S.M. Stevens and S. Saldamarco (Eds.) ICEC 2008, LNCS 5309, pp. 167–172, 2008. © IFIP International Federation for Information Processing 2008 Towards Emotional Characters in Computer Games Robert Schaap and Rafael Bidarra Delft University of Technology Faculty of Electrical Engineering, Mathematics and Computer Science P.O. Box 5031 2600 GA Delft, The Netherlands R.E.J.Schaap@gmail.com, R.Bidarra@ewi.tudelft.nl Abstract. This paper describes our research on integrating emotion aspects into characters of video games. Motivation for this is the significant absence of emo- tive expression in most characters of current games. In order to provide players with a more immersed game experience, it is essential that characters show compelling expressions, in particular, facial expressions. As a research method- ology, we took several intense scenes from classic movies and evaluated what would be necessary to allow a virtual character to reenact the scenes inside a game. The recreated scenes should convey the same emotions as the original scenes. Our approach represents the internal state of a video game characters by using a PAD-based model, as well as modeling the impact on it of many rele- vant environment aspects. Representing this internal state also involves blend- ing together animations to create lively facial expressions. We conclude that the resulting model is good enough to allow scenes to be recreated with an emotional load similar to the original scenes. The approach is also successful inimproving the consistency of the mood of the characters based on their personality. 1 Introduction Recently there have been large improvements regarding video games. The advance- ments in graphics are especially large. Character expression is not getting the atten- tion it deserves to get. Generating interesting and appropriate facial expressions for video game characters is difficult, but it is very important for the overall game-play experience. Most game developers rely heavily on scripting to create the experience they envision. With the expanding scope of current games it becomes more difficult to rely on scripting solely. Game worlds are becoming larger and more complicated. A lot of interaction takes place not just between the players and the game world but also among players and among elements of the game world. Even when we only con- sider single player games, the game worlds of current games are so vast that it has become very hard to determine when certain events will take place. Even worse, it is often not even possible to anticipate which events will be taking place. Imagine the situation where the best friend of the player gets shot and right after that something positive happens, so that the latter event would possibly trigger a