@inproceedings{bashford2011approximate,
  title={Approximate visibility grids for interactive indirect illumination},
  author={Bashford-Rogers, Thomas and Debattista, Kurt and Harvey, Carlo and Chalmers, Alan},
  booktitle={Games and Virtual Worlds for Serious Applications (VS-GAMES), 2011 Third International Conference on},
  pages={55--62},
  year={2011},
  organization={IEEE}
}