 Jin-ichi Itoh , Joseph O'Rourke , Costin Vîlcu

Ghomi proved that every convex polyhedron could be stretched via an affine transformation so that it has an edge-unfolding to a net [Gho14]. A net is a simple planar polygon; in particular, it does not self-overlap. One can view his result…

计算几何 · 计算机科学 2023-02-17 Joseph O'Rourke

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…

计算几何 · 计算机科学 2009-06-24 Jin-ichi Itoh , Joseph O'Rourke , Costin Vîlcu

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.

计算几何 · 计算机科学 2011-06-09 Joseph O'Rourke

We show that every ridge unfolding of an $n$-cube is without self-overlap, yielding a valid net. The results are obtained by developing machinery that translates cube unfolding into combinatorial frameworks. Moreover, the geometry of the…

组合数学 · 数学 2020-07-28 Kristin DeSplinter , Satyan L. Devadoss , Jordan Readyhough , Bryce Wimberly

Deciding whether the union of two convex polyhedra is itself a convex polyhedron is a basic problem in polyhedral computations; having important applications in the field of constrained control and in the synthesis, analysis, verification…

计算几何 · 计算机科学 2009-08-10 Roberto Bagnara , Patricia M. Hill , Enea Zaffanella

It is shown that any smooth closed orientable manifold of dimension $2k + 1$, $k \geq 2$, admits a smooth polynomially convex embedding into $\mathbb C^{3k}$. This improves by $1$ the previously known lower bound of $3k+1$ on the possible…

复变函数 · 数学 2020-09-29 Purvi Gupta , Rasul Shafikov

The construction of an unbounded polyhedron from a "jagged'' convex cap is described, and several of its properties discussed, including its relation to Alexandrov's "limit angle."

计算几何 · 计算机科学 2020-02-18 Joseph O'Rourke

It is well-known that the convex and concave envelope of a multilinear polynomial over a box are polyhedral functions. Exponential-sized extended and projected formulations for these envelopes are also known. We consider the convexification…

最优化与控制 · 数学 2021-06-14 Yibo Xu , Warren Adams , Akshay Gupte

We study efficient combinatorial algorithms to produce the Hasse diagram of the poset of bounded faces of an unbounded polyhedron, given vertex-facet incidences. We also discuss the special case of simple polyhedra and present computational…

组合数学 · 数学 2014-12-23 Sven Herrmann , Michael Joswig , Marc E. Pfetsch