Modelling Expectations and Trust in Virtual Agents

Abstract: Computer graphics has long been the foremost area of advancement in both the gaming and the motion picture industry. Nowadays, as computer graphics is getting difficult to advance any further, other areas begin to interest the developers. One of these areas is artificial intelligence. The gaming industry has begun to create far more intelligent virtual characters that no longer are as predictable as they used to be. Mixing character animation with intelligent agents techniques results in a vastly more interesting experience for the gamer as well as for the developer. This project focuses on introducing expectational behaviour and trust in intelligent virtual characters. The area is highly interesting as it enables a vastly more complex emotional structure for virtual agents than that of reactive, rational behaviour. Although expectations can indeed be rational, often they are not when it comes to humans. This project studies the effects of expectations on the emotional state of agents and the effect that the emotions have on the reasoning abilities and the action selection mechanism. It also examines how trust influences emotions and vice versa and how trust influences the action selection mechanism. One of the requirements of this work is that the computations concerning the triggering of emotions have to be done in real-time. While it is possible to do off-line computations for simulations (such as is often done for the movie industry), it is not what we desire here. It is our goal to create interesting virtual characters that can be interacted with in real-time. Therefore, also expectations and trust must be calculated and managed in real-time.