Shape Rule Types and Spatial Search

Abstract

Searching for spatial objects in CAD tools is mostly based on the ability to compare properties of different objects. Instead, the matching mechanism(s) underlying a shape grammar interpreter offers a much wider potential for search, including the emergence of shapes that were unanticipated at the point of specification. This paper provides an overview of different rule types that can be discerned in the context of shape grammars, and explores the impact these have on the ability for search. It specifically considers two alternative matching algorithms, either determining a transformation matrix or an association of graphical elements, the latter complemented with constraining predicates, applying over different data types, e.g., shapes, shapes augmented with attributes, and descriptions, to provide for a wide range of spatial search variations.