An algorithm of contour offsetting based on the principle of straight skeleton for rapid prototyping

In order to reduce the roughness on the surfaces of parts in the rapid prototyping, a new algorithm based on the straight skeleton is put forward to solve some problems, such as self-intersecting and mutual-intersecting in existing contour offsetting algorithm. The algorithm can improve the computation speed by decomposing the contours as monotone chains and is suitable for multiply connected two-dimensional domains. Before getting the offsetting contours, some offsetting points which may split contour or be degenerated are marked so that the spilt and degenerated contours can be determined by using stacks. Experimental results show that the scanning mode of multi-contour scanning using the algorithm in the rapid prototyping can effectively reduce the roughness of parts and improve the efficiency of production.