Exchange of Parametric Curve and Surface Geometry Between Computer Aided Design Systems
The transfer of geometric data between dissimilar computer aided design (CAD) systems is a problem of great concern to manufacturing industry. It arises when a single organisation uses different systems at different stages of the design/ manufacturing cycle, and also in contractor/subcontractor situations where the two organisations do not use the same system. In either case it is clearly preferable to transfer the data on magnetic tape and have it read automatically than to generate drawings using the sending system and to re-enter them manually into the receiving system. However, different CAD systems use different internal formats for data storage, and the idea of a ‘neutral format’ has arisen to facilitate the interchange. In a draughting context, for example, such a medium provides a neutral, system-independent, means for representing lines, circular arcs and various types of annotation commonly used on drawings. Native information from the sending system is written in this form by a translator known as a preprocessor. A postprocessor is then required to translate the neutral file data into the native internal format of the receiving system.
KeywordsChebyshev Polynomial Parametric Curve Subdivision Strategy Surface Geometry Spline Curve
Unable to display preview. Download preview PDF.
- Goult, R.J.: Parametric Curve and Surface Approximation. In D.C. Handscomb (ed.): The Mathematics of Surfaces III. Oxford University Press (1990). Google Scholar
- IGES: Initial Graphics Exchange Specification, Version 4.0. National Institute of Standards and Technology (NIST), Gaithersburg, Maryland, 1988.Google Scholar
- ISO: First Draft Proposal for the STEP Version 1.0 CAD/ CAM Product Data Exchange Standard, NIST. Gaithersburg, Maryland, 1989.Google Scholar
- Lachance, M.A. Some Experiments on Transferring Polynomial Data. In I. Bey & J. Leuridan (eds.), ESPRIT Project 322: CAD*I (CAD Interfaces) Status Report 3. Report No. KfK-PFT-132, Kernforschungszentrum Karlsruhe, F.R.G., March 1987.Google Scholar
- Lachance M.A.: Data Proliferation in the Exchange of Surfaces. In R.R. Martin (ed.) The Mathematics of Surfaces II. Oxford University Press, 1987. Google Scholar
- Pratt, M.J.: Parametric Curves and Surfaces as used in Computer Aided Design. In J.A. Gregory (ed.) The Mathematics of Surfaces. Oxford University Press, 1986. Google Scholar