Adding the Emotional Dimension to Scripting Character Dialogues

We present an extension of the CrossTalk system that allows to model emotional behaviour on three levels: scripting, processing and expression. CrossTalk is a self-explaining virtual character exhibition for public spaces. Its SceneMaker authoring suite provides authors with a screenplay-like language for scripting character and user interactions. This article presents an extension to the original CrossTalk scripting language by providing a set of appraisal and dialogue act tags, making emotional behaviour generation possible. These extensions rely on CrossTalk’s new EmotionEngine which processes emotions by computing and maintaining emotional states for each character. In combination with the ContextMemory module it enables the characters to adapt to user feedback and to react to previous encounters with users in an emotional way. We describe the use of the appraisal and dialogue act tags, their processing in the EmotionEngine and their impact on the characters’ verbal and non-verbal expressive behaviour.