Coherent and Exact PolygontoPolygon Visibility

Visibility computation is a classical problem in computer graphics. A wide variety of algorithms provides solutions with a different accuracy. However, the four dimensional nature of the 3D visibility has prevented for a long time from leading to exact frompolygon visibility algorithms. Recently, the two first tractable solutions were presented by Nirenstein, then Bittner. Their works give the opportunity to design exact visibility tools for applications that require a high level of accuracy. This paper presents an approach that takes advantage of both Nirenstein and Bittner methods. On the one hand, it relies on an optimisation of Nirenstein’s algorithm that increases the visibility information coherence and the computation robustness. On the other hand, it provides an exact visibility data structure as Bittner does, but also suited for nonoriented polygontopolygon visibility queries