Mathematical Foundation for Modeling Conceptual Design Sketches1

Abstract

This paper aims to establish a mathematical foundation for modeling free-hand design sketches throughout the conceptual design process. Both experimental and theoretical approaches are used. In using the experimental approach, one case study from a book and one case study from an automobile assembly system manufacturer are used to illustrate the characteristics of design sketches. These characteristics provide the requirements for models of sketch representation. In using the theoretical approach, a mathematical structure of design sketches is established. This mathematical structure can naturally and logically model the evolving sketches generated in the design process, through integrating the strengths of set theory and mereology. In addition to the formal representation of design sketches, the mathematical model provides a logical foundation for formally designing sketch interpretation algorithms. An algorithmic structure of three-dimension reconstruction from two-dimension line drawing is derived using this mathematical model.