| The geometric version of visibility in between two points amidst a set of geometric objects is that the points see each other if and only if their connecting straight line segment does not intersect any of the geometric objects. Visibility has been studied extensively. For example, many versions of the so-called art gallery problem have been considered, where visibility within a simple polygon is the topic of study. At Utrecht University we also consider visibility on terrains and in 3D spaces. |
