Large Vector-Field Visualization: Theory and Practice

Abstract

The study of vector fields resulting from simulation and measurement has a rich tradition in the Scientific Visualization community, which is explained by the ubiquity of vector fields across scientific, engineering, and medical application domains. The corresponding visualization techniques have in the past often focussed on fluid flow phenomena. However, other application domains such as e.g. astrophysics, geodynamics, life sciences, and high-energy physics are gaining prominence in visualization practice, thus opening new research avenues for vector field visualization research. In all these domains, numerical simulations produce large, time-varying, and highly complex vector fields. While the visual analysis of these four-dimensional fields creates obvious issues of representation and perception, the rapidly increasing data size coupled with the growing significance of Lagrangian methods poses unique challenges pertaining to data handling and increased computational effort. Obtaining insightful visualization in this setting is therefore both a key objective and an increasingly difficult task for application scientists. The aim of this tutorial is to provide an overview of modern approaches and specifically discuss their suitability for large vector field visualization. To address a broad range of interest and knowledge level, the included topics encompass both theoretical material on the fundamentals of vector field visualization (such as integral curves, Lagrangian techniques, and parallel computation), as well as insights into the implementation and practical application of such methods. In particular, specific application examples involving large vector fields from the areas of thermal hydraulics, biomedical engineering and aeronautics are discussed, and a practical perspective on the current state of the art is proposed. The overall goal is namely to provide participants with a solid knowledge about the possibilities and current limitations of large vector field visualization, and to convey hands-on knowledge in the form of experiences gathered in such scenarios. The material of this tutorial are partly chosen based on feedback and suggestions obtained from participants of IEEE Visualization 2009 tutorial “Visualization of Time-Varying Vector Fields”. The originality of the present tutorial lies in its deliberate focus on largescale problems, which are of paramount importance in research and industrial applications of vector fields. This setting raises fundamental challenges for visualization methods, which have yet to be properly addressed. Our goal is therefore to highlight recent success stories, document ongoing research efforts, and point out open problems.