TY - GEN A1 - Kratz, Andrea A1 - Meyer, Björn A1 - Hotz, Ingrid T1 - A Visual Approach to Analysis of Stress Tensor Fields N2 - We present a visual approach for the exploration of stress tensor fields. Therefore, we introduce the idea of multiple linked views to tensor visualization. In contrast to common tensor visualization methods that only provide a single view to the tensor field, we pursue the idea of providing various perspectives onto the data in attribute and object space. Especially in the context of stress tensors, advanced tensor visualization methods have a young tradition. Thus, we propose a combination of visualization techniques domain experts are used to with statistical views of tensor attributes. The application of this concept to tensor fields was achieved by extending the notion of shape space. It provides an intuitive way of finding tensor invariants that represent relevant physical properties. Using brushing techniques, the user can select features in attribute space, which are mapped to displayable entities in a three-dimensional hybrid visualization in object space. Volume rendering serves as context, while glyphs encode the whole tensor information in focus regions. Tensorlines can be included to emphasize directionally coherent features in the tensor field. We show that the benefit of such a multi-perspective approach is manifold. Foremost, it provides easy access to the complexity of tensor data. Moreover, including wellknown analysis tools, such as Mohr diagrams, users can familiarize themselves gradually with novel visualization methods. Finally, by employing a focus-driven hybrid rendering, we significantly reduce clutter, which was a major problem of other three-dimensional tensor visualization methods. T3 - ZIB-Report - 10-26 KW - Visualisierung KW - Datenanalyse KW - Tensorfelder Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-11915 ER - TY - JOUR A1 - Kratz, Andrea A1 - Baum, Daniel A1 - Hotz, Ingrid T1 - Anisotropic Sampling of Planar and Two-Manifold Domains for Texture Generation and Glyph Distribution JF - Transactions on Visualization and Computer Graphics (TVCG) Y1 - 2013 U6 - https://doi.org/10.1109/TVCG.2013.83 VL - 19 SP - 1782 EP - 1794 ER - TY - JOUR A1 - Kratz, Andrea A1 - Auer, Cornelia A1 - Stommel, Markus A1 - Hotz, Ingrid T1 - Visualization and Analysis of Second-Order Tensors: Moving Beyond the Symmetric Positive-Definite Case JF - Computer Graphics Forum - State of the Art Reports Y1 - 2013 U6 - https://doi.org/10.1111/j.1467-8659.2012.03231.x VL - 1 SP - 49 EP - 74 ER - TY - CHAP A1 - Auer, Cornelia A1 - Stripf, Claudia A1 - Kratz, Andrea A1 - Hotz, Ingrid T1 - Glyph- and Texture-based Visualization of Segmented Tensor Fields T2 - GRAPP/IVAPP Proc. Int. Conf. on Computer Graphics Theory and Applications and Int. Conf. on Information Visualization Theory and Applications Y1 - 2012 SN - 978-989-8565-02-0 U6 - https://doi.org/10.5220/0003857106700677 SP - 670 EP - 677 PB - SciTePress ER - TY - CHAP A1 - Auer, Cornelia A1 - Kasten, Jens A1 - Kratz, Andrea A1 - Zhang, Eugene A1 - Hotz, Ingrid T1 - Automatic, Tensor-Guided Illustrative Vector Field Visualization T2 - Proc. IEEE Pacific Visualization Symposium 2013 Y1 - 2013 U6 - https://doi.org/10.1109/PacificVis.2013.6596154 SP - 265 EP - 275 CY - Sydney, Australia ER - TY - JOUR A1 - Redemann, Stefanie A1 - Baumgart, Johannes A1 - Lindow, Norbert A1 - Shelley, Michael A1 - Nazockdast, Ehssan A1 - Kratz, Andrea A1 - Prohaska, Steffen A1 - Brugués, Jan A1 - Fürthauer, Sebastian A1 - Müller-Reichert, Thomas T1 - C. elegans chromosomes connect to centrosomes by anchoring into the spindle network JF - Nature Communications N2 - The mitotic spindle ensures the faithful segregation of chromosomes. Here we combine the first large-scale serial electron tomography of whole mitotic spindles in early C. elegans embryos with live-cell imaging to reconstruct all microtubules in 3D and identify their plus- and minus-ends. We classify them as kinetochore (KMTs), spindle (SMTs) or astral microtubules (AMTs) according to their positions, and quantify distinct properties of each class. While our light microscopy and mutant studies show that microtubules are nucleated from the centrosomes, we find only a few KMTs directly connected to the centrosomes. Indeed, by quantitatively analysing several models of microtubule growth, we conclude that minus-ends of KMTs have selectively detached and depolymerized from the centrosome. In toto, our results show that the connection between centrosomes and chromosomes is mediated by an anchoring into the entire spindle network and that any direct connections through KMTs are few and likely very transient. Y1 - 2017 U6 - https://doi.org/10.1038/ncomms15288 VL - 8 IS - 15288 ER - TY - CHAP A1 - Hlawitschka, Mario A1 - Hotz, Ingrid A1 - Kratz, Andrea A1 - Marai, G. Elisabeta A1 - Moreno, Rodrigo A1 - Scheuermann, Gerik A1 - Stommel, Markus A1 - Wiebel, Alexander A1 - Zhang, Eugene ED - Westin, Carl-Frederic ED - Burgeth, Bernhard ED - Vilanova, Anna T1 - Top Challenges in the Visualization of Engineering Tensor Fields T2 - Visualization and Processing of Tensors and Higher-Order Descriptors for Multi-Field Data Y1 - 2014 SP - 3 EP - 15 PB - Springer ER - TY - CHAP A1 - Kratz, Andrea A1 - Kettlitz, Nino A1 - Hotz, Ingrid T1 - Particle-Based Anisotropic Sampling for Two-Dimensional Tensor Field Visualization T2 - Vision Modeling and Visualization (VMV’11) Y1 - 2011 SP - 145 EP - 152 PB - Eurographics Association target ER - TY - GEN A1 - Kratz, Andrea A1 - Meyer, Björn A1 - Hotz, Ingrid ED - Hagen, Hans T1 - A Visual Approach to Analysis of Stress Tensor Fields T2 - Scientific Visualization: Interactions, Features, Metaphors Y1 - 2011 UR - http://drops.dagstuhl.de/opus/volltexte/2011/3296 U6 - https://doi.org/10.4230/DFU.Vol2.SciViz.2011.188 VL - 2 SP - 188 EP - 211 PB - Schloss Dagstuhl–Leibniz-Zentrum fuer Informatik CY - Dagstuhl, Germany ER - TY - CHAP A1 - Kratz, Andrea A1 - Schöneich, Marc A1 - Zobel, Valentin A1 - Burgeth, Bernhard A1 - Scheuermann, Gerik A1 - Hotz, Ingrid A1 - Stommel, Markus T1 - Tensor Visualization Driven Mechanical Component Design T2 - Proc. IEEE Pacific Visualization Symposium 2014 Y1 - 2014 U6 - https://doi.org/10.1109/PacificVis.2014.51 SP - 145 EP - 152 ER - TY - JOUR A1 - Schöneich, Marc A1 - Stommel, Markus A1 - Kratz, Andrea A1 - Zobel, Valentin A1 - Scheuermann, Gerik A1 - Hotz, Ingrid A1 - Burgeth, Bernhard T1 - Optimization strategy for the design of ribbed plastic components JF - International Journal of Plastics Technology Y1 - 2014 IS - 10 SP - 160 EP - 175 ER - TY - GEN A1 - Kratz, Andrea A1 - Reininghaus, Jan A1 - Hadwiger, Markus A1 - Hotz, Ingrid T1 - Adaptive Screen-Space Sampling for Volume Ray-Casting N2 - This work is concerned with adaptive screen-space sampling for volume ray-casting. The goal is to reduce the number of rays being cast into the scene and, thus, the overall number of sampling points. We guarantee reliable images through explicit error control using an error estimator that is founded in the field of finite element methods (FEM). FEM theory further provides a well-founded theory to prove the efficiency of the presented algorithm via convergence analysis. We, therefore, compare the convergence behavior of our method against uniform subdivisions and a refinement scheme that was presented in the context of CPU volume ray-casting. Minimizing the number of sampling points is of interest for rendering large datasets where each evaluation might need an expensive decompression. Furthermore, with increasing screen resolutions high-resolution images are created more efficiently with our method. T3 - ZIB-Report - 11-04 Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-12446 ER - TY - THES A1 - Kratz, Andrea T1 - Three-Dimensional Second-Order Tensor Fields: Exploratory Visualization and Anisotropic Sampling N2 - Tensors provide a powerful mathematical language to describe physical phenomena. Consequently, they have a long tradition in physics and appear in various application areas, either as intermediate product or as output of simulations or measurements. The potential of tensors to describe complex anisotropic behavior, however, concurrently complicates their interpretation. The central research question of this thesis is how three-dimensional tensor fields of second order are visualized effectively so that, as a long term goal, their interpretation becomes easier. The focus of this thesis lies on the class of indefinite tensors. The methods that are proposed in this thesis fall into two main categories: (1.) the interactive exploration of the three-dimensional tensor data, and (2.) the geometric reduction of the data to two-dimensional planes or triangulated surfaces. In both cases, possible visualization approaches are presented. For interactive exploration of the data, we propose to combine diagram views with three-dimensional hybrid visualizations. We show that this facilitates familiarizing with the data and leads to exciting analytic queries. If a geometric data reduction is possible, we focus on glyph- and texture-based methods. In this context, the thesis is concerned with methods to improve their quality. Therefore, we propose two algorithms for the efficient creation of anisotropic sample distributions. Moreover, we present a novel visualization method that works on planar slices as well as on triangulated surfaces. The basic idea of this method is to use anisotropic sample distributions for the efficient computation of anisotropic Voronoi cells, which then are used as base elements for texture mapping. Hence, the usage of textures to encode the tensor’s various degrees of freedom becomes possible. We evaluate our methods for the interactive exploration on stress tensor fields from structure simulations. To show the ffectiveness of novel visualization methods, various datasets are presented. KW - visualization KW - tensors of second order KW - exploratory visualization KW - anisotropic sampling of tensor fields Y1 - 2013 UR - http://www.diss.fu-berlin.de/diss/receive/FUDISS_thesis_000000094629 ER - TY - GEN A1 - Kratz, Andrea A1 - Hadwiger, Markus A1 - Hotz, Ingrid T1 - Improved Visual Exploration and Hybrid Rendering of Stress Tensor Fields via Shape-Space Clustering. Y1 - 2011 PB - Poster presentation at the IEEE VisWeek 2011, Providence ER -