Accelerated and Extended Building of Implicit kd-Trees for Volume Ray Tracing

Gerd Marmitt, Roman Brauchle, Heiko Friedrich, and Philipp Slusallek
Proceedings of Vision, Modeling, and Visualization (VMV) 2006,
Aachen, Germany, November 22-24, 2006, (to appear)
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Implicit kd-trees have proven to greatly accelerate
iso-surface rendering by ray tracing, such that interactive
performance can already be achieved on
a dual processor machine. However, the kd-tree
could not be used for semi-transparent rendering
and building the kd-tree was still a slow process that
did not allow for rendering time-varying data sets.
In this paper we extend the kd-tree to provide
a coarse volume representation in addition to the
min/max values that allows to quickly skip homogeneous
regions. Additionally, we replace the recursive
build procedure by an iterative bottom-up
method distributed among several threads. These
extensions enable interactive rendering of semitransparent
and time-varying data sets.