12TH INTERNATIONAL SYMPOSIUM ON FLOW VISUALIZATION
Tobias Schafhitzel, Daniel Weiskopf, Thomas Ertl · 2006
In this paper, we present a fast and accurate method for the combined detection and interactive visualization of vortex structures in 3D flow and their corresponding velocity field. Vortex surfaces are extracted by identifying vortex core lines in combination with isosurfaces of λ2. The velocity field on those vortex surfaces is visualized by a surface LIC method that works in image space. An efficient GPU implementation of surface LIC supports interactive visualization and, therefore, a user-centered exploration of the behavior of the flow in vortical regions is possible. The surface LIC is further improved by applying several illumination techniques. The visualization system also supports the combination of this new visual representation with conventional techniques such as vector arrows, geometric streamlines, and color coding of parameters like vortex strength or velocity magnitude. Furthermore, a detailed investigation of vortices is facilitated by selectively picking vortices, which allows the user to focus on certain areas of interest.