Computing depth orders for fat objects and related problems


Journal Article

Let K be a set of n non-intersecting objects in 3-space. A depth order of K, if it exists, is a linear order < of the objects in K such that if K, L ε{lunate} K and K lies vertically below L then K < L. We present a new technique for computing depth orders, and apply it to several special classes of objects. Our results include: (i) If K is a set of n triangles whose xy-projections are all 'fat', then a depth order for K can be computed in time O(n log5n). (ii) If K is a set of n convex and simply-shaped objects whose xy-projections are all 'fat' and their sizes are within a constant ratio from one another, then a depth order for K can be computed in time O(nλs 1 2(n) log4n), where s is the maximum number of intersections between the boundaries of the xy-projections of any pair of objects in K, and λs(n) is the maximum length of (n,s) Davenport-Schinzel sequences. © 1995.

Full Text

Duke Authors

Cited Authors

  • Agarwal, PK; Katz, MJ; Sharir, M

Published Date

  • January 1, 1995

Published In

Volume / Issue

  • 5 / 4

Start / End Page

  • 187 - 206

International Standard Serial Number (ISSN)

  • 0925-7721

Digital Object Identifier (DOI)

  • 10.1016/0925-7721(95)00005-8

Citation Source

  • Scopus