Interaction System Based on an Avatar Projected on a Pyramidal Display

In this paper an interaction system based on a three dimensional virtual head projected onto a pyramidal display is proposed. The proposed system makes use of a social robot behavioral architecture already developed in our lab, which allows us to interchange developments between our robotic realizations and the 3D avatar. The overall system is divided into two parts: back projection subsystem and expression generator subsystem. The back projection subsystem projects a three-dimensional avatar onto a pyramidal structure in order to achieve a sensation of depth and realism. The expression generator subsystem carries out the avatar animations using shape keys and bones, following the Facial Action Coding System (FACS). The system consists in several nodes that are integrated in ROS middleware (Robotic Operating System), and includes a user interface that makes the avatar teleoperation easier (the package is avaible in github public respository). In order to evaluate the expressiveness of the system, two sets of experiments have been performed: one to analyze the avatar's gestural ability, that is, its capability to perform expressions that can be identified by an observer, and a second experiment to measure the emotion displaying ability in terms of valence and arousal.