Particle-based Flow Visualization

Dynamic Flow Volumes using Particle Level Sets

Typically, flow volumes are represented and visualized by describing their boundary as the iso-surface of a level set function. The particle level set (PLS) method combines the advantages of both grid- and particle-based level set representations.

This work demonstrates that the PLS method can be adapted to volumetric dye advection via streak volumes, and to the visualization by time surfaces and path volumes. This is achieved with a modified and extended PLS, including a model for dye injection. A new algorithmic interpretation of PLS is introduced in order to exploit the efficiency of modern graphics hardware, leading to an interactive visualization. Finally, the high quality and usefulness of PLS flow visualization is demonstrated by providing quantitative results on volume preservation and by discussing typical applications of 3D flow visualization.

demo video

9 MB, 1024 x 768, 1456.3 bps (codec: Xvid, DivX compatible)

GPU-based Particle Flows

Direct flow visualizations can help climate researchers to explore flow characteristics by adjusting parameters and thus controlling the visual output. They provide an intuitive insight into complex flow data sets such as simulated circulations of the atmosphere or the ocean. Recent developments in visualization techniques exploiting programmable features of current graphics processing units (GPUs) have proven to be very powerful. This is especially true for particle-based techniques.

This work presents a complete GPU-based particle engine and framework for the real-time visualization of unsteady climate flow data sets. This involves a proper data work flow from the simulation back-end to the visualizer, the handling of non-uniform data grids and, finally, a proper support for the interactive exploration. We evaluate our framework with a South Asian typhoon simulated by the DKRZ Hamburg.

demo video

101 MB, 640 x 480, 24bpp, 3993.6 kbps (codec: Xvid, DivX compatible)