EuroVisShort2021

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https://diglib.eg.org/handle/10.2312/2633047

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Browsing EuroVisShort2021 by Subject "Computing methodologies"

Now showing 1 - 4 of 4
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    Analytic Ray Splitting for Controlled Precision DVR
    (The Eurographics Association, 2021) Weiss, Sebastian; Westermann, Rüdiger; Agus, Marco and Garth, Christoph and Kerren, Andreas
    For direct volume rendering of post-classified data, we propose an algorithm that analytically splits a ray through a cubical cell at the control points of a piecewise-polynomial transfer function. This splitting generates segments over which the variation of the optical properties is described by piecewise cubic functions. This allows using numerical quadrature rules with controlled precision to obtain an approximation with prescribed error bounds. The proposed splitting scheme can be used to find all piecewise linear or monotonic segments along a ray, and it can thus be used to improve the accuracy of direct volume rendering, scale-invariant volume rendering, and multi-isosurface rendering.
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    Integration-Aware Vector Field Super Resolution
    (The Eurographics Association, 2021) Sahoo, Saroj; Berger, Matthew; Agus, Marco and Garth, Christoph and Kerren, Andreas
    In this work we propose an integration-aware super-resolution approach for 3D vector fields. Recent work in flow field superresolution has achieved remarkable success using deep learning approaches. However, existing approaches fail to account for how vector fields are used in practice, once an upsampled vector field is obtained. Specifically, a cornerstone of flow visualization is the visual analysis of streamlines, or integral curves of the vector field. To this end, we study how to incorporate streamlines as part of super-resolution in a deep learning context, such that upsampled vector fields are optimized to produce streamlines that resemble the ground truth upon integration. We consider common factors of integration as part of our approach - seeding, streamline length - and how these factors impact the resulting upsampled vector field. To demonstrate the effectiveness of our approach, we evaluate our model both quantitatively and qualitatively on different flow field datasets and compare our method against state of the art techniques.
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    RISSAD: Rule-based Interactive Semi-Supervised Anomaly Detection
    (The Eurographics Association, 2021) Deng, Jiahao; Brown, Eli T.; Agus, Marco and Garth, Christoph and Kerren, Andreas
    Anomaly detection has gained increasing attention from researchers in recent times. Owing to a lack of reliable ground-truth labels, many current state-of-art techniques focus on unsupervised learning, which lacks a mechanism for user involvement. Further, these techniques do not provide interpretable results in a way that is understandable to the general public. To address this problem, we present RISSAD: an interactive technique that not only helps users to detect anomalies, but automatically characterizes those anomalies with descriptive rules. The technique employs a semi-supervised learning approach based on an algorithm that relies on a partially-labeled dataset. Addressing the need for feedback and interpretability, the tool enables users to label anomalies individually or in groups, using visual tools. We demonstrate the tool's effectiveness using quantitative experiments simulated on existing anomaly-detection datasets, and a usage scenario that illustrates a real-world application.
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    Visual Analysis of the Relation Between Stiffness Tensor and the Cauchy-Green Tensor
    (The Eurographics Association, 2021) Blecha, Christian; Hergl, Chiara; Nagel, Thomas; Scheuermann, Gerik; Agus, Marco and Garth, Christoph and Kerren, Andreas
    Stress and strain tensors, two well-known quantities in mechanical engineering, are linked through a fourth-order stiffness tensor, which is not considered by many visualizations due to its complexity. Considering an orthotropic material, the tensor naturally decomposes into nine known material properties.We used fiber surfaces to analyze a data set representing a biological tissue. A sphere is pushed into the material to confirm the mathematical link as well as the possibility to extract highly deformed regions even if only the stiffness tensor is available.