NSAIL PLAN: an experience with constraint-based reasoning in planning and animation

A constraint-based reasoning system is used for knowledge representation and reasoning in behavioural animation, specifically in the animation of sailing behaviour. The object-oriented ECHIDNA reasoning and constraint logic programming shell handles the constraints for formulation and execution of plans for intelligent entities. At higher levels of control, the observed motion of an object is a reflection of the reasoning process of an intelligent entity as it reacts to its environment. The environment, internal knowledge and physical structure serve as constraints in developing a plan, which in turn provides additional constraints in the animation of reactive behaviour. An animation approach using constraint-based reasoning is presented focusing on details of the planning process adapted in the approach. The implementation of the NSAIL program reveals further insight into applying this approach towards the development of a high-level intuitive interface for behavioural animation