Partitioned rendering infrastructure for stable accordion navigation
James Slack · cIRcle (University of British Columbia) · 2009
My thesis presents a new rendering infrastructure for information visualization applications that use the accordion drawing navigation metaphor. Accordion drawing techniques use rubber-sheet navigation methods, with the borders tacked down, and provide guaranteed visibility for marked areas of interest. Our accordion drawing algorithms are based on screen-space partitioning, which eliminates overculling and tightly bounds overdrawing. By eliminating the overculling effects of rendering dense regions of data, we guarantee a correct visual representation of any dataset. Also, our pixel-based drawing infrastructure improves the rendering performance of dense dataset regions with strict drawing constraints, which are based on application-specific drawing requirements. The generic infrastructure provides an interface to numerically stable navigation of datasets, with full support for multiple concurrent regions of navigation motion. To evaluate our generic infrastructure, I benchmark our tree comparison application with the performance of TreeJuxtaposer, a previous accordion drawing application with identical features. I describe our tree traversal algorithms, which we use for efficient rendering, culling, and layout of tree datasets. I also discuss tree node marking techniques, which offer several improvements over previous range storage and retrieval techniques, reducing memory requirements and increasing rendering speed. Finally, I evaluate tree-specific navigation techniques from our winning entry in the Info Vis 2003 contest, with TreeJuxtaposer supported by an incremental search feature and an improved user interface.