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A graph with n vertices is 1-planar if it can be drawn in the plane such that each edge is crossed at most once, and is optimal if it has the maximum of 4n-8 edges. We show that optimal 1-planar graphs can be recognized in linear time. Our…

Discrete Mathematics · Computer Science 2018-01-25 Franz J. Brandenburg

This work studies path planning in two-dimensional space, in the presence of polygonal obstacles. We specifically address the problem of building a roadmap graph, that is, an abstract representation of all the paths that can potentially be…

Computational Geometry · Computer Science 2016-06-08 Stéphane Lens , Bernard Boigelot

A shape visibility representation displays a graph so that each vertex is represented by an orthogonal polygon of a particular shape and for each edge there is a horizontal or vertical line of sight between the polygons assigned to its…

Computational Geometry · Computer Science 2018-01-25 Franz J. Brandenburg

We study contact representations of graphs in which vertices are represented by axis-aligned polyhedra in 3D and edges are realized by non-zero area common boundaries between corresponding polyhedra. We show that for every 3-connected…

Computational Geometry · Computer Science 2015-05-05 Md. Jawaherul Alam , William Evans , Stephen G. Kobourov , Sergey Pupyrev , Jackson Toeniskoetter , Torsten Ueckerdt

We study two variants of the well-known orthogonal drawing model: (i) the smooth orthogonal, and (ii) the octilinear. Both models form an extension of the orthogonal, by supporting one additional type of edge segments (circular arcs and…

Data Structures and Algorithms · Computer Science 2017-08-31 Michael A. Bekos , Henry Förster , Michael Kaufmann

In octilinear drawings of planar graphs, every edge is drawn as an alternating sequence of horizontal, vertical and diagonal ($45^\circ$) line-segments. In this paper, we study octilinear drawings of low edge complexity, i.e., with few…

Data Structures and Algorithms · Computer Science 2014-08-27 Michael A. Bekos , Martin Gronemann , Michael Kaufmann , Robert Krug

Orthogonal drawings, i.e., embeddings of graphs into grids, are a classic topic in Graph Drawing. Often the goal is to find a drawing that minimizes the number of bends on the edges. A key ingredient for bend minimization algorithms is the…

Computational Geometry · Computer Science 2019-03-13 Benjamin Niedermann , Ignaz Rutter , Matthias Wolf

Any graph can be represented pictorially as a figure. Moreover, it can be represented as two or more figures that can be have different properties to each other. For the purpose of HCP, we represent a graph by two such figures. In each of…

Optimization and Control · Mathematics 2010-07-02 Ivan I. Goray

In the area of beyond-planar graphs, i.e. graphs that can be drawn with some local restrictions on the edge crossings, the recognition problem is prominent next to the density question for the different graph classes. For 1-planar graphs,…

Data Structures and Algorithms · Computer Science 2021-08-04 Henry Förster , Michael Kaufmann , Chrysanthi N. Raftopoulou

An obstacle representation of a plane graph G is V(G) together with a set of opaque polygonal obstacles such that G is the visibility graph on V(G) determined by the obstacles. We investigate the problem of computing an obstacle…

Computational Geometry · Computer Science 2011-08-15 Matthew P. Johnson , Deniz Sarioz

A drawing of a graph is greedy if for each ordered pair of vertices u and v, there is a path from u to v such that the Euclidean distance to v decreases monotonically at every vertex of the path. The existence of greedy drawings has been…

We first prove a one-to-one correspondence between finding Hamiltonian cycles in a cubic planar graphs and finding trees with specific properties in dual graphs. Using this information, we construct an exact algorithm for finding…

Combinatorics · Mathematics 2015-12-07 Bohao Yao , Charl Ras , Hamid Mokhtar

We investigate two optimization problems on area-proportional rectangle contact representations for layered, embedded planar graphs. The vertices are represented as interior-disjoint unit-height rectangles of prescribed widths, grouped in…

Computational Geometry · Computer Science 2021-08-25 Martin Nöllenburg , Anaïs Villedieu , Jules Wulms

The visual complexity of a graph drawing can be measured by the number of geometric objects used for the representation of its elements. In this paper, we study planar graph drawings where edges are represented by few segments. In such a…

Computational Geometry · Computer Science 2019-08-06 Philipp Kindermann , Tamara Mchedlidze , Thomas Schneck , Antonios Symvonis

We give an algorithm to morph planar graph drawings that achieves small grid size at the expense of allowing a constant number of bends on each edge. The input is an $n$-vertex planar graph and two planar straight-line drawings of the graph…

Computational Geometry · Computer Science 2024-09-09 Therese Biedl , Anna Lubiw , Jack Spalding-Jamieson

A minimally rigid graph, also called Laman graph, models a planar framework which is rigid for a general choice of distances between its vertices. In other words, there are finitely many ways, up to isometries, to realize such a graph in…

Computational Geometry · Computer Science 2022-01-04 Christoph Koutschan

Cartograms are a technique for visually representing geographically distributed statistical data, where values of a numerical attribute are mapped to the size of geographic regions. Contiguous cartograms preserve the adjacencies of the…

Computational Geometry · Computer Science 2026-04-16 Vladimir Molchanov , Hennes Rave , Lars Linsen

Many problems in computational geometry are not stated in graph-theoretic terms, but can be solved efficiently by constructing an auxiliary graph and performing a graph-theoretic algorithm on it. Often, the efficiency of the algorithm…

Computational Geometry · Computer Science 2009-08-28 David Eppstein

Compacting orthogonal drawings is a challenging task. Usually algorithms try to compute drawings with small area or edge length while preserving the underlying orthogonal shape. We present a one-dimensional compaction algorithm that alters…

Data Structures and Algorithms · Computer Science 2017-06-21 Michael Jünger , Petra Mutzel , Christiane Spisla

Given a planar graph $G$ and an integer $b$, OrthogonalPlanarity is the problem of deciding whether $G$ admits an orthogonal drawing with at most $b$ bends in total. We show that OrthogonalPlanarity can be solved in polynomial time if $G$…

Computational Geometry · Computer Science 2019-08-15 Emilio Di Giacomo , Giuseppe Liotta , Fabrizio Montecchiani