DYNAMIC 3D-SKETCHING A design tool for urban and architectural design

Abstract. Sketching by hand is without doubt – alongside building models – the most common tool that architects employ when design-ing. A disadvantage of the sketch is, even if it is a perspective drawing, that it is a purely two-dimensional planar representation of a three-dimensional product: the three-dimensional impression that the sketch communicates is a product of the viewer’s imagination. Digital mod-elling tools on the other hand support the creation of three-dimensional content but fall short in their ease of handling: their com-plexity and potentially un-intuitive operation hinder rather than sup-port the design process. Taking this discrepancy as a starting point, the presented system details the development and prototypical implemen-tation of a dynamic 3D-sketching tool. The underlying core idea is to create a seamless connection between a perspective hand-sketch and the corresponding digital 3D-model in order to benefit from the ad-vantages of hand sketching as a design tool and computer maintained 3D models. The system allows the designer to work as usual, visualiz-ing his or her thoughts using perspective sketches. The user sketches on a touchscreen surface. The 2D drawing is automatically interpreted and converted into a system of 3D lines, surfaces and volumes in real-time