Data exchange
CAD: from geometrical to functional modelling

The exchange of data, and more generally of models between different systems, is a classic problem in computer science, and can be solved in several ways (figure 27):

• by defining an interface (a translator) which transforms the data from one system so that it can be assimilated by the other system (figure 27a);

• by defining a neutral format (figure 27b), which represents a data description format that is a priori independent of the systems under consideration (as we shall see, this is not always the case);

• by providing mechanisms for defining and manipulating data (whether generic or not), without having to worry about the format...