Research (1990-2000)




Roman founded the Computer Visualization Laboratory as a research facility whose mission was to investigate methodologies for integrating computing and visualization, to explore technologies that make feasible the fusion of the two disciplines, and to provide video production and multimedia capabilities for use in research and instruction. The research on program visualization made possible rapid visualization of program executions, reduced (and often completely eliminated) the need to access the program code when building a visualization, offered unprecedented expressive power with minimal notation, and provided several capabilities important to the introduction of program visualization into the industrial setting. The key technical contribution that enabled us to achieve these goals was the notion of declarative visualization, embodied in the design of a visualization system called Pavane. The declarative paradigm treats visualization as a mapping from program states to animated three-dimensional scenes. An extensive evaluation of Pavane in a wide range of settings (formal design, distributed algorithms, scientific visualization, requirements validation, monitoring, debugging, etc.) showed that complex animations of system behaviors can be constructed within three to six hours, often using less than two dozen declarative rules. In addition, Pavane offered a broad range of navigational capabilities to viewers and animators as well as through-the-screen interactions. An interesting byproduct of this work was the development of a proof-based visualization methodology, an approach that exploited formal proofs of concurrent programs to guide the choice of graphical representation and associated animations.