under observation. Although all of the surface of the polyhedron would be surveyed, for some polyhedra there are points in the interior which might not be under surveillance. Possible Usage Scenarios of the Art Gallery Problem The art gallery problem can be used to position multiple cameras when the objective is to cover a large area in view of cameras, using the minimum number of cameras. See also Covering a rectilinear polygon with star polygons Star-shaped polygon, a class of polygon for which the art gallery problem can be solved with a single guard. Illumination problem: does a single guard suffices if walls are mirrored? Notes References Sources . . . . . . . . . . . . . . . . . . . . . . . . Computational geometry Articles containing proofs Covering problems Polygons