Single start end tool path generation for arbitrary porous surfaces

The CNC machining of non-zero genus surfaces in B-rep models has become a prevalent challenge in modern manufacturing. The computational complexity inherent in generating tool paths for such geometries remains a significant hurdle. In this study, an efficient path planning algorithm tailored for porous structures of this nature is presented. Initially, we create a parametric grid using the adaptive iso-scallop height method and subsequently utilize a marching cells algorithm to construct a cell grid capable of preserving arbitrary boundaries. Based on the graph structure naturally induced by marching cells, we employ a designated weighting method to establish a minimum spanning tree, upon which a path with a singular start and end point is generated. We conduct various experiments on examples from industrial scenarios as well as synthetic examples. The results show the superior performance and effectiveness of our method concerning scallop height limits, sharp turns, and structural stability. • Marching cells algorithm for obstacles/holes avoidance with arbitrary shapes. • The weight assignment algorithm based on a greedy strategy that can reduce the number of sharp corners. • A novel single start end point tool path generation framework for arbitrary nonzero-genus structures.