@article{Liu09Min,
  author    = {Min Liu and Yu-Shen Liu and Karthik Ramani},
  title     = {{Computing global visibility maps for regions on the boundaries of polyhedra using Minkowski sums}},
  journal   = {Computer-Aided Design},
  volume    = {41},
  number    = {9},
  pages     = {668--680},
  year      = {2009},
}