Celso de Melo, Jonathan Gratch: “Evolving Expression of Emotions in Virtual Humans using Lights and Pixels”

September 1, 2008 | Tokyo, Japan

Speaker: Celso de Melo, Jonathan Gratch
Host: Intelligent Virtual Agents 2008

Inspired by the arts, this paper addresses the challenge of expressing emotions in virtual humans using the environment’s lights and the screen’s pixels. An evolutionary approach is proposed which relies on genetic algorithms to learn how to map emotions into these forms of expression. The algorithm evolves populations of hypotheses, where each hypothesis represents a configuration of lighting and screen expression. Hypotheses are evaluated by a critic ensemble composed of artificial and human critics. The need for human critics is motivated by a study which reveals the limitations of an approach that relies only on artificial critics that follow principles from art literature. We also address the need for the model to improve with experience and to adapt to the individual, social and cultural values in the arts. Finally, a second study is described where subjects successfully evolved mappings for joy and sadness.