Extracting Algorithm of Characteristics Data Based STEP in Rapid Prototyping Technology

Three-dimensional CAD model of hierarchical processing is the key technology to the rapid prototyping manufacturing. Compared with the method of applying StereoLithography (STL) format, the representation based on a neutral, international standard (ISO10303) STEP-formatted geometric model is more precise. This paper presents theresults of our development of an extraction algorithm, STEP-based standards for the characteristics of rapid prototyping manufacturing data. With extreme tracking method, we extract the characteristics data with surface tangent plane intersection line and directly slice the model. In VC++ and OPENGL programming environment, using of dual circulation list as a data structure, a data acquisition and hierarchical processing is realized, which is based on a neutral document STEP/AP203 of three-dimensional CAD model. The experimental results demonstrate that the algorithm is more accurate, stable and efficient than that of STL model.