Kevin Matthews, matthews@artifice.com
Artifice, Inc., P.O. Box 1588, Eugene, Oregon
Design Integration Laboratory, University of Oregon

Stephen Duff, Donald Corner
Department of Architecture, University of Oregon

Recent advances in computer graphics and 3D user interfaces have enabled the emergence of 3D sketch modeling as a viable approach to architectural design, especially in the early schematic phase. This paper describes how a system can be built and used which integrates the capabilities of a good structural analysis system in the user-friendly working environment of a design-oriented modeling program.

The structure of a building model as seen by finite element algorithms is a schematic idealization of the building's physical structure into nodes, elements, internal releases, boundary conditions, and loads. The more familiar architectural model used for design visualization represents spatial elements such as roofs, floors, walls, and windows.

Rather than treat these models independently, the structural model can be defined in relation to the architectural as a virtual model with inherited common characteristics and additional relational and attribute information, using feature-based geometry data structures to organize topological intelligence in the spatial model. This provides the basis for synchronous modification of structural and architectural aspects of the design.