A formal model for parameterized solids in a visual design language

Software for designing structured objects such as machinery and buildings originated from drawing or drafting, and has evolved into suites of applications for different aspects of design, Modern CAD software usually consists of sophisticated tools for graphically building multidimensional models, together with textual programming languages for dealing with tasks such as specifying parameterized constructs or complex relationships between components. This dichotomy between design with graphics and programming with text divides the users of such systems into two groups with quite different skills. Programming languages, on the other hand, have evolved in the opposite direction, from purely textual descriptions of algorithms and data, to formalisms that rely primarily on graphics. This has led to the conjecture that the usability of design software might be improved by replacing their textual programming facilities by visual programming. Previously, we presented a preliminary proposal for a design language LSD that uses a visual representation of logic programming to provide a homogeneous view of design objects and the operations that transform them. In the current work, we present a model that captures the essential features of solids and operations on solids in a design space, then generalize LSD based on this model. (C) 2000 Academic Press.