28-Issue 2

Permanent URI for this collection

https://diglib7.eg.org/handle/10.2312/144
EG Proceedings

BibTeX (28-Issue 2)
                
@article{
10.1111:j.1467-8659.2009.01355.x,

journal = {Computer Graphics Forum},
title = {{
Frontmatter}},

author = {},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01355.x}

}
                
@article{
10.1111:j.1467-8659.2009.01356.x,

journal = {Computer Graphics Forum},
title = {{
Predicting Display Visibility Under Dynamically Changing Lighting Conditions}},

author = {
Aydin, Tunc Ozan
 and 
Myszkowski, Karol
 and 
Seidel, Hans-Peter
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01356.x}

}
                
@article{
10.1111:j.1467-8659.2009.01357.x,

journal = {Computer Graphics Forum},
title = {{
Temporal Glare: Real-Time Dynamic Simulation of the Scattering in the Human Eye}},

author = {
Ritschel, T.
 and 
Ihrke, M.
 and 
Frisvad, J. R.
 and 
Coppens, J.
 and 
Myszkowski, K.
 and 
Seidel, H.-P.
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01357.x}

}
                
@article{
10.1111:j.1467-8659.2009.01358.x,

journal = {Computer Graphics Forum},
title = {{
Color correction for tone mapping}},

author = {
Mantiuk, R.
 and 
Mantiuk, R.
 and 
Tomaszewska, A.
 and 
Heidrich, W.
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01358.x}

}
                
@article{
10.1111:j.1467-8659.2009.01359.x,

journal = {Computer Graphics Forum},
title = {{
Energy Aware Color Sets}},

author = {
Chuang, Johnson
 and 
Weiskopf, Daniel
 and 
Moeller, Torsten
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01359.x}

}
                
@article{
10.1111:j.1467-8659.2009.01360.x,

journal = {Computer Graphics Forum},
title = {{
Mixing Fluids and Granular Materials}},

author = {
Lenaerts, Toon
 and 
Dutre, Philip
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01360.x}

}
                
@article{
10.1111:j.1467-8659.2009.01361.x,

journal = {Computer Graphics Forum},
title = {{
Hydraulic Erosion Using Smoothed Particle Hydrodynamics}},

author = {
Kristof, P.
 and 
Benes, B.
 and 
Kivanek, J.
 and 
St ava, O.
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01361.x}

}
                
@article{
10.1111:j.1467-8659.2009.01362.x,

journal = {Computer Graphics Forum},
title = {{
Simulation of two-phase flow with sub-scale droplet and bubble effects}},

author = {
Mihalef, Viorel
 and 
Metaxas, Dimitris
 and 
Sussman, Mark
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01362.x}

}
                
@article{
10.1111:j.1467-8659.2009.01363.x,

journal = {Computer Graphics Forum},
title = {{
Scalable real-time animation of rivers}},

author = {
Yu, Qizhi
 and 
Neyret, Fabrice
 and 
Bruneton, Eric
 and 
Holzschuch, Nicolas
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01363.x}

}
                
@article{
10.1111:j.1467-8659.2009.01364.x,

journal = {Computer Graphics Forum},
title = {{
Shadowing Dynamic Scenes with Arbitrary BRDFs}},

author = {
Nowrouzezahrai, Derek
 and 
Kalogerakis, Evangelos
 and 
Fiume, Eugene
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01364.x}

}
                
@article{
10.1111:j.1467-8659.2009.01366.x,

journal = {Computer Graphics Forum},
title = {{
Bidirectional Importance Sampling for Unstructured Direct Illumination}},

author = {
Wang, Rui
 and 
Akerlund, Oskar
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01366.x}

}
                
@article{
10.1111:j.1467-8659.2009.01365.x,

journal = {Computer Graphics Forum},
title = {{
Anisotropic Radiance-Cache Splatting for Efficiently Computing High-Quality Global Illumination with Lightcuts}},

author = {
Herzog, Robert
 and 
Myszkowski, Karol
 and 
Seidel, Hans-Peter
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01365.x}

}
                
@article{
10.1111:j.1467-8659.2009.01367.x,

journal = {Computer Graphics Forum},
title = {{
Physics-driven Multi Dimensional Keyframe Animation for Artist-directable Interactive Character}},

author = {
Mitake, Hironori
 and 
Asano, Kazuyuki
 and 
Aoki, Takafumi
 and 
Marc, Salvati
 and 
Sato, Makoto
 and 
Hasegawa, Shoichi
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01367.x}

}
                
@article{
10.1111:j.1467-8659.2009.01368.x,

journal = {Computer Graphics Forum},
title = {{
Modal Locomotion: Animating Virtual Characters with Natural Vibrations}},

author = {
Kry, P.G.
 and 
Reveret, L.
 and 
Faure, F.
 and 
Cani, M.-P.
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01368.x}

}
                
@article{
10.1111:j.1467-8659.2009.01371.x,

journal = {Computer Graphics Forum},
title = {{
Into the Blue: Better Caustics through Photon Relaxation}},

author = {
Spencer, B.
 and 
Jones, M.W.
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01371.x}

}
                
@article{
10.1111:j.1467-8659.2009.01370.x,

journal = {Computer Graphics Forum},
title = {{
Adaptive Caustic Maps Using Deferred Shading}},

author = {
Wyman, Chris
 and 
Nichols, Greg
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01370.x}

}
                
@article{
10.1111:j.1467-8659.2009.01369.x,

journal = {Computer Graphics Forum},
title = {{
Character Motion Synthesis by Topology Coordinates}},

author = {
Ho, Edmond S.L.
 and 
Komura, Taku
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01369.x}

}
                
@article{
10.1111:j.1467-8659.2009.01373.x,

journal = {Computer Graphics Forum},
title = {{
A Statistical Model of Human Pose and Body Shape}},

author = {
Hasler, N.
 and 
Stoll, C.
 and 
Sunkel, M.
 and 
Rosenhahn, B.
 and 
Seidel, H.-P.
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01373.x}

}
                
@article{
10.1111:j.1467-8659.2009.01372.x,

journal = {Computer Graphics Forum},
title = {{
An Analytical Solution to Single Scattering in Homogeneous Participating Media}},

author = {
Pegoraro, Vincent
 and 
Parker, Steven G.
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01372.x}

}
                
@article{
10.1111:j.1467-8659.2009.01374.x,

journal = {Computer Graphics Forum},
title = {{
Simplification of Articulated Meshes}},

author = {
Landreneau, Eric
 and 
Schaefer, Scott
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01374.x}

}
                
@article{
10.1111:j.1467-8659.2009.01375.x,

journal = {Computer Graphics Forum},
title = {{
Motion Compression using Principal Geodesics Analysis}},

author = {
Tournier, M.
 and 
Wu, X.
 and 
Courty, N.
 and 
Arnaud, E.
 and 
Reveret, L.
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01375.x}

}
                
@article{
10.1111:j.1467-8659.2009.01378.x,

journal = {Computer Graphics Forum},
title = {{
Out-of-core Data Management for Path Tracing on Hybrid Resources}},

author = {
Budge, Brian
 and 
Bernardin, Tony
 and 
Stuart, Jeff A.
 and 
Sengupta, Shubhabrata
 and 
Joy, Kenneth I.
 and 
Owens, John D.
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01378.x}

}
                
@article{
10.1111:j.1467-8659.2009.01376.x,

journal = {Computer Graphics Forum},
title = {{
Fast GPU-based Adaptive Tessellation with CUDA}},

author = {
Schwarz, Michael
 and 
Stamminger, Marc
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01376.x}

}
                
@article{
10.1111:j.1467-8659.2009.01377.x,

journal = {Computer Graphics Forum},
title = {{
Fast BVH Construction on GPUs}},

author = {
Lauterbach, C.
 and 
Garland, M.
 and 
Sengupta, S.
 and 
Luebke, D.
 and 
Manocha, D.
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01377.x}

}
                
@article{
10.1111:j.1467-8659.2009.01379.x,

journal = {Computer Graphics Forum},
title = {{
A Part-aware Surface Metric for Shape Analysis}},

author = {
Liu, Rong
 and 
Zhang, Hao
 and 
Shamir, Ariel
 and 
Cohen-Or, Daniel
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01379.x}

}
                
@article{
10.1111:j.1467-8659.2009.01380.x,

journal = {Computer Graphics Forum},
title = {{
Shape Decomposition using Modal Analysis}},

author = {
Huang, Qi-Xing
 and 
Wicke, Martin
 and 
Adams, Bart
 and 
Guibas, Leonidas
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01380.x}

}
                
@article{
10.1111:j.1467-8659.2009.01381.x,

journal = {Computer Graphics Forum},
title = {{
Linear Time Super-Helices}},

author = {
Bertails, Florence
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01381.x}

}
                
@article{
10.1111:j.1467-8659.2009.01382.x,

journal = {Computer Graphics Forum},
title = {{
Wrinkling Captured Garments Using Space-Time Data-Driven Deformation}},

author = {
Popa, T.
 and 
Zhou, Q.
 and 
Bradley, D.
 and 
Kraevoy, V.
 and 
Fu, H.
 and 
Sheffer, A.
 and 
Heidrich, W.
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01382.x}

}
                
@article{
10.1111:j.1467-8659.2009.01383.x,

journal = {Computer Graphics Forum},
title = {{
Genuinity Signatures: Designing Signatures for Verifying 3D Object Genuinity}},

author = {
Aliaga, Daniel G.
 and 
Atallah, Mikhail J.
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01383.x}

}
                
@article{
10.1111:j.1467-8659.2009.01384.x,

journal = {Computer Graphics Forum},
title = {{
Range Scan Registration Using Reduced Deformable Models}},

author = {
Chang, W.
 and 
Zwicker, M.
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01384.x}

}
                
@article{
10.1111:j.1467-8659.2009.01385.x,

journal = {Computer Graphics Forum},
title = {{
Arches: a Framework for Modeling Complex Terrains}},

author = {
Peytavie, A.
 and 
Galin, E.
 and 
Grosjean, J.
 and 
Merillou, S.
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01385.x}

}
                
@article{
10.1111:j.1467-8659.2009.01386.x,

journal = {Computer Graphics Forum},
title = {{
Structure-Preserving Reshape for Textured Architectural Scenes}},

author = {
Cabral, Marcio
 and 
Lefebvre, Sylvain
 and 
Dachsbacher, Carsten
 and 
Drettakis, George
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01386.x}

}
                
@article{
10.1111:j.1467-8659.2009.01387.x,

journal = {Computer Graphics Forum},
title = {{
Interactive Geometric Simulation of 4D Cities}},

author = {
Weber, Basil
 and 
Mueller, Pascal
 and 
Wonka, Peter
 and 
Gross, Markus
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01387.x}

}
                
@article{
10.1111:j.1467-8659.2009.01388.x,

journal = {Computer Graphics Forum},
title = {{
Feature Preserving Point Set Surfaces based on Non-Linear Kernel Regression}},

author = {
Oeztireli, A. C.
 and 
Guennebaud, G.
 and 
Gross, M.
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01388.x}

}
                
@article{
10.1111:j.1467-8659.2009.01389.x,

journal = {Computer Graphics Forum},
title = {{
Completion and Reconstruction with Primitive Shapes}},

author = {
Schnabel, Ruwen
 and 
Degener, Patrick
 and 
Klein, Reinhard
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01389.x}

}
                
@article{
10.1111:j.1467-8659.2009.01390.x,

journal = {Computer Graphics Forum},
title = {{
Heightfield and spatially varying BRDF Reconstruction for Materials with Interreflections}},

author = {
Ruiters, Roland
 and 
Klein, Reinhard
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01390.x}

}
                
@article{
10.1111:j.1467-8659.2009.01391.x,

journal = {Computer Graphics Forum},
title = {{
Physically Guided Animation of Trees}},

author = {
Habel, Ralf
 and 
Kusternig, Alexander
 and 
Wimmer, Michael
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01391.x}

}
                
@article{
10.1111:j.1467-8659.2009.01393.x,

journal = {Computer Graphics Forum},
title = {{
Wind projection basis for real-time animation of trees}},

author = {
Diener, Julien
 and 
Rodriguez, Mathieu
 and 
Baboud, Lionel
 and 
Reveret, Lionel
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01393.x}

}
                
@article{
10.1111:j.1467-8659.2009.01394.x,

journal = {Computer Graphics Forum},
title = {{
Structure from silhouettes: a new paradigm for fast sketch-based design of trees}},

author = {
Wither, J.
 and 
Boudon, F.
 and 
Cani, M.-P.
 and 
Godin, C.
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01394.x}

}
                
@article{
10.1111:j.1467-8659.2009.01395.x,

journal = {Computer Graphics Forum},
title = {{
Positional, Metric, and Curvature Control for Constraint-Based Surface Deformation}},

author = {
Eigensatz, Michael
 and 
Pauly, Mark
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01395.x}

}
                
@article{
10.1111:j.1467-8659.2009.01396.x,

journal = {Computer Graphics Forum},
title = {{
Implicit Contact Handling for Deformable Objects}},

author = {
Otaduy, Miguel A.
 and 
Tamstorf, Rasmus
 and 
Steinemann, Denis
 and 
Gross, Markus
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01396.x}

}
                
@article{
10.1111:j.1467-8659.2009.01398.x,

journal = {Computer Graphics Forum},
title = {{
Importance Sampling Spherical Harmonics}},

author = {
Jarosz, Wojciech
 and 
Carr, Nathan A.
 and 
Jensen, Henrik Wann
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01398.x}

}
                
@article{
10.1111:j.1467-8659.2009.01397.x,

journal = {Computer Graphics Forum},
title = {{
Continuum-based Strain Limiting}},

author = {
Thomaszewski, Bernhard
 and 
Pabst, Simon
 and 
Strasser, Wolfgang
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01397.x}

}
                
@article{
10.1111:j.1467-8659.2009.01399.x,

journal = {Computer Graphics Forum},
title = {{
Complex Barycentric Coordinates with Applications to Planar Shape Deformation}},

author = {
Weber, Ofir
 and 
Ben-Chen, Mirela
 and 
Gotsman, Craig
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01399.x}

}
                
@article{
10.1111:j.1467-8659.2009.01400.x,

journal = {Computer Graphics Forum},
title = {{
LazyBrush: Flexible Painting Tool for Hand-drawn Cartoons}},

author = {
Sykora, Daniel
 and 
Dingliana, John
 and 
Collins, Steven
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01400.x}

}
                
@article{
10.1111:j.1467-8659.2009.01401.x,

journal = {Computer Graphics Forum},
title = {{
Compressive Dual Photography}},

author = {
Sen, Pradeep
 and 
Darabi, Soheil
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01401.x}

}
                
@article{
10.1111:j.1467-8659.2009.01402.x,

journal = {Computer Graphics Forum},
title = {{
Deblurring by Matching}},

author = {
Ancuti, Cosmin
 and 
Ancuti, Codruta Orniana
 and 
Bekaert, Philippe
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01402.x}

}
                
@article{
10.1111:j.1467-8659.2009.01403.x,

journal = {Computer Graphics Forum},
title = {{
Image Appearance Exploration by Model-Based Navigation}},

author = {
Shapira, L.
 and 
Shamir, A.
 and 
Cohen-Or, D.
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01403.x}

}
                
@article{
10.1111:j.1467-8659.2009.01404.x,

journal = {Computer Graphics Forum},
title = {{
Spectral-Based Group Formation Control}},

author = {
Takahashi, Shigeo
 and 
Yoshida, Kenichi
 and 
Kwon, Taesoo
 and 
Lee, Kang Hoon
 and 
Lee, Jehee
 and 
Shin, Sung Yong
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01404.x}

}
                
@article{
10.1111:j.1467-8659.2009.01405.x,

journal = {Computer Graphics Forum},
title = {{
TopoPlan: a topological path planner for real time human navigation under floor and ceiling constraints}},

author = {
Lamarche, F.
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01405.x}

}
                
@article{
10.1111:j.1467-8659.2009.01407.x,

journal = {Computer Graphics Forum},
title = {{
Dominant Texture and Diffusion Distance Manifolds}},

author = {
Lu, Jianye
 and 
Dorsey, Julie
 and 
Rushmeier, Holly
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01407.x}

}
                
@article{
10.1111:j.1467-8659.2009.01408.x,

journal = {Computer Graphics Forum},
title = {{
Animating Pictures of Fluid using Video Examples}},

author = {
Okabe, Makoto
 and 
Anjyo, Ken
 and 
Igarashi, Takeo
 and 
Seidel, Hans-Peter
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01408.x}

}
                
@article{
10.1111:j.1467-8659.2009.01406.x,

journal = {Computer Graphics Forum},
title = {{
Example-Based Rendering of Eye Movements}},

author = {
Banf, Michael and Blanz, Volker
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01406.x}

}
                
@article{
10.1111:j.1467-8659.2009.01409.x,

journal = {Computer Graphics Forum},
title = {{
Table-based Alpha Compression}},

author = {
Wennersten, Per
 and 
Stroem, Jacob
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01409.x}

}
                
@article{
10.1111:j.1467-8659.2009.01410.x,

journal = {Computer Graphics Forum},
title = {{
Symmetry Detection Using Feature Lines}},

author = {
Bokeloh, M.
 and 
Berner, A.
 and 
Wand, M.
 and 
Seidel, H.-P.
 and 
Schilling, A.
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01410.x}

}
                
@article{
10.1111:j.1467-8659.2009.01411.x,

journal = {Computer Graphics Forum},
title = {{
Detecting Symmetries and Curvilinear Arrangements in Vector Art}},

author = {
Yeh, Yi-Ting
 and 
Mech, Radomir
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01411.x}

}
                
@article{
10.1111:j.1467-8659.2009.01412.x,

journal = {Computer Graphics Forum},
title = {{
Learning good views through intelligent galleries}},

author = {
Vieira, Thales
 and 
Bordignon, Alex
 and 
Peixoto, Adelailson
 and 
Tavares, Geovan
 and 
Lopes, Helio
 and 
Velho, Luiz
 and 
Lewiner, Thomas
},
year = {
2009},

publisher = {
The Eurographics Association and Blackwell Publishing Ltd},


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01412.x}

}

Browse

Recent Submissions

Now showing 1 - 57 of 57
  • Thumbnail Image
    Item
    Frontmatter
    (The Eurographics Association and Blackwell Publishing Ltd, 2009)
  • Thumbnail Image
    Item
    Predicting Display Visibility Under Dynamically Changing Lighting Conditions
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Aydin, Tunc Ozan; Myszkowski, Karol; Seidel, Hans-Peter
    Display devices, more than ever, are finding their ways into electronic consumer goods as a result of recent trends in providing more functionality and user interaction. Combined with the new developments in display technology towards higher reproducible luminance range, the mobility and variation in capability of display devices are constantly increasing. Consequently, in real life usage it is now very likely that the display emission to be distorted by spatially and temporally varying reflections, and the observer s visual system to be not adapted to the particular display that she is viewing at that moment. The actual perception of the display content cannot be fully understood by only considering steady-state illumination and adaptation conditions. We propose an objective method for display visibility analysis formulating the problem as a full-reference image quality assessment problem, where the display emission under ideal conditions is used as the reference for real-life conditions. Our work includes a human visual system model that accounts for maladaptation and temporal recovery of sensitivity. As an example application we integrate our method to a global illumination simulator and analyze the visibility of a car interior display under realistic lighting conditions.
  • Thumbnail Image
    Item
    Temporal Glare: Real-Time Dynamic Simulation of the Scattering in the Human Eye
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Ritschel, T.; Ihrke, M.; Frisvad, J. R.; Coppens, J.; Myszkowski, K.; Seidel, H.-P.
    Glare is a consequence of light scattered within the human eye when looking at bright light sources. This effect can be exploited for tone mapping since adding glare to the depiction of high-dynamic range (HDR) imagery on a low-dynamic range (LDR) medium can dramatically increase perceived contrast. Even though most, if not all, subjects report perceiving glare as a bright pattern that fluctuates in time, up to now it has only been modeled as a static phenomenon. We argue that the temporal properties of glare are a strong means to increase perceived brightness and to produce realistic and attractive renderings of bright light sources. Based on the anatomy of the human eye, we propose a model that enables real-time simulation of dynamic glare on a GPU. This allows an improved depiction of HDR images on LDR media for interactive applications like games, feature films, or even by adding movement to initially static HDR images. By conducting psychophysical studies, we validate that our method improves perceived brightness and that dynamic glare-renderings are often perceived as more attractive depending on the chosen scene.
  • Thumbnail Image
    Item
    Color correction for tone mapping
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Mantiuk, R.; Mantiuk, R.; Tomaszewska, A.; Heidrich, W.
    Tone mapping algorithms offer sophisticated methods for mapping a real-world luminance range to the luminance range of the output medium but they often cause changes in color appearance. In this work we conduct a series of subjective appearance matching experiments to measure the change in image colorfulness after contrast compression and enhancement. The results indicate that the relation between contrast compression and the color saturation correction that matches color appearance is non-linear and smaller color correction is required for small change of contrast. We demonstrate that the relation cannot be fully explained by color appearance models. We propose color correction formulas that can be used with existing tone mapping algorithms. We extend existing global and local tone mapping operators and show that the proposed color correction formulas can preserve original image colors after tone scale manipulation.
  • Thumbnail Image
    Item
    Energy Aware Color Sets
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Chuang, Johnson; Weiskopf, Daniel; Moeller, Torsten
    We present a design technique for colors with the purpose of lowering the energy consumption of the display device. Our approach is based on a screen space variant energy model. The result of our design is a set of distinguishable iso-lightness colors guided by perceptual principles. We present two variations of our approach. One is based on a set of discrete user-named (categorical) colors, which are analyzed according to their energy consumption. The second is based on the constrained continuous optimization of color energy in the perceptually uniform CIELAB color space. We quantitatively compare our two approaches with a traditional choice of colors, demonstrating that we typically save approximately 40 percent of the energy. The color sets are applied to examples from the 2D visualization of nominal data and volume rendering of 3D scalar fields.
  • Thumbnail Image
    Item
    Mixing Fluids and Granular Materials
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Lenaerts, Toon; Dutre, Philip
    Fluid animations in computer graphics show interactions with various kinds of objects. However, fluid flowing through a granular material such as sand is still not possible within current frameworks. In this paper, we present the simulation of fine granular materials interacting with fluids. We propose a unified Smoothed Particle Hydrodynamics framework for the simulation of both fluid and granular material. The granular volume is simulated as a continuous material sampled by particles. By incorporating previous work on porous flow in this simulation framework we are able to fully couple fluid and sand. Fluid can now percolate between sand grains and influence the physical properties of the sand volume. Our method demonstrates various new effects such as dry soil transforming into mud pools by rain or rigid sand structures being eroded by waves.
  • Thumbnail Image
    Item
    Hydraulic Erosion Using Smoothed Particle Hydrodynamics
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Kristof, P.; Benes, B.; Kivanek, J.; St ava, O.
    This paper presents a new technique for modification of 3D terrains by hydraulic erosion. It efficiently couples fluid simulation using a Lagrangian approach, namely the Smoothed Particle Hydrodynamics (SPH) method, and a physically-based erosion model adopted from an Eulerian approach. The eroded sediment is associated with the SPH particles and is advected both implicitly, due to the particle motion, and explicitly, through an additional velocity field, which accounts for the sediment transfer between the particles. We propose a new donor-acceptor scheme for the explicit advection in SPH. Boundary particles associated to the terrain are used to mediate sediment exchange between the SPH particles and the terrain itself. Our results show that this particle-based method is efficient for the erosion of dense, large, and sparse fluid. Our implementation provides interactive results for scenes with up to 25,000 particles.
  • Thumbnail Image
    Item
    Simulation of two-phase flow with sub-scale droplet and bubble effects
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Mihalef, Viorel; Metaxas, Dimitris; Sussman, Mark
    We present a new Eulerian-Lagrangian method for physics-based simulation of fluid flow, which includes automatic generation of sub-scale spray and bubbles. The Marker Level Set method is used to provide a simple geometric criterion for free marker generation. A filtering method, inspired from Weber number thresholding, further controls the free marker generation (in a physics-based manner). Two separate models are used, one for sub-scale droplets, the other for sub-scale bubbles. Droplets are evolved in a Newtonian manner, using a density-extension drag force field, while bubbles are evolved using a model based on Stokes Law. We show that our model for sub-scale droplet and bubble dynamics is simple to couple with a full (macro-scale) Navier-Stokes two-phase flow model and is quite powerful in its applications. Our animations include coarse grained multiphase features interacting with fine scale multiphase features.
  • Thumbnail Image
    Item
    Scalable real-time animation of rivers
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Yu, Qizhi; Neyret, Fabrice; Bruneton, Eric; Holzschuch, Nicolas
    Many recent games and applications target the interactive exploration of realistic large scale worlds. These worlds consist mostly of static terrain models, as the simulation of animated fluids in these virtual worlds is computationally expensive. Adding flowing fluids, such as rivers, to these virtual worlds would greatly enhance their realism, but causes specific issues: as the user is usually observing the world at close range, small scale details such as waves and ripples are important. However, the large scale of the world makes classical methods impractical for simulating these effects. In this paper, we present an algorithm for the interactive simulation of realistic flowing fluids in large virtual worlds. Our method relies on two key contributions: the local computation of the velocity field of a steady flow given boundary conditions, and the advection of small scale details on a fluid, following the velocity field, and uniformly sampled in screen space.
  • Thumbnail Image
    Item
    Shadowing Dynamic Scenes with Arbitrary BRDFs
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Nowrouzezahrai, Derek; Kalogerakis, Evangelos; Fiume, Eugene
    We present a real-time relighting and shadowing method for dynamic scenes with varying lighting, view and BRDFs. Our approach is based on a compact representation of reflectance data that allows for changing the BRDF at run-time and a data-driven method for accurately synthesizing self-shadows on articulated and deformable geometries. Unlike previous self-shadowing approaches, we do not rely on local blocking heuristics. We do not fit a model to the BRDF-weighted visibility, but rather only to the visibility that changes during animation. In this manner, our model is more compact than previous techniques and requires less computation both during fitting and at run-time. Our reflectance product operators can re-integrate arbitrary low-frequency view-dependent BRDF effects on-the-fly and are compatible with all previous dynamic visibility generation techniques as well as our own data-driven visibility model. We apply our reflectance product operators to three different visibility generation models, and our data-driven model can achieve framerates well over 300Hz.
  • Thumbnail Image
    Item
    Bidirectional Importance Sampling for Unstructured Direct Illumination
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Wang, Rui; Akerlund, Oskar
    Recent research in bidirectional importance sampling has focused primarily on structured illumination sources such as distant environment maps, while unstructured illumination has received little attention. In this paper, we present a method for bidirectional importance sampling of unstructured illumination, allowing us to use the same method for sampling both distant as well as local/indirect sources. Building upon recent work in [WFA*05], we model complex illumination as a large set of point lights. The subsequent sampling process draws samples only from this point set. We start by constructing a piecewise constant approximation for the lighting using an illumination cut [CPWAP08]. We show that this cut can be used directly for illumination importance sampling. We then use BRDF importance sampling followed by sample counting to update the cut, resulting in a bidirectional distribution that closely approximates the product of the illumination and BRDF. Drawing visibility samples from this new distribution significantly reduces the sampling variance. As a main advance over previous work, our method allows for unstructured sources, including arbitrary local direct lighting and one-bounce of indirect lighting.
  • Thumbnail Image
    Item
    Anisotropic Radiance-Cache Splatting for Efficiently Computing High-Quality Global Illumination with Lightcuts
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Herzog, Robert; Myszkowski, Karol; Seidel, Hans-Peter
    Computing global illumination in complex scenes is even with todays computational power a demanding task. In this work we propose a novel irradiance caching scheme that combines the advantages of two state-of-the-art algorithms for high-quality global illumination rendering: lightcuts, an adaptive and hierarchical instant-radiosity based algorithm and the widely used (ir)radiance caching algorithm for sparse sampling and interpolation of (ir)radiance in object space. Our adaptive radiance caching algorithm is based on anisotropic cache splatting, which adapts the cache footprints not only to the magnitude of the illumination gradient computed with light-cuts but also to its orientation allowing larger interpolation errors along the direction of coherent illumination while reducing the error along the illumination gradient. Since lightcuts computes the direct and indirect lighting seamlessly, we use a two-layer radiance cache, to store and control the interpolation of direct and indirect lighting individually with different error criteria. In multiple iterations our method detects cache interpolation errors above the visibility threshold of a pixel and reduces the anisotropic cache footprints accordingly. We achieve significantly better image quality while also speeding up the computation costs by one to two orders of magnitude with respect to the well-known photon mapping with (ir)radiance caching procedure.
  • Thumbnail Image
    Item
    Physics-driven Multi Dimensional Keyframe Animation for Artist-directable Interactive Character
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Mitake, Hironori; Asano, Kazuyuki; Aoki, Takafumi; Marc, Salvati; Sato, Makoto; Hasegawa, Shoichi
    Various forms of art and entertainment involve many different characters, and advances in human interfaces have necessitated physical interactions in order to develop an improved sense of reality. In this paper we propose a method for generating the motions of characters using multidimensional keyframe animation in parallel with real-time physical simulation. The method generates characters capable of physical interaction, and also allows animators to use traditional methods for designing character motion. We have implemented the system and confirmed its effectiveness experimentally.
  • Thumbnail Image
    Item
    Modal Locomotion: Animating Virtual Characters with Natural Vibrations
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Kry, P.G.; Reveret, L.; Faure, F.; Cani, M.-P.
    We present a general method to intuitively create a wide range of locomotion controllers for 3D legged characters. The key of our approach is the assumption that efficient locomotion can exploit the natural vibration modes of the body, where these modes are related to morphological parameters such as the shape, size, mass, and joint stiffness. The vibration modes are computed for a mechanical model of any 3D character with rigid bones, elastic joints, and additional constraints as desired. A small number of vibration modes can be selected with respect to their relevance to locomotion patterns and combined into a compact controller driven by very few parameters. We show that these controllers can be used in dynamic simulations of simple creatures, and for kinematic animations of more complex creatures of a variety of shapes and sizes.
  • Thumbnail Image
    Item
    Into the Blue: Better Caustics through Photon Relaxation
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Spencer, B.; Jones, M.W.
    The photon mapping method is one of the most popular algorithms employed in computer graphics today. However, obtaining good results is dependent on several variables including kernel shape and bandwidth, as well as the properties of the initial photon distribution. While the photon density estimation problem has been the target of extensive research, most algorithms focus on new methods of optimising the kernel to minimise noise and bias. In this paper we break from convention and propose a new approach that directly redistributes the underlying photons. We show that by relaxing the initial distribution into one with a blue noise spectral signature we can dramatically reduce background noise, particularly in areas of uniform illumination. In addition, we propose an efficient heuristic to detect and preserve features and discontinuities. We then go on to demonstrate how reconfiguration also permits the use of very low bandwidth kernels, greatly improving render times whilst reducing bias.
  • Thumbnail Image
    Item
    Adaptive Caustic Maps Using Deferred Shading
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Wyman, Chris; Nichols, Greg
  • Thumbnail Image
    Item
    Character Motion Synthesis by Topology Coordinates
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Ho, Edmond S.L.; Komura, Taku
    In this paper, we propose a new method to efficiently synthesize character motions that involve close contacts such as wearing a T-shirt, passing the arms through the strings of a knapsack, or piggy-back carrying an injured person. We introduce the concept of topology coordinates, in which the topological relationships of the segments are embedded into the attributes. As a result, the computation for collision avoidance can be greatly reduced for complex motions that require tangling the segments of the body. Our method can be combinedly used with other prevalent frame-based optimization techniques such as inverse kinematics.
  • Thumbnail Image
    Item
    A Statistical Model of Human Pose and Body Shape
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Hasler, N.; Stoll, C.; Sunkel, M.; Rosenhahn, B.; Seidel, H.-P.
    Generation and animation of realistic humans is an essential part of many projects in today s media industry. Especially, the games and special effects industry heavily depend on realistic human animation. In this work a unified model that describes both, human pose and body shape is introduced which allows us to accurately model muscle deformations not only as a function of pose but also dependent on the physique of the subject. Coupled with the model s ability to generate arbitrary human body shapes, it severely simplifies the generation of highly realistic character animations. A learning based approach is trained on approximately 550 full body 3D laser scans taken of 114 subjects. Scan registration is performed using a non-rigid deformation technique. Then, a rotation invariant encoding of the acquired exemplars permits the computation of a statistical model that simultaneously encodes pose and body shape. Finally, morphing or generating meshes according to several constraints simultaneously can be achieved by training semantically meaningful regressors.
  • Thumbnail Image
    Item
    An Analytical Solution to Single Scattering in Homogeneous Participating Media
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Pegoraro, Vincent; Parker, Steven G.
    Despite their numerous applications, efficiently rendering participating media remains a challenging task due to the intricacy of the radiative transport equation. As they provide a generic means of solving a wide variety of problems, numerical methods are most often used to solve the air-light integral even under simplifying assumptions. In this paper, we present a novel analytical approach to single scattering from isotropic point light sources in homogeneous media. We derive the first closed-form solution to the air-light integral in isotropic media and extend this formulation to anisotropic phase functions. The technique relies neither on pre-computation nor on storage, and we provide a practical implementation allowing for an explicit control on the accuracy of the solutions. Finally, we demonstrate its quantitative and qualitative benefits over both previous numerical and analytical approaches.
  • Thumbnail Image
    Item
    Simplification of Articulated Meshes
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Landreneau, Eric; Schaefer, Scott
    We present a method for simplifying a polygonal character with an associated skeletal deformation such that the simplified character approximates the original shape well when deformed. As input, we require a set of example poses that are representative of the types of deformations the character undergoes and we produce a multi-resolution hierarchy for the simplified character where all simplified vertices also have associated skin weights. We create this hierarchy by minimizing an error metric for a simplified set of vertices and their skin weights, and we show that this quartic error metric can be effectively minimized using alternating quadratic minimization for the vertices and weights separately. To enable efficient GPU accelerated deformations of the simplified character, we also provide a method that guarantees the maximum number of bone weights per simplified vertex is less than a user specified threshold at all levels of the hierarchy.
  • Thumbnail Image
    Item
    Motion Compression using Principal Geodesics Analysis
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Tournier, M.; Wu, X.; Courty, N.; Arnaud, E.; Reveret, L.
    Due to the growing need for large quantities of human animation data in the entertainment industry, it has become a necessity to compress motion capture sequences in order to ease their storage and transmission. We present a novel, lossy compression method for human motion data that exploits both temporal and spatial coherence. Given one motion, we first approximate the poses manifold using Principal Geodesics Analysis (PGA) in the configuration space of the skeleton. We then search this approximate manifold for poses matching end-effectors constraints using an iterative minimization algorithm that allows for real-time, data-driven inverse kinematics. The compression is achieved by only storing the approximate manifold parametrization along with the end-effectors and root joint trajectories, also compressed, in the output data. We recover poses using the IK algorithm given the end-effectors trajectories. Our experimental results show that considerable compression rates can be obtained using our method, with few reconstruction and perceptual errors.
  • Thumbnail Image
    Item
    Out-of-core Data Management for Path Tracing on Hybrid Resources
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Budge, Brian; Bernardin, Tony; Stuart, Jeff A.; Sengupta, Shubhabrata; Joy, Kenneth I.; Owens, John D.
    We present a software system that enables path-traced rendering of complex scenes. The system consists of two primary components: an application layer that implements the basic rendering algorithm, and an out-of-core scheduling and data-management layer designed to assist the application layer in exploiting hybrid computational resources (e.g., CPUs and GPUs) simultaneously. We describe the basic system architecture, discuss design decisions of the system s data-management layer, and outline an efficient implementation of a path tracer application, where GPUs perform functions such as ray tracing, shadow tracing, importance-driven light sampling, and surface shading. The use of GPUs speeds up the runtime of these components by factors ranging from two to twenty, resulting in a substantial overall increase in rendering speed. The path tracer scales well with respect to CPUs, GPUs and memory per node as well as scaling with the number of nodes. The result is a system that can render large complex scenes with strong performance and scalability.
  • Thumbnail Image
    Item
    Fast GPU-based Adaptive Tessellation with CUDA
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Schwarz, Michael; Stamminger, Marc
    Compact surface descriptions like higher-order surfaces are popular representations for both modeling and animation. However, for fast graphics-hardware-assisted rendering, they usually need to be converted to triangle meshes. In this paper, we introduce a new framework for performing on-the-fly crack-free adaptive tessellation of surface primitives completely on the GPU. Utilizing CUDA and its flexible memory write capabilities, we parallelize the tessellation task at the level of single surface primitives. We are hence able to derive tessellation factors, perform surface evaluation as well as generate the tessellation topology in real-time even for large collections of primitives. We demonstrate the power of our framework by exemplarily applying it to both bicubic rational Bezier patches and PN triangles.
  • Thumbnail Image
    Item
    Fast BVH Construction on GPUs
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Lauterbach, C.; Garland, M.; Sengupta, S.; Luebke, D.; Manocha, D.
    We present two novel parallel algorithms for rapidly constructing bounding volume hierarchies on manycore GPUs. The first uses a linear ordering derived from spatial Morton codes to build hierarchies extremely quickly and with high parallel scalability. The second is a top-down approach that uses the surface area heuristic (SAH) to build hierarchies optimized for fast ray tracing. Both algorithms are combined into a hybrid algorithm that removes existing bottlenecks in the algorithm for GPU construction performance and scalability leading to significantly decreased build time. The resulting hierarchies are close in to optimized SAH hierarchies, but the construction process is substantially faster, leading to a significant net benefit when both construction and traversal cost are accounted for. Our preliminary results show that current GPU architectures can compete with CPU implementations of hierarchy construction running on multicore systems. In practice, we can construct hierarchies of models with up to several million triangles and use them for fast ray tracing or other applications.
  • Thumbnail Image
    Item
    A Part-aware Surface Metric for Shape Analysis
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Liu, Rong; Zhang, Hao; Shamir, Ariel; Cohen-Or, Daniel
    The notion of parts in a shape plays an important role in many geometry problems, including segmentation, correspondence, recognition, editing, and animation. As the fundamental geometric representation of 3D objects in computer graphics is surface-based, solutions of many such problems utilize a surface metric, a distance function defined over pairs of points on the surface, to assist shape analysis and understanding. The main contribution of our work is to bring together these two fundamental concepts: shape parts and surface metric. Specifically, we develop a surface metric that is part-aware. To encode part information at a point on a shape, we model its volumetric context - called the volumetric shape image (VSI) - inside the shape s enclosed volume, to capture relevant visibility information. We then define the part-aware metric by combining an appropriate VSI distance with geodesic distance and normal variation. We show how the volumetric view on part separation addresses certain limitations of the surface view, which relies on concavity measures over a surface as implied by the well-known minima rule. We demonstrate how the new metric can be effectively utilized in various applications including mesh segmentation, shape registration, part-aware sampling and shape retrieval.
  • Thumbnail Image
    Item
    Shape Decomposition using Modal Analysis
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Huang, Qi-Xing; Wicke, Martin; Adams, Bart; Guibas, Leonidas
    We introduce a novel algorithm that decomposes a deformable shape into meaningful parts requiring only a single input pose. Using modal analysis, we are able to identify parts of the shape that tend to move rigidly. We define a deformation energy on the shape, enabling modal analysis to find the typical deformations of the shape. We then find a decomposition of the shape such that the typical deformations can be well approximated with deformation fields that are rigid in each part of the decomposition. We optimize for the best decomposition, which captures how the shape deforms. A hierarchical refinement scheme makes it possible to compute more detailed decompositions for some parts of the shape.Although our algorithm does not require user intervention, it is possible to control the process by directly changing the deformation energy, or interactively refining the decomposition as necessary. Due to the construction of the energy function and the properties of modal analysis, the computed decompositions are robust to changes in pose as well as meshing, noise, and even imperfections such as small holes in the surface.
  • Thumbnail Image
    Item
    Linear Time Super-Helices
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Bertails, Florence
    Thin elastic rods such as cables, phone coils, tree branches, or hair, are common objects in the real world but computing their dynamics accurately remains challenging. The recent Super-Helix model, based on the discrete equations of Kirchhoff for a piecewise helical rod, is one of the most promising models for simulating non-stretchable rods that can bend and twist. However, this model suffers from a quadratic complexity in the number of discrete elements, which, in the context of interactive applications, makes it limited to a few number of degrees of freedom - or equivalently to a low number of variations in curvature along the mean curve. This paper proposes a new, recursive scheme for the dynamics of a Super-Helix, inspired by the popular algorithm of Featherstone for serial multibody chains. Similarly to Featherstone s algorithm, we exploit the recursive kinematics of a Super-Helix to propagate elements inertias from the free end to the clamped end of the rod, while the dynamics is solved within a second pass traversing the rod in the reverse way. Besides the gain in linear complexity, which allows us to simulate a rod of complex shape much faster than the original approach, our algorithm makes it straightforward to simulate tree-like structures of Super-Helices, which turns out to be particularly useful for animating trees and plants realistically, under large displacements.
  • Thumbnail Image
    Item
    Wrinkling Captured Garments Using Space-Time Data-Driven Deformation
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Popa, T.; Zhou, Q.; Bradley, D.; Kraevoy, V.; Fu, H.; Sheffer, A.; Heidrich, W.
    The presence of characteristic fine folds is important for modeling realistic looking virtual garments. While recent garment capture techniques are quite successful at capturing the low-frequency garment shape and motion over time, they often fail to capture the numerous high-frequency folds, reducing the realism of the reconstructed space-time models. In our work we propose a method for reintroducing fine folds into the captured models using data-driven dynamic wrinkling. We first estimate the shape and position of folds based on the original video footage used for capture and then wrinkle the surface based on those estimates using space-time deformation. Both steps utilize the unique geometric characteristics of garments in general, and garment folds specifically, to facilitate the modeling of believable folds. We demonstrate the effectiveness of our wrinkling method on a variety of garments that have been captured using several recent techniques.
  • Thumbnail Image
    Item
    Genuinity Signatures: Designing Signatures for Verifying 3D Object Genuinity
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Aliaga, Daniel G.; Atallah, Mikhail J.
    3D computer graphics models and digitally-controlled manufacturing have come together to enable the design, visualization, simulation, and automated creation of complex 3D objects. In our work, we propose and implement a framework for designing computer graphics objects and digitally manufacturing them such that no adversary can make imitations or counterfeit copies of the physical object, even if the adversary has a large number of original copies of the object, knowledge of the original object design, and has manufacturing precision that is comparable to or superior to that of the legitimate creator of the object. Our approach is to design and embed a signature on the surface of the object which acts as a certificate of genuinity of the object. The signature is detectable by a signature-reading device, based on methods in computer graphics and computer vision, which contains some of the secret information that was used when marking the physical object. Further, the compromise of a signature-reading device by an adversary who is able to extract all its secrets, does not enable the adversary to create counterfeit objects that fool other readers, thereby still enabling reliable copy detection. We implemented a prototype of our scheme end-to-end, including the production of the physical object and the genuinity-testing device.
  • Thumbnail Image
    Item
    Range Scan Registration Using Reduced Deformable Models
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Chang, W.; Zwicker, M.
    We present an unsupervised method for registering range scans of deforming, articulated shapes. The key idea is to model the motion of the underlying object using a reduced deformable model. We use a linear skinning model for its simplicity and represent the weight functions on a regular grid localized to the surface geometry. This decouples the deformation model from the surface representation and allows us to deal with the severe occlusion and missing data that is inherent in range scan data. We formulate the registration problem using an objective function that enforces close alignment of the 3D data and includes an intuitive notion of joints. This leads to an optimization problem that we solve using an efficient EM-type algorithm. With our algorithm we obtain smooth deformations that accurately register pairs of range scans with significant motion and occlusion. The main advantages of our approach are that it does not require user specified markers, a template, nor manual segmentation of the surface geometry into rigid parts.
  • Thumbnail Image
    Item
    Arches: a Framework for Modeling Complex Terrains
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Peytavie, A.; Galin, E.; Grosjean, J.; Merillou, S.
    In this paper, we present a framework for representing complex terrains with such features as overhangs, arches and caves and including different materials such as sand and rocks. Our hybrid model combines a volumetric discrete data structure that stores the different materials and an implicit representation for sculpting and reconstructing the surface of the terrain. Complex scenes can be edited and sculpted interactively with high level tools. We also propose an original rock generation technique that enables us to automatically generate complex rocky sceneries with piles of rocks without any computationally demanding physically-based simulation.
  • Thumbnail Image
    Item
    Structure-Preserving Reshape for Textured Architectural Scenes
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Cabral, Marcio; Lefebvre, Sylvain; Dachsbacher, Carsten; Drettakis, George
    Modeling large architectural environments is a difficult task due to the intricate nature of these models and the complex dependencies between the structures represented. Moreover, textures are an essential part of architectural models. While the number of geometric primitives is usually relatively low (i.e., many walls are at surfaces), textures actually contain many detailed architectural elements.We present an approach for modeling architectural scenes by reshaping and combining existing textured models, where the manipulation of the geometry and texture are tightly coupled. For geometry, preserving angles such as oor orientation or vertical walls is of key importance. We thus allow the user to interactively modify lengths of edges, while constraining angles. Our texture reshaping solution introduces a measure of directional autosimilarity to focus stretching in areas of stochastic content and to preserve details in such areas.We show results on several challenging models, and show two applications: Building complex road structures from simple initial pieces and creating complex game-levels from an existing game based on pre-existing model pieces.
  • Thumbnail Image
    Item
    Interactive Geometric Simulation of 4D Cities
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Weber, Basil; Mueller, Pascal; Wonka, Peter; Gross, Markus
    We present a simulation system that can simulate a three-dimensional urban model over time. The main novelty of our approach is that we do not rely on land-use simulation on a regular grid, but instead build a complete and inherently geometric simulation that includes exact parcel boundaries, streets of arbitrary orientation, street widths, 3D street geometry, building footprints, and 3D building envelopes. The second novelty is the fast simulation time and user interaction at interactive speed of about 1 second per time step.
  • Thumbnail Image
    Item
    Feature Preserving Point Set Surfaces based on Non-Linear Kernel Regression
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Oeztireli, A. C.; Guennebaud, G.; Gross, M.
    Moving least squares (MLS) is a very attractive tool to design effective meshless surface representations. However, as long as approximations are performed in a least square sense, the resulting definitions remain sensitive to outliers, and smooth-out small or sharp features. In this paper, we address these major issues, and present a novel point based surface definition combining the simplicity of implicit MLS surfaces [SOS04,Kol05] with the strength of robust statistics. To reach this new definition, we review MLS surfaces in terms of local kernel regression, opening the doors to a vast and well established literature from which we utilize robust kernel regression. Our novel representation can handle sparse sampling, generates a continuous surface better preserving fine details, and can naturally handle any kind of sharp features with controllable sharpness. Finally, it combines ease of implementation with performance competing with other non-robust approaches.
  • Thumbnail Image
    Item
    Completion and Reconstruction with Primitive Shapes
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Schnabel, Ruwen; Degener, Patrick; Klein, Reinhard
    We consider the problem of reconstruction from incomplete point-clouds. To find a closed mesh the reconstruction is guided by a set of primitive shapes which has been detected on the input point-cloud (e.g. planes, cylinders etc.). With this guidance we not only continue the surrounding structure into the holes but also synthesize plausible edges and corners from the primitives intersections. To this end we give a surface energy functional that incorporates the primitive shapes in a guiding vector field. The discretized functional can be minimized with an efficient graph-cut algorithm. A novel greedy optimization strategy is proposed to minimize the functional under the constraint that surface parts corresponding to a given primitive must be connected. From the primitive shapes our method can also reconstruct an idealized model that is suitable for use in a CAD system.
  • Thumbnail Image
    Item
    Heightfield and spatially varying BRDF Reconstruction for Materials with Interreflections
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Ruiters, Roland; Klein, Reinhard
    Photo-realistic reproduction of material appearance from images has widespread use in applications ranging from movies over advertising to virtual prototyping. A common approach to this task is to reconstruct the small scale geometry of the sample and to capture the reflectance properties using spatially varying BRDFs. For this, multi-view and photometric stereo reconstruction can be used, both of which are limited regarding the amount of either view or light directions and suffer from either low- or high-frequency artifacts, respectively. In this paper, we propose a new algorithm combining both techniques to recover heightfields and spatially varying BRDFs while at the same time overcoming the above mentioned drawbacks. Our main contribution is a novel objective function which allows for the reconstruction of a heightfield and high quality SVBRDF including view dependent effects. Thereby, our method also avoids both low and high frequency artifacts. Additionally, our algorithm takes inter-reflections into account allowing for the reconstruction of undisturbed representations of the underlying material. In our experiments, including synthetic and real-world data, we show that our approach is superior to state-of-the-art methods regarding reconstruction error as well as visual impression. Both the reconstructed geometry and the recovered SVBRDF are highly accurate, resulting in a faithful reproduction of the materials characteristic appearance, which is of paramount importance in the context of material rendering.
  • Thumbnail Image
    Item
    Physically Guided Animation of Trees
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Habel, Ralf; Kusternig, Alexander; Wimmer, Michael
    This paper presents a new method to animate the interaction of a tree with wind both realistically and in real time. The main idea is to combine statistical observations with physical properties in two major parts of tree animation. First, the interaction of a single branch with the forces applied to it is approximated by a novel efficient two step nonlinear deformation method, allowing arbitrary continuous deformations and circumventing the need to segment a branch to model its deformation behavior. Second, the interaction of wind with the dynamic system representing a tree is statistically modeled. By precomputing the response function of branches to turbulent wind in frequency space, the motion of a branch can be synthesized efficiently by sampling a 2D motion texture.Using a hierarchical form of vertex displacement, both methods can be combined in a single vertex shader, fully leveraging the power of modern GPUs to realistically animate thousands of branches and ten thousands of leaves at practically no cost.
  • Thumbnail Image
    Item
    Wind projection basis for real-time animation of trees
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Diener, Julien; Rodriguez, Mathieu; Baboud, Lionel; Reveret, Lionel
    This paper presents a real-time method to animate complex scenes of thousands of trees under a user-controllable wind load. Firstly, modal analysis is applied to extract the main modes of deformation from the mechanical model of a 3D tree. The novelty of our contribution is to precompute a new basis of the modal stress of the tree under wind load. At runtime, this basis allows to replace the modal projection of the external forces by a direct mapping for any directional wind. We show that this approach can be efficiently implemented on graphics hardware. This modal animation can be simulated at low computation cost even for large scenes containing thousands of trees.
  • Thumbnail Image
    Item
    Structure from silhouettes: a new paradigm for fast sketch-based design of trees
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Wither, J.; Boudon, F.; Cani, M.-P.; Godin, C.
    Modeling natural elements such as trees in a plausible way, while offering simple and rapid user control, is a challenge. This paper presents a method based on a new structure from silhouettes paradigm. We claim that sketching the silhouettes of foliage at multiple scales is quicker and more intuitive for a user than having to sketch each branch of a tree. This choice allows us to incorporate botanical knowledge, enabling us to infer branches that connect in a plausible way to their parent branch and have a correct distribution in 3D. We illustrate these ideas by presenting a seamless sketch-based interface, used for sketching foliage silhouettes from the scale of an entire tree to the scale of a leaf. Each sketch serves for inferring both the branches at that level and construction lines to serve as support for sub-silhouette refinement. When the user finally zooms out, the style inferred for the branching systems he has refined (in terms of branch density, angle, length distribution and shape) is duplicated to the unspecified branching systems at the same level. Meanwhile, knowledge from botany is again used for extending the branch distribution to 3D, resulting in a full, plausible 3D tree that fits the user-sketched contours. As our results show, this system can be of interest to both experts and novice users. While experts can fully specify all parts of a tree and over-sketch specific branches if required, any user can design a basic 3D tree in one or two minutes, as easily as sketching it with paper and pen.
  • Thumbnail Image
    Item
    Positional, Metric, and Curvature Control for Constraint-Based Surface Deformation
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Eigensatz, Michael; Pauly, Mark
    We present a geometry processing framework that allows direct manipulation or preservation of positional, metric, and curvature constraints anywhere on the surface of a geometric model. Target values for these properties can be specified point-wise or as integrated quantities over curves and surface patches embedded in the shape. For example, the user can draw several curves on the surface and specify desired target lengths, manipulate the normal curvature along these curves, or modify the area or principal curvature distribution of arbitrary surface patches. This user input is converted into a set of non-linear constraints. A global optimization finds the new deformed surface that best satisfies the constraints, while minimizing adaptable measures for metric and curvature distortion that provide explicit control of the deformation semantics. We illustrate how this approach enables flexible surface processing and shape editing operations not available in current systems.
  • Thumbnail Image
    Item
    Implicit Contact Handling for Deformable Objects
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Otaduy, Miguel A.; Tamstorf, Rasmus; Steinemann, Denis; Gross, Markus
    We present an algorithm for robust and efficient contact handling of deformable objects. By being aware of the internal dynamics of the colliding objects, our algorithm provides smooth rolling and sliding, stable stacking, robust impact handling, and seamless coupling of heterogeneous objects, all in a unified manner. We achieve dynamicsawareness through a constrained dynamics formulation with implicit complementarity constraints, and we present two major contributions that enable an efficient solution of the constrained dynamics problem: a time stepping algorithm that robustly ensures non-penetration and progressively refines the formulation of constrained dynamics, and a new solver for large mixed linear complementarity problems, based on iterative constraint anticipation. We show the application of our algorithm in challenging scenarios such as multi-layered cloth moving at high velocities, or colliding deformable solids simulated with large time steps.
  • Thumbnail Image
    Item
    Importance Sampling Spherical Harmonics
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Jarosz, Wojciech; Carr, Nathan A.; Jensen, Henrik Wann
    In this paper we present the first practical method for importance sampling functions represented as spherical harmonics (SH). Given a spherical probability density function (PDF) represented as a vector of SH coefficients, our method warps an input point set to match the target PDF using hierarchical sample warping. Our approach is efficient and produces high quality sample distributions. As a by-product of the sampling procedure we produce a multi-resolution representation of the density function as either a spherical mip-map or Haar wavelet. By exploiting this implicit conversion we can extend the method to distribute samples according to the product of an SH function with a spherical mip-map or Haar wavelet. This generalization has immediate applicability in rendering, e.g., importance sampling the product of a BRDF and an environment map where the lighting is stored as a single high-resolution wavelet and the BRDF is represented in spherical harmonics. Since spherical harmonics can be efficiently rotated, this product can be computed on-the-fly even if the BRDF is stored in local-space. Our sampling approach generates over 6 million samples per second while significantly reducing precomputation time and storage requirements compared to previous techniques.
  • Thumbnail Image
    Item
    Continuum-based Strain Limiting
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Thomaszewski, Bernhard; Pabst, Simon; Strasser, Wolfgang
    We present Continuum-based Strain Limiting (CSL) - a new method for limiting deformations in physically-based cloth simulations. Despite recent developments for nearly inextensible materials, the efficient simulation of general biphasic textiles and their anisotropic behavior remains challenging. Many approaches use soft materials and enforce limits on edge elongations, leading to discretization-dependent behavior. Moreover, they offer no explicit control over shearing and stretching unless specifically aligned meshes are used. Based on a continuum deformation measure, our method allows accurate control over all strain components using individual thresholds. We impose deformation limits element-wise and cast the problem as a 6x6 system of linear equations. CSL can be combined with any cloth simulator and, as a velocity filter, integrates seamlessly into standard collision handling.
  • Thumbnail Image
    Item
    Complex Barycentric Coordinates with Applications to Planar Shape Deformation
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Weber, Ofir; Ben-Chen, Mirela; Gotsman, Craig
  • Thumbnail Image
    Item
    LazyBrush: Flexible Painting Tool for Hand-drawn Cartoons
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Sykora, Daniel; Dingliana, John; Collins, Steven
    In this paper we present LazyBrush, a novel interactive tool for painting hand-made cartoon drawings and animations. Its key advantage is simplicity and flexibility. As opposed to previous custom tailored approaches [SBv05, QWH06] LazyBrush does not rely on style specific features such as homogenous regions or pattern continuity yet still offers comparable or even less manual effort for a broad class of drawing styles. In addition to this, it is not sensitive to imprecise placement of color strokes which makes painting less tedious and brings significant time savings in the context cartoon animation. LazyBrush originally stems from requirements analysis carried out with professional ink-and-paint illustrators who established a list of useful features for an ideal painting tool. We incorporate this list into an optimization framework leading to a variant of Potts energy with several interesting theoretical properties. We show how to minimize it efficiently and demonstrate its usefulness in various practical scenarios including the ink-and-paint production pipeline.
  • Thumbnail Image
    Item
    Compressive Dual Photography
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Sen, Pradeep; Darabi, Soheil
    The accurate measurement of the light transport characteristics of a complex scene is an important goal in computer graphics and has applications in relighting and dual photography. However, since the light transport data sets are typically very large, much of the previous research has focused on adaptive algorithms that capture them efficiently. In this work, we propose a novel, non-adaptive algorithm that takes advantage of the compressibility of the light transport signal in a transform domain to capture it with less acquisitions than with standard approaches. To do this, we leverage recent work in the area of compressed sensing, where a signal is reconstructed from a few samples assuming that it is sparse in a transform domain. We demonstrate our approach by performing dual photography and relighting by using a much smaller number of acquisitions than would normally be needed. Because our algorithm is not adaptive, it is also simpler to implement than many of the current approaches.
  • Thumbnail Image
    Item
    Deblurring by Matching
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Ancuti, Cosmin; Ancuti, Codruta Orniana; Bekaert, Philippe
    Restoration of the photographs damaged by the camera shake is a challenging task that manifested increasing attention in the recent period. Despite of the important progress of the blind deconvolution techniques, due to the ill-posed nature of the problem, the finest details of the kernel blur cannot be recovered entirely. Moreover, the additional constraints and prior assumptions make these approaches to be relative limited.In this paper we introduce a novel technique that removes the undesired blur artifacts from photographs taken by hand-held digital cameras. Our approach is based on the observation that in general several consecutive photographs taken by the users share image regions that project the same scene content. Therefore, we took advantage of additional sharp photographs of the same scene. Based on several invariant local feature points, filtered from the given blurred/non-blurred images, our approach matches the keypoints and estimates the blur kernel using additional statistical constraints.We also present a simple deconvolution technique that preserves edges while minimizing the ringing artifacts in the restored latent image. The experimental results prove that our technique is able to infer accurately the blur kernel while reducing significantly the artifacts of the spoilt images.
  • Thumbnail Image
    Item
    Image Appearance Exploration by Model-Based Navigation
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Shapira, L.; Shamir, A.; Cohen-Or, D.
    Changing the appearance of an image can be a complex and non-intuitive task. Many times the target image colors and look are only known vaguely and many trials are needed to reach the desired results. Moreover, the effect of a specific change on an image is difficult to envision, since one must take into account spatial image considerations along with the color constraints. Tools provided today by image processing applications can become highly technical and non-intuitive including various gauges and knobs.In this paper we introduce a method for changing image appearance by navigation, focusing on recoloring images. The user visually navigates a high dimensional space of possible color manipulations of an image. He can either explore in it for inspiration or refine his choices by navigating into sub regions of this space to a specific goal. This navigation is enabled by modeling the chroma channels of an image s colors using a Gaussian Mixture Model (GMM). The Gaussians model both color and spatial image coordinates, and provide a high dimensional parameterization space of a rich variety of color manipulations. The user s actions are translated into transformations of the parameters of the model, which recolor the image. This approach provides both inspiration and intuitive navigation in the complex space of image color manipulations.
  • Thumbnail Image
    Item
    Spectral-Based Group Formation Control
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Takahashi, Shigeo; Yoshida, Kenichi; Kwon, Taesoo; Lee, Kang Hoon; Lee, Jehee; Shin, Sung Yong
    Given a pair of keyframe formations for a group consisting of multiple individuals, we present a spectral-based approach to smoothly transforming a source group formation into a target formation while respecting the clusters of the involved individuals. The proposed method provides an effective means for controlling the macroscopic spatiotemporal arrangement of individuals for applications such as expressive formations in mass performances and tactical formations in team sports. Our main idea is to formulate this problem as rotation interpolation of the eigenbases for the Laplacian matrices, each of which represents how the individuals are clustered in a given keyframe formation. A stream of time-varying formations is controlled by editing the underlying adjacency relationships among individuals as well as their spatial positions at each keyframe, and interpolating the keyframe formations while producing plausible collective behaviors over a period of time. An interactive system of editing existing group behaviors in a hierarchical fashion has been implemented to provide flexible formation control of large crowds.
  • Thumbnail Image
    Item
    TopoPlan: a topological path planner for real time human navigation under floor and ceiling constraints
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Lamarche, F.
    In this article we present TopoPlan, a topological planner dedicated to real-time humanoid path-planning and motion adaptation to floor and ceiling constraints inside complex static environments. This planner analyzes unstructured 3D triangular meshes in order to automatically determine their topology. The analysis is based on a prismatic spatial subdivision which is analyzed, taking into account humanoid characteristics, in order to extract navigable surfaces and precisely identify environmental constraints such as floors, ceilings, walls, steps and bottlenecks. The technique also provides a lightweight roadmap computation covering all accessible free space. We demonstrate the properties of our topological planner within the context of two reactive motion control processes: an on-the-fly trajectory optimization and foot print generation process that correctly handles climbing of complex staircases, and a reactive ceiling adaptation process that handles beam avoidance and motion adaptation to irregular floors and ceilings. We further show that the computation cost of these processes is compatible with the real time animation of several dozens of virtual humans.
  • Thumbnail Image
    Item
    Dominant Texture and Diffusion Distance Manifolds
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Lu, Jianye; Dorsey, Julie; Rushmeier, Holly
    Texture synthesis techniques require nearly uniform texture samples, however identifying suitable texture samples in an image requires significant data preprocessing. To eliminate this work, we introduce a fully automatic pipeline to detect dominant texture samples based on a manifold generated using the diffusion distance. We define the characteristics of dominant texture and three different types of outliers that allow us to efficiently identify dominant texture in feature space. We demonstrate how this method enables the analysis/synthesis of a wide range of natural textures. We compare textures synthesized from a sample image, with and without dominant texture detection. We also compare our approach to that of using a texture segmentation technique alone, and to using Euclidean, rather than diffusion, distances between texture features.
  • Thumbnail Image
    Item
    Animating Pictures of Fluid using Video Examples
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Okabe, Makoto; Anjyo, Ken; Igarashi, Takeo; Seidel, Hans-Peter
    We propose a system that allows the user to design a continuous flow animation starting from a still fluid image. The basic idea is to apply the fluid motion extracted from a video example to the target image. The system first decomposes the video example into three components, an average image, a flow field and residuals. The user then specifies equivalent information over the target image. The user manually paints the rough flow field, and the system automatically refines it using the estimated gradients of the target image. The user semi-automatically transfers the residuals onto the target image. The system then approximates the average image and synthesizes an animation on the target image by adding the transferred residuals and warping them according to the user-specified flow field. Finally, the system adjusts the appearance of the resulting animation by applying histogram matching. We designed animations of various pictures, such as rivers, waterfalls, fires, and smoke.
  • Thumbnail Image
    Item
    Example-Based Rendering of Eye Movements
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Banf, Michael and Blanz, Volker
    This paper describes a model for example-based, photo-realistic rendering of eye movements in 3D facial animation. Based on 3D scans of a face with different gaze directions, the model captures the motion of the eyeball along with the deformation of the eyelids and the surrounding skin. These deformations are represented in a 3D morphable model.Unlike the standard procedure in facial animation, the eyeball is not modeled as a rotating 3D sphere located behind the skin surface. Instead, the visible region of the eyeball is part of a continuous face mesh, and displacements of the iris as well as occlusions by the lids are modeled in a texture mapping approach. The algorithm avoids artifacts that are widely encountered in 3D facial animation, and it presents a new concept of handling occlusions and discontinuities in morphing algorithms.
  • Thumbnail Image
    Item
    Table-based Alpha Compression
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Wennersten, Per; Stroem, Jacob
  • Thumbnail Image
    Item
    Symmetry Detection Using Feature Lines
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Bokeloh, M.; Berner, A.; Wand, M.; Seidel, H.-P.; Schilling, A.
    In this paper, we describe a new algorithm for detecting structural redundancy in geometric data sets. Our algorithm computes rigid symmetries, i.e., subsets of a surface model that reoccur several times within the model differing only by translation, rotation or mirroring. Our algorithm is based on matching locally coherent constellations of feature lines on the object surfaces. In comparison to previous work, the new algorithm is able to detect a large number of symmetric parts without restrictions to regular patterns or nested hierarchies. In addition, working on relevant features only leads to a strong reduction in memory and processing costs such that very large data sets can be handled. We apply the algorithm to a number of real world 3D scanner data sets, demonstrating high recognition rates for general patterns of symmetry.
  • Thumbnail Image
    Item
    Detecting Symmetries and Curvilinear Arrangements in Vector Art
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Yeh, Yi-Ting; Mech, Radomir
    Understanding symmetries and arrangements in existing content is the first step towards providing higher level content aware editing capabilities. Such capabilities may include edits that both preserve existing structure as well as synthesize entirely new structures based on the extracted pattern rules. In this paper we show how to detect regular symmetries and arrangement along curved segments in vector art. We determine individual elements in the art by using the transformation similarity for sequences of sample points on the input curves. Then we detect arrangements of those elements along an arbitrary curved path. We can un-warp the arrangement path to detect symmetries near the path. We introduce novel applications inform of editing elements that are arranged along a curved path. This includes their sliding along the path, changing of their spacing, or their scale. We also allow the user to brush the elements that the system recognized along new paths.
  • Thumbnail Image
    Item
    Learning good views through intelligent galleries
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Vieira, Thales; Bordignon, Alex; Peixoto, Adelailson; Tavares, Geovan; Lopes, Helio; Velho, Luiz; Lewiner, Thomas
    The definition of a good view of a 3D scene is highly subjective and strongly depends on both the scene content and the 3D application. Usually, camera placement is performed directly by the user, and that task may be laborious. Existing automatic virtual cameras guide the user by optimizing a single rule, e.g. maximizing the visible silhouette or the projected area. However, the use of a static pre-defined rule may fail in respecting the user s subjective understanding of the scene. This work introduces intelligent design galleries, a learning approach for subjective problems such as the camera placement. The interaction of the user with a design gallery teaches a statistical learning machine. The trained machine can then imitate the user, either by pre-selecting good views or by automatically placing the camera. The learning process relies on a Support Vector Machines for classifying views from a collection of descriptors, ranging from 2D image quality to 3D features visibility. Experiments of the automatic camera placement demonstrate that the proposed technique is efficient and handles scenes with occlusion and high depth complexities. This work also includes user validations of the intelligent gallery interface.