A STEP-based Approach of Direct Slicing of CAD Models for Layered Manufacturing

摘要

Direct slicing generates exact slice contours from original CAD model and avoids the error detecting and repairing process of STL file. However, at present, most direct slicing approaches are restricted to some CSG solids or some particular CAD systems. In this paper, a direct slicing approach of CAD models based on STEP for layered manufacturing is presented. The CAD model is transferred from CAD systems to the slicing system by the STEP standard format. Using OpenGL graphics libraries, the solid model is then displayed and the user is prompted to specify the layer thickness. Lastly the CAD model is sliced directly and the sliced model is exported by SSL (Stratasys Layer interface files) file format which can be sent to many kinds of rapid prototyping systems for fabrication directly. Not only the STEP-based direct slicing is more flexible and does not rely on any specific CAD system, but also the STEP files of parts are greatly smaller than STL files and are propitious to the data exchange in the distributed design and manufacturing. Implementation details and results are also presented.