A tolerant slicing algorithm for layered manufacturing

This paper proposes a tolerant slicing algorithm for processing slice contours for Layered Manufacturing (LM). The algorithm aims to overcome the constraints of computer memory and the computation instability commonly inherent in conventional slicing methodologies. It minimizes memory usage by adopting a pick-and-drop approach, which extracts one facet for slicing from the Stereolithography (STL) file at a time. The facets that intersect with the cutting plane are read in, sliced and then disposed of from the memory one by one for subsequent construction of slice contours. Only the slice data and the associated topological information of the current layer are temporarily stored in the memory. This approach greatly reduces the amount of computer memory required and it involves much less computationally intensive searching operations. Thus, STL models of virtually unlimited file size can be sliced to facilitate the LM processes. The algorithm is also relatively fault-tolerant in that common defects of STL models may be tolerated and the resultant inconsistent contours are effectively repaired.