Predictable Modelling Interaction Using High-Level Constraints: Making Objects Behave as They Would in Our Environment

An approach for a graphical CAD system that is capable of representing physical and geometric aspects of a design using high-level constraints (HLCs) is presented. A prototype spatial planning system incorporating constraints is used in an interactive manner to refine designs by following an iterative approach which uses visual information to evaluate the design at each stage of iteration. High-level constraints aid this iterative approach by influencing (or constraining) the behaviour of objects as they are interactively manipulated during the design stage of problem solving. High-level constraints also define the scaling properties of objects which are useful during the construction stage of problem solving. This system and its implications for the design of CAD systems incorporating HLCs are discussed