Migrating from IGES to STEP: one to one translation of IGES drawing to STEP drafting data

This paper focuses on a procedure for converting product design data from an Initial Graphic Exchange Specification (IGES) format into Standard for the Exchange of Product Model Data (STEP) format. IGES is used for representing design and topology information in a platform independent format. The failure of the IGES standard to provide information other than drawing and solid modeling has led to the emergence of a new international standard for product model data exchange (ISO 10303) called STEP. STEP is designed to support a product through its entire life cycle. The STEP standard consists of a set of application protocols. An application protocol is specific to a particular engineering domain. In this case, STEP application protocol 202 is used because it defines the constructs necessary to represent the associative draughting information described by IGES. The translator parses the IGES file and converts it into the corresponding STEP (AP202) format. To test the conformance of the generated STEP file we have written code to enable visualization of an Application Protocol 202 (AP202) STEP file. The visualization uses the Open Inventor Toolkit available for the Silicon Graphics platform. The visualizer reads the STEP (AP202) file and converts the geometry and related annotations into the corresponding Inventor specific format. The file can then be viewed using the default Inventor viewer. (C) 2000 Elsevier Science B.V. All rights reserved.