Path planning with offset curves for layered fabrication processes

Construction of families of equidistant offset curves as a strategy for filling plane areas is discussed in the context of path planning for rapid prototyping or layered manufacturing processes. Whereas the offset computations for piecewise-linear/circular boundary curves are elementary—and hence comparatively robust in implementation—the extension to freeform curvilinear boundaries has been frustrated by the absence of exact (that is, rational) offset representations that are compatible with established CAD system standards. Recent mathematical developments offer a resolution to this dilemma, thereby promising significant enhancements in the accuracy and speed of offset computations based on analytic solid model representations.