Browsing by Author "Kolditz, Olaf"

Now showing 1 - 4 of 4
  • Thumbnail Image
    Item
    Fiber Surfaces for many Variables
    (The Eurographics Association and John Wiley & Sons Ltd., 2020) Blecha, Christian; Raith, Felix; Präger, Arne Jonas; Nagel, Thomas; Kolditz, Olaf; Maßmann, Jobst; Röber, Niklas; Böttinger, Michael; Scheuermann, Gerik; Viola, Ivan and Gleicher, Michael and Landesberger von Antburg, Tatiana
    Scientific visualization deals with increasingly complex data consisting of multiple fields. Typical disciplines generating multivariate data are fluid dynamics, structural mechanics, geology, bioengineering, and climate research. Quite often, scientists are interested in the relation between some of these variables. A popular visualization technique for a single scalar field is the extraction and rendering of isosurfaces. With this technique, the domain can be split into two parts, i.e. a volume with higher values and one with lower values than the selected isovalue. Fiber surfaces generalize this concept to two or three scalar variables up to now. This article extends the notion further to potentially any finite number of scalar fields. We generalize the fiber surface extraction algorithm of Raith et al. [RBN*19] from 3 to d dimensions and demonstrate the technique using two examples from geology and climate research. The first application concerns a generic model of a nuclear waste repository and the second one an atmospheric simulation over central Europe. Both require complex simulations which involve multiple physical processes. In both cases, the new extended fiber surfaces helps us finding regions of interest like the nuclear waste repository or the power supply of a storm due to their characteristic properties.
  • Thumbnail Image
    Item
    A Virtual Geographic Environment for the Exploration of Hydro-Meteorological Extremes
    (The Eurographics Association, 2021) Rink, Karsten; Sen, Özgür Ozan; Hannemann, Marco; Ködel, Uta; Nixdorf, Erik; Weber, Ute; Werban, Ulrike; Schrön, Martin; Kalbacher, Thomas; Kolditz, Olaf; Dutta, Soumya and Feige, Kathrin and Rink, Karsten and Zeckzer, Dirk
    We propose a Virtual Geographic Environment for the exploration of hydro-meteorological events. Focussing on the catchment of the Müglitz River in south-eastern Germany, a large collection of observation data acquired via a wide range of measurement devices has been integrated in a geographical reference frame for the region. Results of area-wide numerical simulations for both groundwater and soil moisture have been added to the scene and allow for the exploration of the delayed consequences of transient phenomena such as heavy rainfall events and their impact on the catchment scale. Implemented in a framework based on Unity, this study focusses on the concurrent visualisation and synchronised animation of multiple area wide datasets from different environmental compartments. The resulting application allows to explore the region of interest during specific hydrological events for an assessment of the interrelation of processes. As such, it offers the opportunity for knowledge transfer between researchers of different domains as well as for outreach to an interested public.
  • Thumbnail Image
    Item
    Visual Analysis of a Full-Scale-Emplacement Experiment in the Underground Rock Laboratory Mont Terri using Fiber Surfaces
    (The Eurographics Association, 2020) Raith, Felix; Blecha, Christian; Rink, Karsten; Wang, Wenqing; Kolditz, Olaf; Shao, Hua; Scheuermann, Gerik; Dutta, Soumya and Feige, Kathrin and Rink, Karsten and Zeckzer, Dirk
    In the Underground Rock Laboratory Mont Terri, research has been conducted for over 20 years into the storage of radioactive waste in Opalinus Clay. The fitness for such storage depends on the prevailing geological material. Experiments and multiphysics simulations investigate the long-term changes in the Opalinus Clay. The resulting data are highly multivariate, and environmental scientists visually analyze the data using predefined color lookup tables. The fiber surfaces of Raith et al. offer the researchers a new approach for visual analysis. However, the existing algorithm for the calculation is subject to certain limitations due to special cases that lead to no or incomplete fiber surfaces. In this paper, we improve the fiber surface algorithm of Raith et al., which reduces numerical errors and accelerates the existing algorithm. This improvement also makes it possible that the interactor no longer needs to be closed and convex. We then use the Full-Scale Emplacement Experiment to show how the improved algorithm can help in the visual analysis of multivariate data.
  • Thumbnail Image
    Item
    A Visual-Scenario-Based Environmental Analysis Approach to the Model-Based Management of Water Extremes in Urban Regions
    (The Eurographics Association, 2023) Sen, Özgür Ozan; Backhaus, Lars; Farrokhzadeh, Siamak; Graebling, Nico; Guemar, Sara; Kiszkurno, Feliks; Krebs, Peter; Novoa, Diego; Stamm, Jürgen; Kolditz, Olaf; Rink, Karsten; Dutta, Soumya; Feige, Kathrin; Rink, Karsten; Zeckzer, Dirk
    Due to the present climate crisis, the increasing frequency of the water extreme events around urban regions in river basins may result in drastic losses. One of the most effective preventive measures is a prior analysis of the eventual effects to comprehend the future risks of such water extremes. As well as analysis of historical impacts, the model-based management of water extremes have also a crucial role. Therefore, we present a 3-dimensional visual-scenario-based environmental analysis framework by utilising a Virtual Geographic Environment for the visualisation and the exploration of model-based management of hydrological events in urban regions. Within the study, we focused on the City of Dresden in eastern Germany located in the basin of the Elbe River. We integrated a large set of historical observation data and the results of numerical simulations to explore the consequences of modelled heavy precipitation events within different scenarios. Utilising a framework developed in Unity, the resulting visualisation of different scenarios dealing with water extremes simulated with coupled numerical models constitute the overall focus of this particular study. The resulting application is intended as a collaboration platform in terms of the knowledge transfer among domain scientists, stakeholders and the interested public.