English
Related papers

Related papers: Reconstructing a convex polygon from its $\omega$-…

200 papers

The goal of this paper is to present a general and novel approach for the reconstruction of any convex d-dimensional polytope P, from knowledge of its moments. In particular, we show that the vertices of an N-vertex polytope in R^d can be…

Numerical Analysis · Mathematics 2012-09-13 Nick Gravin , Jean Lasserre , Dmitrii Pasechnik , Sinai Robins

$\cal{A}$ point $P \in \Real^n$ is represented in Parallel Coordinates by a polygonal line $\bar{P}$ (see \cite{Insel99a} for a recent survey). Earlier \cite{inselberg85plane}, a surface $\sigma$ was represented as the {\em envelope} of the…

Other Computer Science · Computer Science 2007-05-23 Zur Izhakian

Recent years have witnessed the growth of point cloud based applications because of its realistic and fine-grained representation of 3D objects and scenes. However, it is a challenging problem to compress sparse, unstructured, and…

Image and Video Processing · Electrical Eng. & Systems 2020-11-10 Jianqiang Wang , Dandan Ding , Zhu Li , Zhan Ma

We investigate the problem of exact cluster recovery using oracle queries. Previous results show that clusters in Euclidean spaces that are convex and separated with a margin can be reconstructed exactly using only $O(\log n)$ same-cluster…

Machine Learning · Computer Science 2021-07-14 Marco Bressan , Nicolò Cesa-Bianchi , Silvio Lattanzi , Andrea Paudice

To investigate the topological structure of planar polygon decomposition on trapezoids, which is formed by height functions. We use the oriented Reeb graph of the function with a marked vertex. We describe all possible optimal Reeb graphs…

Geometric Topology · Mathematics 2024-04-11 Oleksandr Pryshliak , Karolina Haieva

We prove that, for any two polyhedral manifolds $\mathcal P, \mathcal Q$, there is a polyhedral manifold $\mathcal I$ such that $\mathcal P, \mathcal I$ share a common unfolding and $\mathcal I,\mathcal Q$ share a common unfolding. In other…

Computational Geometry · Computer Science 2025-10-08 Lily Chung , Erik D. Demaine , Jenny Diomidova , Tonan Kamata , Jayson Lynch , Ryuhei Uehara , Hanyu Alice Zhang

Let $\mathcal{P}$ be an $n$-dimensional convex polytope and $\mathcal{S}$ be a hypersurface in $\mathbb{R}^n$. This paper investigates potentials to reconstruct $\mathcal{P}$ or at least to compute significant properties of $\mathcal{P}$ if…

Mathematical Physics · Physics 2022-12-29 Konrad Engel , Bastian Laasch

Not only is the geometry of rock fragments often well approximated by ideal convex polyhedra having few faces and vertices, but these numbers carry vital geophysical information on the fragmentation process. Despite their significance, the…

Geophysics · Physics 2025-04-16 Janos Torok , Gabor Domokos

Guarding a polygon with few guards is an old and well-studied problem in computational geometry. Here we consider the following variant: We assume that the polygon is orthogonal and thin in some sense, and we consider a point $p$ to guard a…

Computational Geometry · Computer Science 2016-04-26 Therese Biedl , Saeed Mehrabi

Motivated by the problem of redistricting, we study area-preserving reconfigurations of connected subdivisions of a simple polygon. A connected subdivision of a polygon $\mathcal{R}$, called a district map, is a set of interior disjoint…

Computational Geometry · Computer Science 2023-07-04 Hugo A. Akitaya , Andrei Gonczi , Diane L. Souvaine , Csaba D. Tóth , Thomas Weighill

In this paper we present several results on the expected complexity of a convex hull of $n$ points chosen uniformly and independently from a convex shape. (i) We show that the expected number of vertices of the convex hull of $n$ points,…

Computational Geometry · Computer Science 2011-11-24 Sariel Har-Peled

The convex rope problem is to find a counterclockwise or clockwise convex rope starting at the vertex a and ending at the vertex b of a simple polygon P, where a is a vertex of the convex hull of P and b is visible from infinity. The convex…

Optimization and Control · Mathematics 2023-05-22 Le Hong Trang , Nguyen Thi Le , Phan Thanh An

A planar orthogonal drawing {\Gamma} of a connected planar graph G is a geometric representation of G such that the vertices are drawn as distinct points of the plane, the edges are drawn as chains of horizontal and vertical segments, and…

Computational Geometry · Computer Science 2025-02-06 Walter Didimo , Giuseppe Liotta , Giacomo Ortali , Maurizio Patrignani

We are given a finite set of n points (guards) G in the plane R^2 and an angle 0 < theta < 2 pi. A theta-cone is a cone with apex angle theta. We call a theta-cone empty (with respect to G) if it does not contain any point of G. A point p…

Computational Geometry · Computer Science 2008-09-11 Domagoj Matijević , Ralf Osbild

We present PolyGNN, a polyhedron-based graph neural network for 3D building reconstruction from point clouds. PolyGNN learns to assemble primitives obtained by polyhedral decomposition via graph node classification, achieving a watertight…

Computer Vision and Pattern Recognition · Computer Science 2024-10-15 Zhaiyu Chen , Yilei Shi , Liangliang Nan , Zhitong Xiong , Xiao Xiang Zhu

Surface reconstruction from point clouds is a fundamental step in many applications in computer vision. In this paper, we develop an efficient iterative method on a variational model for the surface reconstruction from point clouds. The…

Numerical Analysis · Mathematics 2020-05-26 Dong Wang

A set of n points in low dimensions takes Theta(n w) bits to store on a w-bit machine. Surface reconstruction and mesh refinement impose a requirement on the distribution of the points they process. I show how to use this assumption to…

Computational Geometry · Computer Science 2009-09-18 Benoît Hudson

We investigate rigidity-type problems on the real line and the circle in the non-generic setting. Specifically, we consider the problem of uniquely determining the positions of $n$ distinct points $V = {v_1, \ldots, v_n}$ given a set of…

Metric Geometry · Mathematics 2024-01-30 Itai Benjamini , Elad Tzalik

We are interested in reconstructing the mesh representation of object surfaces from point clouds. Surface reconstruction is a prerequisite for downstream applications such as rendering, collision avoidance for planning, animation, etc.…

Computer Vision and Pattern Recognition · Computer Science 2020-10-01 Minghua Liu , Xiaoshuai Zhang , Hao Su

A vertex $v$ of a connected graph $G$ is said to be a boundary vertex of $G$ if for some other vertex $u$ of $G$, no neighbor of $v$ is further away from $u$ than $v$. The boundary $\partial(G)$ of $G$ is the set of all of its boundary…

Combinatorics · Mathematics 2024-12-30 José Cáceres , Ignacio M. Pelayo