CAD Product Data Exchange: Conversions for Curves and Surfaces

摘要

Increasingly and for various reasons product data are exchanged between Computer Aided Design (CAD) systems. More and more, the data exchange causes problems. One of these problems concerns the exchange of geometrical representations of products. The problem can be solved by methods for the conversion of these representations into each other. In the thesis, the reasons to exchange are described as well as the type of product data which are exchanged and the problems which can occur if these data are exchanged. Next, a number of methods are described to convert the geometrical representations of curves and free-formed surfaces. The currently used geometrical representations on CAD systems have been taken into consideration. The geometry conversions needed, have been determined. It appeared to be necessary to be able to change the degree or parameter area of the representation and to convert an implicit description into an explicit one. Methods for these conversions have been developed and described. Software programs are available for the conversions.