Interactive Exploration of Volumetric Data Sets with a Combined Visual and Haptic Interface

The analysis of complex volumetric data sets is a critical component of many scientific and engineering applications. The difficulty of understanding the increasing amount of data generated by these applications motivates the need for effective and intuitive visualization approaches that allow users to extract relevant information from the data in a relatively short amount of time. Even though a great variety of visualization techniques are available today, the effectiveness of a particular approach is often limited by the ability of the user to interact with the presented information. Incorporating three-dimensional interaction metaphors into the visualization environment has great potential to assist the user during the data exploration process. This dissertation develops and evaluates interactive visualization methods that combine three-dimensional graphical and haptic displays for the exploration of volumetric data sets. A number of techniques are suggested that are suitable for augmenting the traditional visualization interface with visual and haptic interaction methods for guiding the user during exploration. The advantage of the presented approach is that the rendering algorithms do not require a preprocessing stage to extract intermediate geometric representations from the data. Thus, the user has direct control over the visual and haptic display via a set of visualization parameters. In addition to demonstrating the effectiveness of the presented methods over previous approaches, the dissertation describes a controlled experiment that examines the contribution of haptic guidance to vector field exploration tasks. The results of the evaluation suggest that properly combined visual and haptic feedback can significantly improve the speed and accuracy of volumetric data exploration. The presented methods are further illustrated with examples of representative visualization applications.