Viewspace Partitioning of Densely Occluded Scenes

Computing the visibility of out-door scenes is often much harder than of in-door scenes. A typical urban scene, for example, is densely occluded, and it is effective to precompute its visibility space, since from a given point only a small fraction of the scene is visible. The difficulty is that although the majority of objects are hidden, some parts might be visible at a distance in an arbitrary location, and it is not clear how to detect them quickly. In this paper we presenta method to partition the viewspace into cells containing a conservative supersetof the visible objects. For a given cell the method tests the visibility of all the objects in the scene. For each object it searches for a strong occluder which guarantees that the object is not visible from any point within the cell. We show analytically that in a densely occluded scene, the vast majority of objects are strongly occluded, and the overhead of using conservative visibility (rather than visibility) is small. These r...

• Type: Conference
• Year: 1998
• Where: COMPGEOM
• Authors: Yiorgos Chrysanthou, Daniel Cohen-Or, Eyal Zadicario
• Keywords: COMPGEOM 1998, Discrete Geometry, Typical Urban Scene, Visibility, Visibility Space