𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Ray Shooting Amidst Convex Polygons in 2D

✍ Scribed by Pankaj K. Agarwal; Micha Sharir


Publisher
Elsevier Science
Year
1996
Tongue
English
Weight
220 KB
Volume
21
Category
Article
ISSN
0196-6774

No coin nor oath required. For personal study only.

✦ Synopsis


We consider the problem of ray shooting in a two-dimensional scene consisting of m convex polygons with a total of n edges. We present a data structure that Ε½ . requires O mn log m space and preprocessing time and that answers a ray Ε½ 2 2 . shooting query in O log m log n time. If the polygons are pairwise disjoint, the Ε½Ε½ 2 . . Ε½ Ε½ 2 space and preprocessing time can be improved to O m q n log m and O m q . . nlog n log m , respectively. Our algorithm also works for a collection of disjoint Ε½ . simple polygons. We also show that if we allow only O n space, a ray shooting query among a collection of disjoint simple polygons can be answered in time 1q 2 ' Ε½u v . O mr n log n time, for any ) 0.


πŸ“œ SIMILAR VOLUMES


A Distributed Formation of Smallest Faul
✍ Jie Wu πŸ“‚ Article πŸ“… 2002 πŸ› Elsevier Science 🌐 English βš– 229 KB

The rectangular faulty block model is the most commonly used fault model for designing fault-tolerant and deadlock-free routing algorithms in meshconnected multicomputers. The convexity of a rectangle facilitates simple and efficient ways to route messages around fault regions using relatively few v

Hierarchical representation of 2-D shape
✍ O. El Badawy; M.S. Kamel πŸ“‚ Article πŸ“… 2005 πŸ› Elsevier Science 🌐 English βš– 688 KB

A concavity tree is a data structure for hierarchically representing the shape of two-dimensional silhouettes using convex polygons. In this paper, we present a new algorithm for concavity tree extraction. The algorithm is fast, works directly on the pixel grid of the shape, and uses exact convex hu