Dynamic Import Verification:

In order to be able to implement the outlined import flow, which involves iterative attempts of data rewrites and renewed imports, it is essential to be able to recognize import failures. Each data type stored in the UPR, including the unified data types and all of their rewrites, need to have success verification mechanisms associated with them. In some cases, success verification is only a matter of obtaining a binary answer from the CAD system (yes or no). In most cases, however, success verification requires additional data to be stored within the data type. For example, the success of an extrusion feature can really only be verified by comparing the geometry generated by it in the source CAD system with that generated by the target CAD system.

            Data import verification in general, and feature verification in particular, are topics that merit a detailed discussion which is certainly beyond the scope of this paper. For the purposes of this paper it is adequate to recognize that provisions for storing verification data should be made within the UPR data structures, and that import verification is a basic ingredient of the import flow execution. In practice, it is sometimes possible to relax those strict verification requirements. For example, suppose that we have no rewrites for design features and we must invoke a final geometry' global solid rewrite whenever there exists a single feature that does not produce accurate geometry. In this case we do not need verification data for every feature, and it is sufficient to store verification data only for the final, global geometry.