Interactive Particle Tracing for Visualizing Large, Time-Varying Flow Fields

Delft University Of Technology, 2009

Technical Report VIS2009-01

Interactive Particle Tracing for Visualizing Large, Time-Varying Flow Fields
Dylan Dussel, Eric J. Griffith, Michal Koutek and Frits H. Post
Data Visualization Group, Delft University of Technology, Netherlands Technical Report VIS 2009-01

Abstract Particle tracing is a classical method of flow field visualization. For interactive exploration, particles must be advected and displayed in real-time. Graphics Processor Unit (GPU) based techniques can advect hundreds of thousands or millions of particles in real-time. We have investigated such GPU-based techniques for interactive exploration of large, time-varying flow fields. Our approach can be roughly divided into three categories: data preprocessing, visualization and interaction. The preprocessing involves data compression, region of interest computation and preparation of multi-resolution data. For flow visualization, we use use the GPU for both data decompression and particle advection. More than 1,000,000 particles can be visualized at interactive frame rates and data rates. We support the standard particle visualization techniques of pathlines, streamlines and streaklines. We also represent particles as flow-oriented ellipsoids, which can additionally be moved over their traversed pathlines to explore their behavior in time. Dynamic features in the data are explored by interactively seeding and tracking particles through time in both a standard display screen and a stereoscopic virtual environment. Further, we have validated our particle system by comparing its particle trajectories with those generated by a Large-eddy Simulation. Categories and Subject Descriptors (according to ACM CCS): I.3.8 [Computer Graphics]: ApplicationsFlow Visualization

1. Introduction Computational Fluid Dynamics (CFD) techniques such as Large-Eddy Simulation (LES) or Direct Numerical Simulation (DNS) can produce very large, time-varying, multi-field data sets.

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