Editing Visibility graph (section)

==Related problems==
The [[art gallery problem]] is the problem of finding a small set of points such that all other non-obstacle points are visible from this set. Certain forms of the art gallery problem may be interpreted as finding a [[dominating set]] in a visibility graph.

The [[bitangent]]s of a system of polygons or curves are lines that touch two of them without penetrating them at their points of contact. The bitangents of a set of polygons form a subset of the visibility graph that has the polygon's vertices as its nodes and the polygons themselves as the obstacles. The visibility graph approach to the Euclidean shortest path problem may be sped up by forming a graph from the bitangents instead of using all visibility edges, since a Euclidean shortest path may only enter or leave the boundary of an obstacle along a bitangent.<ref>{{harvtxt|de Berg|van Kreveld|Overmars|Schwarzkopf|2000}}, p. 316.</ref>