Topic/Type: 2.6 Scientific visualization, Oral

Scientific Visualization of Particle Simulation Data by Virtual Reality System

H.Ohtani1, 2, N.Ohno3, R.Horiuchi1, 2

1 NIFS, Toki, Japan
2 The Graduate University for Advanced Studies(SOKENDAI), Toki, Japan
3 JAMSTEC, Yokohama, Japan

In the simulation research, it is important to develop an analysis tool to bring out useful physical information from the massive simulation data. The progress in computer technology makes it possible to perform large-scale and detailed three-dimensional (3-D) simulations. In the conventional visualization analysis, we use so called ?visualization software? on graphic workstations (GWS). When the complex 3-D structures of simulation results (ex. vector fields, particle trajectories and so on) are shown on the two-dimensional plane through the GWS?s monitor, it is difficult to grasp the spatial structures because of the lack of information of depth. In order to understand the complex spatial structures, it is indispensable to analyze them in 3-D space by scientific visualization technology. For our purpose of the visualization of particle simulation data, a deep absorption into the virtual reality (VR) world is needed. One of the most successful immersive VR systems is the CAVE [1]. The CAVE system can produce three important visual factors; stereo view, immersive view and interactive view. For the scientific VR visualization by the CAVE system, general purpose VR visualization software ?VFIVE? has been developed [2-3]. This software can show the vector fields as lines, arrows and so on, and the scalar fields as isosurface, contour and volume rendering. It was expanded to trace the particle trajectories in the electromagnetic fields obtained by simulation [4].
It is important to study what influence the time evolution of electromagnetic fields gives to the particle trajectories in the plasma simulation researches (ex, magnetic reconnection). We are advancing the software VFIVE to trace the particle trajectories in the time-evolution of electromagnetic fields, which is obtained by simulation data. For the time-evolution of fields, we add an animation function to VFIVE. In the animation function, the advanced VFIVE loads and visualizes the simulation data, and then saves the polygonal data of visualized objects on hard drive, sequentially. When the data are visualized, the same visualization parameters, such as isosurface level and seeds of field lines, are kept. During this procedure, the visualized objects at each time step are displayed in the CAVE. After finishing this procedure on all the time steps, VFIVE starts to load the polygonal data from hard drive and displays them in the CAVE one after another. The equation of motion for a single particle is given by the Newton-Lorentz equation in the sequentially loaded fields. The initial position of particle in the VR world is pointed by the 3-D mouse?Wand.?The initial velocity is given by the flow velocity, which is given by simulation data.
We will demonstrate the analysis results by this tool in this talk.

[1] Cruz-Neira, C. et al: ACM SIGGRAPH 93 (1988) 65.

[2]A.Kageyama, Y.Tamura and T.Sato: Trans. Virtual Reality Soc. Japan, 4 (1999) 717.

[3]N.Ohno and A.Kageyama: Earth Planet. Interiors, 163 (2007) 305.

[4]H.Ohtani and R.Horiuchi: PFR 3 (2008) 054 [ DOI: 10.1585/pfr.3.054].