Fast exact from-region visibility in urban scenes
Jiřı́ Bittner, Peter Wonka, Michael H. Wimmer · Eurographics Symposium on Rendering Techniques · 2005
We present a fast exact from-region visibility algorithm for 2.5D urban scenes. The algorithm uses a subdivision of line space for identifying visibility interactions in a 2D footprint of the scene. Visibility in the remaining vertical dimension is resolved by testing for the existence of lines stabbing sequences of virtual portals. Our results show that exact analytic from-region visibility in urban scenes can be computed at times comparable or even superior to recent conservative methods.