Facial Expressions Modeling for Interactive Virtual Environments

Nowadays, in Human-Machine Interaction systems, the communication between user and the machine (robot, computer, etc.) may be performed using a graphical representation of human often called avatar. Such graphical form needs a realistic human motion synthesis mechanisms which are becoming more and more popular in the virtual environments. Therefore the paper is focussed on the problem of facial motion modeling for interactive virtual humans using events-based interaction rules. First, the most frequent emotional states and two types of personalities have been selected. For both personalities the transitions of the emotional states have been performed based on the motion probabilities. Then, for animation process a set of the facial expression subtypes has been introduced. In such case it is possible to get a quite natural reactions of the avatar for various emotional states. Also, the transition probabilities have been defined for sub-states. Having obtained transition probabilities, a temporal duration of emotional state have been calculated. Finally, the architecture of the system for interaction between user and avatar based on facial animation modeling has been proposed.