SCA 12: Eurographics/SIGGRAPH Symposium on Computer Animation

Permanent URI for this collection

https://diglib.eg.org/handle/10.2312/424

Efficient Simulation of Example-Based Materials

[meta data] [files:
001-008.pdf ,
ebem2_final.mp4
]
Schumacher, Christian
; 
Thomaszewski, Bernhard
; 
Coros, Stelian
; 
Martin, Sebastian
; 
Sumner, Robert
; 
Gross, Markus

Enriching Coarse Interactive Elastic Objects with High-Resolution Data-Driven Deformations

[meta data] [files:
009-017.pdf ,
seiler.sca2012.x264.mp4
]
Seiler, Martin
; 
Spillmann, Jonas
; 
Harders, Matthias

Real-Time Example-Based Elastic Deformation

[meta data] [files:
019-024.pdf ,
video.mp4
]
Koyama, Yuki
; 
Takayama, Kenshi
; 
Umetani, Nobuyuki
; 
Igarashi, Takeo

Energetically Consistent Invertible Elasticity

[meta data] [files:
025-032.pdf ,
tech-report-elasticity.pdf ,
video.mov
]
Stomakhin, Alexey
; 
Howes, Russell
; 
Schroeder, Craig
; 
Teran, Joseph M.

Combining Marker-based Mocap and RGB-D Camera for Acquiring High-fidelity Hand Motion Data

[meta data] [files:
033-042.pdf ,
hand_mocap_sca2012.avi
]
Zhao, Wenping
; 
Chai, Jinxiang
; 
Xu, Ying-Qing

Finger Walking: Motion Editing with Contact-Based Hand Performance

[meta data] [files:
043-052.pdf ,
fingerwalking_final.mp4
]
Lockwood, Noah
; 
Singh, Karan

Interactive Steering of Mesh Animations

[meta data] [files:
053-058.pdf ,
steering_mesh_animations.avi
]
Vögele, Anna
; 
Hermann, Max
; 
Krüger, Björn
; 
Klein, Reinhard

Occlusion-free Camera Control for Multiple Targets

[meta data] [files:
059-064.pdf ,
sca-2012.mp4
]
Christie, Marc
; 
Normand, Jean-Marie
; 
Olivier, Patrick

Smoke Sheets for Graph-Structured Vortex Filaments

[meta data] [files:
077-086.pdf ,
video.mp4
]
Barnat, Alfred
; 
Pollard, Nancy S.

Efficient Composition for Virtual Camera Control

[meta data] [files:
065-070.pdf ,
technical_final.mp4
]
Lino, Christophe
; 
Christie, Marc

Mathematical Analysis on Affine Maps for 2D Shape Interpolation

[meta data] [files:
071-076.pdf ,
20120716.mp4
]
Kaji, Shizuo
; 
Hirose, Sampei
; 
Sakata, Shigehiro
; 
Mizoguchi, Yoshihiro
; 
Anjyo, Ken

Linear-Time Smoke Animation with Vortex Sheet Meshes

[meta data] [files:
087-095.pdf ,
bkb2012.mov
]
Brochu, Tyson
; 
Keeler, Todd
; 
Bridson, Robert

Multiphase Flow of Immiscible Fluids on Unstructured Moving Meshes

[meta data] [files:
097-106.pdf ,
three_fluids_angle.mp4
]
Misztal, Marek Krzysztof
; 
Erleben, Kenny
; 
Bargteil, Adam
; 
Fursund, Jens
; 
Christensen, Brian Bunch
; 
Bærentzen, J. Andreas
; 
Bridson, Robert

Tiling Motion Patches

[meta data] [files:
117-126.pdf ,
sca2012_cameraready.mp4
]
Kim, Manmyung
; 
Hwang, Youngseok
; 
Hyun, Kyunglyul
; 
Lee, Jehee

Simulating Free Surface Flow with Very Large Time Steps

[meta data] [files:
107-116.pdf ,
sca2012-final.mp4
]
Lentine, Michael
; 
Cong, Matthew
; 
Patkar, Saket
; 
Fedkiw, Ronald

Contact-Invariant Optimization for Hand Manipulation

[meta data] [files:
137-144.pdf ,
sca2012.mov
]
Mordatch, Igor
; 
Popovic, Zoran
; 
Todorov, Emanuel

Precomputed Motion Maps for Unstructured Motion Capture

[meta data] [files:
127-136.pdf ,
sca12_mov.mov
]
Mahmudi, Mentar
; 
Kallmann, Marcelo

Task-driven Posture Optimization for Virtual Characters

[meta data] [files:
155-164.pdf ,
video_paper1009_mpeg.mpeg
]
Liu, Mingxing
; 
Micaelli, Alain
; 
Evrard, Paul
; 
Escande, Adrien

Learning Motion Controllers with Adaptive Depth Perception

[meta data] [files:
145-154.pdf ,
sca12.mov
]
Lo, Wan-Yen
; 
Knaus, Claude
; 
Zwicker, Matthias

Component-based Locomotion Composition

[meta data] [files:
165-173.pdf ,
paper1043_final.mp4
]
Kim, Yejin
; 
Neff, Michael

Evaluating the Plausibility of Edited Throwing Animations

[meta data] [files:
175-182.pdf ,
sca2012.mp4
]
Vicovaro, Michele
; 
Hoyet, Ludovic
; 
Burigana, Luigi
; 
O'Sullivan, Carol

Environment-aware Real-Time Crowd Control

[meta data] [files:
193-200.pdf ,
sca.avi
]
Henry, Joseph
; 
Shum, Hubert P. H.
; 
Komura, Taku

Quaternion Space Sparse Decomposition for Motion Compression and Retrieval

[meta data] [files:
183-192.pdf ,
scademo.mp4
]
Zhu, Mingyang
; 
Sun, Huaijiang
; 
Deng, Zhigang

Cloning Crowd Motions

[meta data] [files:
201-210.pdf ,
sca12_50mb.mp4
]
Li, Yi
; 
Christie, Marc
; 
Siret, Orianne
; 
Kulpa, Richard
; 
Pettré, Julien

Simple Data-Driven Control for Simulated Bipeds

[meta data] [files:
211-219.pdf ,
1105_video_1.wmv ,
1105_video_2.wmv
]
Geijtenbeek, T.
; 
Pronost, Nicolas
; 
Stappen, A. F. van der

Physically Plausible Simulation for Character Animation

[meta data] [files:
221-230.pdf ,
quasiphysical.mp4
]
Levine, Sergey
; 
Popovic, Jovan

Misconceptions of PD Control in Animation

[meta data] [files:
231-234.pdf
]
Allen, Brian F.
; 
Faloutsos, Petros

Principal Geodesic Dynamics

[meta data] [files:
235-244.pdf ,
paper1047.mp4
]
Tournier, Maxime
; 
Reveret, Lionel

Mass-Conserving Eulerian Liquid Simulation

[meta data] [files:
245-254.pdf ,
sca2012_30fps.avi
]
Chentanez, Nuttapong
; 
Müller, Matthias

Controlling Liquids Using Meshes

[meta data] [files:
255-264.pdf ,
controllingliquids-sca2012.mov
]
Raveendran, Karthik
; 
Thuerey, Nils
; 
Wojtan, Chris
; 
Turk, Greg

Faster Acceleration Noise for Multibody Animations using Precomputed Soundbanks

[meta data] [files:
265-274.pdf ,
sca_video.mp4
]
Chadwick, Jeffrey N.
; 
Zheng, Changxi
; 
James, Doug L.

Dynamic Units of Visual Speech

[meta data] [files:
275-284.pdf ,
visemes-sca-2012-720-final.mov
]
Taylor, Sarah L.
; 
Mahler, Moshe
; 
Theobald, Barry-John
; 
Matthews, Iain

Efficient Collision Detection for Brittle Fracture

[meta data] [files:
285-294.pdf ,
efficient_collision_detection_for_brittle_fracture.mp4
]
Glondu, Loeiz
; 
Schvartzman, Sara C.
; 
Marchal, Maud
; 
Dumont, Georges
; 
Otaduy, Miguel A.

Multi-linear Data-Driven Dynamic Hair Model with Efficient Hair-Body Collision Handling

[meta data] [files:
295-304.pdf ,
hair_sca_final_submission_compressed2.mov
]
Guan, Peng
; 
Sigal, Leonid
; 
Reznitskaya, Valeria
; 
Hodgins, Jessica K.

The Intersection Contour Minimization Method for Untangling Oriented Deformable Surfaces

[meta data] [files:
311-316.pdf
]
Ye, Juntao
; 
Zhao, Jing

Long Range Attachments - A Method to Simulate Inextensible Clothing in Computer Games

[meta data] [files:
305-310.pdf ,
capelra.avi ,
capenolra.avi ,
capeushu.avi ,
figure2left.avi
]
Kim, Tae-Yong
; 
Chentanez, Nuttapong
; 
Müller-Fischer, Matthias

BibTeX (SCA 12: Eurographics/SIGGRAPH Symposium on Computer Animation)
@inproceedings{
:10.2312/SCA/SCA12/001-008,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Efficient Simulation of Example-Based Materials}},

author = {
Schumacher, Christian
 and 
Thomaszewski, Bernhard
 and 
Coros, Stelian
 and 
Martin, Sebastian
 and 
Sumner, Robert
 and 
Gross, Markus
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/001-008}

}
@inproceedings{
:10.2312/SCA/SCA12/009-017,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Enriching Coarse Interactive Elastic Objects with High-Resolution Data-Driven Deformations}},

author = {
Seiler, Martin
 and 
Spillmann, Jonas
 and 
Harders, Matthias
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/009-017}

}
@inproceedings{
:10.2312/SCA/SCA12/019-024,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Real-Time Example-Based Elastic Deformation}},

author = {
Koyama, Yuki
 and 
Takayama, Kenshi
 and 
Umetani, Nobuyuki
 and 
Igarashi, Takeo
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/019-024}

}
@inproceedings{
:10.2312/SCA/SCA12/025-032,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Energetically Consistent Invertible Elasticity}},

author = {
Stomakhin, Alexey
 and 
Howes, Russell
 and 
Schroeder, Craig
 and 
Teran, Joseph M.
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/025-032}

}
@inproceedings{
:10.2312/SCA/SCA12/033-042,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Combining Marker-based Mocap and RGB-D Camera for Acquiring High-fidelity Hand Motion Data}},

author = {
Zhao, Wenping
 and 
Chai, Jinxiang
 and 
Xu, Ying-Qing
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/033-042}

}
@inproceedings{
:10.2312/SCA/SCA12/043-052,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Finger Walking: Motion Editing with Contact-Based Hand Performance}},

author = {
Lockwood, Noah
 and 
Singh, Karan
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/043-052}

}
@inproceedings{
:10.2312/SCA/SCA12/053-058,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Interactive Steering of Mesh Animations}},

author = {
Vögele, Anna
 and 
Hermann, Max
 and 
Krüger, Björn
 and 
Klein, Reinhard
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/053-058}

}
@inproceedings{
:10.2312/SCA/SCA12/059-064,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Occlusion-free Camera Control for Multiple Targets}},

author = {
Christie, Marc
 and 
Normand, Jean-Marie
 and 
Olivier, Patrick
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/059-064}

}
@inproceedings{
:10.2312/SCA/SCA12/077-086,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Smoke Sheets for Graph-Structured Vortex Filaments}},

author = {
Barnat, Alfred
 and 
Pollard, Nancy S.
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/077-086}

}
@inproceedings{
:10.2312/SCA/SCA12/065-070,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Efficient Composition for Virtual Camera Control}},

author = {
Lino, Christophe
 and 
Christie, Marc
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/065-070}

}
@inproceedings{
:10.2312/SCA/SCA12/071-076,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Mathematical Analysis on Affine Maps for 2D Shape Interpolation}},

author = {
Kaji, Shizuo
 and 
Hirose, Sampei
 and 
Sakata, Shigehiro
 and 
Mizoguchi, Yoshihiro
 and 
Anjyo, Ken
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/071-076}

}
@inproceedings{
:10.2312/SCA/SCA12/087-095,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Linear-Time Smoke Animation with Vortex Sheet Meshes}},

author = {
Brochu, Tyson
 and 
Keeler, Todd
 and 
Bridson, Robert
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/087-095}

}
@inproceedings{
:10.2312/SCA/SCA12/097-106,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Multiphase Flow of Immiscible Fluids on Unstructured Moving Meshes}},

author = {
Misztal, Marek Krzysztof
 and 
Erleben, Kenny
 and 
Bargteil, Adam
 and 
Fursund, Jens
 and 
Christensen, Brian Bunch
 and 
Bærentzen, J. Andreas
 and 
Bridson, Robert
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/097-106}

}
@inproceedings{
:10.2312/SCA/SCA12/117-126,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Tiling Motion Patches}},

author = {
Kim, Manmyung
 and 
Hwang, Youngseok
 and 
Hyun, Kyunglyul
 and 
Lee, Jehee
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/117-126}

}
@inproceedings{
:10.2312/SCA/SCA12/107-116,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Simulating Free Surface Flow with Very Large Time Steps}},

author = {
Lentine, Michael
 and 
Cong, Matthew
 and 
Patkar, Saket
 and 
Fedkiw, Ronald
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/107-116}

}
@inproceedings{
:10.2312/SCA/SCA12/137-144,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Contact-Invariant Optimization for Hand Manipulation}},

author = {
Mordatch, Igor
 and 
Popovic, Zoran
 and 
Todorov, Emanuel
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/137-144}

}
@inproceedings{
:10.2312/SCA/SCA12/127-136,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Precomputed Motion Maps for Unstructured Motion Capture}},

author = {
Mahmudi, Mentar
 and 
Kallmann, Marcelo
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/127-136}

}
@inproceedings{
:10.2312/SCA/SCA12/155-164,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Task-driven Posture Optimization for Virtual Characters}},

author = {
Liu, Mingxing
 and 
Micaelli, Alain
 and 
Evrard, Paul
 and 
Escande, Adrien
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/155-164}

}
@inproceedings{
:10.2312/SCA/SCA12/145-154,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Learning Motion Controllers with Adaptive Depth Perception}},

author = {
Lo, Wan-Yen
 and 
Knaus, Claude
 and 
Zwicker, Matthias
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/145-154}

}
@inproceedings{
:10.2312/SCA/SCA12/165-173,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Component-based Locomotion Composition}},

author = {
Kim, Yejin
 and 
Neff, Michael
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/165-173}

}
@inproceedings{
:10.2312/SCA/SCA12/175-182,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Evaluating the Plausibility of Edited Throwing Animations}},

author = {
Vicovaro, Michele
 and 
Hoyet, Ludovic
 and 
Burigana, Luigi
 and 
O'Sullivan, Carol
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/175-182}

}
@inproceedings{
:10.2312/SCA/SCA12/193-200,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Environment-aware Real-Time Crowd Control}},

author = {
Henry, Joseph
 and 
Shum, Hubert P. H.
 and 
Komura, Taku
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/193-200}

}
@inproceedings{
:10.2312/SCA/SCA12/183-192,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Quaternion Space Sparse Decomposition for Motion Compression and Retrieval}},

author = {
Zhu, Mingyang
 and 
Sun, Huaijiang
 and 
Deng, Zhigang
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/183-192}

}
@inproceedings{
:10.2312/SCA/SCA12/201-210,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Cloning Crowd Motions}},

author = {
Li, Yi
 and 
Christie, Marc
 and 
Siret, Orianne
 and 
Kulpa, Richard
 and 
Pettré, Julien
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/201-210}

}
@inproceedings{
:10.2312/SCA/SCA12/211-219,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Simple Data-Driven Control for Simulated Bipeds}},

author = {
Geijtenbeek, T.
 and 
Pronost, Nicolas
 and 
Stappen, A. F. van der
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/211-219}

}
@inproceedings{
:10.2312/SCA/SCA12/221-230,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Physically Plausible Simulation for Character Animation}},

author = {
Levine, Sergey
 and 
Popovic, Jovan
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/221-230}

}
@inproceedings{
:10.2312/SCA/SCA12/231-234,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Misconceptions of PD Control in Animation}},

author = {
Allen, Brian F.
 and 
Faloutsos, Petros
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/231-234}

}
@inproceedings{
:10.2312/SCA/SCA12/235-244,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Principal Geodesic Dynamics}},

author = {
Tournier, Maxime
 and 
Reveret, Lionel
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/235-244}

}
@inproceedings{
:10.2312/SCA/SCA12/245-254,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Mass-Conserving Eulerian Liquid Simulation}},

author = {
Chentanez, Nuttapong
 and 
Müller, Matthias
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/245-254}

}
@inproceedings{
:10.2312/SCA/SCA12/255-264,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Controlling Liquids Using Meshes}},

author = {
Raveendran, Karthik
 and 
Thuerey, Nils
 and 
Wojtan, Chris
 and 
Turk, Greg
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/255-264}

}
@inproceedings{
:10.2312/SCA/SCA12/265-274,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Faster Acceleration Noise for Multibody Animations using Precomputed Soundbanks}},

author = {
Chadwick, Jeffrey N.
 and 
Zheng, Changxi
 and 
James, Doug L.
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/265-274}

}
@inproceedings{
:10.2312/SCA/SCA12/275-284,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Dynamic Units of Visual Speech}},

author = {
Taylor, Sarah L.
 and 
Mahler, Moshe
 and 
Theobald, Barry-John
 and 
Matthews, Iain
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/275-284}

}
@inproceedings{
:10.2312/SCA/SCA12/285-294,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Efficient Collision Detection for Brittle Fracture}},

author = {
Glondu, Loeiz
 and 
Schvartzman, Sara C.
 and 
Marchal, Maud
 and 
Dumont, Georges
 and 
Otaduy, Miguel A.
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/285-294}

}
@inproceedings{
:10.2312/SCA/SCA12/295-304,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Multi-linear Data-Driven Dynamic Hair Model with Efficient Hair-Body Collision Handling}},

author = {
Guan, Peng
 and 
Sigal, Leonid
 and 
Reznitskaya, Valeria
 and 
Hodgins, Jessica K.
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/295-304}

}
@inproceedings{
:10.2312/SCA/SCA12/311-316,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
The Intersection Contour Minimization Method for Untangling Oriented Deformable Surfaces}},

author = {
Ye, Juntao
 and 
Zhao, Jing
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/311-316}

}
@inproceedings{
:10.2312/SCA/SCA12/305-310,

booktitle = {
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation},

editor = {
Jehee Lee and Paul Kry
},
title = {{
Long Range Attachments - A Method to Simulate Inextensible Clothing in Computer Games}},

author = {
Kim, Tae-Yong
 and 
Chentanez, Nuttapong
 and 
Müller-Fischer, Matthias
},
year = {
2012},

publisher = {
The Eurographics Association},


ISSN = {1727-5288},
ISBN = {978-3-905674-37-8},

DOI = {
/10.2312/SCA/SCA12/305-310}

}

Browse

Recent Submissions

Now showing 1 - 36 of 36
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    Efficient Simulation of Example-Based Materials
    (The Eurographics Association, 2012) Schumacher, Christian; Thomaszewski, Bernhard; Coros, Stelian; Martin, Sebastian; Sumner, Robert; Gross, Markus; Jehee Lee and Paul Kry
    We present a new method for efficiently simulating art-directable deformable materials. We use example poses to define subspaces of desirable deformations via linear interpolation. As a central aspect of our approach, we use an incompatible representation for input and interpolated poses that allows us to interpolate between elements individually. This enables us to bypass costly reconstruction steps and we thus achieve significant performance improvements compared to previous work. As a natural continuation, we furthermore present a formulation of example-based plasticity. Finally, we extend the directability of example-based materials and explore a number of powerful control mechanisms. We demonstrate these novel concepts on a number of solid and shell animations including artistic deformation behaviors, cartoon physics, and example-based pose space dynamics.
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    Enriching Coarse Interactive Elastic Objects with High-Resolution Data-Driven Deformations
    (The Eurographics Association, 2012) Seiler, Martin; Spillmann, Jonas; Harders, Matthias; Jehee Lee and Paul Kry
    Efficient approximate deformation models allow to interactively simulate elastic objects. However, these approaches usually cannot reproduce the complex deformation behavior governed by geometric and material nonlinearities. In addition, objects having slender shapes require dense simulation meshes, which necessitates additional computational effort. We propose an approach where a dynamic interactive coarse simulation is enriched with details stemming from a more accurate quasi-static simulation in a data-driven way. While the coarse simulation is based on a low-resolution (low-res) mesh and a fast linear deformation model the accurate simulation employs a quasi-static non-linear deformation model at a higher mesh resolution (high-res). We pre-compute pairs of low-res mesh deformations and corresponding high-res details by applying a series of training interactions on both the coarse and the accurate model. At run-time, we only run the coarse simulation and correlate the current state to the training states. Subsequently, we blend detail data in order to obtain a spatio-temporally smooth displacement field that we super-impose on the surface skin, resulting in a plausible display of the non-linearly deformed object at real-time rates. We present examples from both computer animation and medical simulation.
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    Real-Time Example-Based Elastic Deformation
    (The Eurographics Association, 2012) Koyama, Yuki; Takayama, Kenshi; Umetani, Nobuyuki; Igarashi, Takeo; Jehee Lee and Paul Kry
    We present an example-based elastic deformation method that runs in real time. Example-based elastic deformation was originally presented by Martin et al. [MTGG11], where an artist can intuitively control elastic material behaviors by simply giving example poses. Their FEM-based approach is, however, computationally expensive requiring nonlinear optimization, which hinders its use in real-time applications such as games. Our contribution is to formulate an analogous concept using the shape matching framework, which is fast, robust, and easy to implement. The key observation is that each overlapping local region's right stretch tensor obtained by polar decomposition is a natural choice for a deformation descriptor. This descriptor allows us to represent the pose space as a linear blending of examples. At each time step, the current deformation descriptor is linearly projected onto the example manifold, and then used to modify the rest shape of each local region when computing goal positions. Our approach is two orders of magnitude faster than Martin et al.'s approach while producing comparable example-based elastic deformations.
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    Energetically Consistent Invertible Elasticity
    (The Eurographics Association, 2012) Stomakhin, Alexey; Howes, Russell; Schroeder, Craig; Teran, Joseph M.; Jehee Lee and Paul Kry
    We provide a smooth extension of arbitrary isotropic hyperelastic energy density functions to inverted configurations. This extension is designed to improve robustness for elasticity simulations with ex- tremely large deformations and is analogous to the extension given to the first Piola-Kirchoff stress in [ITF04]. We show that our energy-based approach is significantly more robust to large deformations than the first Piola-Kirchoff fix. Furthermore, we show that the robustness and stability of a hyper- elastic model can be predicted from a characteristic contour, which we call its primary contour. The extension to inverted configurations is defined via extrapolation from a convex threshold surface that lies in the uninverted portion of the principal stretches space. The extended hyperelastic energy den- sity yields continuous stress and unambiguous stress derivatives in all inverted configurations, unlike in [TSIF05]. We show that our invertible energy-density-based approach outperforms the popular hy- perelastic corotated model, and we also show how to use the primary contour methodology to improve the robustness of this model to large deformations.
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    Combining Marker-based Mocap and RGB-D Camera for Acquiring High-fidelity Hand Motion Data
    (The Eurographics Association, 2012) Zhao, Wenping; Chai, Jinxiang; Xu, Ying-Qing; Jehee Lee and Paul Kry
    Motion capture data has been pivotal to the success of creating realistic animation for human characters. There are a number of public full-body motion databases available, but large and heterogeneous databases for hand articulations are not available. In this paper, we introduce a novel acquisition framework for acquiring a wide range of high-fidelity hand motion data. Our key idea is to leverage marker position data recorded by a twelvecamera optical motion capture system and RGB/Depth data obtained from a single Microsoft Kinect camera. We formulate the hand motion capture problem in a nonlinear optimization framework by maximizing consistency between the reconstructed motion and observed measurement. We introduce an efficient optimization technique to estimate the optimal hand pose that best matches observed data.We have demonstrated the power and effectiveness of our system by capturing a wide variety of delicate hand articulations, even in case of significant self-occlusion.
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    Finger Walking: Motion Editing with Contact-Based Hand Performance
    (The Eurographics Association, 2012) Lockwood, Noah; Singh, Karan; Jehee Lee and Paul Kry
    We present a system for generating full-body animations from the performance on a touch-sensitive tabletop of ''finger walking'', where two fingers are used to pantomime leg movements. A user study was conducted to explore how users can communicate full-body motion using their hands, which concluded that finger walking is a naturally-chosen and comfortable performance method. Based on contact data recorded during this study, the properties of a variety of performed locomotion types were analyzed to determine which motion parameters are most reliable and expressive for the purpose of generating corresponding full-body animations. Based on this analysis, a compact set of motion features was developed for classifying the locomotion type of a finger performance. A prototype interactive animation system was implemented to generate full-body animations of a known locomotion type from finger walking by estimating the motion path of a finger performance, and editing the path of a corresponding animation to match. The classification accuracy and output animation quality of this system was evaluated in a second user study, demonstrating that satisfying full-body animations can be reliably generated from finger performances.
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    Interactive Steering of Mesh Animations
    (The Eurographics Association, 2012) Vögele, Anna; Hermann, Max; Krüger, Björn; Klein, Reinhard; Jehee Lee and Paul Kry
    Creating geometrically detailed mesh animations is an involved and resource-intensive process in digital content creation. In this work we present a method to rapidly combine available sparse motion capture data with existing mesh sequences to produce a large variety of new animations. The key idea is to model shape changes correlated to the pose of the animated object via a part-based statistical shape model. We observe that compact linear models suffice for a segmentation into nearly rigid parts. The same segmentation further guides the parameterization of the pose which is learned in conjunction with the marker movement. Besides the inherent high geometric detail, further benefits of the presented method arise from its robustness against errors in segmentation and pose parameterization. Due to efficiency of both learning and synthesis phase, our model allows to interactively steer virtual avatars based on few markers extracted from video data or input devices like the Kinect sensor.
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    Occlusion-free Camera Control for Multiple Targets
    (The Eurographics Association, 2012) Christie, Marc; Normand, Jean-Marie; Olivier, Patrick; Jehee Lee and Paul Kry
    Maintaining the visibility of target objects is a fundamental problem in automatic camera control for 3D graphics applications. Practical real-time camera control algorithms generally only incorporate mechanisms for the evaluation of the visibility of target objects from a single viewpoint, and idealize the geometric complexity of target objects. Drawing on work in soft shadow generation, we perform low resolution projections, from target objects to rapidly compute their visibility for a sample of locations around the current camera position. This computation is extended to aggregate visibility in a temporal window to improve camera stability in the face of partial and sudden onset occlusion. To capture the full spatial extent of target objects we use a stochastic approximation of their surface area. Our implementation is the first practical occlusion-free real-time camera control framework for multiple target objects. The result is a robust component that can be integrated to any virtual camera control system that requires the precise computation of visibility for multiple targets.
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    Smoke Sheets for Graph-Structured Vortex Filaments
    (The Eurographics Association, 2012) Barnat, Alfred; Pollard, Nancy S.; Jehee Lee and Paul Kry
    Smoke is one of the core phenomena which fluid simulation techniques in computer graphics have attempted to capture. It is both well understood mathematically and important in lending realism to computer generated effects. In an attempt to overcome the diffusion inherent to Eulerian grid-based simulators, a technique has recently been developed which represents velocity using a sparse set of vortex filaments. This has the advantage of providing an easily understandable and controllable model for fluid velocity, but is computationally expensive because each filament affects the fluid velocity over an unbounded region of the simulation space. We present an alternative to existing techniques which merge adjacent filament rings, instead allowing filaments to form arbitrary structures, and we develop a new set of reconnection criteria to take advantage of this filament graph. To complement this technique, we also introduce a method for smoke surface tracking and rendering designed to minimize the number of sample points without introducing excessive diffusion or blurring. Though this representation lends itself to straightforward real-time rendering, we also present a method which renders the thin sheets and curls of smoke as diffuse volumes using any GPU capable of supporting geometry shaders.
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    Efficient Composition for Virtual Camera Control
    (The Eurographics Association, 2012) Lino, Christophe; Christie, Marc; Jehee Lee and Paul Kry
    Automatically positioning a virtual camera in a 3D environment given the specification of visual properties to be satisfied (on-screen layout of subjects, vantage angles, visibility) is a complex and challenging problem. Most approaches tackle the problem by expressing visual properties as constraints or functions to optimize, and rely on computationally expensive search techniques to explore the solution space. We show here how to express and solve the exact on-screen positioning of two or three subjects using a simple and very efficient technique. We express the solution space for each couple of subjects as a 2D manifold surface. We demonstrate how to use this manifold surface to solve Blinn's spacecraft problem with a straightforward algebraic approach. We extend the solution to three subjects and we show how to cast the complex 6D optimization problem tackled by most contributions in the field in a simple 2D optimization on the manifold surface by pruning large portions of the search space. The result is a robust and very efficient technique which finds a wide range of applications in virtual camera control and more generally in computer graphics.
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    Mathematical Analysis on Affine Maps for 2D Shape Interpolation
    (The Eurographics Association, 2012) Kaji, Shizuo; Hirose, Sampei; Sakata, Shigehiro; Mizoguchi, Yoshihiro; Anjyo, Ken; Jehee Lee and Paul Kry
    This paper gives a simple mathematical framework for 2D shape interpolation methods that preserve rigidity. An interpolation technique in this framework works for given the source and target 2D shapes, which are compatibly triangulated. Focusing on the local affine maps between the corresponding triangles, we describe a global transformation as a piecewise affine map. Several existing rigid shape interpolation techniques are discussed and mathematically analyzed through this framework. This gives us not only a useful comprehensive understanding of existing approaches, but also new algorithms and a few improvements of previous approaches.
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    Linear-Time Smoke Animation with Vortex Sheet Meshes
    (The Eurographics Association, 2012) Brochu, Tyson; Keeler, Todd; Bridson, Robert; Jehee Lee and Paul Kry
    We present the first quality physics-based smoke animation method which runs in time approximately linear in the size of the rendered two-dimensional visual detail. Our fundamental representation is a closed triangle mesh surface dividing space between clear air and a uniformly smoky region, on which we compute vortex sheet dynamics to accurately solve inviscid buoyant flow. We handle arbitrary moving no-stick solid boundaries and by default handle an infinite domain. The simulation itself runs in time linear to the number of triangles thanks to the use of a well-conditioned integral equation treatment together with a Fast Multipole Method for linear-time summations, providing excellent performance. Basic zero-albedo smoke rendering, with embedded solids, is easy to implement for interactive rates, and the mesh output can also serve as an extremely compact and detailed input to more sophisticated volume rendering.
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    Multiphase Flow of Immiscible Fluids on Unstructured Moving Meshes
    (The Eurographics Association, 2012) Misztal, Marek Krzysztof; Erleben, Kenny; Bargteil, Adam; Fursund, Jens; Christensen, Brian Bunch; Bærentzen, J. Andreas; Bridson, Robert; Jehee Lee and Paul Kry
    In this paper, we present a method for animating multiphase flow of immiscible fluids using unstructured moving meshes. Our underlying discretization is an unstructured tetrahedral mesh, the deformable simplicial complex (DSC), that moves with the flow in a Lagrangian manner. Mesh optimization operations improve element quality and avoid element inversion. In the context of multiphase flow, we guarantee that every element is occupied by a single fluid and, consequently, the interface between fluids is represented by a set of faces in the simplicial complex. This approach ensures that the underlying discretization matches the physics and avoids the additional book-keeping required in grid-based methods where multiple fluids may occupy the same cell. Our Lagrangian approach naturally leads us to adopt a finite element approach to simulation, in contrast to the finite volume approaches adopted by a majority of fluid simulation techniques that use tetrahedral meshes. We characterize fluid simulation as an optimization problem allowing for full coupling of the pressure and velocity fields and the incorporation of a second-order surface energy. We introduce a preconditioner based on the diagonal Schur complement and solve our optimization on the GPU. We provide the results of parameter studies as well as a performance analysis of our method.
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    Tiling Motion Patches
    (The Eurographics Association, 2012) Kim, Manmyung; Hwang, Youngseok; Hyun, Kyunglyul; Lee, Jehee; Jehee Lee and Paul Kry
    Simulating multiple character interaction is challenging because character actions must be carefully coordinated to align their spatial locations and synchronized with each other. We present an algorithm to create a dense crowd of virtual characters interacting with each other. The interaction may involve physical contacts, such as hand shaking, hugging, and carrying a heavy object collaboratively. We address the problem by collecting deformable motion patches, each of which describes an episode of multiple interacting characters, and tiling them spatially and temporally. The tiling of motion patches generates a seamless simulation of virtual characters interacting with each other in a non-trivial manner. Our tiling algorithm uses a combination of stochastic sampling and deterministic search to address the discrete and continuous aspects of the tiling problem. Our tiling algorithm made it possible to automatically generate highly-complex animation of multiple interacting characters. We achieved the level of complexity far beyond the current state-of-the-art animation techniques could generate, in terms of the diversity of human behaviors and the spatial/temporal density of interpersonal interactions.
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    Simulating Free Surface Flow with Very Large Time Steps
    (The Eurographics Association, 2012) Lentine, Michael; Cong, Matthew; Patkar, Saket; Fedkiw, Ronald; Jehee Lee and Paul Kry
    We provide a novel simulation method for incompressible free surface flows that allows for large time steps on the order of 10-40 times bigger than the typical explicit time step restriction would allow. Although semi-Lagrangian advection allows for this from the standpoint of stability, large time steps typically produce significant visual errors. This was addressed in previous work for smoke simulation using a mass and momentum conserving version of semi-Lagrangian advection, and while its extension to water for momentum conservation for small time steps was addressed, pronounced issues remain when taking large time steps. The main difference between smoke and water is that smoke has a globally defined velocity field whereas water needs to move in a manner uninfluenced by the surrounding air flow, and this poses real issues in determining an appropriate extrapolated velocity field. We alleviate problems with the extrapolated velocity field by not using it when it is incorrect, which we determine via conservative advection of a color function which adds forwardly advected semi-Lagrangian rays to maintain conservation when mass is lost. We note that one might also use a more traditional volume-of-fluid method which is more explicitly focused on the geometry of the interface but can be less visually appealing it is also unclear how to extend volume-of-fluid methods to have larger time steps. Finally, we prefer the visual smoothness of a particle level set method coupled to a traditional backward tracing semi-Lagrangian advection where possible, only using our forward traced color function solution in areas of the flow where the particle level set method fails due to the extremely large time steps.
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    Contact-Invariant Optimization for Hand Manipulation
    (The Eurographics Association, 2012) Mordatch, Igor; Popovic, Zoran; Todorov, Emanuel; Jehee Lee and Paul Kry
    We present a method for automatic synthesis of dexterous hand movements, given only high-level goals specifying what should happen to the object being manipulated. Results are presented on a wide range of tasks including grasping and picking up objects, twirling them between the fingers, tossing and catching, drawing. This work is an extension of the recent contact-invariant optimization (CIO) method, which introduced auxiliary decision variables directly specifying when and where contacts should occur, and optimized these variables together with the movement trajectory. Our contribution here is extending the unique contact model used in CIO which was specific to locomotion tasks, as well as applying the extended method systematically to hand manipulation.
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    Precomputed Motion Maps for Unstructured Motion Capture
    (The Eurographics Association, 2012) Mahmudi, Mentar; Kallmann, Marcelo; Jehee Lee and Paul Kry
    We present in this paper a solution for extracting high-quality motions from unstructured motion capture databases at interactive rates. The proposed solution is based on automatically-built motion graphs, and offers two key contributions. First, we show how precomputed expansion trees (or motion maps) coupled with new heuristics and backtracking techniques are able to significantly improve the time taken to search for motions satisfying user constraints. Second, we show that when feature-based transitions are employed for constructing the underlying motion graph, the connectivity of motion maps is greatly increased, allowing the overall method to perform search and synthesis at interactive frame rates. We demonstrate the effectiveness of our approach with the problem of extracting path-following motions around obstacles from a motion graph structure at interactive performances.
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    Task-driven Posture Optimization for Virtual Characters
    (The Eurographics Association, 2012) Liu, Mingxing; Micaelli, Alain; Evrard, Paul; Escande, Adrien; Jehee Lee and Paul Kry
    This paper presents a generic approach to find optimal postures, including contact positions, for manipulation tasks. It can be used in either the preparation for a task, or the evaluation of the feasibility of a task during planning stages. With such an approach, an animator can control a virtual character from a high level by just specifying a task, such as moving an object along a desired path to a desired position; the animator does not need to manually find suitable postures for the task. For each task, an optimization problem is solved, which considers not only geometric and kinematic constraints, but also force and moment constraints. The optimized postures allow the virtual character to apply manipulation forces as strongly as possible, and meanwhile to avoid foot slipping. Moreover, potential perturbation forces can be taken into account in the optimization to make postures more robust. The realism of our approach is demonstrated with different types of manipulation tasks.
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    Learning Motion Controllers with Adaptive Depth Perception
    (The Eurographics Association, 2012) Lo, Wan-Yen; Knaus, Claude; Zwicker, Matthias; Jehee Lee and Paul Kry
    We present a novel approach to real-time character animation that allows a character to move autonomously based on vision input. By allowing the character to ''see'' the environment directly using depth perception, we can skip the manual design phase of parameterizing the state space in a reinforcement learning framework. In previous work, this is done manually since finding a minimal set of parameters for describing a character's environment is crucial for efficient learning. Learning from raw vision input, however, suffers from the ''curse of dimensionality'', which we avoid by introducing a hierarchical state model and a novel regression algorithm. We demonstrate that our controllers allow a character to navigate and survive in environments containing arbitrarily shaped obstacles, which is hard to achieve with existing reinforcement learning frameworks.
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    Component-based Locomotion Composition
    (The Eurographics Association, 2012) Kim, Yejin; Neff, Michael; Jehee Lee and Paul Kry
    When generating locomotion, it is particularly challenging to adjust the motion's style. This paper introduces a component-based system for human locomotion composition that drives off a set of example locomotion clips. The distinctive style of each example is analyzed in the form of sub-motion components decomposed from separate body parts via independent component analysis (ICA). During the synthesis process, we use these components as combinatorial ingredients to generate new locomotion sequences that are stylistically different from the example set. Our system is designed for novice users who do not have much knowledge of important locomotion properties, such as the correlations throughout the body. Thus, the proposed system analyzes the examples in a unsupervised manner and synthesizes an output locomotion from a small number of control parameters. Our experimental results show that the system can generate physically plausible locomotion in a desired style at interactive speed.
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    Evaluating the Plausibility of Edited Throwing Animations
    (The Eurographics Association, 2012) Vicovaro, Michele; Hoyet, Ludovic; Burigana, Luigi; O'Sullivan, Carol; Jehee Lee and Paul Kry
    Animation budget constraints during the development of a game often call for the use of a limited set of generic motions. Editing operations are thus generally required to animate virtual characters with a sufficient level of variety. Evaluating the perceptual plausibility of edited animations can therefore contribute greatly towards producing visually plausible animations. In this paper we study observers' sensitivity to manipulations of overarm and underarm biological throwing animations. In our first experiment, we used Dynamic Time Warping to edit the biological throwing motions, and modified the release velocity of the ball accordingly. We found that observers are more tolerant to speeding up of the original throwing motion than to slowing down, and that slowed down underarm throws are perceived as particularly unnatural. In our second experiment, we modified separately horizontal and vertical components of the release velocity of the ball, while leaving the motion of the thrower unchanged. We found that observers are more sensitive to manipulations of the horizontal component in overarm throws, and of the vertical component in underarm throws. As in the first experiment, we found that observers are most disturbed by decreases in the velocity of the ball in underarm throws. Our results provide valuable insights for developers of games and VR applications by specifying thresholds for the perceptual plausibility of throwing manipulations.
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    Environment-aware Real-Time Crowd Control
    (The Eurographics Association, 2012) Henry, Joseph; Shum, Hubert P. H.; Komura, Taku; Jehee Lee and Paul Kry
    Real-time crowd control has become an important research topic due to the recent advancement in console game quality and hardware processing capability. The degrees of freedom of a crowd is much higher than that provided by a standard user input device. As a result most crowd control systems require the user to design the crowd move- ments through multiple passes, such as first specifying the crowd's start and goal points, then providing the agent trajectories with streamlines. Such a multi-pass control would spoil the responsiveness and excitement of real- time games. In this paper, we propose a new, single-pass algorithm to control crowds using a deformable mesh. When controlling crowds, we observe that most of the low level details are related to passive interactions between the crowd and the environment, such as obstacle avoidance and diverging/merging at cross points. Therefore, we simplify the crowd control problem by representing the crowd with a deformable mesh that passively reacts to the environment. As a result, the user can focus on high level control that is more important for context delivery. Our algorithm provides an efficient crowd control framework while maintaining the quality of the simulation, which is useful for real-time applications such as strategy games.
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    Quaternion Space Sparse Decomposition for Motion Compression and Retrieval
    (The Eurographics Association, 2012) Zhu, Mingyang; Sun, Huaijiang; Deng, Zhigang; Jehee Lee and Paul Kry
    Quaternion has become one of the most widely used representations for rotational transformations in 3D graphics for decades. Due to the sparse nature of human motion in both the spatial domain and the temporal domain, an unexplored yet challenging research problem is how to directly represent intrinsically sparse human motion data in quaternion space. In this paper we propose a novel quaternion space sparse decomposition (QSSD) model that decomposes human rotational motion data into two meaningful parts (namely, the dictionary part and the weight part) with the sparseness constraint on the weight part. Specifically, a linear combination (addition) operation in Euclidean space is equivalently modeled as a quaternion multiplication operation, and the weight of linear combination is modeled as a power operation on quaternion. Besides validations of the robustness, convergence, and accuracy of the QSSD model, we also demonstrate its two selected applications: human motion data compression and content-based human motion retrieval. Through numerous experiments and quantitative comparisons, we demonstrate that the QSSD-based approaches can soundly outperform existing state-of-the-art human motion compression and retrieval approaches.
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    Cloning Crowd Motions
    (The Eurographics Association, 2012) Li, Yi; Christie, Marc; Siret, Orianne; Kulpa, Richard; Pettré, Julien; Jehee Lee and Paul Kry
    This paper introduces a method to clone crowd motion data. Our goal is to efficiently animate large crowds from existing examples of motions of groups of characters by applying an enhanced copy and paste technique on them. Specifically, we address spatial and temporal continuity problems to enable animation of significantly larger crowds than our initial data. We animate many characters from the few examples with no limitation on duration. Moreover, our animation technique answers the needs of real-time applications through a technique of linear complexity. Therefore, it is significantly more efficient than any existing crowd simulation-based technique, and in addition, we ensure a predictable level of realism for animations. We provide virtual population designers and animators with a powerful framework which (i) enables them to clone crowd motion examples while preserving the complexity and the aspect of group motion and (ii) is able to animate large-scale crowds in real-time. Our contribution is the formulation of the cloning problem as a double search problem. Firstly, we search for almost periodic portions of crowd motion data through the available examples. Secondly, we search for almost symmetries between the conditions at the limits of these portions in order to interconnect them. The result of our searches is a set of crowd patches that contain portions of example data that can be used to compose large and endless animations. Through several examples prepared from real crowd motion data, we demonstrate the advantageous properties of our approach as well as identify its potential for future developments.
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    Simple Data-Driven Control for Simulated Bipeds
    (The Eurographics Association, 2012) Geijtenbeek, T.; Pronost, Nicolas; Stappen, A. F. van der; Jehee Lee and Paul Kry
    We present a framework for controlling physics-based bipeds in a simulated environment, based on a variety of reference motions. Unlike existing methods for control based on reference motions, our framework does not require preprocessing of the reference motion, nor does it rely on inverse dynamics or on-line optimization methods for torque computation. It consists of three components: Proportional-Derivative Control to mimic motion characteristics, a specific form of Jacobian Transpose Control for balance control, and Covariance Matrix Adaption for off-line parameter optimization, based on a novel high-level reward function. The framework can easily be implemented using common off-the-shelf physics engines, and generates simulations at approximately 4x realtime on a single core of a modern PC. Our framework advances the state-of-the-art by demonstrating motions of a diversity and dynamic nature previously unseen in comparable methods, including squatting, bowing, kicking, and dancing motions. We also demonstrate its ability to withstand external perturbations and adapt to changes in character morphology.
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    Physically Plausible Simulation for Character Animation
    (The Eurographics Association, 2012) Levine, Sergey; Popovic, Jovan; Jehee Lee and Paul Kry
    Artist-created animated characters can exhibit stylized, engaging behavior, but require considerable effort to construct, while interactive applications require numerous motions and variations to create a dynamic, believable character. This paper describes a method for generating some of these variations automatically: given a stream of poses, our method simulates plausible responses to physical disturbances and environmental variations. Our quasi-physical simulation accounts for the dynamics of the character and surrounding objects, but does not require the motion to be physically valid, making it suitable for both realistic and stylized, cartoony motions. It further does not require any preprocessing, allowing it to run as an online filter that transforms the output of any real-time animation system. Our prototype runs at 50 Hz, on bipeds and quadrupeds with over 50 degrees of freedom, and generates plausible variations for walking, running, hopping, crawling, rolling, cartwheeling, and other motions.
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    Misconceptions of PD Control in Animation
    (The Eurographics Association, 2012) Allen, Brian F.; Faloutsos, Petros; Jehee Lee and Paul Kry
    In this paper, we address certain misconceptions that have been perpetuated in the animation practice and research for quite some time related to the proportional-derivative (PD) control of physics-based systems. Because in animation we often think in terms of targeting keyframes, we tend to forget that PD control, in its simple form, has a very specific asymptotic behavior that approaches zero (or an offset) with zero velocity as time approaches infinity. We pay particular attention to the issue of introducing a ''desired'' or ''end'' velocity term in the equation of a proportional-derivative controller, and discuss how this term should be interpreted and how it relates to feedforward control rather than an end derivative problem.
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    Principal Geodesic Dynamics
    (The Eurographics Association, 2012) Tournier, Maxime; Reveret, Lionel; Jehee Lee and Paul Kry
    This paper presents a new integration of a data-driven approach using dimension reduction and a physicallybased simulation for real-time character animation. We exploit Lie group statistical analysis techniques (Principal Geodesic Analysis, PGA) to approximate the pose manifold of a motion capture sequence by a reduced set of pose geodesics. We integrate this kinematic parametrization into a physically-based animation approach of virtual characters, by using the PGA-reduced parametrization directly as generalized coordinates of a Lagrangian formulation of mechanics. In order to achieve real-time without sacrificing stability, we derive an explicit time integrator by approximating existing variational integrators. Finally, we test our approach in task-space motion control. By formulating both physical simulation and inverse kinematics time stepping schemes as two quadratic programs, we propose a features-based control algorithm that interpolates between the two metrics. This allows for an intuitive trade-off between realistic physical simulation and controllable kinematic manipulation.
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    Mass-Conserving Eulerian Liquid Simulation
    (The Eurographics Association, 2012) Chentanez, Nuttapong; Müller, Matthias; Jehee Lee and Paul Kry
    We present a GPU friendly, Eulerian, free surface fluid simulation method that conserves mass locally and globally without the use of Lagrangian components. Local mass conservation prevents small scale details of the free surface from disappearing, a problem that plagues many previous approaches, while global mass conservation ensures that the total volume of the liquid does not decrease over time. Our method handles moving solid boundaries as well as cells that are partially filled with solids. Due to its stability, it allows the use of large time steps which makes it suitable for both off-line and real-time applications. We achieve this by using density based surface tracking with a novel, unconditionally stable, conservative advection scheme and a novel interface sharpening method. While our approach conserves mass, volume loss is still possible but only temporarily. With constant mass, local volume loss causes a local increase of the density used for surface tracking which we detect and correct over time. We also propose a density post-processing method to reveal sub-grid details of the liquid surface.We show the effectiveness of the proposed method in several practical examples all running either at interactive rates or in real-time.
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    Controlling Liquids Using Meshes
    (The Eurographics Association, 2012) Raveendran, Karthik; Thuerey, Nils; Wojtan, Chris; Turk, Greg; Jehee Lee and Paul Kry
    We present an approach for artist-directed animation of liquids using multiple levels of control over the simulation, ranging from the overall tracking of desired shapes to highly detailed secondary effects such as dripping streams, separating sheets of fluid, surface waves and ripples. The first portion of our technique is a volume preserving morph that allows the animator to produce a plausible fluid-like motion from a sparse set of control meshes. By rasterizing the resulting control meshes onto the simulation grid, the mesh velocities act as boundary conditions during the projection step of the fluid simulation. We can then blend this motion together with uncontrolled fluid velocities to achieve a more relaxed control over the fluid that captures natural inertial effects. Our method can produce highly detailed liquid surfaces with control over sub-grid details by using a mesh-based surface tracker on top of a coarse grid-based fluid simulation. We can create ripples and waves on the fluid surface attracting the surface mesh to the control mesh with spring-like forces and also by running a wave simulation over the surface mesh. Our video results demonstrate how our control scheme can be used to create animated characters and shapes that are made of water.
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    Faster Acceleration Noise for Multibody Animations using Precomputed Soundbanks
    (The Eurographics Association, 2012) Chadwick, Jeffrey N.; Zheng, Changxi; James, Doug L.; Jehee Lee and Paul Kry
    We introduce an efficient method for synthesizing rigid-body acceleration noise for complex multibody scenes. Existing acceleration noise synthesis methods for animation require object-specific precomputation, which is prohibitively expensive for scenes involving rigid-body fracture or other sources of small, procedurally generated debris. We avoid precomputation by introducing a proxy-based method for acceleration noise synthesis in which precomputed acceleration noise data is only generated for a small set of ellipsoidal proxies and stored in a proxy soundbank. Our proxy model is shown to be effective at approximating acceleration noise from scenes with lots of small debris (e.g., pieces produced by rigid-body fracture). This approach is not suitable for synthesizing acceleration noise from larger objects with complicated non-convex geometry; however, it has been shown in previous work that acceleration noise from objects such as these tends to be largely masked by modal vibration sound. We manage the cost of our proxy soundbank with a new wavelet-based compression scheme for acceleration noise and use our model to significantly improve sound synthesis results for several multibody animations.
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    Dynamic Units of Visual Speech
    (The Eurographics Association, 2012) Taylor, Sarah L.; Mahler, Moshe; Theobald, Barry-John; Matthews, Iain; Jehee Lee and Paul Kry
    We present a new method for generating a dynamic, concatenative, unit of visual speech that can generate realistic visual speech animation. We redefine visemes as temporal units that describe distinctive speech movements of the visual speech articulators. Traditionally visemes have been surmized as the set of static mouth shapes representing clusters of contrastive phonemes (e.g. /p, b, m/, and /f, v/). In this work, the motion of the visual speech articulators are used to generate discrete, dynamic visual speech gestures. These gestures are clustered, providing a finite set of movements that describe visual speech, the visemes. Dynamic visemes are applied to speech animation by simply concatenating viseme units. We compare to static visemes using subjective evaluation. We find that dynamic visemes are able to produce more accurate and visually pleasing speech animation given phonetically annotated audio, reducing the amount of time that an animator needs to spend manually refining the animation.
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    Efficient Collision Detection for Brittle Fracture
    (The Eurographics Association, 2012) Glondu, Loeiz; Schvartzman, Sara C.; Marchal, Maud; Dumont, Georges; Otaduy, Miguel A.; Jehee Lee and Paul Kry
    In complex scenes with many objects, collision detection plays a key role in the simulation performance. This is particularly true for fracture simulation, where multiple new objects are dynamically created. In this paper, we present novel algorithms and data structures for collision detection in real-time brittle fracture simulations. We build on a combination of well-known efficient data structures, namely distance fields and sphere trees, making our algorithm easy to integrate on existing simulation engines. We propose novel methods to construct these data structures, such that they can be efficiently updated upon fracture events and integrated in a simple yet effective self-adapting contact selection algorithm. Altogether, we drastically reduce the cost of both collision detection and collision response. We have evaluated our global solution for collision detection on challenging scenarios, achieving high frame rates suited for hard real-time applications such as video games or haptics. Our solution opens promising perspectives for complex brittle fracture simulations involving many dynamically created objects.
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    Multi-linear Data-Driven Dynamic Hair Model with Efficient Hair-Body Collision Handling
    (The Eurographics Association, 2012) Guan, Peng; Sigal, Leonid; Reznitskaya, Valeria; Hodgins, Jessica K.; Jehee Lee and Paul Kry
    We present a data-driven method for learning hair models that enables the creation and animation of many interactive virtual characters in real-time (for gaming, character pre-visualization and design). Our model has a number of properties that make it appealing for interactive applications: (i) it preserves the key dynamic properties of physical simulation at a fraction of the computational cost, (ii) it gives the user continuous interactive control over the hair styles (e.g., lengths) and dynamics (e.g., softness) without requiring re-styling or re-simulation, (iii) it deals with hair-body collisions explicitly using optimization in the low-dimensional reduced space, (iv) it allows modeling of external phenomena (e.g., wind). Our method builds on the recent success of reduced models for clothing and fluid simulation, but extends them in a number of significant ways. We model motion of hair in a conditional reduced sub-space, where the hair basis vectors, which encode dynamics, are linear functions of userspecified hair parameters. We formulate collision handling as an optimization in this reduced sub-space using fast iterative least squares. We demonstrate our method by building dynamic, user-controlled models of hair styles.
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    The Intersection Contour Minimization Method for Untangling Oriented Deformable Surfaces
    (The Eurographics Association, 2012) Ye, Juntao; Zhao, Jing; Jehee Lee and Paul Kry
    The Intersection Contour Minimization (ICM) method [VM06] has been proven to be an effective history-free algorithm for resolving collisions between non-oriented deformable surfaces. In many circumstances, however, surface orientation information are often implied in the context. Being completely blind to such information in the ICM method often leads to unexpected result: either failure or slow convergence in certain intersection config- urations. By introducing the concept of ''repulsive normal'' into ICM, many of those once-failure configurations can be resolved successfully. Even for those once-successful configurations, repulsive normals usually speed-up the convergence. Moreover, the ICM method that was originally designed for polygonal meshes can actually be adapted to resolve collisions between a polygon mesh and an analytical surface. This paper presents one such extension collisions between a polygon mesh and a capsule.
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    Long Range Attachments - A Method to Simulate Inextensible Clothing in Computer Games
    (The Eurographics Association, 2012) Kim, Tae-Yong; Chentanez, Nuttapong; Müller-Fischer, Matthias; Jehee Lee and Paul Kry
    Inextensibility is one of the most fundamental properties of cloth. Existing approaches to handle inextensibility often require solving global non-linear systems and remain computationally expensive for computer game uses. Real time performance can be achieved by allowing damping or stretching at reduced solver costs, but these compromise visual realism - the cloth either looks stretchy or fine wrinkles get lost. Our long range attachment (LRA) method exploits that typical game character clothing tends to be attached to some kinematic parts of the character. LRA method applies unilateral distance constraint between free particles of the cloth to distant attachment point on the character, preventing them from stretching away from the kinematically driven attachments (e.g. shoulder for a cape). This simple step provides an efficient shortcut for enforcing global inextensibility that can be readily implemented into existing game physics methods such as PBD.