Wonka, PeterWimmer, MichaelSillion, Francois X.2015-02-162015-02-1620011467-8659https://doi.org/10.1111/1467-8659.00534We present an online occlusion culling system which computes visibility in parallel to the rendering pipeline. We show how to use point visibility algorithms to quickly calculate a tight potentially visible set (PVS) which is valid for several frames, by shrinking the occluders used in visibility calculations by an adequate amount. These visibility calculations can be performed on a visibility server, possibly a distinct computer communicating with the display host over a local network. The resulting system essentially combines the advantages of online visibility processing and region-based visibility calculations, allowing asynchronous processing of visibility and display operations. We analyze two different types of hardware-based point visibility algorithms and address the problem of bounded calculation time which is the basis for true real-time behavior. Our results show reliable, sustained 60 Hz performance in a walkthrough with an urban environment of nearly 2 million polygons, and a terrain flyover.10.1111/1467-8659.00534411-421