DEIRA is a virtual agent commenting on virtual horse races in real time. DEIRA analyses the state of the race, acts emotionally and comments about the situation in a believable and engaging way, using synthesized speech and facial expressions. In this paper we discuss the challenges, explain the computational models for the cognitive, emotional and communicative behavior, and account on implementation and feedback from users. Categories and Subject Descriptors I.2.7 [Artificial Intelligence]: Language Generation and Speech Synthesis; J.4 [Computer Applications]: Social and Behavioral Sciences; H.5.1 [Multimedia Information Systems]: Animations and Audio output; I.3.7 [Three-Dimensional Graphics and Realism]: Animation General Terms Algorithms, Performance, Design, Experimentation, Human Factors, Languages. Keywords Intelligent virtual agent, multimodal communication, emotion modeling, facial expressions, synthetic speech.
François L. A. Knoppel, Almer S. Tigelaar,