Worst-case optimal algorithms for constructing visibility polygons with holes
SCG '86 Proceedings of the second annual symposium on Computational geometry
Worst-case optimal hidden-surface removal
ACM Transactions on Graphics (TOG)
Simulation of simplicity: a technique to cope with degenerate cases in geometric algorithms
ACM Transactions on Graphics (TOG)
Visibility, occlusion, and the aspect graph
International Journal of Computer Vision
Efficiently Computing and Representing Aspect Graphs of Polyhedral Objects
IEEE Transactions on Pattern Analysis and Machine Intelligence
Visibility with a moving point of view
SODA '90 Proceedings of the first annual ACM-SIAM symposium on Discrete algorithms
Three-dimensional weak visibility: complexity and applications
Theoretical Computer Science
Computational Line Geometry
Multi-visibility maps of triangulated terrains
International Journal of Geographical Information Science
Hi-index | 0.00 |
Let T be a set of n disjoint triangles in three-dimensional space, let s be a line segment, and let t be a triangle, both disjoint from T. We consider the visibility map of s with respect to T, i.e., the portions of T that are visible from s. The visibility map of t is defined analogously. We look at two different notions of visibility: strong (complete) visibility, and weak (partial) visibility. The trivial Ω(n2) lower bound for the combinatorial complexity of the strong visibility map of both s and t is almost tight: we prove an O(n2 log n) upper bound for both structures. Furthermore, we prove that the weak visibility map of s has complexity Θ(n5), and the weak visibility map of t has complexity Θ(n7). If T is a polyhedral terrain, the complexity of the weak visibility map is Ω(n4) and O(n5), both for a segment and a triangle. We also present efficient algorithms to compute all discussed structures.