Inner-Cover of Non-Convex Shapes

Visibility methods are often based on the existence of large convex occluders. We present an algorithm that for a given simple non-convex polygon P finds an approximate inner-cover by large convex polygons. The algorithm is based on an initial partitioning of P into a set C of disjoint convex polygons which are an exact tessellation of P . The algorithm then builds a set of large convex polygons contained in P by constructing the convex hulls of subsets of C. We discuss different strategies for selecting the subsets and we claim that in most cases our algorithm produces an effective approximation of P .