A pedestrian approach to ray shooting: shoot a ray, take a walk
John Hershberger,Subhash Suri +1 more
- Vol. 18, Iss: 3, pp 54-63
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TLDR
In this paper, a simple Steiner triangulation of a simple polygon with the property that a ray can intersect at most O(log n) triangles before reaching the polygon boundary is presented.Abstract:
We propose a very simple ray-shooting algorithm, whose only data structure is a triangulation. The query algorithm, after locating the triangle containing the origin of the ray, walks along the ray, advancing from one triangle to a neighboring one until the polygon boundary is reached. The key result of the paper is a Steiner triangulation of a simple polygon with the property that a ray can intersect at most O(log n) triangles before reaching the polygon boundary. We are able to compute such a triangulation in linear sequential time, or in O(log n) parallel time using O(n/log n) processors. This gives a simple, yet optimal, ray-shooting algorithm for a simple polygon. Using a well-known technique, we can extend our triangulation procedure to a multiconnected polygon with k components and n vertices, so that a ray intersects at most O(√κ log n) triangles. © 1995 Academic Press, Inc.read more
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Geometric Range Searching and Its Relatives
Pankaj K. Agarwal,Je Erickson +1 more
TL;DR: This volume provides an excellent opportunity to recapitulate the current status of geometric range searching and to summarize the recent progress in this area.
Journal ArticleDOI
Optimal output-sensitive convex hull algorithms in two and three dimensions
TL;DR: This work presents simple output-sensitive algorithms that construct the convex hull of a set of n points in two or three dimensions in worst-case optimalO (n logh) time and O (n) space, whereh denotes the number of vertices of the conveX hull.
Journal ArticleDOI
On range searching with semialgebraic sets
Pankaj K. Agarwal,Jirí Matousek +1 more
TL;DR: A solution with nearly linear space and preprocessing time and withO(n1−1/b+δ) query time is given, whered≤b≤2d−3 and δ>0 is an arbitrarily small constant.
Proceedings ArticleDOI
Touring a sequence of polygons
TL;DR: The touring polygons problem is a strict generalization of some classic problems in computational geometry, including the safari problem, the zoo-keeper problem, and the watchman route problem in a simple polygon and it is shown that for nonconvex polygons this "touring polygons" problem is NP-hard.
Journal ArticleDOI
TSP with neighborhoods of varying size
Mark de Berg,Joachim Gudmundsson,Matthew J. Katz,Christos Levcopoulos,Mark H. Overmars,A. Frank van der Stappen +5 more
TL;DR: In this paper, the first polynomial-time constant-factor approximation algorithm for disjoint convex fat neighborhoods of arbitrary size was presented, where the neighborhoods can overlap and are not required to be convex or fat.
References
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Journal ArticleDOI
Optimal Search in Planar Subdivisions
TL;DR: This work presents a practical algorithm for subdivision search that achieves the same (optimal) worst case complexity bounds as the significantly more complex algorithm of Lipton and Tarjan, namely $O(\log n)$ search time with $O(n)$ storage.
Journal Article
Triangulating a simple polygon in linear time
TL;DR: A deterministic algorithm for triangulating a simple polygon in linear time is given, using the polygon-cutting theorem and the planar separator theorem, whose role is essential in the discovery of new diagonals.
Journal ArticleDOI
Triangulating a simple polygon in linear time
TL;DR: In this paper, a deterministic algorithm for triangulating a simple polygon in linear time is presented. But the main tools used are the polygon-cutting theorem, which provides us with a balancing scheme, and the planar separator theorem, whose role is essential in the discovery of new diagonals.
Journal ArticleDOI
Optimal point location in a monotone subdivision
TL;DR: A substantial refinement of the technique of Lee and Preparata for locating a point in $\mathcal{S}$ based on separating chains is exhibited, which can be implemented in a simple and practical way, and is extensible to subdivisions with edges more general than straight-line segments.
Journal ArticleDOI
Linear-time algorithms for visibility and shortest path problems inside triangulated simple polygons
Leonidas J. Guibas,John Hershberger,Daniel Leven,Micha Sharir,Micha Sharir,Robert E. Tarjan,Robert E. Tarjan +6 more
TL;DR: Given a triangulation of a simple polygonP, linear-time algorithms for solving a collection of problems concerning shortest paths and visibility withinP are presented.