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While orthogonal drawings have a long history, smooth orthogonal drawings have been introduced only recently. So far, only planar drawings or drawings with an arbitrary number of crossings per edge have been studied. Recently, a lot of…

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 2021-06-11 Lukas Barth , Benjamin Niedermann , Ignaz Rutter , Matthias Wolf

An obstacle representation of a graph $G$ is a set of points in the plane representing the vertices of $G$, together with a set of polygonal obstacles such that two vertices of $G$ are connected by an edge in $G$ if and only if the line…

Combinatorics · Mathematics 2017-07-18 Martin Balko , Josef Cibulka , Pavel Valtr

We show that finding orthogonal grid-embeddings of plane graphs (planar with fixed combinatorial embedding) with the minimum number of bends in the so-called Kandinsky model (which allows vertices of degree $> 4$) is NP-complete, thus…

Computational Geometry · Computer Science 2014-05-12 Thomas Bläsius , Guido Brückner , Ignaz Rutter

Octilinear graph drawings are a standard paradigm extending the orthogonal graph drawing style by two additional slopes (+1 and -1). We are interested in two constrained drawing problems where the input specifies a so-called representation,…

Computational Geometry · Computer Science 2025-11-26 Henry Förster , Giacomo Ortali , Lena Schlip

Orthogonal graph drawings are used in applications such as UML diagrams, VLSI layout, cable plans, and metro maps. We focus on drawing planar graphs and assume that we are given an \emph{orthogonal representation} that describes the desired…

Computational Geometry · Computer Science 2025-08-14 Walter Didimo , Siddharth Gupta , Philipp Kindermann , Giuseppe Liotta , Alexander Wolff , Meirav Zehavi

An obstacle representation of a graph $G$ consists of a set of pairwise disjoint simply-connected closed regions and a one-to-one mapping of the vertices of $G$ to points such that two vertices are adjacent in $G$ if and only if the line…

Computational Geometry · Computer Science 2025-02-25 Martin Balko , Steven Chaplick , Robert Ganian , Siddharth Gupta , Michael Hoffmann , Pavel Valtr , Alexander Wolff

Let $\langle G_r,G_b \rangle$ be a pair of plane $st$-graphs with the same vertex set $V$. A simultaneous visibility representation with L-shapes of $\langle G_r,G_b \rangle$ is a pair of bar visibility representations…

Computational Geometry · Computer Science 2019-09-04 William S. Evans , Giuseppe Liotta , Fabrizio Montecchiani

We consider a graph representation in the plane, called the transparent rectangle visibility graph (TRVG), where each vertex is represented by a rectangle in the plane with sides parallel to the plane axes, in a way that any two vertices…

The visibility graph of a simple polygon represents visibility relations between its vertices. Knowing the correct order of the vertices around the boundary of a polygon and its visibility graph, it is an open problem to locate the vertices…

Computational Geometry · Computer Science 2019-05-03 Sahar Mehrpour , Alireza Zarei

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

We study contact representations for graphs, which we call pixel representations in 2D and voxel representations in 3D. Our representations are based on the unit square grid whose cells we call pixels in 2D and voxels in 3D. Two pixels are…

Discrete Mathematics · Computer Science 2015-07-07 Muhammad Jawaherul Alam , Thomas Bläsius , Ignaz Rutter , Torsten Ueckerdt , Alexander Wolff

Obstacle representations of graphs have been investigated quite intensely over the last few years. We focus on graphs that can be represented by a single obstacle. Given a (topologically open) polygon $C$ and a finite set $P$ of points in…

Computational Geometry · Computer Science 2016-09-02 Steven Chaplick , Fabian Lipp , Ji-won Park , Alexander Wolff

Over the past twenty years, rectangle visibility graphs have generated considerable interest, in part due to their applicability to VLSI chip design. Here we study unit rectangle visibility graphs, with fixed dimension restrictions more…

Combinatorics · Mathematics 2007-10-12 Alice Dean , Joanna A. Ellis-Monaghan , Sarah Hamilton , Greta Pangborn

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

An orthogonal drawing is an embedding of a plane graph into a grid. In a seminal work of Tamassia (SIAM Journal on Computing 1987), a simple combinatorial characterization of angle assignments that can be realized as bend-free orthogonal…

Computational Geometry · Computer Science 2025-04-09 Yi-Jun Chang

We study the planar orthogonal drawing style within the framework of partial representation extension. Let $(G,H,{\Gamma}_H )$ be a partial orthogonal drawing, i.e., G is a graph, $H\subseteq G$ is a subgraph and ${\Gamma}_H$ is a planar…

Discrete Mathematics · Computer Science 2020-08-25 Patrizio Angelini , Ignaz Rutter , Sandhya T P

A matching of a graph is a set of edges without common end vertex. A graph is called 1-planar if it admits a drawing in the plane such that each edge is crossed at most once. Recently, Biedl and Wittnebel proved that every 1-planar graph…

Combinatorics · Mathematics 2022-07-11 Yuanqiu Huang , Zhangdong Ouyang , Fengming Dong

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

It is known that the vertex connectivity of a planar graph can be computed in linear time. We extend this result to the class of locally maximal 1-plane graphs: graphs that have an embedding with at most one crossing per edge such that the…

Combinatorics · Mathematics 2021-12-14 Therese Biedl , Karthik Murali