Annual Report 2010 - Fachgruppe Informatik an der RWTH Aachen ...

VisPME - Visualization in Parallel Manycore Environments
T. Rick, A. Kelle-Emden, T. Kuhlen
Current changes in the development of future hardware architectures in the domain of high
performance computing will considerably increase the complexity of scientific simulations.
For instance, simulations in computational fluid dynamics (CFD) result in very large three
dimensional transient datasets which are usually represented at as unstructured grid.
Therefore, interactive visualization techniques are a prerequisite for gaining a deeper
knowledge and understanding of the data at hand.
Hence, the main objectives of the BMBF project VisPME, carried out by HLRS Stuttgart,
ZAIK and MPI Cologne, the VR Group in Aachen and industrial partners, can be summarized
as:
• create a generic and scalable framework for parallel data processing and interactive
visualization for a wide range of application domains like CFD, Medical Sciences, etc.
• transform and enhance visualization algorithms (i.e. particle tracing) to a distributed
manycore environment in order to benefit from the massively parallel computing power
• parallel approaches to data reduction to support extremely low latency requirements of
real-time data interaction techniques
• assure quality and applicability of the developed concepts by close collaboration with
application domain experts
The resulting computational requirements will be met by the use of large visualization
clusters instead of single workstations. Such clusters are comprised of multiple nodes which
are connected by high bandwidth, low latency networks (e.g. Infiniband). Each node is a
parallel system itself, composed of several multi-core processors and one or more graphics
cards which offer extensive rendering capabilities. Additionally, today's graphics cards can
also serve as compute platforms for highly parallel computations that do not have to be
directly related to image synthesis, necessarily.
Within the overall project, the VR group focuses on interactive particle tracing, which is an
excellent technique for depicting the movement of matter within complex flow phenomena.
In an experimental setting particle tracing can be imagined as the injection of smoke or ink in
a real world flow field. In virtual environments however, this technique requires considerate
computational resources as it relies heavily on the advection of a massive amount of particle
trajectories in order to convey distinct flow structures.
For the first time, the widespread availability of massively parallel multi-core architectures,
within remote computing resources and nearby visualization systems (e.g. GPUs) as well,
allows the application of interactive particle tracing on the original simulation grids, rather
than on downsampled Cartesian grids.
Furthermore, with the utilization of parallel manycore architectures the computation of
derived quantities like the Eigenvalue analysis now becomes possible to advect in real-time
for every single particle. An excellent example for the necessity of such derived quantities is
provided by the stress analysis of red blood cells in ventricular assist devices while blood is
being pumped through.
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