Conceptual design and editing of parameterized models of 3D solids, or assemblies of patterns of such solids, often requires user-interactions with a large number of types of entities and relations.
In this paper we present a concept that simplifies design by integrating various data structures and control structures into uniform building blocks called cells. Cells define assemblies of CSG solids and can be grouped bottom-up into more complex cells or, alternatively, can be designed top-down during the design process. Fast and efficient specification of complex cells and patterns is made possible through the use of automatic default values, multiple instantiation, repetition and recursion.
A multiple-view interface enables the designer to view and edit both the cell parameters and the hierarchical structure of the model. The interface provides integrated textual, 2D graphical and 3D direct manipulation techniques for specifying primitive dimensions and relative transformations, and provides hypertext techniques for fast traversal and selective display of part-hierarchies.