Interactive Animation of Virtual Characters: Application to Virtual Kung-Fu Fighting

This paper aims at proposing a framework for animating virtual humans that can efficiently interact with real users in virtual reality (VR). If the user´s order can be modeled as targets and commands, the system searches a database for the most convenient behavior. In order to avoid using a huge database that can deal with any kind of situation, we propose to associate this searching process to an adaptation module. Hence, even if the selected motion is not perfectly suited with the situation, it can be adapted in order to reach accurately the target specified by the user. This framework is illustrated with a kung-fu fighter example. Two people are involved in this example: the user and the supervisor. The user is displacing in the real environment while the position of his head is tracked in real-time thanks to reflective markers. The virtual opponent follows the displacement of the user to stay close to him. At any time, the supervisor can ask the virtual character to kick or punch the user. Our system automatically searches for the convenient motion in an average-size database (75 motions compared to hundreds of motions required for motion graphs) and adapts it to the current situation.