Freeform Tools in CAD Systems

From 13th-17th May, 1991 the Centre for Applied Mathematics at the Darmstadt University of Technology and at the University of Kaiserslautern in cooperation with the European Consortium for Mathematics in Industry {ECMIl has organized the Workshop: "Practice of Computer Aided Gemetric Design - What CAD Systems are really capable of". Some of the most im portant software vendors had been invited to participate in the workshop and to demonstrate their developments in the area of free form surface technology. The following systems were presented: CATIA (IBM/Dassault); EUCLID (Matra); ICEM (CDC); SYRKO (Mercedes-Benzl; STRIM (Cisigraph); UNIGRAPHICS (McDonnel Douglas) and in addition the visualization system WAVEFRONT (mental images) was introduced. The presentations were supposed to focus on the following topics: re presentation of analytical curves/surfaces; Coons-Eace-Top-Elements; multisurfs; triangular patches; offset surfaces; volume elements; inter secting algorithms; operations for combination of curves, surfaces and volumes; sweeping elements/fillets; blending methods; parametrization of data; interpolation/approximation of irregular data/NC data; NC control (three axes, five axes milling). - Demonstrations of the systems were also given on work stations. Besides, a qUestionnaire should have given a short overview on the implementations. Beside these presentations of software systems, the participants had the opportunity to hear lectures on developments for interfaces.

Inhalt
I Presentations of CAD Systems.- CATIA/IBM, Dassault.- Curve and Surface Representation in Catia System.- A Case for CAD.- Digitising Sculptured Surfaces.- ICEM / Control Data.- Representations and Operations in the ICEM Systems.- ICEM MESH A Mesh Generation Tool for Free-Form Surfaces.- STRIM/cisigraph.- Practice of Computer Aided Geometric Design.- SYRKO/Merces Benz.- Car Body Design and Manufacturing with SYRKO.- UNIGRAPHICS/McDonnel Douglas.- Curves and Surfaces in Unigraphics and Parasolid.- EUCLID / Matra.- UNISURF IV The advanced Solids & Surfaces Module of EUCLID-IS.- II Visualisation System.- WAVEFRONT MENTAL RAY/mental images.- High Quality Visualization of CAD Data.- III Lectures on Developments for Interfaces.- The Development Methodology of STEP and its Concept for Shape Representation.- Integration of Physical Phenomena into CAD.- General Matrix Representation for NURBS Curves and Surfaces for Interfaces.- Approximate Conversion and Merging of Spline Surface Patches.- IV Questionnaire on Curve/Surface/Volume Implementations.- ANSWERS Part I (EUCLID, STRIM, ICEM).- ANSWERS Part II (UNIGRAPHICS, SYRKO, CATIA).- V Excerpts of the Panel Discussion.