CIGRO: A minimal instruction set calligraphic interface for sketch-based modeling

Abstract

Although CAD systems have evolved considerably in functionality, expressiveness and modeling power over the last decades, their user interfaces are still tied to legacy principles and are not suited to the initial stages of product development. They exhibit steep learning curves, cumber-some and overly structured dialogues, including hundreds of commands. While much of this functionality may be required by the sheer complexity of the tasks these systems are designed to help, we believe the user interface could benefit from simpler paradigms based on sketching and drawing to reduce unneeded complexity, especially in the conceptual design phase. In what follows, we present the CIGRO system that provides a reduced instruction set calligraphic interface to create polyhedral objects using an incremental drawing paradigm evocative of paper and pencil drawings. Users draw lines using an axonometric projection, which are automatically beautified and connected to existing elements of the drawing. Such line drawings are then converted to a three-dimensional model through a reconstruction process guided by an axonometric inflation method. © Springer-Verlag 2003.