Towards a shape editor: the implementation of a shape generation system

A fundamental problem in editing shapes is the recognition of partial shapes in a drawing to which changes are to be made. In this paper the possibility of using shape rules as a mechanism for effecting such changes is explored. Shape rules represent spatial relationships between two shapes α and β with the interpretation that any instance of α in a shape can be replaced by a ‘similar’ instance of β. A shape generation system implemented in PROLOG is described.