TRIM LOOP CLOSURE FOR ENHANCED CAD INTEROPERABILITY

摘要

The transfer of design data among different CAD systems or subsequent downstream analysis applications is critically important to the acceleration of the product development cycle. Since each vendor has its own proprietary native file format, this transfer of data among differing systems is difficult at best. International standards such as IGES and STEP have evolved to address this challenge, but they are generally not sufficiently explicit. Each vendor writes its own "flavor" of the standard that other applications may not understand. This paper bridges a gap between disparate systems by developing a strategy to assess the completeness and robustness of models represented in IGES or STEP format, and a technique to either repair the representation or add missing information so that a downstream application can properly interpret it. The method ensures that the receiving system gets a full and accurate NURBS-based representation: the original surfaces, the corresponding full complement of model space trim curves, and the corresponding full complement of parameter space trim curves. With all the information present, the downstream system is more likely to receive the information it requires to interpret the model.