41-Issue 1

Permanent URI for this collection

Issue Information

Issue Information

Articles

At‐Most‐Hexa Meshes

Bukenberger, Dennis R.
Tarini, Marco
Lensch, Hendrik P. A.
Major Revision from Pacific Graphics

Economic Upper Bound Estimation in Hausdorff Distance Computation for Triangle Meshes

Zheng, Yicun
Sun, Haoran
Liu, Xinguo
Bao, Hujun
Huang, Jin
Articles

Embedding QR Code onto Triangulated Meshes using Horizon Based Ambient Occlusion

Papp, György
Hoffmann, Miklós
Papp, Ildikó
Articles

Seamless Parametrization of Spheres with Controlled Singularities

Levi, Zohar
Major Revision from EuroVis Symposium

EHR STAR: The State‐Of‐the‐Art in Interactive EHR Visualization

Wang, Q.
Laramee, R.S.
Articles

Dynamic Diffuse Global Illumination Resampling

Majercik, Zander
Müller, Thomas
Keller, Alexander
Nowrouzezahrai, Derek
McGuire, Morgan
Articles

Comparison of Modern Omnidirectional Precise Shadowing Techniques Versus Ray Tracing

Kobrtek, Jozef
Milet, Tomas
Tóth, Michal
Herout, Adam
Articles

A Survey on Deep Learning for Skeleton‐Based Human Animation

Mourot, Lucas
Hoyet, Ludovic
Le Clerc, François
Schnitzler, François
Hellier, Pierre
Articles

Shadow Layers for Participating Media

Desrichard, François
Vanderhaeghe, David
Paulin, Mathias
Major Revision from Eurographics Conference

Path Guiding Using Spatio‐Directional Mixture Models

Dodik, Ana
Papas, Marios
Öztireli, Cengiz
Müller, Thomas
Major Revision from EuroVis Symposium

Immersive Analytics with Abstract 3D Visualizations: A Survey

Kraus, Matthias
Fuchs, Johannes
Sommer, Björn
Klein, Karsten
Engelke, Ulrich
Keim, Daniel
Schreiber, Falk
Major Revision from EuroVis Symposium

Visual Analysis of Two‐Phase Flow Displacement Processes in Porous Media

Frey, Steffen
Scheller, Stefan
Karadimitriou, Nikolaos
Lee, Dongwon
Reina, Guido
Steeb, Holger
Ertl, Thomas
Articles

Stroke‐Based Drawing and Inbetweening with Boundary Strokes

Jiang, Jie
Seah, Hock Soon
Liew, Hong Ze
Major Revision from EuroVis Symposium

Design and Evaluation Study of Visual Analytics Decision Support Tools in Air Traffic Control

Zohrevandi, E.
Westin, C. A. L.
Lundberg, J.
Ynnerman, A.
Articles

Using Position‐Based Dynamics for Simulating Mitral Valve Closure and Repair Procedures

Walczak, Lars
Georgii, Joachim
Tautz, Lennart
Neugebauer, Mathias
Wamala, Isaac
Sündermann, Simon
Falk, Volkmar
Hennemuth, Anja
Major Revision from EuroVis Symposium

Evaluating Data‐type Heterogeneity in Interactive Visual Analyses with Parallel Axes

Matute, José
Linsen, Lars
Major Revision from EuroVis Symposium

Augmenting Digital Sheet Music through Visual Analytics

Miller, Matthias
Fürst, Daniel
Hauptmann, Hanna
Keim, Daniel A.
El‐Assady, Mennatallah
Major Revision from EG Symposium on Geometry

Complex Functional Maps: A Conformal Link Between Tangent Bundles

Donati, Nicolas
Corman, Etienne
Melzi, Simone
Ovsjanikov, Maks
ARTICLES

A Stereo Matching Algorithm for High‐Precision Guidance in a Weakly Textured Industrial Robot Environment Dominated by Planar Facets

Wei, Hui
Meng, Lingjiang
Major Revision from EG Symposium on Rendering

Modelling Surround‐aware Contrast Sensitivity for HDR Displays

Yi, Shinyoung
Jeon, Daniel S.
Serrano, Ana
Jeong, Se‐Yoon
Kim, Hui‐Yong
Gutierrez, Diego
Kim, Min H.
ARTICLES

Placing Arrows in Directed Graph Layouts: Algorithms and Experiments

Binucci, Carla
Didimo, Walter
Kaufmann, Michael
Liotta, Giuseppe
Montecchiani, Fabrizio
Major Revision from EuroVis Symposium

A Survey of Tasks and Visualizations in Multiverse Analysis Reports

Hall, Brian D.
Liu, Yang
Jansen, Yvonne
Dragicevic, Pierre
Chevalier, Fanny
Kay, Matthew
Major Revision from Pacific Graphics

Feature‐Adaptive and Hierarchical Subdivision Gradient Meshes

Zhou, J.
Hettinga, G.J.
Houwink, S.
Kosinka, J.
Major Revision from Pacific Graphics

GlassNet: Label Decoupling‐based Three‐stream Neural Network for Robust Image Glass Detection

Zheng, Chengyu
Shi, Ding
Yan, Xuefeng
Liang, Dong
Wei, Mingqiang
Yang, Xin
Guo, Yanwen
Xie, Haoran
Articles

Learning Camera Control in Dynamic Scenes from Limited Demonstrations

Hanocka, R.
Assa, J.
Cohen‐Or, D.
Giryes, R.
Major Revision from EuroVis Symposium

A Survey on Cross‐Virtuality Analytics

Fröhler, B.
Anthes, C.
Jetter, H.‐C.
Heinzl, C.
Pointecker, F.
Friedl, J.
Schwajda, D.
Riegler, A.
Tripathi, S.
Holzmann, C.
Brunner, M.
Jodlbauer, H.
Major Revision from Pacific Graphics

Real‐Time Microstructure Rendering with MIP‐Mapped Normal Map Samples

Tan, Haowen
Zhu, Junqiu
Xu, Yanning
Meng, Xiangxu
Wang, Lu
Yan, Ling‐Qi
Articles

Graphical Tools for Visualization of Missing Data in Large Longitudinal Phenomena

Jiménez, Edgar
Macías, Rodrigo
Major Revision from Pacific Graphics

A Generative Framework for Image‐based Editing of Material Appearance using Perceptual Attributes

Delanoy, J.
Lagunas, M.
Condor, J.
Gutierrez, D.
Masia, B.


BibTeX (41-Issue 1)
                
@article{
10.1111:cgf.14275,
journal = {Computer Graphics Forum}, title = {{
Issue Information}},
author = {}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14275}
}
                
@article{
10.1111:cgf.14393,
journal = {Computer Graphics Forum}, title = {{
At‐Most‐Hexa Meshes}},
author = {
Bukenberger, Dennis R.
 and
Tarini, Marco
 and
Lensch, Hendrik P. A.
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14393}
}
                
@article{
10.1111:cgf.14395,
journal = {Computer Graphics Forum}, title = {{
Economic Upper Bound Estimation in Hausdorff Distance Computation for Triangle Meshes}},
author = {
Zheng, Yicun
 and
Sun, Haoran
 and
Liu, Xinguo
 and
Bao, Hujun
 and
Huang, Jin
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14395}
}
                
@article{
10.1111:cgf.14394,
journal = {Computer Graphics Forum}, title = {{
Embedding QR Code onto Triangulated Meshes using Horizon Based Ambient Occlusion}},
author = {
Papp, György
 and
Hoffmann, Miklós
 and
Papp, Ildikó
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14394}
}
                
@article{
10.1111:cgf.14423,
journal = {Computer Graphics Forum}, title = {{
Seamless Parametrization of Spheres with Controlled Singularities}},
author = {
Levi, Zohar
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14423}
}
                
@article{
10.1111:cgf.14424,
journal = {Computer Graphics Forum}, title = {{
EHR STAR: The State‐Of‐the‐Art in Interactive EHR Visualization}},
author = {
Wang, Q.
 and
Laramee, R.S.
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14424}
}
                
@article{
10.1111:cgf.14427,
journal = {Computer Graphics Forum}, title = {{
Dynamic Diffuse Global Illumination Resampling}},
author = {
Majercik, Zander
 and
Müller, Thomas
 and
Keller, Alexander
 and
Nowrouzezahrai, Derek
 and
McGuire, Morgan
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14427}
}
                
@article{
10.1111:cgf.14425,
journal = {Computer Graphics Forum}, title = {{
Comparison of Modern Omnidirectional Precise Shadowing Techniques Versus Ray Tracing}},
author = {
Kobrtek, Jozef
 and
Milet, Tomas
 and
Tóth, Michal
 and
Herout, Adam
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14425}
}
                
@article{
10.1111:cgf.14426,
journal = {Computer Graphics Forum}, title = {{
A Survey on Deep Learning for Skeleton‐Based Human Animation}},
author = {
Mourot, Lucas
 and
Hoyet, Ludovic
 and
Le Clerc, François
 and
Schnitzler, François
 and
Hellier, Pierre
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14426}
}
                
@article{
10.1111:cgf.14429,
journal = {Computer Graphics Forum}, title = {{
Shadow Layers for Participating Media}},
author = {
Desrichard, François
 and
Vanderhaeghe, David
 and
Paulin, Mathias
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14429}
}
                
@article{
10.1111:cgf.14428,
journal = {Computer Graphics Forum}, title = {{
Path Guiding Using Spatio‐Directional Mixture Models}},
author = {
Dodik, Ana
 and
Papas, Marios
 and
Öztireli, Cengiz
 and
Müller, Thomas
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14428}
}
                
@article{
10.1111:cgf.14430,
journal = {Computer Graphics Forum}, title = {{
Immersive Analytics with Abstract 3D Visualizations: A Survey}},
author = {
Kraus, Matthias
 and
Fuchs, Johannes
 and
Sommer, Björn
 and
Klein, Karsten
 and
Engelke, Ulrich
 and
Keim, Daniel
 and
Schreiber, Falk
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14430}
}
                
@article{
10.1111:cgf.14432,
journal = {Computer Graphics Forum}, title = {{
Visual Analysis of Two‐Phase Flow Displacement Processes in Porous Media}},
author = {
Frey, Steffen
 and
Scheller, Stefan
 and
Karadimitriou, Nikolaos
 and
Lee, Dongwon
 and
Reina, Guido
 and
Steeb, Holger
 and
Ertl, Thomas
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14432}
}
                
@article{
10.1111:cgf.14433,
journal = {Computer Graphics Forum}, title = {{
Stroke‐Based Drawing and Inbetweening with Boundary Strokes}},
author = {
Jiang, Jie
 and
Seah, Hock Soon
 and
Liew, Hong Ze
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14433}
}
                
@article{
10.1111:cgf.14431,
journal = {Computer Graphics Forum}, title = {{
Design and Evaluation Study of Visual Analytics Decision Support Tools in Air Traffic Control}},
author = {
Zohrevandi, E.
 and
Westin, C. A. L.
 and
Lundberg, J.
 and
Ynnerman, A.
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14431}
}
                
@article{
10.1111:cgf.14434,
journal = {Computer Graphics Forum}, title = {{
Using Position‐Based Dynamics for Simulating Mitral Valve Closure and Repair Procedures}},
author = {
Walczak, Lars
 and
Georgii, Joachim
 and
Tautz, Lennart
 and
Neugebauer, Mathias
 and
Wamala, Isaac
 and
Sündermann, Simon
 and
Falk, Volkmar
 and
Hennemuth, Anja
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14434}
}
                
@article{
10.1111:cgf.14438,
journal = {Computer Graphics Forum}, title = {{
Evaluating Data‐type Heterogeneity in Interactive Visual Analyses with Parallel Axes}},
author = {
Matute, José
 and
Linsen, Lars
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14438}
}
                
@article{
10.1111:cgf.14436,
journal = {Computer Graphics Forum}, title = {{
Augmenting Digital Sheet Music through Visual Analytics}},
author = {
Miller, Matthias
 and
Fürst, Daniel
 and
Hauptmann, Hanna
 and
Keim, Daniel A.
 and
El‐Assady, Mennatallah
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14436}
}
                
@article{
10.1111:cgf.14437,
journal = {Computer Graphics Forum}, title = {{
Complex Functional Maps: A Conformal Link Between Tangent Bundles}},
author = {
Donati, Nicolas
 and
Corman, Etienne
 and
Melzi, Simone
 and
Ovsjanikov, Maks
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14437}
}
                
@article{
10.1111:cgf.14435,
journal = {Computer Graphics Forum}, title = {{
A Stereo Matching Algorithm for High‐Precision Guidance in a Weakly Textured Industrial Robot Environment Dominated by Planar Facets}},
author = {
Wei, Hui
 and
Meng, Lingjiang
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14435}
}
                
@article{
10.1111:cgf.14439,
journal = {Computer Graphics Forum}, title = {{
Modelling Surround‐aware Contrast Sensitivity for HDR Displays}},
author = {
Yi, Shinyoung
 and
Jeon, Daniel S.
 and
Serrano, Ana
 and
Jeong, Se‐Yoon
 and
Kim, Hui‐Yong
 and
Gutierrez, Diego
 and
Kim, Min H.
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14439}
}
                
@article{
10.1111:cgf.14440,
journal = {Computer Graphics Forum}, title = {{
Placing Arrows in Directed Graph Layouts: Algorithms and Experiments}},
author = {
Binucci, Carla
 and
Didimo, Walter
 and
Kaufmann, Michael
 and
Liotta, Giuseppe
 and
Montecchiani, Fabrizio
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14440}
}
                
@article{
10.1111:cgf.14443,
journal = {Computer Graphics Forum}, title = {{
A Survey of Tasks and Visualizations in Multiverse Analysis Reports}},
author = {
Hall, Brian D.
 and
Liu, Yang
 and
Jansen, Yvonne
 and
Dragicevic, Pierre
 and
Chevalier, Fanny
 and
Kay, Matthew
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14443}
}
                
@article{
10.1111:cgf.14442,
journal = {Computer Graphics Forum}, title = {{
Feature‐Adaptive and Hierarchical Subdivision Gradient Meshes}},
author = {
Zhou, J.
 and
Hettinga, G.J.
 and
Houwink, S.
 and
Kosinka, J.
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14442}
}
                
@article{
10.1111:cgf.14441,
journal = {Computer Graphics Forum}, title = {{
GlassNet: Label Decoupling‐based Three‐stream Neural Network for Robust Image Glass Detection}},
author = {
Zheng, Chengyu
 and
Shi, Ding
 and
Yan, Xuefeng
 and
Liang, Dong
 and
Wei, Mingqiang
 and
Yang, Xin
 and
Guo, Yanwen
 and
Xie, Haoran
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14441}
}
                
@article{
10.1111:cgf.14444,
journal = {Computer Graphics Forum}, title = {{
Learning Camera Control in Dynamic Scenes from Limited Demonstrations}},
author = {
Hanocka, R.
 and
Assa, J.
 and
Cohen‐Or, D.
 and
Giryes, R.
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14444}
}
                
@article{
10.1111:cgf.14447,
journal = {Computer Graphics Forum}, title = {{
A Survey on Cross‐Virtuality Analytics}},
author = {
Fröhler, B.
 and
Anthes, C.
 and
Jetter, H.‐C.
 and
Heinzl, C.
 and
Pointecker, F.
 and
Friedl, J.
 and
Schwajda, D.
 and
Riegler, A.
 and
Tripathi, S.
 and
Holzmann, C.
 and
Brunner, M.
 and
Jodlbauer, H.
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14447}
}
                
@article{
10.1111:cgf.14448,
journal = {Computer Graphics Forum}, title = {{
Real‐Time Microstructure Rendering with MIP‐Mapped Normal Map Samples}},
author = {
Tan, Haowen
 and
Zhu, Junqiu
 and
Xu, Yanning
 and
Meng, Xiangxu
 and
Wang, Lu
 and
Yan, Ling‐Qi
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14448}
}
                
@article{
10.1111:cgf.14445,
journal = {Computer Graphics Forum}, title = {{
Graphical Tools for Visualization of Missing Data in Large Longitudinal Phenomena}},
author = {
Jiménez, Edgar
 and
Macías, Rodrigo
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14445}
}
                
@article{
10.1111:cgf.14446,
journal = {Computer Graphics Forum}, title = {{
A Generative Framework for Image‐based Editing of Material Appearance using Perceptual Attributes}},
author = {
Delanoy, J.
 and
Lagunas, M.
 and
Condor, J.
 and
Gutierrez, D.
 and
Masia, B.
}, year = {
2022},
publisher = {
© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.14446}
}

Browse

Recent Submissions

Now showing 1 - 30 of 30
  • Item
    Issue Information
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Hauser, Helwig and Alliez, Pierre
  • Item
    At‐Most‐Hexa Meshes
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Bukenberger, Dennis R.; Tarini, Marco; Lensch, Hendrik P. A.; Hauser, Helwig and Alliez, Pierre
    Volumetric polyhedral meshes are required in many applications, especially for solving partial differential equations on finite element simulations. Still, their construction bears several additional challenges compared to boundary‐based representations. Tetrahedral meshes and (pure) hex‐meshes are two popular formats in scenarios like CAD applications, offering opposite advantages and disadvantages. Hex‐meshes are more intricate to construct due to the global structure of the meshing, but feature much better regularity, alignment, are more expressive, and offer the same simulation accuracy with fewer elements. Hex‐dominant meshes, where most but not all cell elements have a hexahedral structure, constitute an attractive compromise, potentially unlocking benefits from both structures, but their generality makes their employment in downstream applications difficult. In this work, we introduce a strict subset of general hex‐dominant meshes, which we term ‘at‐most‐hexa meshes’, in which most cells are still hexahedral, but no cell has more than six boundary faces, and no face has more than four sides. We exemplify the ease of construction of at‐most‐hexa meshes by proposing a frugal and straightforward method to generate high‐quality meshes of this kind, starting directly from hulls or point clouds, for example, from a 3D scan. In contrast to existing methods for (pure) hexahedral meshing, ours does not require an intermediate parameterization of other costly pre‐computations and can start directly from surfaces or samples. We leverage a Lloyd relaxation process to exploit the synergistic effects of aligning an orientation field in a modified 3D Voronoi diagram using the norm for cubical cells. The extracted geometry incorporates regularity as well as feature alignment, following sharp edges and curved boundary surfaces. We introduce specialized operations on the three‐dimensional graph structure to enforce consistency during the relaxation. The resulting algorithm allows for an efficient evaluation with parallel algorithms on GPU hardware and completes even large reconstructions within minutes.
  • Item
    Economic Upper Bound Estimation in Hausdorff Distance Computation for Triangle Meshes
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Zheng, Yicun; Sun, Haoran; Liu, Xinguo; Bao, Hujun; Huang, Jin; Hauser, Helwig and Alliez, Pierre
    The Hausdorff distance is one of the most fundamental metrics for comparing 3D shapes. To compute the Hausdorff distance efficiently from a triangular mesh to another triangular mesh , one needs to cull the unnecessary triangles on quickly. These triangles have no chance to improve the Hausdorff distance estimation, that is the parts with local upper bound smaller than the global lower bound. The local upper bound estimation should be tight, use fast distance computation, and involve a small number of triangles in during the reduction phase for efficiency. In this paper, we propose to use point‐triangle distance, and only involve at most four triangles in in the reduction phase. Comparing with the state‐of‐the‐art proposed by Tang et al. in 2009, which uses more costly triangle‐triangle distance and may involve a large number of triangles in reduction phase, our local upper bound estimation is faster, and with only a small impact on the tightness of the bound on error estimation. Such a more economic strategy boosts the overall performance significantly. Experiments on the Thingi10K dataset show that our method can achieve several (even over 20) times speedup on average. On a few models with different placements and resolutions, we show that close placement and large difference in resolution bring big challenges to Hausdorff distance computation, and explain why our method can achieve more significant speedup on challenging cases.
  • Item
    Embedding QR Code onto Triangulated Meshes using Horizon Based Ambient Occlusion
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Papp, György; Hoffmann, Miklós; Papp, Ildikó; Hauser, Helwig and Alliez, Pierre
    QR code is a widely used format to encode information through images that can be easily decoded using a smartphone. These devices play a significant role in most people's everyday lives, making the encoded information widely accessible. However, decoding the QR code becomes challenging when significant deformations occur in the label. An easy and quick solution to keep the deformation on a minimum level is to affix the label that contains the QR code onto a developable surface patch of a 3D model. The perspective distortion that can appear is efficiently dealt with during the decoding process. In recent years an alternative method has emerged. In the work of Kikuchi et al., the QR code is embedded onto B‐spline surfaces of CAD models to give more freedom in providing additional information. This method was further improved and extended by Peng et al. embed QR codes onto the surface of general meshes. This paper introduces a solution to embed QR codes onto the surface of general meshes without densely triangulating the selected area of the QR code. It uses the deferred shading technique to extract the surface normals and the depth values around the QR code's user‐given centre. We propose two methods for automatically finding the projection direction even when highly curved areas are selected based on the retrieved information while rendering the model. Besides, we introduce two methods needing a projection direction and a QR code centre to determine a size for automatically embedding the QR code. We propose patterns for decreasing the carving depth of the embedded QR codes, and we use the Horizon‐Based Ambient Occlusion to speed up the engraving process. We validate our method by comparing our results to the outcomes of Peng et al.
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    Seamless Parametrization of Spheres with Controlled Singularities
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Levi, Zohar; Hauser, Helwig and Alliez, Pierre
    We present a method for constructing seamless parametrization for genus‐0 surfaces, which can handle any feasible cone configuration, thus allowing users to arbitrarily design and tailor a mapping as desired. The method directly constructs a self‐overlapping metapolygon of the domain boundary of the mapped cut mesh, which relieves the need of using an auxiliary surface. This simplifies the pipeline and allows for a necessary optimization of the boundary polygon before mapping the interior. Moreover, it enables handling larger meshes with more cones than previous methods can handle. Our construction is purely combinatorial, and it guarantees that the mapping is locally injective – a prerequisite to today's advanced optimization methods. This is achieved via careful construction of a simple domain boundary polygon, where existence of such a polygon is proven for all cases. We offer a numerically robust algorithm to automate the construction, which involves a solution of two linear problems. We offer a full pipeline, suggesting elegant solutions to sub‐problems, and demonstrate robustness through extensive experiments.
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    EHR STAR: The State‐Of‐the‐Art in Interactive EHR Visualization
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Wang, Q.; Laramee, R.S.; Hauser, Helwig and Alliez, Pierre
    Since the inception of electronic health records (EHR) and population health records (PopHR), the volume of archived digital health records is growing rapidly. Large volumes of heterogeneous health records require advanced visualization and visual analytics systems to uncover valuable insight buried in complex databases. As a vibrant sub‐field of information visualization and visual analytics, many interactive EHR and PopHR visualization (EHR Vis) systems have been proposed, developed, and evaluated by clinicians to support effective clinical analysis and decision making. We present the state‐of‐the‐art (STAR) of EHR Vis literature and open access healthcare data sources and provide an up‐to‐date overview on this important topic. We identify trends and challenges in the field, introduce novel literature and data classifications, and incorporate a popular medical terminology standard called the Unified Medical Language System (UMLS). We provide a curated list of electronic and population healthcare data sources and open access datasets as a resource for potential researchers, in order to address one of the main challenges in this field. We classify the literature based on multidisciplinary research themes stemming from reoccurring topics. The survey provides a valuable overview of EHR Vis revealing both mature areas and potential future multidisciplinary research directions.
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    Dynamic Diffuse Global Illumination Resampling
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Majercik, Zander; Müller, Thomas; Keller, Alexander; Nowrouzezahrai, Derek; McGuire, Morgan; Hauser, Helwig and Alliez, Pierre
    Interactive global illumination remains a challenge in radiometrically and geometrically complex scenes. Specialized sampling strategies are effective for specular and near‐specular transport because the scattering has relatively low directional variance per scattering event. In contrast, the high variance from transport paths comprising multiple rough glossy or diffuse scattering events remains notoriously difficult to resolve with a small number of samples. We extend unidirectional path tracing to address this by combining screen‐space reservoir resampling and sparse world‐space probes, significantly improving sample efficiency for transport contributions that terminate on diffuse scattering events. Our experiments demonstrate a clear improvement—at equal time and equal quality—over purely path traced and purely probe‐based baselines. Moreover, when combined with commodity denoisers, we are able to interactively render global illumination in complex scenes.
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    Comparison of Modern Omnidirectional Precise Shadowing Techniques Versus Ray Tracing
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Kobrtek, Jozef; Milet, Tomas; Tóth, Michal; Herout, Adam; Hauser, Helwig and Alliez, Pierre
    This paper presents an in depth comparison of state‐of‐the‐art precise shadowing techniques for an omnidirectional point light. We chose several types of modern shadowing algorithms, starting from stencil shadow volumes, methods using traversal of acceleration structures to hardware‐accelerated ray‐traced shadows. Some methods were further improved – robustness, increased performance; we also provide the first multi‐platform implementations of some of the tested algorithms. All the methods are evaluated on several test scenes in different resolutions and on two hardware platforms – with and without dedicated hardware units for ray tracing. We conclude our findings based on speed and memory consumption. Ray‐tracing is the fastest and one of the easiest methods to implement with small memory footprint. The Omnidirectional Frustum‐Traced Shadows method has a predictable memory footprint and is the second fastest algorithm tested. Our stencil shadow volumes are faster than some newer algorithms. Per‐Triangle Shadow Volumes and Clustered Per‐Triangle Shadow Volumes are difficult to implement and require the most memory; the latter method scales well with the scene complexity and resolution. Deep Partitioned Shadow Volumes does not excel in any of the measured parameters and is suitable for smaller scenes. The source codes of the testing framework have been made publicly available.
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    A Survey on Deep Learning for Skeleton‐Based Human Animation
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Mourot, Lucas; Hoyet, Ludovic; Le Clerc, François; Schnitzler, François; Hellier, Pierre; Hauser, Helwig and Alliez, Pierre
    Human character animation is often critical in entertainment content production, including video games, virtual reality or fiction films. To this end, deep neural networks drive most recent advances through deep learning (DL) and deep reinforcement learning (DRL). In this article, we propose a comprehensive survey on the state‐of‐the‐art approaches based on either DL or DRL in skeleton‐based human character animation. First, we introduce motion data representations, most common human motion datasets and how basic deep models can be enhanced to foster learning of spatial and temporal patterns in motion data. Second, we cover state‐of‐the‐art approaches divided into three large families of applications in human animation pipelines: motion synthesis, character control and motion editing. Finally, we discuss the limitations of the current state‐of‐the‐art methods based on DL and/or DRL in skeletal human character animation and possible directions of future research to alleviate current limitations and meet animators' needs.
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    Shadow Layers for Participating Media
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Desrichard, François; Vanderhaeghe, David; Paulin, Mathias; Hauser, Helwig and Alliez, Pierre
    In the movie industry pipeline, rendering programs output the main image along with a collection of Arbitrary Output Variable layers (AOVs) that retain specific information on light transport and scene properties in image space. Compositing artists use AOVs to improve the quality and appearance of the rendered picture during post‐processing, according to the artistic goal of the shot. In particular, cast shadows are manipulated to support narration and storytelling, as the human perception tolerates non‐physical edits. Conventional path tracing renderers often propose a shadow matte AOV containing radiance lost when shadow rays are occluded. Previous work has shown that they incorrectly estimate shadow and miss occluded radiance from indirect light sources, and that shadow layers must be used to correctly recover radiance from single, solid occluders. In this paper, we generalise shadow layers to an arbitrary number of occluders, and add support for participating media. We begin by quantifying the radiance loss between the radiative transfer equation and the rendering equation, and translate it into a path integral formulation for an efficient Monte Carlo integration. We propose a prototype implementation that renders the main image and shadow layers in a single pass with an affordable computational overhead.
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    Path Guiding Using Spatio‐Directional Mixture Models
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Dodik, Ana; Papas, Marios; Öztireli, Cengiz; Müller, Thomas; Hauser, Helwig and Alliez, Pierre
    We propose a learning‐based method for light‐path construction in path tracing algorithms, which iteratively optimizes and samples from what we refer to as spatio‐directional Gaussian mixture models (SDMMs). In particular, we approximate incident radiance as an online‐trained 5D mixture that is accelerated by a D‐tree. Using the same framework, we approximate BSDFs as pre‐trained D mixtures, where is the number of BSDF parameters. Such an approach addresses two major challenges in path‐guiding models. First, the 5D radiance representation naturally captures correlation between the spatial and directional dimensions. Such correlations are present in, for example parallax and caustics. Second, by using a tangent‐space parameterization of Gaussians, our spatio‐directional mixtures can perform approximate product sampling with arbitrarily oriented BSDFs. Existing models are only able to do this by either foregoing anisotropy of the mixture components or by representing the radiance field in local (normal aligned) coordinates, which both make the radiance field more difficult to learn. An additional benefit of the tangent‐space parameterization is that each individual Gaussian is mapped to the solid sphere with low distortion near its centre of mass. Our method performs especially well on scenes with small, localized luminaires that induce high spatio‐directional correlation in the incident radiance.
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    Immersive Analytics with Abstract 3D Visualizations: A Survey
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Kraus, Matthias; Fuchs, Johannes; Sommer, Björn; Klein, Karsten; Engelke, Ulrich; Keim, Daniel; Schreiber, Falk; Hauser, Helwig and Alliez, Pierre
    After a long period of scepticism, more and more publications describe basic research but also practical approaches to how abstract data can be presented in immersive environments for effective and efficient data understanding. Central aspects of this important research question in immersive analytics research are concerned with the use of 3D for visualization, the embedding in the immersive space, the combination with spatial data, suitable interaction paradigms and the evaluation of use cases. We provide a characterization that facilitates the comparison and categorization of published works and present a survey of publications that gives an overview of the state of the art, current trends, and gaps and challenges in current research.
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    Visual Analysis of Two‐Phase Flow Displacement Processes in Porous Media
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Frey, Steffen; Scheller, Stefan; Karadimitriou, Nikolaos; Lee, Dongwon; Reina, Guido; Steeb, Holger; Ertl, Thomas; Hauser, Helwig and Alliez, Pierre
    We developed a new visualization approach to gain a better understanding of the displacement of one fluid phase by another in porous media. This is based on a recent experimental parameter study with varying capillary numbers and viscosity ratios. We analyse the temporal evolution of characteristic values in this two‐phase flow scenario and discuss how to directly compare experiments across different temporal scales. To enable spatio‐temporal analysis, we introduce a new abstract visual representation showing which paths through the porous medium were occupied and for how long. These transport networks allow to assess the impact of different acting forces and they are designed to yield expressive comparability and linking to the experimental parameter space both supported by additional visual cues. This joint work of porous media experts and visualization researchers yields new insights regarding two‐phase flow on the microscale, and our visualization approach contributes towards the overarching goal of the domain scientists to characterize porous media flow based on capillary numbers and viscosity ratios.
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    Stroke‐Based Drawing and Inbetweening with Boundary Strokes
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Jiang, Jie; Seah, Hock Soon; Liew, Hong Ze; Hauser, Helwig and Alliez, Pierre
    In conventional 2D drawing systems, a drawing usually consists of multiple layers and is composited by rendering layers from back to front. A shape in a higher layer occludes contents in lower layers. However, shapes must have boundaries that form closed regions for occlusion. This limitation causes problems in occlusion resolution. We therefore propose a method to allow users to specify and resolve occlusion in stroke‐based drawing with boundary strokes. Rather than defining shapes, we introduce boundary strokes, which are strokes with occluding sides that work as occluding surfaces. We further introduce a series of user interactions, such as grouping, linking and inverting, on the boundary strokes to realize different occlusion effects. Geometry is then used to find the regions of occluding surfaces to resolve occlusion. The drawings are ready to be coloured, if needed. We extend our method to resolve occlusion in 2D stroke‐based inbetweening. We demonstrate the effectiveness of our method by applying it to resolve occlusion in single drawings and 2D stroke‐based inbetweening.
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    Design and Evaluation Study of Visual Analytics Decision Support Tools in Air Traffic Control
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Zohrevandi, E.; Westin, C. A. L.; Lundberg, J.; Ynnerman, A.; Hauser, Helwig and Alliez, Pierre
    Operators in air traffic control facing time‐ and safety‐critical situations call for efficient, reliable and robust real‐time processing and interpretation of complex data. Automation support tools aid controllers in these processes to prevent separation losses between aircraft. Issues of current support tools include limited ‘what‐if’ and ‘what‐else’ probe functionalities in relation to vertical solutions. This work presents the design and evaluation of two visual analytics interfaces that promote contextual awareness and support ‘what‐if’ and ‘what‐else’ probes in the spatio‐temporal domain aiming to improve information integration and support controllers in prioritising conflict resolution. Both interfaces visualize vertical solution spaces against a time‐altitude graph. The main contributions of this paper are: (a) the presentation of two interfaces for supporting conflict solving; (b) the novel representation of how vertical information and aircraft rate of climb and descent affect conflicts and (c) an evaluation and comparison of the interfaces with a traditional air traffic control support system. The evaluation study was performed with domain experts to compare the effects of visualization concepts on operator engagement in processing solutions suggested by the tools. Results show that the visualizations support operators' ability to understand and resolve conflicts. Based on the results, general design guidelines for time‐critical domains are proposed.
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    Using Position‐Based Dynamics for Simulating Mitral Valve Closure and Repair Procedures
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Walczak, Lars; Georgii, Joachim; Tautz, Lennart; Neugebauer, Mathias; Wamala, Isaac; Sündermann, Simon; Falk, Volkmar; Hennemuth, Anja; Hauser, Helwig and Alliez, Pierre
    To achieve the best treatment of mitral valve disease in a patient, surgeons aim to optimally combine complementary surgical techniques. Image‐based simulation as well as visualization of the mitral valve dynamics can support the visual analysis of the patient‐specific valvular dynamics and enable an exploration of different therapy options. The usage in a time‐constrained clinical environment requires a mitral valve model that is cost‐effective, easy to set up, parameterize and evaluate. Working towards this goal, we develop a simplified model of the mitral valve and analyse its applicability for the sketched use‐case. We propose a novel approach to simulate the mitral valve with position‐based dynamics. The resulting mitral valve model can be deformed to simulate the closing and opening, and incorporate changes caused by virtual interventions in the simulation. Ten mitral valves were reconstructed from transesophageal echocardiogram sequences of patients with normal and abnormal physiology for evaluation. Simulation results showed good agreements with expert annotations of the original image data and reproduced valve closure in all cases. In four of five pathological cases, abnormal closing behaviour was correctly reproduced. In future research, we aim to improve the parameterization of the model in terms of biomechanical correctness and perform a more extensive validation.
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    Evaluating Data‐type Heterogeneity in Interactive Visual Analyses with Parallel Axes
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Matute, José; Linsen, Lars; Hauser, Helwig and Alliez, Pierre
    The application of parallel axes for the interactive visual analysis of multidimensional data is a widely used concept. While multidimensional data sets are commonly heterogeneous in nature, i.e. data items contain both numerical and categorical (including ordinal) attribute values, the use of parallel axes often assumes either numerical or categorical attributes. While Parallel Coordinates and their large variety of extensions focus on numerical data, Parallel Sets and related methods focus on categorical attributes. While both concepts allow for displaying heterogeneous data, no clear strategies have been defined for representing categories in Parallel Coordinates or discretization of continuous ranges in Parallel Sets. In practice, type conversion as a pre‐processing step can be used as well as coordinated views of numerical and categorical data visualizations. We evaluate traditional and state‐of‐the‐art approaches with respect to the interplay of categorical and numerical dimensions for querying probability‐based events. We also compare against a heterogeneous Parallel Coordinates/Parallel Set approach with a novel interface between categorical and numerical axes . We show that approaches for mapping categorical data to numerical axis representations can lead to lower accuracy in answering probability‐based questions and higher response times than hybrid approaches in multiple‐event scenarios.
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    Augmenting Digital Sheet Music through Visual Analytics
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Miller, Matthias; Fürst, Daniel; Hauptmann, Hanna; Keim, Daniel A.; El‐Assady, Mennatallah; Hauser, Helwig and Alliez, Pierre
    Music analysis tasks, such as structure identification and modulation detection, are tedious when performed manually due to the complexity of the common music notation (CMN). Fully automated analysis instead misses human intuition about relevance. Existing approaches use abstract data‐driven visualizations to assist music analysis but lack a suitable connection to the CMN. Therefore, music analysts often prefer to remain in their familiar context. Our approach enhances the traditional analysis workflow by complementing CMN with interactive visualization entities as minimally intrusive augmentations. Gradual step‐wise transitions empower analysts to retrace and comprehend the relationship between the CMN and abstract data representations. We leverage glyph‐based visualizations for harmony, rhythm and melody to demonstrate our technique's applicability. Design‐driven visual query filters enable analysts to investigate statistical and semantic patterns on various abstraction levels. We conducted pair analytics sessions with 16 participants of different proficiency levels to gather qualitative feedback about the intuitiveness, traceability and understandability of our approach. The results show that MusicVis supports music analysts in getting new insights about feature characteristics while increasing their engagement and willingness to explore.
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    Complex Functional Maps: A Conformal Link Between Tangent Bundles
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Donati, Nicolas; Corman, Etienne; Melzi, Simone; Ovsjanikov, Maks; Hauser, Helwig and Alliez, Pierre
    In this paper, we introduce complex functional maps, which extend the functional map framework to conformal maps between tangent vector fields on surfaces. A key property of these maps is their . More specifically, we demonstrate that unlike regular functional maps that link of two manifolds, our complex functional maps establish a link between , thus permitting robust and efficient transfer of tangent vector fields. By first endowing and then exploiting the tangent bundle of each shape with a complex structure, the resulting operations become naturally orientation‐aware, thus favouring across shapes, without relying on descriptors or extra regularization. Finally, and perhaps more importantly, we demonstrate how these objects enable several practical applications within the functional map framework. We show that functional maps and their complex counterparts can be estimated jointly to promote orientation preservation, regularizing pipelines that previously suffered from orientation‐reversing symmetry errors.
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    A Stereo Matching Algorithm for High‐Precision Guidance in a Weakly Textured Industrial Robot Environment Dominated by Planar Facets
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Wei, Hui; Meng, Lingjiang; Hauser, Helwig and Alliez, Pierre
    Although many algorithms perform very well on certain datasets, existing stereo matching algorithms still fail to obtain ideal disparity images with high precision in practical robotic applications with weak or untextured objects. This greatly limits the application of binocular vision for robotic arm guidance. Traditional stereo matching algorithms suffer from disparity loss, dilation and other problems, and deep learning algorithms have weakly generalization ability, making high‐accuracy results impossible with non‐training images. We propose an algorithm that uses segments and edges as matching units. We find the mapping relationship between two‐dimensional images and three‐dimensional scenes using segments. The algorithm obtains highly accurate results in industrial robotic applications with mainly planar facets. We combine it with a deep learning algorithm to obtain very good high‐accuracy results in both general scenes and applications of industrial robots. The algorithm effectively improves the non‐linear optimization ability of traditional algorithms and generalization ability of deep learning, and provides an effective method for the binocular vision guidance of industrial robotic scenes. We used the algorithm to guide the robot arm for threading with a success rate of 70%.
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    Modelling Surround‐aware Contrast Sensitivity for HDR Displays
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Yi, Shinyoung; Jeon, Daniel S.; Serrano, Ana; Jeong, Se‐Yoon; Kim, Hui‐Yong; Gutierrez, Diego; Kim, Min H.; Hauser, Helwig and Alliez, Pierre
    Despite advances in display technology, many existing applications rely on psychophysical datasets of human perception gathered using older, sometimes outdated displays. As a result, there exists the underlying assumption that such measurements can be carried over to the new viewing conditions of more modern technology. We have conducted a series of psychophysical experiments to explore contrast sensitivity using a state‐of‐the‐art HDR display, taking into account not only the spatial frequency and luminance of the stimuli but also their surrounding luminance levels. From our data, we have derived a novel surround‐aware contrast sensitivity function (CSF), which predicts human contrast sensitivity more accurately. We additionally provide a practical version that retains the benefits of our full model, while enabling easy backward compatibility and consistently producing good results across many existing applications that make use of CSF models. We show examples of effective HDR video compression using a transfer function derived from our CSF, tone‐mapping and improved accuracy in visual difference prediction.
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    Placing Arrows in Directed Graph Layouts: Algorithms and Experiments
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Binucci, Carla; Didimo, Walter; Kaufmann, Michael; Liotta, Giuseppe; Montecchiani, Fabrizio; Hauser, Helwig and Alliez, Pierre
    We study how to place arrow heads in directed graph drawings aiming at minimizing their overlaps and avoiding intersections between arrow heads and edges. The objective is to support users to correctly and quickly recognize edge orientations, i.e. to deduce unambiguously the edge orientations. Our contribution is two‐fold: (i) We present exact and heuristic algorithms for this arrow placement problem, along with an extensive experimental analysis of these techniques; and (ii) we report on a user study aimed to understand the impact of different arrow placement strategies on performing global and local analysis tasks on directed graph layouts.
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    A Survey of Tasks and Visualizations in Multiverse Analysis Reports
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Hall, Brian D.; Liu, Yang; Jansen, Yvonne; Dragicevic, Pierre; Chevalier, Fanny; Kay, Matthew; Hauser, Helwig and Alliez, Pierre
    Analysing data from experiments is a complex, multi‐step process, often with multiple defensible choices available at each step. While analysts often report a single analysis without documenting how it was chosen, this can cause serious transparency and methodological issues. To make the sensitivity of analysis results to analytical choices transparent, some statisticians and methodologists advocate the use of ‘multiverse analysis’: reporting the full range of outcomes that result from all combinations of defensible analytic choices. Summarizing this combinatorial explosion of statistical results presents unique challenges; several approaches to visualizing the output of multiverse analyses have been proposed across a variety of fields (e.g. psychology, statistics, economics, neuroscience). In this article, we (1) introduce a consistent conceptual framework and terminology for multiverse analyses that can be applied across fields; (2) identify the tasks researchers try to accomplish when visualizing multiverse analyses and (3) classify multiverse visualizations into ‘archetypes’, assessing how well each archetype supports each task. Our work sets a foundation for subsequent research on developing visualization tools and techniques to support multiverse analysis and its reporting.
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    Feature‐Adaptive and Hierarchical Subdivision Gradient Meshes
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Zhou, J.; Hettinga, G.J.; Houwink, S.; Kosinka, J.; Hauser, Helwig and Alliez, Pierre
    Gradient meshes, an advanced vector graphics primitive, are widely used by designers for creating scalable vector graphics. Traditional variants require a regular rectangular topology, which is a severe design restriction. The more advanced subdivision gradient mesh allows for an arbitrary manifold topology and is based on subdivision techniques to define the resulting colour surface. This also allows the artists to manipulate the geometry and colours at various levels of subdivision. Recent advances allow for the interpolation of both geometry and colour, local detail following edits at coarser subdivision levels and sharp colour transitions. A shortcoming of all existing methods is their dependence on global refinement, which makes them unsuitable for real‐time (commercial) design applications. We present a novel method that incorporates the idea of feature‐adaptive subdivision and uses approximating patches suitable for hardware tessellation with real‐time performance. Further novel features include multiple interaction mechanisms and self‐intersection prevention during interactive design/editing.
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    GlassNet: Label Decoupling‐based Three‐stream Neural Network for Robust Image Glass Detection
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Zheng, Chengyu; Shi, Ding; Yan, Xuefeng; Liang, Dong; Wei, Mingqiang; Yang, Xin; Guo, Yanwen; Xie, Haoran; Hauser, Helwig and Alliez, Pierre
    Most of the existing object detection methods generate poor glass detection results, due to the fact that the transparent glass shares the same appearance with arbitrary objects behind it in an image. Different from traditional deep learning‐based wisdoms that simply use the object boundary as an auxiliary supervision, we exploit label decoupling to decompose the original labelled ground‐truth (GT) map into an interior‐diffusion map and a boundary‐diffusion map. The GT map in collaboration with the two newly generated maps breaks the imbalanced distribution of the object boundary, leading to improved glass detection quality. We have three key contributions to solve the transparent glass detection problem: (1) We propose a three‐stream neural network (call GlassNet for short) to fully absorb beneficial features in the three maps. (2) We design a multi‐scale interactive dilation module to explore a wider range of contextual information. (3) We develop an attention‐based boundary‐aware feature Mosaic module to integrate multi‐modal information. Extensive experiments on the benchmark dataset exhibit clear improvements of our method over SOTAs, in terms of both the overall glass detection accuracy and boundary clearness.
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    Learning Camera Control in Dynamic Scenes from Limited Demonstrations
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Hanocka, R.; Assa, J.; Cohen‐Or, D.; Giryes, R.; Hauser, Helwig and Alliez, Pierre
    In this work, we present our strategy for camera control in dynamic scenes with multiple people (sports teams). We learn a generic model of the player dynamics offline in simulation. We use only a few sparse demonstrations of a user's camera control policy to learn a reward function to drive camera motion in an ongoing dynamic scene. Key to our approach is the creation of a low‐dimensional representation of the scene dynamics which is independent of the environment action and rewards, which enables learning the reward function using only a small number of examples. We cast the user‐specific control objective as an inverse reinforcement learning problem, aiming to learn an expert's intention from a small number of demonstrations. The learned reward function is used in combination with a visual model predictive controller (MPC). We learn a generic scene dynamics model that is agnostic to the user‐specific reward, enabling reusing the same dynamics model for different camera control policies. We show the effectiveness of our method on simulated and real soccer matches.
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    A Survey on Cross‐Virtuality Analytics
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Fröhler, B.; Anthes, C.; Pointecker, F.; Friedl, J.; Schwajda, D.; Riegler, A.; Tripathi, S.; Holzmann, C.; Brunner, M.; Jodlbauer, H.; Jetter, H.‐C.; Heinzl, C.; Hauser, Helwig and Alliez, Pierre
    Cross‐virtuality analytics (XVA) is a novel field of research within immersive analytics and visual analytics. A broad range of heterogeneous devices across the reality–virtuality continuum, along with respective visual metaphors and analysis techniques, are currently becoming available. The goal of XVA is to enable visual analytics that use transitional and collaborative interfaces to seamlessly integrate different devices and support multiple users. In this work, we take a closer look at XVA and analyse the existing body of work for an overview of its current state. We classify the related literature regarding ways of establishing cross‐virtuality by interconnecting different stages in the reality–virtuality continuum, as well as techniques for transitioning and collaborating between the different stages. We provide insights into visualization and interaction techniques employed in current XVA systems. We report on ways of evaluating such systems, and analyse the domains where such systems are becoming available. Finally, we discuss open challenges in XVA, giving directions for future research.
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    Real‐Time Microstructure Rendering with MIP‐Mapped Normal Map Samples
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Tan, Haowen; Zhu, Junqiu; Xu, Yanning; Meng, Xiangxu; Wang, Lu; Yan, Ling‐Qi; Hauser, Helwig and Alliez, Pierre
    Normal map‐based microstructure rendering can generate both glint and scratch appearance accurately. However, the extra high‐resolution normal map that defines every microfacet normal may incur high storage and computation costs. We present an example‐based real‐time rendering method for arbitrary microstructure materials, which significantly reduces the required storage space. Our method takes a small‐size normal map sample as input. We implicitly synthesize a high‐resolution normal map from the normal map sample and construct MIP‐mapped 4D position‐normal Gaussian lobes. Based on the above MIP‐mapped 4D lobes and a LUT (lookup table) data structure for the synthesized high‐resolution normal map, an efficient Gaussian query method is presented to evaluate ‐NDFs (position‐normal distribution functions) for shading. We can render complex scenes with glint and scratch surfaces in real time (30 fps) with a full high‐definition resolution, and the space required for each microstructure material is decreased to 30 MB.
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    Graphical Tools for Visualization of Missing Data in Large Longitudinal Phenomena
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Jiménez, Edgar; Macías, Rodrigo; Hauser, Helwig and Alliez, Pierre
    The analysis of large quantities of longitudinal data requires quick decision tools to ensure data quality and to find useful patterns for analysis in exploratory stages. We propose algorithms based on ordering, sampling and grouping applied to lasagna plots, a special kind of matrix plot, which are heat maps created to visualize longitudinal studies. These algorithms can be applied to large data sets to find patterns of interest, monotone and intermittent, in the missing data with low computational cost compared to previous alternatives. Visualization with these algorithms addresses a trade‐off in visualization design: reducing visual clutter versus increasing the information content in a visualization. The method enables the visualization of missing data in a clear and concise way. We apply our techniques to four real‐world data sets of different origins and sizes that share analysis and visualization tasks and discuss the patterns found within them.
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    A Generative Framework for Image‐based Editing of Material Appearance using Perceptual Attributes
    (© 2022 Eurographics ‐ The European Association for Computer Graphics and John Wiley & Sons Ltd, 2022) Delanoy, J.; Lagunas, M.; Condor, J.; Gutierrez, D.; Masia, B.; Hauser, Helwig and Alliez, Pierre
    Single‐image appearance editing is a challenging task, traditionally requiring the estimation of additional scene properties such as geometry or illumination. Moreover, the exact interaction of light, shape and material reflectance that elicits a given perceptual impression is still not well understood. We present an image‐based editing method that allows to modify the material appearance of an object by increasing or decreasing high‐level perceptual attributes, using a single image as input. Our framework relies on a two‐step generative network, where the first step drives the change in appearance and the second produces an image with high‐frequency details. For training, we augment an existing material appearance dataset with perceptual judgements of high‐level attributes, collected through crowd‐sourced experiments, and build upon training strategies that circumvent the cumbersome need for original‐edited image pairs. We demonstrate the editing capabilities of our framework on a variety of inputs, both synthetic and real, using two common perceptual attributes ( and ), and validate the perception of appearance in our edited images through a user study.