Protecting critical facets in layered manufacturing: implementation and experimental results
In layered manufacturing (LM), a three-dimensional polyhedral object is built by slicing its (virtual) CAD model, and manufacturing the slices successively. During this process, support structures are used to prop up overhangs. An important process-planning step in LM is choosing a suitable build direction, as it affects, among other things, the location of support structures on the part, which in turn impacts process speed and part finish. We describe a robust, exact, and efficient implementation of an algorithm that computes a description of a subset of all build directions for which a prescribed facet is not in contact with supports. We also present test results on models obtained from industry, and on collections of random triangles.
layered manufacturing implementation computational geometry spherical geometry union of convex polygons