Virtual Occluders: An Efficient Intermediate PVS Representation

In this paper we introduce the notion of virtual occluders. Given a scene and a viewcell, a virtual occluder is a view-dependent (simple) convex object, which is guaranteed to be fully occluded from any given point within the viewcell and which serves as an effective occluder from the given viewcell. Virtual occluders are a compact intermediate representation of the aggregate occlusion for a given cell. The introduction of such view-dependent virtual occluders enables applying an effective region-to-region or cell-to-cell culling technique and efficiently computing a potential visibility set (PVS) from a region/cell. We present a technique that synthesizes such virtual occluders by aggregating the visibility of a set of individual occluders and we show the technique’s effectiveness.