Abstract
We present PRISAD, the first generic rendering infrastructure for
information visualization applications that use the accordion drawing
technique: rubber-sheet navigation with guaranteed visibility for
marked areas of interest. Our new rendering algorithms are based on
the partitioning of screen-space, which allows us to handle dense dataset
regions correctly. The algorithms in previous work led to incorrect
visual representations because of overculling, and to inefficiencies due
to overdrawing multiple items in the same region. Our pixel-based
drawing infrastructure guarantees correctness by eliminating
overculling, and improves rendering performance with tight bounds on
overdrawing.
PRITree and PRISeq are applications built on PRISAD, with the feature
sets of TreeJuxtaposer and SequenceJuxtaposer, respectively. We
describe our PRITree and PRISeq dataset traversal algorithms, which are used for
efficient rendering, culling, and layout of datasets within the
PRISAD framework. We also discuss PRITree node marking techniques,
which offer order-of-magnitude improvements to both memory and time
performance versus previous range storage and retrieval techniques.
Our PRITree implementation features a five-fold
increase in rendering speed for non-trivial tree structures, and also
reduces memory requirements in some real-world datasets by up to eight
times, so we are able to handle trees of several million nodes. PRISeq
renders fifteen times faster and handles datasets twenty times larger
than previous work.
Software: Olduvai Sourceforge page
Video: PRISAD
video [110 MB, QuickTime with voiceover]
Talk: PPT
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Last modified: Tue Mar 11 00:20:28 PDT 2014