Fat Pencil & Cocktail Napkin 1 The Fat Pencil , the Cocktail Napkin , and the Slide Library

The paper describes recent explorations in sketch recognition and management to support architectural design. The exploration and decision-making of early, conceptual design better suited to freehand drawing, sketching, and diagramming than to the hard-line drawing and construction kit approaches of traditional CAD. However, current sketch programs that simulate paper and pencil fail to take advantage of symbolic manipulation and interactive editing offered by computational environments. The paper presents a ‘computer as cocktail napkin’ program, which recognizes and interprets hand-drawn diagrams and provides a graphical search facility, simulated tracing paper, and a multi-user shared drawing surface. The cocktail napkin is the basis of Stretch-A-Sketch, a constraint based draw program that maintains spatial relations initially specified by a diagram. The cocktail napkin program is also the basis for a query-by-diagram scheme to access a case based design aid as well as to a small collection of images of famous buildings. The paper briefly reviews these extensions of the cocktail napkin program.