Visualization of Anatomical Structures Based on Implicit Surfaces and Displacement Mapping

Ángel del Río
University of Tübingen
WSI/GRIS Department
72076 Tübingen
Germany

e-mail: anxo@gris.uni-tuebingen.de

http://www.gris.uni-tuebingen.de/~anxo/index.html

Abstract

 Implicit models provide an accurate and flexible
representation of a surface. Although they have been widely used
in modeling contexts, their application to visualization has been
relatively limited due to rendering difficulties. Typical
explicit triangulation of the surface, though effective, results
in a redundant representation and a high load on the bus between
the CPU and the graphics pipeline.
In this work, we present an alternative method that allows high
quality visualization of iso-surfaces with lower communication
requirements. Our proposal is based on the combination of implicit
surfaces with displacement mapping techniques. The application of
displacement maps on a coarse mesh approximating the implicit
model avoids the necessity of explicit triangulation and reduces
the bus load without loss of image quality. The examination of the
iso-surface contour, by means of a frequency analysis, allows for
automatic creation of the displacement map which better suits to
the implicit model in question. In this study we demonstrate the
validity of the proposal as an efficient alternative to polygonization
of implicit surfaces, thus opening many new possibilities to its
application to volume visualization.