Mitered offsets and straight skeletons for circular arc polygons

We generalize the offsetting process that defines straight skeletons of polygons to circular arc polygons. The offsets and the associated skeleton are obtained by applying an evolution process to the boundary and tracing the paths of vertices. These paths define the associated patch decomposition. While the skeleton is a forest, the patches of the decomposition possess a radial monotonicity property. Analyzing the events that occur during the evolution process is non-trivial. This leads us to an event-driven algorithm for offset and skeleton computation. Several examples (both manually created ones and approximations of planar free-form shapes by arc polygons) are presented and used to analyze the performance of our algorithm.