Full Papers 2014 - CGF 33-Issue 2

Permanent URI for this collection


Preface and Table of Contents


Spatio-Temporal Geometry Fusion for Multiple Hybrid Cameras using Moving Least Squares Surfaces

Kuster, Claudia
Bazin, Jean-Charles
Öztireli, Cengiz
Deng, Teng
Martin, Tobias
Popa, Tiberiu
Gross, Markus

Detection and Reconstruction of Freeform Sweeps

Barton, Michael
Pottmann, Helmut
Wallner, Johannes

Object Detection and Classification from Large-Scale Cluttered Indoor Scans

Mattausch, Oliver
Panozzo, Daniele
Mura, Claudio
Sorkine-Hornung, Olga
Pajarola, Renato

Coded Exposure HDR Light-Field Video Recording

Schedl, David C.
Birklbauer, Clemens
Bimber, Oliver

Panorama Light-Field Imaging

Birklbauer, Clemens
Bimber, Oliver

Optimizing Stereo-to-Multiview Conversion for Autostereoscopic Displays

Chapiro, Alexandre
Heinzle, Simon
Aydin, Tunç Ozan
Poulakos, Steven
Zwicker, Matthias
Smolic, Aljosa
Gross, Markus

Manipulating Refractive and Reflective Binocular Disparity

Dabala, Lukasz
Kellnhofer, Petr
Ritschel, Tobias
Didyk, Piotr
Templin, Krzysztof
Myszkowski, Karol
Rokita, P.
Seidel, Hans-Peter

Parallel Generation of Architecture on the GPU

Steinberger, Markus
Kenzel, Michael
Kainz, Bernhard
Müller, Jörg
Wonka, Peter
Schmalstieg, Dieter

SAFE: Structure-aware Facade Editing

Dang, Minh
Ceylan, Duygu
Neubert, Boris
Pauly, Mark

Game Level Layout from Design Specification

Ma, Chongyang
Vining, Nicholas
Lefebvre, Sylvain
Sheffer, Alla

On-the-fly Generation and Rendering of Infinite Cities on the GPU

Steinberger, Markus
Kenzel, Michael
Kainz, Bernhard
Wonka, Peter
Schmalstieg, Dieter

Recurring Part Arrangements in Shape Collections

Zheng, Youyi
Cohen-Or, Daniel
Averkiou, Melinos
Mitra, Niloy J.

ShapeSynth: Parameterizing Model Collections for Coupled Shape Exploration and Synthesis

Averkiou, Melinos
Kim, Vladimir G.
Zheng, Youyi
Mitra, Niloy J.

3D Timeline: Reverse Engineering of a Part-based Provenance from Consecutive 3D Models

Dobos, Jozef
Mitra, Niloy J.
Steed, Anthony

Compressing Dynamic Meshes with Geometric Laplacians

Vasa, Libor
Marras, Stefano
Hormann, Kai
Brunnett, Guido

Self-similarity for Accurate Compression of Point Sampled Surfaces

Digne, Julie
Chaine, Raphaëlle
Valette, Sébastien

SimSelect: Similarity-based Selection for 3D Surfaces

Guy, Emilie
Thiery, Jean-Marc
Boubekeur, Tamy

Analogy-Driven 3D Style Transfer

Ma, Chongyang
Huang, Haibin
Sheffer, Alla
Kalogerakis, Evangelos
Wang, Rui

Light Montage for Perceptual Image Enhancement

Hosu, Vlad
Ha, Mai Lan
Sim, Terence

Perceptual Depth Compression for Stereo Applications

Pajak, Dawid
Herzog, Robert
Mantiuk, Radoslaw
Didyk, Piotr
Eisemann, Elmar
Myszkowski, Karol
Pulli, Kari

A Randomized Algorithm for Natural Object Colorization

Jin, Sou-Young
Choi, Ho Jin
Tai, Yu-Wing

Laplacian Colormaps: a Framework for Structure-preserving Color Transformations

Eynard, Davide
Kovnatsky, Artiom
Bronstein, Michael M.

Feedback Control for Rotational Movements in Feature Space

Borno, Mazen Al
Fiume, Eugene
Hertzmann, A.
Lasa, M. de

Efficient Enforcement of Hard Articulation Constraints in the Presence of Closed Loops and Contacts

Tomcin, Robin
Sibbing, Dominik
Kobbelt, Leif

On-line Real-time Physics-based Predictive Motion Control with Balance Recovery

Han, Daseong
Noh, Junyong
Jin, Xiaogang
Shin), Joseph S. Shin (formerly Sung Y.

IISPH-FLIP for Incompressible Fluids

Cornelis, Jens
Ihmsen, Markus
Peer, Andreas
Teschner, Matthias

Crack-free Rendering of Dynamically Tesselated B-Rep Models

Claux, Frédéric
Barthe, Loïc
Vanderhaeghe, David
Jessel, Jean-Pierre
Paulin, Mathias

Rate-distortion Optimized Compression of Motion Capture Data

Vasa, Libor
Brunnett, Guido

Interactive Motion Mapping for Real-time Character Control

Rhodin, Helge
Tompkin, James
Kim, Kwang In
Varanasi, Kiran
Seidel, Hans-Peter
Theobalt, Christian

Pose Partitioning for Multi-resolution Segmentation of Arbitrary Mesh Animations

Vasilakis, Andreas A.
Fudos, Ioannis

Parameter Estimation and Comparative Evaluation of Crowd Simulations

Wolinski, David
Guy, Stephen
Olivier, Anne-Helene
Lin, Ming
Manocha, Dinesh
Pettré, Julien

Optimizing BRDF Orientations for the Manipulation of Anisotropic Highlights

Raymond, Boris
Guennebaud, Gaël
Barla, Pascal
Pacanowski, Romain
Granier, Xavier

Efficient Monte Carlo Rendering with Realistic Lenses

Hanika, Johannes
Dachsbacher, Carsten

Interactive Cloth Rendering of Microcylinder Appearance Model under Environment Lighting

Iwasaki, Kei
Mizutani, Kazutaka
Dobashi, Yoshinori
Nishita, Tomoyuki

Adaptive Texture Space Shading for Stochastic Rendering

Andersson, Magnus
Hasselgren, Jon
Toth, Robert
Akenine-Möller, Tomas

Crowd Sculpting: A Space-time Sculpting Method for Populating Virtual Environments

Jordao, Kevin
Pettré, Julien
Christie, Marc
Cani, Marie-Paule

Thumbnail Galleries for Procedural Models

Lienhard, Stefan
Specht, Matthias
Neubert, Boris
Pauly, Mark
Müller, Pascal

4D Video Textures for Interactive Character Appearance

Casas, Dan
Volino, Marco
Collomosse, John
Hilton, Adrian

Temporally Coherent and Spatially Accurate Video Matting

Shahrian, Ehsan
Price, Brian
Cohen, Scott
Rajan, Deepu

Art-Photographic Detail Enhancement

Son, Minjung
Lee, Yunjin
Kang, Henry
Lee, Seungyong

Content-Aware Surface Parameterization for Interactive Restoration of Historical Documents

Pal, Kazim
Schüller, Christian
Panozzo, Daniele
Sorkine-Hornung, Olga
Weyrich, Tim

Designing Large-Scale Interactive Traffic Animations for Urban Modeling

Garcia-Dorado, Ignacio
Aliaga, Daniel G.
Ukkusuri, Satish V.

Accurate and Efficient Lighting for Skinned Models

Tarini, Marco
Panozzo, Daniele
Sorkine-Hornung, Olga

Deformation with Enforced Metrics on Length, Area and Volume

Jin, Shuo
Zhang, Yunbo
Wang, Charlie C. L.

Automatic Generation of Tourist Brochures

Birsak, Michael
Musialski, Przemyslaw
Wonka, Peter
Wimmer, Michael

Flower Reconstruction from a Single Photo

Yan, Feilong
Gong, Minglun
Cohen-Or, Daniel
Deussen, Oliver
Chen, Baoquan

ExploreMaps: Efficient Construction and Ubiquitous Exploration of Panoramic View Graphs of Complex 3D Environments

Benedetto, Marco Di
Ganovelli, Fabio
Rodriguez, Marcos Balsa
Villanueva, Alberto Jaspe
Scopigno, Roberto
Gobbetti, Enrico

Clean Color: Improving Multi-filament 3D Prints

Hergel, Jean
Lefebvre, Sylvain

Dual-Color Mixing for Fused Deposition Modeling Printers

Reiner, Tim
Carr, Nathan
Mech, Radomir
Stava, Ondrej
Dachsbacher, Carsten
Miller, Gavin

Multi-style Paper Pop-up Designs from 3D Models

Jr., Conrado R. Ruiz
Le, Sang N.
Yu, Jinze
Low, Kok-Lim

Pathline Glyphs

Hlawatsch, Marcel
Sadlo, Filip
Jang, Hajun
Weiskopf, Daniel

Hierarchical Opacity Optimization for Sets of 3D Line Fields

Günther, Tobias
Rössl, Christian
Theisel, Holger


BibTeX (Full Papers 2014 - CGF 33-Issue 2)
                
@article{
https::/diglib.eg.org/handle/10.1111/000_preface_eg2014,
journal = {Computer Graphics Forum}, title = {{
Preface and Table of Contents}},
author = {}, year = {
2014},
publisher = {
The Eurographics Association and Blackwell Publishing Ltd.},
ISSN = {1467-8659},
DOI = {
https://diglib.eg.org/handle/10.1111/000_preface_eg2014}
}
                
@article{
10.1111:cgf.12285,
journal = {Computer Graphics Forum}, title = {{
Spatio-Temporal Geometry Fusion for Multiple Hybrid Cameras using Moving Least Squares Surfaces}},
author = {
Kuster, Claudia
and
Bazin, Jean-Charles
and
Öztireli, Cengiz
and
Deng, Teng
and
Martin, Tobias
and
Popa, Tiberiu
and
Gross, Markus
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12285}
}
                
@article{
10.1111:cgf.12287,
journal = {Computer Graphics Forum}, title = {{
Detection and Reconstruction of Freeform Sweeps}},
author = {
Barton, Michael
and
Pottmann, Helmut
and
Wallner, Johannes
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12287}
}
                
@article{
10.1111:cgf.12286,
journal = {Computer Graphics Forum}, title = {{
Object Detection and Classification from Large-Scale Cluttered Indoor Scans}},
author = {
Mattausch, Oliver
and
Panozzo, Daniele
and
Mura, Claudio
and
Sorkine-Hornung, Olga
and
Pajarola, Renato
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12286}
}
                
@article{
10.1111:cgf.12288,
journal = {Computer Graphics Forum}, title = {{
Coded Exposure HDR Light-Field Video Recording}},
author = {
Schedl, David C.
and
Birklbauer, Clemens
and
Bimber, Oliver
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12288}
}
                
@article{
10.1111:cgf.12289,
journal = {Computer Graphics Forum}, title = {{
Panorama Light-Field Imaging}},
author = {
Birklbauer, Clemens
and
Bimber, Oliver
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12289}
}
                
@article{
10.1111:cgf.12291,
journal = {Computer Graphics Forum}, title = {{
Optimizing Stereo-to-Multiview Conversion for Autostereoscopic Displays}},
author = {
Chapiro, Alexandre
and
Heinzle, Simon
and
Aydin, Tunç Ozan
and
Poulakos, Steven
and
Zwicker, Matthias
and
Smolic, Aljosa
and
Gross, Markus
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12291}
}
                
@article{
10.1111:cgf.12290,
journal = {Computer Graphics Forum}, title = {{
Manipulating Refractive and Reflective Binocular Disparity}},
author = {
Dabala, Lukasz
and
Kellnhofer, Petr
and
Ritschel, Tobias
and
Didyk, Piotr
and
Templin, Krzysztof
and
Myszkowski, Karol
and
Rokita, P.
and
Seidel, Hans-Peter
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12290}
}
                
@article{
10.1111:cgf.12312,
journal = {Computer Graphics Forum}, title = {{
Parallel Generation of Architecture on the GPU}},
author = {
Steinberger, Markus
and
Kenzel, Michael
and
Kainz, Bernhard
and
Müller, Jörg
and
Wonka, Peter
and
Schmalstieg, Dieter
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12312}
}
                
@article{
10.1111:cgf.12313,
journal = {Computer Graphics Forum}, title = {{
SAFE: Structure-aware Facade Editing}},
author = {
Dang, Minh
and
Ceylan, Duygu
and
Neubert, Boris
and
Pauly, Mark
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12313}
}
                
@article{
10.1111:cgf.12314,
journal = {Computer Graphics Forum}, title = {{
Game Level Layout from Design Specification}},
author = {
Ma, Chongyang
and
Vining, Nicholas
and
Lefebvre, Sylvain
and
Sheffer, Alla
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12314}
}
                
@article{
10.1111:cgf.12315,
journal = {Computer Graphics Forum}, title = {{
On-the-fly Generation and Rendering of Infinite Cities on the GPU}},
author = {
Steinberger, Markus
and
Kenzel, Michael
and
Kainz, Bernhard
and
Wonka, Peter
and
Schmalstieg, Dieter
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12315}
}
                
@article{
10.1111:cgf.12309,
journal = {Computer Graphics Forum}, title = {{
Recurring Part Arrangements in Shape Collections}},
author = {
Zheng, Youyi
and
Cohen-Or, Daniel
and
Averkiou, Melinos
and
Mitra, Niloy J.
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12309}
}
                
@article{
10.1111:cgf.12310,
journal = {Computer Graphics Forum}, title = {{
ShapeSynth: Parameterizing Model Collections for Coupled Shape Exploration and Synthesis}},
author = {
Averkiou, Melinos
and
Kim, Vladimir G.
and
Zheng, Youyi
and
Mitra, Niloy J.
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12310}
}
                
@article{
10.1111:cgf.12311,
journal = {Computer Graphics Forum}, title = {{
3D Timeline: Reverse Engineering of a Part-based Provenance from Consecutive 3D Models}},
author = {
Dobos, Jozef
and
Mitra, Niloy J.
and
Steed, Anthony
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12311}
}
                
@article{
10.1111:cgf.12304,
journal = {Computer Graphics Forum}, title = {{
Compressing Dynamic Meshes with Geometric Laplacians}},
author = {
Vasa, Libor
and
Marras, Stefano
and
Hormann, Kai
and
Brunnett, Guido
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12304}
}
                
@article{
10.1111:cgf.12305,
journal = {Computer Graphics Forum}, title = {{
Self-similarity for Accurate Compression of Point Sampled Surfaces}},
author = {
Digne, Julie
and
Chaine, Raphaëlle
and
Valette, Sébastien
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12305}
}
                
@article{
10.1111:cgf.12306,
journal = {Computer Graphics Forum}, title = {{
SimSelect: Similarity-based Selection for 3D Surfaces}},
author = {
Guy, Emilie
and
Thiery, Jean-Marc
and
Boubekeur, Tamy
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12306}
}
                
@article{
10.1111:cgf.12307,
journal = {Computer Graphics Forum}, title = {{
Analogy-Driven 3D Style Transfer}},
author = {
Ma, Chongyang
and
Huang, Haibin
and
Sheffer, Alla
and
Kalogerakis, Evangelos
and
Wang, Rui
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12307}
}
                
@article{
10.1111:cgf.12292,
journal = {Computer Graphics Forum}, title = {{
Light Montage for Perceptual Image Enhancement}},
author = {
Hosu, Vlad
and
Ha, Mai Lan
and
Sim, Terence
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12292}
}
                
@article{
10.1111:cgf.12293,
journal = {Computer Graphics Forum}, title = {{
Perceptual Depth Compression for Stereo Applications}},
author = {
Pajak, Dawid
and
Herzog, Robert
and
Mantiuk, Radoslaw
and
Didyk, Piotr
and
Eisemann, Elmar
and
Myszkowski, Karol
and
Pulli, Kari
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12293}
}
                
@article{
10.1111:cgf.12294,
journal = {Computer Graphics Forum}, title = {{
A Randomized Algorithm for Natural Object Colorization}},
author = {
Jin, Sou-Young
and
Choi, Ho Jin
and
Tai, Yu-Wing
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12294}
}
                
@article{
10.1111:cgf.12295,
journal = {Computer Graphics Forum}, title = {{
Laplacian Colormaps: a Framework for Structure-preserving Color Transformations}},
author = {
Eynard, Davide
and
Kovnatsky, Artiom
and
Bronstein, Michael M.
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12295}
}
                
@article{
10.1111:cgf.12321,
journal = {Computer Graphics Forum}, title = {{
Feedback Control for Rotational Movements in Feature Space}},
author = {
Borno, Mazen Al
and
Fiume, Eugene
and
Hertzmann, A.
and
Lasa, M. de
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12321}
}
                
@article{
10.1111:cgf.12322,
journal = {Computer Graphics Forum}, title = {{
Efficient Enforcement of Hard Articulation Constraints in the Presence of Closed Loops and Contacts}},
author = {
Tomcin, Robin
and
Sibbing, Dominik
and
Kobbelt, Leif
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12322}
}
                
@article{
10.1111:cgf.12323,
journal = {Computer Graphics Forum}, title = {{
On-line Real-time Physics-based Predictive Motion Control with Balance Recovery}},
author = {
Han, Daseong
and
Noh, Junyong
and
Jin, Xiaogang
and
Shin), Joseph S. Shin (formerly Sung Y.
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12323}
}
                
@article{
10.1111:cgf.12324,
journal = {Computer Graphics Forum}, title = {{
IISPH-FLIP for Incompressible Fluids}},
author = {
Cornelis, Jens
and
Ihmsen, Markus
and
Peer, Andreas
and
Teschner, Matthias
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12324}
}
                
@article{
10.1111:cgf.12308,
journal = {Computer Graphics Forum}, title = {{
Crack-free Rendering of Dynamically Tesselated B-Rep Models}},
author = {
Claux, Frédéric
and
Barthe, Loïc
and
Vanderhaeghe, David
and
Jessel, Jean-Pierre
and
Paulin, Mathias
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12308}
}
                
@article{
10.1111:cgf.12326,
journal = {Computer Graphics Forum}, title = {{
Rate-distortion Optimized Compression of Motion Capture Data}},
author = {
Vasa, Libor
and
Brunnett, Guido
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12326}
}
                
@article{
10.1111:cgf.12325,
journal = {Computer Graphics Forum}, title = {{
Interactive Motion Mapping for Real-time Character Control}},
author = {
Rhodin, Helge
and
Tompkin, James
and
Kim, Kwang In
and
Varanasi, Kiran
and
Seidel, Hans-Peter
and
Theobalt, Christian
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12325}
}
                
@article{
10.1111:cgf.12327,
journal = {Computer Graphics Forum}, title = {{
Pose Partitioning for Multi-resolution Segmentation of Arbitrary Mesh Animations}},
author = {
Vasilakis, Andreas A.
and
Fudos, Ioannis
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12327}
}
                
@article{
10.1111:cgf.12328,
journal = {Computer Graphics Forum}, title = {{
Parameter Estimation and Comparative Evaluation of Crowd Simulations}},
author = {
Wolinski, David
and
Guy, Stephen
and
Olivier, Anne-Helene
and
Lin, Ming
and
Manocha, Dinesh
and
Pettré, Julien
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12328}
}
                
@article{
10.1111:cgf.12300,
journal = {Computer Graphics Forum}, title = {{
Optimizing BRDF Orientations for the Manipulation of Anisotropic Highlights}},
author = {
Raymond, Boris
and
Guennebaud, Gaël
and
Barla, Pascal
and
Pacanowski, Romain
and
Granier, Xavier
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12300}
}
                
@article{
10.1111:cgf.12301,
journal = {Computer Graphics Forum}, title = {{
Efficient Monte Carlo Rendering with Realistic Lenses}},
author = {
Hanika, Johannes
and
Dachsbacher, Carsten
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12301}
}
                
@article{
10.1111:cgf.12302,
journal = {Computer Graphics Forum}, title = {{
Interactive Cloth Rendering of Microcylinder Appearance Model under Environment Lighting}},
author = {
Iwasaki, Kei
and
Mizutani, Kazutaka
and
Dobashi, Yoshinori
and
Nishita, Tomoyuki
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12302}
}
                
@article{
10.1111:cgf.12303,
journal = {Computer Graphics Forum}, title = {{
Adaptive Texture Space Shading for Stochastic Rendering}},
author = {
Andersson, Magnus
and
Hasselgren, Jon
and
Toth, Robert
and
Akenine-Möller, Tomas
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12303}
}
                
@article{
10.1111:cgf.12316,
journal = {Computer Graphics Forum}, title = {{
Crowd Sculpting: A Space-time Sculpting Method for Populating Virtual Environments}},
author = {
Jordao, Kevin
and
Pettré, Julien
and
Christie, Marc
and
Cani, Marie-Paule
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12316}
}
                
@article{
10.1111:cgf.12317,
journal = {Computer Graphics Forum}, title = {{
Thumbnail Galleries for Procedural Models}},
author = {
Lienhard, Stefan
and
Specht, Matthias
and
Neubert, Boris
and
Pauly, Mark
and
Müller, Pascal
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12317}
}
                
@article{
10.1111:cgf.12296,
journal = {Computer Graphics Forum}, title = {{
4D Video Textures for Interactive Character Appearance}},
author = {
Casas, Dan
and
Volino, Marco
and
Collomosse, John
and
Hilton, Adrian
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12296}
}
                
@article{
10.1111:cgf.12297,
journal = {Computer Graphics Forum}, title = {{
Temporally Coherent and Spatially Accurate Video Matting}},
author = {
Shahrian, Ehsan
and
Price, Brian
and
Cohen, Scott
and
Rajan, Deepu
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12297}
}
                
@article{
10.1111:cgf.12298,
journal = {Computer Graphics Forum}, title = {{
Art-Photographic Detail Enhancement}},
author = {
Son, Minjung
and
Lee, Yunjin
and
Kang, Henry
and
Lee, Seungyong
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12298}
}
                
@article{
10.1111:cgf.12299,
journal = {Computer Graphics Forum}, title = {{
Content-Aware Surface Parameterization for Interactive Restoration of Historical Documents}},
author = {
Pal, Kazim
and
Schüller, Christian
and
Panozzo, Daniele
and
Sorkine-Hornung, Olga
and
Weyrich, Tim
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12299}
}
                
@article{
10.1111:cgf.12329,
journal = {Computer Graphics Forum}, title = {{
Designing Large-Scale Interactive Traffic Animations for Urban Modeling}},
author = {
Garcia-Dorado, Ignacio
and
Aliaga, Daniel G.
and
Ukkusuri, Satish V.
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12329}
}
                
@article{
10.1111:cgf.12330,
journal = {Computer Graphics Forum}, title = {{
Accurate and Efficient Lighting for Skinned Models}},
author = {
Tarini, Marco
and
Panozzo, Daniele
and
Sorkine-Hornung, Olga
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12330}
}
                
@article{
10.1111:cgf.12331,
journal = {Computer Graphics Forum}, title = {{
Deformation with Enforced Metrics on Length, Area and Volume}},
author = {
Jin, Shuo
and
Zhang, Yunbo
and
Wang, Charlie C. L.
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12331}
}
                
@article{
10.1111:cgf.12333,
journal = {Computer Graphics Forum}, title = {{
Automatic Generation of Tourist Brochures}},
author = {
Birsak, Michael
and
Musialski, Przemyslaw
and
Wonka, Peter
and
Wimmer, Michael
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12333}
}
                
@article{
10.1111:cgf.12332,
journal = {Computer Graphics Forum}, title = {{
Flower Reconstruction from a Single Photo}},
author = {
Yan, Feilong
and
Gong, Minglun
and
Cohen-Or, Daniel
and
Deussen, Oliver
and
Chen, Baoquan
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12332}
}
                
@article{
10.1111:cgf.12334,
journal = {Computer Graphics Forum}, title = {{
ExploreMaps: Efficient Construction and Ubiquitous Exploration of Panoramic View Graphs of Complex 3D Environments}},
author = {
Benedetto, Marco Di
and
Ganovelli, Fabio
and
Rodriguez, Marcos Balsa
and
Villanueva, Alberto Jaspe
and
Scopigno, Roberto
and
Gobbetti, Enrico
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12334}
}
                
@article{
10.1111:cgf.12318,
journal = {Computer Graphics Forum}, title = {{
Clean Color: Improving Multi-filament 3D Prints}},
author = {
Hergel, Jean
and
Lefebvre, Sylvain
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12318}
}
                
@article{
10.1111:cgf.12319,
journal = {Computer Graphics Forum}, title = {{
Dual-Color Mixing for Fused Deposition Modeling Printers}},
author = {
Reiner, Tim
and
Carr, Nathan
and
Mech, Radomir
and
Stava, Ondrej
and
Dachsbacher, Carsten
and
Miller, Gavin
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12319}
}
                
@article{
10.1111:cgf.12320,
journal = {Computer Graphics Forum}, title = {{
Multi-style Paper Pop-up Designs from 3D Models}},
author = {
Jr., Conrado R. Ruiz
and
Le, Sang N.
and
Yu, Jinze
and
Low, Kok-Lim
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12320}
}
                
@article{
10.1111:cgf.12335,
journal = {Computer Graphics Forum}, title = {{
Pathline Glyphs}},
author = {
Hlawatsch, Marcel
and
Sadlo, Filip
and
Jang, Hajun
and
Weiskopf, Daniel
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12335}
}
                
@article{
10.1111:cgf.12336,
journal = {Computer Graphics Forum}, title = {{
Hierarchical Opacity Optimization for Sets of 3D Line Fields}},
author = {
Günther, Tobias
and
Rössl, Christian
and
Theisel, Holger
}, year = {
2014},
publisher = {
The Eurographics Association and John Wiley and Sons Ltd.},
ISSN = {1467-8659},
DOI = {
10.1111/cgf.12336}
}

Browse

Recent Submissions

Now showing 1 - 53 of 53
  • Item
    Preface and Table of Contents
    (The Eurographics Association and Blackwell Publishing Ltd., 2014) B. Levy and J. Kautz
  • Item
    Spatio-Temporal Geometry Fusion for Multiple Hybrid Cameras using Moving Least Squares Surfaces
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Kuster, Claudia; Bazin, Jean-Charles; Öztireli, Cengiz; Deng, Teng; Martin, Tobias; Popa, Tiberiu; Gross, Markus; B. Levy and J. Kautz
    Multi-view reconstruction aims at computing the geometry of a scene observed by a set of cameras. Accurate 3D reconstruction of dynamic scenes is a key component for a large variety of applications, ranging from special effects to telepresence and medical imaging. In this paper we propose a method based on Moving Least Squares surfaces which robustly and efficiently reconstructs dynamic scenes captured by a calibrated set of hybrid color+depth cameras. Our reconstruction provides spatio-temporal consistency and seamlessly fuses color and geometric information. We illustrate our approach on a variety of real sequences and demonstrate that it favorably compares to state-of-the-art methods.
  • Item
    Detection and Reconstruction of Freeform Sweeps
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Barton, Michael; Pottmann, Helmut; Wallner, Johannes; B. Levy and J. Kautz
    We study the difficult problem of deciding if parts of a freeform surface can be generated, or approximately generated, by the motion of a planar profile through space. While this task is basic for understanding the geometry of shapes as well as highly relevant for manufacturing and building construction, previous approaches were confined to special cases like kinematic surfaces or moulding surfaces. The general case remained unsolved so far. We approach this problem by a combination of local and global methods: curve analysis with regard to movability , curve comparison by common substring search in curvature plots, an exhaustive search through all planar cuts enhanced by quick rejection procedures, the ordering of candidate profiles and finally, global optimization. The main applications of our method are digital reconstruction of CAD models exhibiting sweep patches, and aiding in manufacturing freeform surfaces by pointing out those parts which can be approximated by sweeps.
  • Item
    Object Detection and Classification from Large-Scale Cluttered Indoor Scans
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Mattausch, Oliver; Panozzo, Daniele; Mura, Claudio; Sorkine-Hornung, Olga; Pajarola, Renato; B. Levy and J. Kautz
    We present a method to automatically segment indoor scenes by detecting repeated objects. Our algorithm scales to datasets with 198 million points and does not require any training data. We propose a trivially parallelizable preprocessing step, which compresses a point cloud into a collection of nearly-planar patches related by geometric transformations. This representation enables us to robustly filter out noise and greatly reduces the computational cost and memory requirements of our method, enabling execution at interactive rates. We propose a patch similarity measure based on shape descriptors and spatial configurations of neighboring patches. The patches are clustered in a Euclidean embedding space based on the similarity matrix to yield the segmentation of the input point cloud. The generated segmentation can be used to compress the raw point cloud, create an object database, and increase the clarity of the point cloud visualization.
  • Item
    Coded Exposure HDR Light-Field Video Recording
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Schedl, David C.; Birklbauer, Clemens; Bimber, Oliver; B. Levy and J. Kautz
    Capturing exposure sequences to compute high dynamic range (HDR) images causes motion blur in cases of camera movement. This also applies to light-field cameras: frames rendered from multiple blurred HDR lightfield perspectives are also blurred. While the recording times of exposure sequences cannot be reduced for a single-sensor camera, we demonstrate how this can be achieved for a camera array. Thus, we decrease capturing time and reduce motion blur for HDR light-field video recording. Applying a spatio-temporal exposure pattern while capturing frames with a camera array reduces the overall recording time and enables the estimation of camera movement within one light-field video frame. By estimating depth maps and local point spread functions (PSFs) from multiple perspectives with the same exposure, regional motion deblurring can be supported. Missing exposures at various perspectives are then interpolated.
  • Item
    Panorama Light-Field Imaging
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Birklbauer, Clemens; Bimber, Oliver; B. Levy and J. Kautz
    We present a novel approach to recording and computing panorama light fields. In contrast to previous methods that estimate panorama light fields from focal stacks or naive multi-perspective image stitching, our approach is the first that processes ray entries directly and does not require depth reconstruction or matching of image features. Arbitrarily complex scenes can therefore be captured while preserving correct occlusion boundaries, anisotropic reflections, refractions, and other light effects that go beyond diffuse reflections of Lambertian surfaces.
  • Item
    Optimizing Stereo-to-Multiview Conversion for Autostereoscopic Displays
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Chapiro, Alexandre; Heinzle, Simon; Aydin, Tunç Ozan; Poulakos, Steven; Zwicker, Matthias; Smolic, Aljosa; Gross, Markus; B. Levy and J. Kautz
    We present a novel stereo-to-multiview video conversion method for glasses-free multiview displays. Different from previous stereo-to-multiview approaches, our mapping algorithm utilizes the limited depth range of autostereoscopic displays optimally and strives to preserve the scene s artistic composition and perceived depth even under strong depth compression. We first present an investigation of how perceived image quality relates to spatial frequency and disparity. The outcome of this study is utilized in a two-step mapping algorithm, where we (i) compress the scene depth using a non-linear global function to the depth range of an autostereoscopic display, and (ii) enhance the depth gradients of salient objects to restore the perceived depth and salient scene structure. Finally, an adapted image domain warping algorithm is proposed to generate the multiview output, which enables overall disparity range extension.
  • Item
    Manipulating Refractive and Reflective Binocular Disparity
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Dabala, Lukasz; Kellnhofer, Petr; Ritschel, Tobias; Didyk, Piotr; Templin, Krzysztof; Myszkowski, Karol; Rokita, P.; Seidel, Hans-Peter; B. Levy and J. Kautz
    Presenting stereoscopic content on 3D displays is a challenging task, usually requiring manual adjustments. A number of techniques have been developed to aid this process, but they account for binocular disparity of surfaces that are diffuse and opaque only. However, combinations of transparent as well as specular materials are common in the real and virtual worlds, and pose a significant problem. For example, excessive disparities can be created which cannot be fused by the observer. Also, multiple stereo interpretations become possible, e. g., for glass, that both reflects and refracts, which may confuse the observer and result in poor 3D experience. In this work, we propose an efficient method for analyzing and controlling disparities in computer-generated images of such scenes where surface positions and a layer decomposition are available. Instead of assuming a single per-pixel disparity value, we estimate all possibly perceived disparities at each image location. Based on this representation, we define an optimization to find the best per-pixel camera parameters, assuring that all disparities can be easily fused by a human. A preliminary perceptual study indicates, that our approach combines comfortable viewing with realistic depiction of typical specular scenes.
  • Item
    Parallel Generation of Architecture on the GPU
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Steinberger, Markus; Kenzel, Michael; Kainz, Bernhard; Müller, Jörg; Wonka, Peter; Schmalstieg, Dieter; B. Levy and J. Kautz
    In this paper, we present a novel approach for the parallel evaluation of procedural shape grammars on the graphics processing unit (GPU). Unlike previous approaches that are either limited in the kind of shapes they allow, the amount of parallelism they can take advantage of, or both, our method supports state of the art procedural modeling including stochasticity and context-sensitivity. To increase parallelism, we explicitly express independence in the grammar, reduce inter-rule dependencies required for context-sensitive evaluation, and introduce intra-rule parallelism. Our rule scheduling scheme avoids unnecessary back and forth between CPU and GPU and reduces round trips to slow global memory by dynamically grouping rules in on-chip shared memory. Our GPU shape grammar implementation is multiple orders of magnitude faster than the standard in CPU-based rule evaluation, while offering equal expressive power. In comparison to the state of the art in GPU shape grammar derivation, our approach is nearly 50 times faster, while adding support for geometric context-sensitivity.
  • Item
    SAFE: Structure-aware Facade Editing
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Dang, Minh; Ceylan, Duygu; Neubert, Boris; Pauly, Mark; B. Levy and J. Kautz
    Many man-made objects, in particular building facades, exhibit dominant structural relations such as symmetry and regularity. When editing these shapes, a common objective is to preserve these relations. However, often there are numerous plausible editing results that all preserve the desired structural relations of the input, creating ambiguity. We propose an interactive facade editing framework that explores this structural ambiguity. We first analyze the input in a semi-automatic manner to detect different groupings of the facade elements and the relations among them. We then provide an incremental editing process where a set of variations that preserve the detected relations in a particular grouping are generated at each step. Starting from one input example, our system can quickly generate various facade configurations
  • Item
    Game Level Layout from Design Specification
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Ma, Chongyang; Vining, Nicholas; Lefebvre, Sylvain; Sheffer, Alla; B. Levy and J. Kautz
    The design of video game environments, or levels, aims to control gameplay by steering the player through a sequence of designer-controlled steps, while simultaneously providing a visually engaging experience. Traditionally these levels are painstakingly designed by hand, often from pre-existing building blocks, or space templates. In this paper, we propose an algorithmic approach for automatically laying out game levels from user-specified blocks. Our method allows designers to retain control of the gameplay flow via user-specified level connectivity graphs, while relieving them from the tedious task of manually assembling the building blocks into a valid, plausible layout. Our method produces sequences of diverse layouts for the same input connectivity, allowing for repeated replay of a given level within a visually different, new environment. We support complex graph connectivities and various building block shapes, and are able to compute complex layouts in seconds. The two key components of our algorithm are the use of configuration spaces defining feasible relative positions of building blocks within a layout and a graph-decomposition based layout strategy that leverages graph connectivity to speed up convergence and avoid local minima. Together these two tools quickly steer the solution toward feasible layouts. We demonstrate our method on a variety of real-life inputs, and generate appealing layouts conforming to user specifications
  • Item
    On-the-fly Generation and Rendering of Infinite Cities on the GPU
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Steinberger, Markus; Kenzel, Michael; Kainz, Bernhard; Wonka, Peter; Schmalstieg, Dieter; B. Levy and J. Kautz
    In this paper, we present a new approach for shape-grammar-based generation and rendering of huge cities in real-time on the graphics processing unit (GPU). Traditional approaches rely on evaluating a shape grammar and storing the geometry produced as a preprocessing step. During rendering, the pregenerated data is then streamed to the GPU. By interweaving generation and rendering, we overcome the problems and limitations of streaming pregenerated data. Using our methods of visibility pruning and adaptive level of detail, we are able to dynamically generate only the geometry needed to render the current view in real-time directly on the GPU. We also present a robust and efficient way to dynamically update a scene s derivation tree and geometry, enabling us to exploit frame-to-frame coherence. Our combined generation and rendering is significantly faster than all previous work. For detailed scenes, we are capable of generating geometry more rapidly than even just copying pregenerated data from main memory, enabling us to render cities with thousands of buildings at up to 100 frames per second, even with the camera moving at supersonic speed.
  • Item
    Recurring Part Arrangements in Shape Collections
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Zheng, Youyi; Cohen-Or, Daniel; Averkiou, Melinos; Mitra, Niloy J.; B. Levy and J. Kautz
    Extracting semantically related parts across models remains challenging, especially without supervision. The common approach is to co-analyze a model collection, while assuming the existence of descriptive geometric features that can directly identify related parts. In the presence of large shape variations, common geometric features, however, are no longer sufficiently descriptive. In this paper, we explore an indirect top-down approach, where instead of part geometry, part arrangements extracted from each model are compared. The key observation is that while a direct comparison of part geometry can be ambiguous, part arrangements, being higher level structures, remain consistent, and hence can be used to discover latent commonalities among semantically related shapes. We show that our indirect analysis leads to the detection of recurring arrangements of parts, which are otherwise difficult to discover in a direct unsupervised setting. We evaluate our algorithm on ground truth datasets and report advantages over geometric similarity-based bottom-up co-segmentation algorithms.
  • Item
    ShapeSynth: Parameterizing Model Collections for Coupled Shape Exploration and Synthesis
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Averkiou, Melinos; Kim, Vladimir G.; Zheng, Youyi; Mitra, Niloy J.; B. Levy and J. Kautz
    Recent advances in modeling tools enable non-expert users to synthesize novel shapes by assembling parts extracted from model databases. A major challenge for these tools is to provide users with relevant parts, which is especially difficult for large repositories with significant geometric variations. In this paper we analyze unorganized collections of 3D models to facilitate explorative shape synthesis by providing high-level feedback of possible synthesizable shapes. By jointly analyzing arrangements and shapes of parts across models, we hierarchically embed the models into low-dimensional spaces. The user can then use the parameterization to explore the existing models by clicking in different areas or by selecting groups to zoom on specific shape clusters. More importantly, any point in the embedded space can be lifted to an arrangement of parts to provide an abstracted view of possible shape variations. The abstraction can further be realized by appropriately deforming parts from neighboring models to produce synthesized geometry. Our experiments show that users can rapidly generate plausible and diverse shapes using our system, which also performs favorably with respect to previous modeling tools.
  • Item
    3D Timeline: Reverse Engineering of a Part-based Provenance from Consecutive 3D Models
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Dobos, Jozef; Mitra, Niloy J.; Steed, Anthony; B. Levy and J. Kautz
    We present a novel tool for reverse engineering of modeling histories from consecutive 3D files based on a timeline abstraction. Although a timeline interface is commonly used in 3D modeling packages for animations, it has not been used on geometry manipulation before. Unlike previous visualization methods that require instrumentation of editing software, our approach does not rely on pre-recorded editing instructions. Instead, each stand-alone 3D file is treated as a keyframe of a construction flow from which the editing provenance is reverse engineered. We evaluate this tool on six complex 3D sequences created in a variety of modeling tools by different professional artists and conclude that it provides useful means of visualizing and understanding the editing history. A comparative user study suggests the tool is well suited for this purpose.
  • Item
    Compressing Dynamic Meshes with Geometric Laplacians
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Vasa, Libor; Marras, Stefano; Hormann, Kai; Brunnett, Guido; B. Levy and J. Kautz
    This paper addresses the problem of representing dynamic 3D meshes in a compact way, so that they can be stored and transmitted efficiently. We focus on sequences of triangle meshes with shared connectivity, avoiding the necessity of having a skinning structure. Our method first computes an average mesh of the whole sequence in edge shape space. A discrete geometric Laplacian of this average surface is then used to encode the coefficients that describe the trajectories of the mesh vertices. Optionally, a novel spatio-temporal predictor may be applied to the trajectories to further improve the compression rate. We demonstrate that our approach outperforms the current state of the art in terms of low data rate at a given perceived distortion, as measured by the STED and KG error metrics.
  • Item
    Self-similarity for Accurate Compression of Point Sampled Surfaces
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Digne, Julie; Chaine, Raphaëlle; Valette, Sébastien; B. Levy and J. Kautz
    Most surfaces, be it from a fine-art artifact or a mechanical object, are characterized by a strong self-similarity. This property finds its source in the natural structures of objects but also in the fabrication processes: regularity of the sculpting technique, or machine tool. In this paper, we propose to exploit the self-similarity of the underlying shapes for compressing point cloud surfaces which can contain millions of points at a very high precision. Our approach locally resamples the point cloud in order to highlight the self-similarity of the shape, while remaining consistent with the original shape and the scanner precision. It then uses this self-similarity to create an ad hoc dictionary on which the local neighborhoods will be sparsely represented, thus allowing for a light-weight representation of the total surface. We demonstrate the validity of our approach on several point clouds from finearts and mechanical objects, as well as a urban scene. In addition, we show that our approach also achieves a filtering of noise whose magnitude is smaller than the scanner precision.
  • Item
    SimSelect: Similarity-based Selection for 3D Surfaces
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Guy, Emilie; Thiery, Jean-Marc; Boubekeur, Tamy; B. Levy and J. Kautz
    Surface selection is one of the fundamental interactions in shape modeling. In the case of complex models, this task is often tedious for at least two reasons: firstly the local geometry of a given region may be hard to manually select and needs great accuracy; secondly the selection process may have to be repeated a large number of times for similar regions requiring similar subsequent editing. We propose SimSelect, a new system for interactive selection on 3D surfaces addressing these two issues. We cope with the accuracy issue by classifying selections in different types, namely components, parts and patches for which we independently optimize the selection process. Second, we address the repetitiveness issue by introducing an expansion process based on shape recognition which automatically retrieves potential selections similar to the user-defined one. As a result, our system provides the user with a compact set of simple interaction primitives providing a smooth select-and-edit workflow.
  • Item
    Analogy-Driven 3D Style Transfer
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Ma, Chongyang; Huang, Haibin; Sheffer, Alla; Kalogerakis, Evangelos; Wang, Rui; B. Levy and J. Kautz
    Style transfer aims to apply the style of an exemplar model to a target one, while retaining the target s structure. The main challenge in this process is to algorithmically distinguish style from structure, a high-level, potentially ill-posed cognitive task. Inspired by cognitive science research we recast style transfer in terms of shape analogies. In IQ testing, shape analogy queries present the subject with three shapes: source, target and exemplar, and ask them to select an output such that the transformation, or analogy, from the exemplar to the output is similar to that from the source to the target. The logical process involved in identifying the source-to-target analogies implicitly detects the structural differences between the source and target and can be used effectively to facilitate style transfer. Since the exemplar has a similar structure to the source, applying the analogy to the exemplar will provide the output we seek. The main technical challenge we address is to compute the source to target analogies, consistent with human logic. We observe that the typical analogies we look for consist of a small set of simple transformations, which when applied to the exemplar generate a continuous, seamless output model. To assemble a shape analogy, we compute an optimal set of source-to-target transformations, such that the assembled analogy best fits these criteria. The assembled analogy is then applied to the exemplar shape to produce the desired output model. We use the proposed framework to seamlessly transfer a variety of style properties between 2D and 3D objects and demonstrate significant improvements over the state of the art in style transfer. We further show that our framework can be used to successfully complete partial scans with the help of a user provided structural template, coherently propagating scan style across the completed surfaces.
  • Item
    Light Montage for Perceptual Image Enhancement
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Hosu, Vlad; Ha, Mai Lan; Sim, Terence; B. Levy and J. Kautz
    Recent photography techniques such as sculpting with light show great potential in compositing beautiful images from fixed-viewpoint photos under multiple illuminations. The process relies heavily on the artists experience and skills using the available tools. An apparent trend in recent works is to facilitate the interaction making it less timeconsuming and addressable not only to experts, but also novices. We propose a method that automatically creates enhanced light montages that are comparable to those produced by artists. It detects and emphasizes cues that are important for perception by introducing a technique to extract depth and shape edges from an unconstrained light stack. Studies show that these cues are associated with silhouettes and suggestive contours which artists use to sketch and construct the layout of paintings. Textures, due to perspective distortion, offer essential cues that depict shape and surface slant. We balance the emphasis between depth edges and reflectance textures to enhance the sense of both shape and reflectance properties. Our light montage technique works perfectly with a few to hundreds of illuminations for each scene. Experiments show great results for static scenes making it practical for small objects, interiors and small-scale outdoor scenes. Dynamic scenes may be captured using spatially distributed light setups such as light domes. The approach could also be applied to time-lapse photos, with the sun as the main light source.
  • Item
    Perceptual Depth Compression for Stereo Applications
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Pajak, Dawid; Herzog, Robert; Mantiuk, Radoslaw; Didyk, Piotr; Eisemann, Elmar; Myszkowski, Karol; Pulli, Kari; B. Levy and J. Kautz
    Conventional depth video compression uses video codecs designed for color images. Given the performance of current encoding standards, this solution seems efficient. However, such an approach suffers from many issues stemming from discrepancies between depth and light perception. To exploit the inherent limitations of human depth perception, we propose a novel depth compression method that employs a disparity perception model. In contrast to previous methods, we account for disparity masking, and model a distinct relation between depth perception and contrast in luminance. Our solution is a natural extension to the H.264 codec and can easily be integrated into existing decoders. It significantly improves both the compression efficiency without sacrificing visual quality of depth of rendered content, and the output of depth-reconstruction algorithms or depth cameras.
  • Item
    A Randomized Algorithm for Natural Object Colorization
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Jin, Sou-Young; Choi, Ho Jin; Tai, Yu-Wing; B. Levy and J. Kautz
    Natural objects often contain vivid color distribution with wide variety of colors. Conventional colorization techniques, on the other hand, produce colors that are relatively flat with little color variation. In this paper, we introduce a randomized algorithm which considers not only the value of target color but also the distribution of target color. In essence, our algorithm paints a color distribution to a region which synthesizes color distribution of a natural object. Our approach models the correlation between intensity and color in HSV color space in terms of H - S, H - V and S - V joint histogram. During the colorization process, we randomly swap and reassign color of a pixel to minimize a cost function that measures color consistency to its neighborhood and intensity-to-color correlation captured in the joint histogram. We tested our algorithm extensively on many natural objects and our user study confirms that our results are more vivid and natural compared to results from previous techniques.
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    Laplacian Colormaps: a Framework for Structure-preserving Color Transformations
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Eynard, Davide; Kovnatsky, Artiom; Bronstein, Michael M.; B. Levy and J. Kautz
    Mappings between color spaces are ubiquitous in image processing problems such as gamut mapping, decolorization, and image optimization for color-blind people. Simple color transformations often result in information loss and ambiguities, and one wishes to find an image-specific transformation that would preserve as much as possible the structure of the original image in the target color space. In this paper, we propose Laplacian colormaps, a generic framework for structure-preserving color transformations between images. We use the image Laplacian to capture the structural information, and show that if the color transformation between two images preserves the structure, the respective Laplacians have similar eigenvectors, or in other words, are approximately jointly diagonalizable. Employing the relation between joint diagonalizability and commutativity of matrices, we use Laplacians commutativity as a criterion of color mapping quality and minimize it w.r.t. the parameters of a color transformation to achieve optimal structure preservation. We show numerous applications of our approach, including color-to-gray conversion, gamut mapping, multispectral image fusion, and image optimization for color deficient viewers.
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    Feedback Control for Rotational Movements in Feature Space
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Borno, Mazen Al; Fiume, Eugene; Hertzmann, A.; Lasa, M. de; B. Levy and J. Kautz
    Synthesizing controllers for rotational movements in feature space is an open research problem and is particularly challenging because of the need to precisely regulate the character s global orientation, angular momentum and inertia. This paper presents feature-based controllers for a wide variety of rotational movements, including cartwheels, dives and flips. We show that the controllers can be made robust to large external disturbances by using a time-invariant control scheme. The generality of the control laws is demonstrated by providing examples of the flip controller with different apexes, the diving controller with different heights and styles, the cartwheel controller with different speeds and straddle widths, etc. The controllers do not rely on any input motion or offline optimization.
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    Efficient Enforcement of Hard Articulation Constraints in the Presence of Closed Loops and Contacts
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Tomcin, Robin; Sibbing, Dominik; Kobbelt, Leif; B. Levy and J. Kautz
    In rigid body simulation, one must distinguish between contacts (so-called unilateral constraints) and articulations (bilateral constraints). For contacts and friction, iterative solution methods have proven most useful for interactive applications, often in combination with Shock-Propagation in cases with strong interactions between contacts (such as stacks), prioritizing performance and plausibility over accuracy. For articulation constraints, direct solution methods are preferred, because one can rely on a factorization with linear time complexity for tree-like systems, even in ill-conditioned cases caused by large mass-ratios or high complexity. Despite recent advances, combining the advantages of direct and iterative solution methods wrt. performance has proven difficult and the intricacy of articulations in interactive applications is often limited by the convergence speed of the iterative solution method in the presence of closed kinematic loops (i.e. auxiliary constraints) and contacts. We identify common performance bottlenecks in the dynamic simulation of unilateral and bilateral constraints and are able to present a simulation method, that scales well in the number of constraints even in ill-conditioned cases with frictional contacts, collisions and closed loops in the kinematic graph. For cases where many joints are connected to a single body, we propose a technique to increase the sparsity of the positive definite linear system. A solution to these bottlenecks is presented in this paper to make the simulation of a wider range of mechanisms possible in real-time without extensive parameter tuning.
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    On-line Real-time Physics-based Predictive Motion Control with Balance Recovery
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Han, Daseong; Noh, Junyong; Jin, Xiaogang; Shin), Joseph S. Shin (formerly Sung Y.; B. Levy and J. Kautz
    In this paper, we present an on-line real-time physics-based approach to motion control with contact repositioning based on a low-dimensional dynamics model using example motion data. Our approach first generates a reference motion in run time according to an on-line user request by transforming an example motion extracted from a motion library. Guided by the reference motion, it repeatedly generates an optimal control policy for a small time window one at a time for a sequence of partially overlapping windows, each covering a couple of footsteps of the reference motion, which supports an on-line performance. On top of this, our system dynamics and problem formulation allow to derive closed-form derivative functions by exploiting the low-dimensional dynamics model together with example motion data. These derivative functions and their sparse structures facilitate a real-time performance. Our approach also allows contact foot repositioning so as to robustly respond to an external perturbation or an environmental change as well as to perform locomotion tasks such as stepping on stones effectively.
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    IISPH-FLIP for Incompressible Fluids
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Cornelis, Jens; Ihmsen, Markus; Peer, Andreas; Teschner, Matthias; B. Levy and J. Kautz
    We propose to use Implicit Incompressible Smoothed Particle Hydrodynamics (IISPH) for pressure projection and boundary handling in Fluid-Implicit-Particle (FLIP) solvers for the simulation of incompressible fluids. This novel combination addresses two issues of existing SPH and FLIP solvers, namely mass preservation in FLIP and efficiency and memory consumption in SPH. First, the SPH component enables the simulation of incompressible fluids with perfect mass preservation. Second, the FLIP component efficiently enriches the SPH component with detail that is comparable to a standard SPH simulation with the same number of particles, while improving the performance by a factor of 7 and significantly reducing the memory consumption. We demonstrate that the proposed IISPH-FLIP solver can simulate incompressible fluids with a quantifiable, imperceptible density deviation below 0.1 percent. We show large-scale scenarios with up to 160 million particles that have been processed on a single desktop PC using only 15GB of memory. One- and two-way coupled solids are illustrated.
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    Crack-free Rendering of Dynamically Tesselated B-Rep Models
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Claux, Frédéric; Barthe, Loïc; Vanderhaeghe, David; Jessel, Jean-Pierre; Paulin, Mathias; B. Levy and J. Kautz
    We propose a versatile pipeline to render B-Rep models interactively, precisely and without rendering-related artifacts such as cracks. Our rendering method is based on dynamic surface evaluation using both tesselation and ray-casting, and direct GPU surface trimming. An initial rendering of the scene is performed using dynamic tesselation. The algorithm we propose reliably detects then fills up cracks in the rendered image. Crack detection works in image space, using depth information, while crack-filling is either achieved in image space using a simple classification process, or performed in object space through selective ray-casting. The crack filling method can be dynamically changed at runtime. Our image space crack filling approach has a limited runtime cost and enables high quality, real-time navigation. Our higher quality, object space approach results in a rendering of similar quality than full-scene ray-casting, but is 2 to 6 times faster, can be used during navigation and provides accurate, reliable rendering. Integration of our work with existing tesselation-based rendering engines is straightforward.
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    Rate-distortion Optimized Compression of Motion Capture Data
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Vasa, Libor; Brunnett, Guido; B. Levy and J. Kautz
    Lossy compression of motion capture data can alleviate the problems of efficient storage and transmission by exploiting the redundancy and the superfluous precision of the data. When considering the acceptable amount of distortion, perceptual issues have to be taken into account. Current state of the art methods reduce the data rate required for high quality storage of motion capture data using various techniques. Most of them, however, do not use the common tools of general data compression, such as the method of Lagrange multipliers, and thus they obtain sub-optimal results, making it difficult to do a fair comparison of their performance. In this paper, we present a general preprocessing step based on Lagrange multipliers, which allows to rigorously adjust the precision in each of the degrees of freedom of the input data according to the amount of influence the given degree of freedom has on the overall distortion. We then present a simple compression method based on Principal Component Analysis, which in combination with the proposed preprocessing achieves significantly better results than current state of the art methods. It allows optimization with respect to various distortion metrics, and we discuss the choice of the metric in two common but distinct scenarios, proposing a perceptually oriented comparison metric based on the relation of the problem at hand to the problem of compression of dynamic meshes.
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    Interactive Motion Mapping for Real-time Character Control
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Rhodin, Helge; Tompkin, James; Kim, Kwang In; Varanasi, Kiran; Seidel, Hans-Peter; Theobalt, Christian; B. Levy and J. Kautz
    Abstract It is now possible to capture the 3D motion of the human body on consumer hardware and to puppet in real time skeleton-based virtual characters. However, many characters do not have humanoid skeletons. Characters such as spiders and caterpillars do not have boned skeletons at all, and these characters have very different shapes and motions. In general, character control under arbitrary shape and motion transformations is unsolved - how might these motions be mapped? We control characters with a method which avoids the rigging-skinning pipeline - source and target characters do not have skeletons or rigs. We use interactively-defined sparse pose correspondences to learn a mapping between arbitrary 3D point source sequences and mesh target sequences. Then, we puppet the target character in real time. We demonstrate the versatility of our method through results on diverse virtual characters with different input motion controllers. Our method provides a fast, flexible, and intuitive interface for arbitrary motion mapping which provides new ways to control characters for real-time animation.
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    Pose Partitioning for Multi-resolution Segmentation of Arbitrary Mesh Animations
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Vasilakis, Andreas A.; Fudos, Ioannis; B. Levy and J. Kautz
    We present a complete approach to efficiently deriving a varying level-of-detail segmentation of arbitrary animated objects. An over-segmentation is built by combining sets of initial segments computed for each input pose, followed by a fast progressive simplification which aims at preserving rigid segments. The final segmentation result can be efficiently adjusted for cases where pose editing is performed or new poses are added at arbitrary positions in the mesh animation sequence. A smooth view of pose-to-pose segmentation transitions is offered by merging the partitioning of the current pose with that of the next pose. A perceptually friendly visualization scheme is also introduced for propagating segment colors between consecutive poses.We report on the efficiency and quality of our framework as compared to previous methods under a variety of skeletal and highly deformable mesh animations.
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    Parameter Estimation and Comparative Evaluation of Crowd Simulations
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Wolinski, David; Guy, Stephen; Olivier, Anne-Helene; Lin, Ming; Manocha, Dinesh; Pettré, Julien; B. Levy and J. Kautz
    We present a novel framework to evaluate multi-agent crowd simulation algorithms based on real-world observations of crowd movements. A key aspect of our approach is to enable fair comparisons by automatically estimating the parameters that enable the simulation algorithms to best fit the given data. We formulate parameter estimation as an optimization problem, and propose a general framework to solve the combinatorial optimization problem for all parameterized crowd simulation algorithms. Our framework supports a variety of metrics to compare reference data and simulation outputs. The reference data may correspond to recorded trajectories, macroscopic parameters, or artist-driven sketches. We demonstrate the benefits of our framework for example-based simulation, modeling of cultural variations, artist-driven crowd animation, and relative comparison of some widely-used multi-agent simulation algorithms.
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    Optimizing BRDF Orientations for the Manipulation of Anisotropic Highlights
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Raymond, Boris; Guennebaud, Gaël; Barla, Pascal; Pacanowski, Romain; Granier, Xavier; B. Levy and J. Kautz
    This paper introduces a system for the direct editing of highlights produced by anisotropic BRDFs, which we call anisotropic highlights. We first provide a comprehensive analysis of the link between the direction of anisotropy and the shape of highlight curves for arbitrary object surfaces. The gained insights provide the required ingredients to infer BRDF orientations from a prescribed highlight tangent field. This amounts to a non-linear optimization problem, which is solved at interactive framerates during manipulation. Taking inspiration from sculpting software, we provide tools that give the impression of manipulating highlight curves while actually modifying their tangents. Our solver produces desired highlight shapes for a host of lighting environments and anisotropic BRDFs.
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    Efficient Monte Carlo Rendering with Realistic Lenses
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Hanika, Johannes; Dachsbacher, Carsten; B. Levy and J. Kautz
    In this paper we present a novel approach to simulate image formation for a wide range of real world lenses in the Monte Carlo ray tracing framework. Our approach sidesteps the overhead of tracing rays through a system of lenses and requires no tabulation. To this end we first improve the precision of polynomial optics to closely match ground-truth ray tracing. Second, we show how the Jacobian of the optical system enables efficient importance sampling, which is crucial for difficult paths such as sampling the aperture which is hidden behind lenses on both sides. Our results show that this yields converged images significantly faster than previous methods and accurately renders complex lens systems with negligible overhead compared to simple models, e.g. the thin lens model. We demonstrate the practicality of our method by incorporating it into a bidirectional path tracing framework and show how it can provide information needed for sophisticated light transport algorithms.
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    Interactive Cloth Rendering of Microcylinder Appearance Model under Environment Lighting
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Iwasaki, Kei; Mizutani, Kazutaka; Dobashi, Yoshinori; Nishita, Tomoyuki; B. Levy and J. Kautz
    This paper proposes an interactive rendering method of cloth fabrics under environment lighting. The outgoing radiance from cloth fabrics in the microcylinder model is calculated by integrating the product of the distant environment lighting, the visibility function, the weighting function that includes shadowing/masking effects of threads, and the light scattering function of threads. The radiance calculation at each shading point of the cloth fabrics is simplified to a linear combination of triple product integrals of two circular Gaussians and the visibility function, multiplied by precomputed spherical Gaussian convolutions of the weighting function. We propose an efficient calculation method of the triple product of two circular Gaussians and the visibility function by using the gradient of signed distance function to the visibility boundary where the binary visibility changes in the angular domain of the hemisphere. Our GPU implementation enables interactive rendering of static cloth fabrics with dynamic viewpoints and lighting. In addition, interactive editing of parameters for the scattering function (e.g. thread s albedo) that controls the visual appearances of cloth fabrics can be achieved.
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    Adaptive Texture Space Shading for Stochastic Rendering
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Andersson, Magnus; Hasselgren, Jon; Toth, Robert; Akenine-Möller, Tomas; B. Levy and J. Kautz
    When rendering effects such as motion blur and defocus blur, shading can become very expensive if done in a naïve way, i.e. shading each visibility sample. To improve performance, previous work often decouple shading from visibility sampling using shader caching algorithms. We present a novel technique for reusing shading in a stochastic rasterizer. Shading is computed hierarchically and sparsely in an object-space texture, and by selecting an appropriate mipmap level for each triangle, we ensure that the shading rate is sufficiently high so that no noticeable blurring is introduced in the rendered image. Furthermore, with a two-pass algorithm, we separate shading from reuse and thus avoid GPU thread synchronization. Our method runs at real-time frame rates and is up to 3x faster than previous methods. This is an important step forward for stochastic rasterization in real time.
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    Crowd Sculpting: A Space-time Sculpting Method for Populating Virtual Environments
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Jordao, Kevin; Pettré, Julien; Christie, Marc; Cani, Marie-Paule; B. Levy and J. Kautz
    We introduce "Crowd Sculpting": a method to interactively design populated environments by using intuitive deformation gestures to drive both the spatial coverage and the temporal sequencing of a crowd motion. Our approach assembles large environments from sets of spatial elements which contain inter-connectible, periodic crowd animations. Such a Crowd Patches approach allows us to avoid expensive and difficult-to-control simulations. It also overcomes the limitations of motion editing, that would result into animations delimited in space and time. Our novel methods allows the user to control the crowd patches layout in ways inspired by elastic shape sculpting: the user creates and tunes the desired populated environment through stretching, bending, cutting and merging gestures, applied either in space or time. Our examples demonstrate that our method allows the space-time editing of very large populations and results into endless animation, while offering real-time, intuitive control and maintaining animation quality.
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    Thumbnail Galleries for Procedural Models
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Lienhard, Stefan; Specht, Matthias; Neubert, Boris; Pauly, Mark; Müller, Pascal; B. Levy and J. Kautz
    Procedural modeling allows for the generation of innumerable variations of models from a parameterized, conditional or stochastic rule set. Due to the abstractness, complexity and stochastic nature of rule sets, it is often very difficult to have an understanding of the diversity of models that a given rule set defines. We address this problem by presenting a novel system to automatically generate, cluster, rank, and select a series of representative thumbnail images out of a rule set. We introduce a set of view attributes that can be used to measure the suitability of an image to represent a model, and allow for comparison of different models derived from the same rule set. To find the best thumbnails, we exploit these view attributes on images of models obtained by stochastically sampling the parameter space of the rule set. The resulting thumbnail gallery gives a representative visual impression of the procedural modeling potential of the rule set. Performance is discussed by means of a number of distinct examples and compared to state-of-the-art approaches.
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    4D Video Textures for Interactive Character Appearance
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Casas, Dan; Volino, Marco; Collomosse, John; Hilton, Adrian; B. Levy and J. Kautz
    animation from a database of 4D actor performance captured in a multiple camera studio. 4D performance capture reconstructs dynamic shape and appearance over time but is limited to free-viewpoint video replay of the same motion. Interactive animation from 4D performance capture has so far been limited to surface shape only. 4DVT is the final piece in the puzzle enabling video-realistic interactive animation through two contributions: a layered view-dependent texture map representation which supports efficient storage, transmission and rendering from multiple view video capture; and a rendering approach that combines multiple 4DVT sequences in a parametric motion space, maintaining video quality rendering of dynamic surface appearance whilst allowing high-level interactive control of character motion and viewpoint. 4DVT is demonstrated for multiple characters and evaluated both quantitatively and through a user-study which confirms that the visual quality of captured video is maintained. The 4DVT representation achieves >90% reduction in size and halves the rendering cost.
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    Temporally Coherent and Spatially Accurate Video Matting
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Shahrian, Ehsan; Price, Brian; Cohen, Scott; Rajan, Deepu; B. Levy and J. Kautz
    Image and video matting are still challenging problems in areas with low foreground-background contrast. Video matting also has the challenge of ensuring temporally coherent mattes because the human visual system is highly sensitive to temporal jitter and flickering. On the other hand, video provides the opportunity to use information from other frames to improve the matte accuracy on a given frame. In this paper, we present a new video matting approach that improves the temporal coherence while maintaining high spatial accuracy in the computed mattes. We build sample sets of temporal and local samples that cover all the color distributions of the object and background over all previous frames. This helps guarantee spatial accuracy and temporal coherence by ensuring that proper samples are found even when distantly located in space or time. An explicit energy term encourages temporal consistency in the mattes derived from the selected samples. In addition, we use localized texture features to improve spatial accuracy in low contrast regions where color distributions overlap. The proposed method results in better spatial accuracy and temporal coherence than existing video matting methods.
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    Art-Photographic Detail Enhancement
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Son, Minjung; Lee, Yunjin; Kang, Henry; Lee, Seungyong; B. Levy and J. Kautz
    We present a novel method for enhancing details in a digital photograph, inspired by the principle of art photography. In contrast to the previous methods that primarily rely on tone scaling, our technique provides a flexible tone transform model that consists of two operators: shifting and scaling. This model permits shifting of the tonal range in each image region to enable significant detail boosting regardless of the original tone. We optimize these shift and scale factors in our constrained optimization framework to achieve extreme detail enhancement across the image in a piecewise smooth fashion, as in art photography. The experimental results show that the proposed method brings out a significantly large amount of details even from an ordinary low-dynamic range image.
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    Content-Aware Surface Parameterization for Interactive Restoration of Historical Documents
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Pal, Kazim; Schüller, Christian; Panozzo, Daniele; Sorkine-Hornung, Olga; Weyrich, Tim; B. Levy and J. Kautz
    We present an interactive method to restore severely damaged historical parchments. When damaged by heat in a fire, such manuscripts undergo a complex deformation and contain various geometric distortions such as wrinkling, buckling, and shrinking, rendering them nearly illegible. They cannot be physically flattened due to the risk of further damage. We propose a virtual restoration framework to estimate the non-rigid deformation the parchment underwent and to revert it, making reading the text significantly easier whilst maintaining the veracity of the textual content. We estimate the deformation by combining automatically extracted constraints with user-provided hints informed by domain knowledge. We demonstrate that our method successfully flattens and straightens the text on a variety of pages scanned from a 17th century document which fell victim to fire damage.
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    Designing Large-Scale Interactive Traffic Animations for Urban Modeling
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Garcia-Dorado, Ignacio; Aliaga, Daniel G.; Ukkusuri, Satish V.; B. Levy and J. Kautz
    Designing and optimizing traffic behavior and animation is a challenging problem of interest to virtual environment content generation and to urban planning and design. While some traffic simulation methods have appeared in computer graphics, most related systems focus on the design of buildings, roads, or cities but without explicitly considering urban traffic. To our knowledge, our work provides the first interactive approach which enables a designer to specify a desired vehicular traffic behavior (e.g., road occupancy, travel time, emissions, etc.) and the system will automatically compute what realistic 3D urban model (e.g., an interconnected network of roads, parcels, and buildings) yields the specified behavior. Our system both altered and improved traffic behavior in novel procedurally-generated cities and in road networks of existing cities. Our urban models contain up to 360 km of roads, 300,000 vehicles, and typically cover four hours of simulated peak traffic time. The typical editing session time to "paint" a new traffic pattern and to compute the new/changed urban model is two to five minutes.
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    Accurate and Efficient Lighting for Skinned Models
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Tarini, Marco; Panozzo, Daniele; Sorkine-Hornung, Olga; B. Levy and J. Kautz
    In the context of real-time, GPU-based rendering of animated skinned meshes, we propose a new algorithm to compute surface normals with minimal overhead both in terms of the memory footprint and the required per-vertex operations. By accounting for the variation of the skinning weights over the surface, we achieve a higher visual quality compared to the standard approximation ubiquitously used in video-game engines and other real-time applications. Our method supports Linear Blend Skinning and Dual Quaternion Skinning. We demonstrate the advantages of our technique on a variety of datasets and provide a complete open-source implementation, including GLSL shaders.
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    Deformation with Enforced Metrics on Length, Area and Volume
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Jin, Shuo; Zhang, Yunbo; Wang, Charlie C. L.; B. Levy and J. Kautz
    Techniques have been developed to deform a mesh with multiple types of constraints. One limitation of prior methods is that the accuracy of demanded metrics on the resultant model cannot be guaranteed. Adding metrics directly as hard constraints to an optimization functional often leads to unexpected distortion when target metrics differ significant from what are on the input model. In this paper, we present an effective framework to deform mesh models by enforcing demanded metrics on length, area and volume. To approach target metrics stably and minimize distortion, an iterative scale-driven deformation is investigated, and a global optimization functional is exploited to balance the scaling effect at different parts of a model. Examples demonstrate that our approach provides a user-friendly tool for designers who are used to semantic input.
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    Automatic Generation of Tourist Brochures
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Birsak, Michael; Musialski, Przemyslaw; Wonka, Peter; Wimmer, Michael; B. Levy and J. Kautz
    We present a novel framework for the automatic generation of tourist brochures that include routing instructions and additional information presented in the form of so-called detail lenses. The first contribution of this paper is the automatic creation of layouts for the brochures. Our approach is based on the minimization of an energy function that combines multiple goals: positioning of the lenses as close as possible to the corresponding region shown in an overview map, keeping the number of lenses low, and an efficient numbering of the lenses. The second contribution is a route-aware simplification of the graph of streets used for traveling between the points of interest (POIs). This is done by reducing the graph consisting of all shortest paths through the minimization of an energy function. The output is a subset of street segments that enable traveling between all the POIs without considerable detours, while at the same time guaranteeing a clutter-free visualization.
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    Flower Reconstruction from a Single Photo
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Yan, Feilong; Gong, Minglun; Cohen-Or, Daniel; Deussen, Oliver; Chen, Baoquan; B. Levy and J. Kautz
    We present a semi-automatic method for reconstructing flower models from a single photograph. Such reconstruction is challenging since the 3D structure of a flower can appear ambiguous in projection. However, the flower head typically consists of petals embedded in 3D space that share similar shapes and form certain level of regular structure. Our technique employs these assumptions by first fitting a cone and subsequently a surface of revolution to the flower structure and then computing individual petal shapes from their projection in the photo. Flowers with multiple layers of petals are handled through processing different layers separately. Occlusions are dealt with both within and between petal layers. We show that our method allows users to quickly generate a variety of realistic 3D flowers from photographs and to animate an image using the underlying models reconstructed from our method.
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    ExploreMaps: Efficient Construction and Ubiquitous Exploration of Panoramic View Graphs of Complex 3D Environments
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Benedetto, Marco Di; Ganovelli, Fabio; Rodriguez, Marcos Balsa; Villanueva, Alberto Jaspe; Scopigno, Roberto; Gobbetti, Enrico; B. Levy and J. Kautz
    We introduce a novel efficient technique for automatically transforming a generic renderable 3D scene into a simple graph representation named ExploreMaps, where nodes are nicely placed point of views, called probes, and arcs are smooth paths between neighboring probes. Each probe is associated with a panoramic image enriched with preferred viewing orientations, and each path with a panoramic video. Our GPU-accelerated unattended construction pipeline distributes probes so as to guarantee coverage of the scene while accounting for perceptual criteria before finding smooth, good looking paths between neighboring probes. Images and videos are precomputed at construction time with off-line photorealistic rendering engines, providing a convincing 3D visualization beyond the limits of current real-time graphics techniques. At run-time, the graph is exploited both for creating automatic scene indexes and movie previews of complex scenes and for supporting interactive exploration through a low-DOF assisted navigation interface and the visual indexing of the scene provided by the selected viewpoints. Due to negligible CPU overhead and very limited use of GPU functionality, real-time performance is achieved on emerging web-based environments based on WebGL even on low-powered mobile devices.
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    Clean Color: Improving Multi-filament 3D Prints
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Hergel, Jean; Lefebvre, Sylvain; B. Levy and J. Kautz
    Fused Filament Fabrication is an additive manufacturing process by which a 3D object is created from plastic filament. The filament is pushed through a hot nozzle where it melts. The nozzle deposits plastic layer after layer to create the final object. This process has been popularized by the RepRap community. Several printers feature multiple extruders, allowing objects to be formed from multiple materials or colors. The extruders are mounted side by side on the printer carriage. However, the print quality suffers when objects with color patterns are printed a disappointment for designers interested in 3D printing their colored digital models. The most severe issue is the oozing of plastic from the idle extruders: Plastics of different colors bleed onto each other giving the surface a smudged aspect, excess strings oozing from the extruder deposit on the surface, and holes appear due to this missing plastic. Fixing this issue is difficult: increasing the printing speed reduces oozing but also degrades surface quality on large prints the required speed level become impractical. Adding a physical mechanism increases cost and print time as extruders travel to a cleaning station. Instead, we rely on software and exploit degrees of freedom of the printing process. We introduce three techniques that complement each other in improving the print quality significantly. We first reduce the impact of oozing plastic by choosing a better azimuth angle for the printed part. We build a disposable rampart in close proximity of the part, giving the extruders the opportunity to wipe oozing strings and refill with hot plastic. We finally introduce a toolpath planner avoiding and hiding most of the defects due to oozing, and seamlessly integrating the rampart. We demonstrate our technique on several challenging multiple color prints, and show that our tool path planner improves the surface finish of single color prints as well.
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    Dual-Color Mixing for Fused Deposition Modeling Printers
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Reiner, Tim; Carr, Nathan; Mech, Radomir; Stava, Ondrej; Dachsbacher, Carsten; Miller, Gavin; B. Levy and J. Kautz
    In this work we detail a method that leverages the two color heads of recent low-end fused deposition modeling (FDM) 3D printers to produce continuous tone imagery. The challenge behind producing such two-tone imagery is how to finely interleave the two colors while minimizing the switching between print heads, making each color printed span as long and continuous as possible to avoid artifacts associated with printing short segments. The key insight behind our work is that by applying small geometric offsets, tone can be varied without the need to switch color print heads within a single layer. We can now effectively print (two-tone) texture mapped models capturing both geometric and color information in our output 3D prints.
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    Multi-style Paper Pop-up Designs from 3D Models
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Jr., Conrado R. Ruiz; Le, Sang N.; Yu, Jinze; Low, Kok-Lim; B. Levy and J. Kautz
    Paper pop-ups are interesting three-dimensional books that fascinate people of all ages. The design and construction of these pop-up books however are done manually and require a lot of time and effort. This has led to computer-assisted or automated tools for designing paper pop-ups. This paper proposes an approach for automatically converting a 3D model into a multi-style paper pop-up. Previous automated approaches have only focused on single-style pop-ups, where each is made of a single type of pop-up mechanisms. In our work, we combine multiple styles in a pop-up, which is more representative of actual artist s creations. Our method abstracts a 3D model using suitable primitive shapes that both facilitate the formation of the considered pop-up mechanisms and closely approximate the input model. Each shape is then abstracted using a set of 2D patches that combine to form a valid pop-up. We define geometric conditions that ensure the validity of the combined pop-up structures. In addition, our method also employs an image-based approach for producing the patches to preserve the textures, finer details and important contours of the input model. Finally, our system produces a printable design layout and decides an assembly order for the construction instructions. The feasibility of our results is verified by constructing the actual paper pop-ups from the designs generated by our system.
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    Pathline Glyphs
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Hlawatsch, Marcel; Sadlo, Filip; Jang, Hajun; Weiskopf, Daniel; B. Levy and J. Kautz
    Visualization of pathlines is common and highly relevant for the analysis of unsteady flow. However, pathlines can intersect, leading to visual clutter and perceptual issues. This makes it intrinsically difficult to provide expressive visualizations of the entire domain by an arrangement of multiple pathlines, in contrast to well-established streamline placement techniques. We present an approach to reduce these problems. It is inspired by glyph-based visualization and small multiples: we partition the domain into cells, each corresponding to a downscaled version of the entire domain. Inside these cells, a single downscaled pathline is drawn. On the overview scale, our pathline glyphs lead to emergent visual patterns that provide insight into time-dependent flow behavior. Zooming-in allows us to analyze individual pathlines in detail and compare neighboring lines. The overall approach is complemented with a context-preserving zoom lens and interactive pathline-based exploration. While we primarily target the visualization of 2D flow, we also address the extension to 3D. Our evaluation includes several examples, comparison to other flow visualization techniques, and a user study with domain experts.
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    Hierarchical Opacity Optimization for Sets of 3D Line Fields
    (The Eurographics Association and John Wiley and Sons Ltd., 2014) Günther, Tobias; Rössl, Christian; Theisel, Holger; B. Levy and J. Kautz
    Abstract The selection of meaningful lines for 3D line data visualization has been intensively researched in recent years. Most approaches focus on single line fields where one line passes through each domain point. This paper presents a selection approach for sets of line fields which is based on a global optimization of the opacity of candidate lines. For this, existing approaches for single line fields are modified such that significantly larger amounts of line representatives are handled. Furthermore, time coherence is addressed for animations, making this the first approach that solves the line selection problem for 3D time-dependent flow. We apply our technique to visualize dense sets of pathlines, sets of magnetic field lines, and animated sets of pathlines, streaklines and masslines.