Collision-free finishing toolpaths from visibility data

We present a series of algorithms and heuristics for generating collision-free 5-axis CNC finishing toolpaths automatically. These algorithms are based on the core concept of visibility, which can be generated in high resolution by discretizing the part and using graphics hardware as described in earlier papers by the authors. Using this visibility data for finish machining is a challenge, and we show how it can be used to generate globally collision-free 5-axis finishing toolpaths while also considering machine limits, tool tilt, cusp height limits, tool pitch limits and the need to keep toolpaths continuous. We then show how the toolpath can be verified during the path generation process, how collision-free interpolation can be carried out and how the sampling can be adjusted to ensure that the finishing toolpaths are accurate. We end with examples of 5-axis toolpaths generated for complex parts.