Evaluation of Stereoscopy and Lit Shading for a Counting Task in Knot Visualization.pdf

Evaluation of Stereoscopy and Lit Shading for a Counting Task in Knot Visualization Nicholas G. Lipari Christoph W. Borst Center for Advanced Computer Studies Center for Advanced Computer Studies University of Louisiana at Lafayette University of Louisiana at Lafayette Lafayette, LA, USA Lafayette, LA, USA Abstract We present an experiment on depth cues for knot visualization in desktop virtual reality (fish- tank VR). We used a within-subjects experiment to in- vestigate stereoscopic visuals and 3D lit shading. Par- ticipants were required to count crossings in visualized knots – a fundamental task in classical knot diagram in- terpretation. Participants made significantly more er- rors with stereoscopic visuals than with monoscopic vi- suals, while no effect was detected for shading. Since this contrasts evaluations of fishtank VR for other appli- cations, it provides knowledge about limitations of stereo imaging. In addition to the experiment, we outline our knot visualization approach, which uses a dynamic sim- ulation and charged rope analogy to generate knot shape, and includes a technique for rendering gaps like those Figure 1: A knot rendered with shading and gaps. found in classical knot diagrams. Keywords: Knot Visualization, Stereoscopy, Fishtank mance and accuracy in other tasks, e.g., by [6], [7], Virtual Reality, Counting Tasks, Dynamic Simulation [10], [11], [15], and [16]. In contrast to these stud- ies, our work shows that, for a fundamental count-