Occlusion Tiling

Dorian Gomez, Pierre Poulin, and Mathias Paulin

Proc. Graphics Interface 2011., St John, Newfoundland (Canada).

[bibtex] [video1]


Real-time shadow generation techniques try to provide shadows with realistic penumbrae. However, most techniques are whether non-physically based or too simplified to produce convicing results. The penumbra-wedges algorithm is a physical approach based on the assumption that penumbrae are non-overlapping. In this paper, we propose an algorithm taking the advantage of the penumbra-wedges and solving the "non-overlapping" limitation. We first store the light occlusion position. Then we use this information to detect the areas where penumbrae are overlapping and we perform a realistic penumbra blending.

Occlusion tiling : aerial view Occlusion tiling : ground view

The view cell in blue is surrounded by a first-ring neighborhood of tiles in red. The second ring and further away rings, drawn in grey, are invisible from the view cell if the observer is located between the ground and the top of the smallest building.