Free-form contour packing based on material grid approximation and lowest-gravity-center methods

Freeform surfaces, also called sculptured surfaces, have wide applications in clinical prosthesis and manufacturing. The free-form contour of product needs to be packed before it is machined from raw materials. The No-Fit Polygon methods are not suitable to the complex contours packing because calculating No-Fit Polygons for non-convex polygons is time-consuming. A contour packing algorithm for free-form contour machining is proposed in this paper. The parking area of materials is discretized based on a bottom-left and the lowest gravity center strategy. The packing contour is collided in four directions to increase the material utilization. Experimental results show that the packing time is reduced and the material utilization is improved using the proposed algorithm.