Jiri Bittner, Oliver Mattausch, Peter Wonka, Vlastimil Havran, Michael Wimmer. Adaptive Global Visibility Sampling. ACM Transactions on Graphics (Proceedings of ACM SIGGRAPH 2009), vol. 28, no. 3, p. 94:1-94:10.
In this paper we propose a global visibility algorithm which computes from-region visibility for all view cells simultaneously in a progressive manner. We cast rays to sample visibility interactions and use the information carried by a ray for all view cells it intersects. The main contribution of the paper is a set of adaptive sampling strategies based on ray mutations that exploit the spatial coherence of visibility. Our method achieves more than an order of magnitude speedup compared to per-view cell sampling. This provides a practical solution to visibility preprocessing and also enables a new type of interactive visibility analysis application, where it is possible to quickly inspect and modify a coarse global visibility solution that is constantly refined.
