William H. Bares, James C. Lester
Rich 3D animated explanations can have a powerful impact on students interacting with immersive knowledge-based learning environments. By generating 3D animated explanations in realtime, a learning environment can create engaging explanations that are tailored to individual students. This paper presents the immersive explanation planning framework for generating pedagogically-customized 3D animated explanations in realtime. In this framework, an explanation system selects 3D models and their relevant behaviors, creates camera shots that most clearly depict complex phenomena, constructs a temporal organization that synchronizes narrative utterances with visual elements, plans the movement of the virtual camera that "films" the explanation, and incorporates specialized visual effects to focus students’ attention on the most salient concepts. The framework has been implemented in RAPID, an explanation system that plans and renders customized 3D animated explanations of dynamic phenomena in realtime. Results of a focus group evaluation of RAPID are encouraging.