N. John Habraken (john@habraken.org)

Emergent coherent behavior

Emergent Coherent Behavior of Complex Configurations through Automated Maintenance of Dominance relations. With J.Willem R. Langelaan.In: Proceedings ISARC 2003, 20th. International Symposium on Automation and Robotics in Construction. Eindhoven the Netherlands.Ger Maas, Frans van Gassel, Ed.

ABSTRACT: When we change a configuration by displacing or removing one object in it, desired adjustment of related objects usually follows established relational conventions. If, for instance, we displace a wall in which a window is found, we will expect the window to remain in the wall. At the same time we expect to be free to shift the position of the window in the wall without adjustment of the wall. This asymmetrical relationship is one of Dominance. Relations of dominance are the main reason for structural and functional coherence. CAD programs may have ad-hoc performance of dominance, like with the window in the wall, but do not know the general principle, nor do they allow us to inform the computer about dominance relations we want it to maintain.

Subordinate behavior drives the system. Dominant behavior results by implication. The methods defining subordinate behavior are encapsulated in the object class. The designer determines the unique behavior of an object instance by specification of attribute values. Data input per instance related to class allows the computer to perform adjustments in an instance-to instance chain, maintaining coherence of a complex configuration without need of global checking of relational data.

This paper demonstrates a notation and interface system by which dynamic relations, including those of dominance, between any two objects can be conveyed to the computer, enabling it, when properly programmed, to follow up adjusting when we design.

The paper further elaborates the concept of dominance leading to computer supported autonomous editing of a virtual building model as intended by the proposed interface and resulting in emergent coherent behavior of its constituent elements.

KEYWORDS: Design, Emergent behavior, Dominance relations, bidirectional editing.

[Emergent coherent behavior]