Three-Dimensional Web-Based Algorithm Animations

Over the past few years, we have developed JCAT, a system for building Web-based collaborative active textbooks on algorithms. JCAT augments the expressive power of Web pages for publishing passive multimedia information with a full-fledged interactive algorithm animation system. Views of a running program can reside on different machines; in an electronic classroom or distance learning setting, a teacher controls the animation, while students view the animation by pointing their Web browsers at the appropriate page. In this report, we integrate our earlier work on using interactive 3D graphics for algorithm animation into the JCAT system, and we present three new animations. The JCAT architecture is well-suited for 3D animations because each user can interact with the 3D views locally, independent of the views on other machines. The ability to interactively control a 3D scene provides motion cues that are crucial for resolving ambiguities of 3D scenes displayed on flat screens.