Head Movements of 3D Virtual Head in HMI Systems using Rigid Elements

This paper focuses on rigid head motion synthesis for a virtual person in human–machine interaction systems. Head gestures transmit additional, nonverbal information in human communication and can be used to increase the emotional context of the facial animation authentically simulating human behaviour. The presented method includes the head motion of the expressive face. The proposed motion model was described using Lie algebra for four rigid objects, which reflect the character of the neck and head skeleton movement and jaw bone. The obtained dependencies were used to generate three-dimensional motion of the head model, which was made considering the anatomical structure of the human head. The description presented in this article has the main advantage that it can be extended with additionally rigid elements. It means that we can get a description of the movement of the entire human skeleton, which reflects human anatomy. The proposed motion description eliminates the requirement to use motion capture whenever we need avatar movement in a particular situation, and we use it only for measurement data acquisition.