Object-Oriented Application Development in CAD

Abstract

This report describes a graduate interdisciplinary course offered to students in the graduate program of the School of Architecture at Carnegie Mellon and related departments in fall 2000. The motivation was the realization that when commercial CAD (Computer-Aided Design) systems recently switched from procedural application programming languages to object-oriented ones, third-party application must undergo a significant cognitive retoolingi, i. e. they must know more than the syntax and semantics of the new programming language to be used and must be able to employ appropriate software development strategies that are appropriate for the new paradigm. especially with respect to the importance of modelling, a distinguishing characteristic of object-oriented programming. The goal of the course was (a) to introduce and test strategies of object-oriented application development in general and in the context of MicroStation, a state-of-the-art commercial CAD package, (b) to develop-as a course team project-an interesting application that gives students practice with these strategies and team work, and (c) to document our approach and findings so that others can learn from them. The strategies introduced were the use-case approach of Jacobson et al. and the complementary object-modelling tools of Rumbaugh that were recently integrated into the Unified Modelling Language UML. The software platform supporting the course comprised MicroStation, JMDL (a superset of Java) and ProjectBank on the CAD side and RationalRose on the modelling side. The application developed by students in the course supports the generation of drawings for remodelling projects from a set of dgn files describing the existing state of the building to be remodeled. The course was supported by a grant and in-kind contributions from Bentley with matching funds from the Pennsylvania Infrastructure Technology Alliance (PITA).