Towards Autonomous, Perceptive, and Intelligent Virtual Actors

This paper explains methods to provide autonomous virtual humans with the skills necessary to perform stand-alone role in films, games and interactive television. We present current research developments in the Virtual Life of autonomous synthetic actors. After a brief description of our geometric, physical, and auditory Virtual Environments, we introduce the perception action principles with a few simple examples. We emphasize the concept of virtual sensors for virtual humans. In particular, we describe our experiences in implementing virtual sensors such as vision sensors , tactile sensors, and hearing sensors. We then describe knowledge-based navigation, knowledge-based locomotion and in more details sensor-based tennis. From Behavioral Animation to Virtual Life This paper explains methods to provide virtual actors with the skills necessary to perform stand-alone role in films, games (Bates et al. 1992) and interactive television (Magnenat Thalmann and Thalmann 1995). For the modeling of actor behaviors, the ultimate objective is to build intelligent autonomous virtual humans with adaptation, perception and memory. These virtual humans should be able to act freely and emotionally. They should be conscious and unpredictable. But can we expect in the near future to represent in the computer the concepts of behavior, intelligence, autonomy, adaptation, perception, memory, freedom, emotion, consciousness, and unpredictability ? First, we will try to define these terms. More details may be found in [Magnenat Thalmann and Thalmann 1994). • Behavior for virtual humans may be defined as a manner of conducting themselves. it is also the response of an individual, group, or species to its environment. • Intelligence may be defined as the ability to learn or understand or to deal with new or trying situations. • Autonomy is generally defined as the quality or state of being self-governing. • Adaptation: an artificial organism is adaptive as long as it may "survive" in more or less unpredictable and dangerous environments. • Perception is defined as the awareness of the elements of environment through physical sensation. • Memory is generally defined as the power or process of reproducing or recalling what has been learned and retained especially through associative mechanisms. • Emotion may be defined as the affective aspect of consciousness; this is a state of feeling, a psychic and physical reaction subjectively experienced as strong feeling and physiologically involving changes that prepare the body for immediate vigorous. • Consciousness may be defined as the quality or state of being aware especially of something within oneself or the state of being characterized by sensation, emotion, volition, and thought.