Graphic Standards: IGES and PDES in an AEC Environment

The idea made a lot of sense: many diverse CAD systems communicating a common project data-base through a neutral format translator. The “Initial Graphics Exchange Specification”, kindly known as IGES (pronounced “I guess” by its proponents, and “I guess noti by its opponents) was the the initial effort, and is either loved or hated, there is no “neutral” ground. Has it succeeded? Has it failed? Is there a future in this neutral format business? Was CAD meant to be “design” or “drafting”? Does industry support it? What does it mean for architecture? Is a “one-to-many” translator a wonderful idea, but impossible to implement? Is a complete set of “one-to-one” translators a better idea? This paper will give a short history of IGES, discuss its reason for being, list its strengths and weaknesses, examine its inner workings, and introduce the current effort of the IGES committee: a total “Product Design Exchange Specification”, PDES (and internationally as STEP). It will also discuss the techniques used by the PDES application committees to model their various products, and give a case study of the effort of the AEC committee in modelling an architectural “product”. The paper will conclude with the opinions on the future of IGES by the author (a four year member of the IGES/PDES organization)