A Parametric Strategy for Freeform Glass Structures Using Quadrilateral Planar Facets

Abstract

The design and construction of freeform glass roofing structures is generally accomplished through theuse of either planar triangular glass facets or curved (formed) glass panes. This paper describesongoing research on the constructability of such structures using planar quadrilateral glass facets for theJerusalem Museum of Tolerance project by Gehry Partners, in collaboration with Schlaich Bergermann& Partners, engineers. The challenge here lies not only in the development of a geometric strategy forgenerating quadrilateral planar facet solutions, but also in the fact that said solutions must closely matchthe designs created initially in physical model form by the architects.We describe a simple but robust geometric method for achieving the structure by incorporating thenecessary geometric principles into a computational parametric framework using the CATIA Version 5system. This generative system consists of a hierarchical set of geometric ‘control elements’, that drivethe design toward constructible configurations. Optimization techniques for approximating the generatedstructural shape to the original created by the designers are also described. The paper presents theunderlying geometric principles to the strategy and the resulting computational approach.