Issue 3

Permanent URI for this collection

https://diglib7.eg.org/handle/10.2312/111
EG 2003 Conference Proceedings

BibTeX (Issue 3)
                
@article{
https::/diglib.eg.org/xmlui/handle/10.2312/8745,

journal = {Computer Graphics Forum},
title = {{
Table of Contents CGF 22-3}},

author = {
Fellner, Dieter W.
 and 
Brunet, Pere
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
https://diglib.eg.org/xmlui/handle/10.2312/8745}

}
                
@article{
10.1111:1467-8659.00670,

journal = {Computer Graphics Forum},
title = {{
Field Functions for Blending Range Controls on Soft Objects}},

author = {
Hsu, P. C.
 and 
Lee, C.
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00670}

}
                
@article{
10.1111:1467-8659.00678,

journal = {Computer Graphics Forum},
title = {{
Planning Collision-Free Reaching Motions for Interactive Object Manipulation and Grasping}},

author = {
Kallmann, Marcelo
 and 
Aubel, Amaury
 and 
Abaci, Tolga
 and 
Thalmann, Daniel
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00678}

}
                
@article{
10.1111:1467-8659.00675,

journal = {Computer Graphics Forum},
title = {{
Multi-scale Feature Extraction on Point-Sampled Surfaces}},

author = {
Pauly, Mark
 and 
Keiser, Richard
 and 
Gross, Markus
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00675}

}
                
@article{
10.1111:1467-8659.00680,

journal = {Computer Graphics Forum},
title = {{
Compression of 2D Vector Fields Under Guaranteed Topology Preservation}},

author = {
Theisel, H.
 and 
Rossl, Ch.
 and 
Seidel, H.-P.
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00680}

}
                
@article{
10.1111:1467-8659.00668,

journal = {Computer Graphics Forum},
title = {{
Open Issues in Photo-realistic Rendering}},

author = {
Purgathofer, Werner
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00668}

}
                
@article{
10.1111:1467-8659.00673,

journal = {Computer Graphics Forum},
title = {{
Cloth Motion Capture}},

author = {
Pritchard, D.
 and 
Heidrich, W.
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00673}

}
                
@article{
10.1111:1467-8659.00671,

journal = {Computer Graphics Forum},
title = {{
Fast Photo-Realistic Rendering of Trees in Daylight}},

author = {
Qin, Xueying
 and 
Nakamae, Eihachiro
 and 
Tadamura, Katsumi
 and 
Nagai, Yasuo
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00671}

}
                
@article{
10.1111:1467-8659.00687,

journal = {Computer Graphics Forum},
title = {{
Particle-Based Simulation of Fluids}},

author = {
Premzoe, Simon
 and 
Tasdizen, Tolga
 and 
Bigler, James
 and 
Lefohn, Aaron
 and 
Whitaker, Ross T.
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00687}

}
                
@article{
10.1111:1467-8659.00683,

journal = {Computer Graphics Forum},
title = {{
Rendering and Affect}},

author = {
Duke, D.J.
 and 
Barnard, P.J.
 and 
Halper, N.
 and 
Mellin, M.
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00683}

}
                
@article{
10.1111:1467-8659.00682,

journal = {Computer Graphics Forum},
title = {{
Hierarchical Context-based Pixel Ordering}},

author = {
Bar-Joseph, Ziv
 and 
Cohen-Or, Daniel
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00682}

}
                
@article{
10.1111:1467-8659.00677,

journal = {Computer Graphics Forum},
title = {{
Volumetric cell-and-portal generation}},

author = {
Haumont, D.
 and 
Debeir, O.
 and 
Sillion, F.
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00677}

}
                
@article{
10.1111:1467-8659.00684,

journal = {Computer Graphics Forum},
title = {{
Precise Ink Drawing of 3D Models}},

author = {
Sousa, Mario Costa
 and 
Foster, Kevin
 and 
Wyvill, Brian
 and 
Samavati, Faramarz
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00684}

}
                
@article{
10.1111:1467-8659.00679,

journal = {Computer Graphics Forum},
title = {{
Hierarchical and Heterogenous Reactive Agents for Real-Time Applications}},

author = {
Niederberger, C.
 and 
Gross, M.
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00679}

}
                
@article{
10.1111:1467-8659.00686,

journal = {Computer Graphics Forum},
title = {{
Realistic Animation of Fluid with Splash and Foam}},

author = {
Takahashi, Tsunemi
 and 
Fujii, Hiroko
 and 
Kunimatsu, Atsushi
 and 
Hiwada, Kazuhiro
 and 
Saito, Takahiro and Tanaka, Ken and Ueki, Heihachi
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00686}

}
                
@article{
10.1111:1467-8659.00681,

journal = {Computer Graphics Forum},
title = {{
Out-of-core compression and decompression of large n-dimensional scalar fields}},

author = {
Ibarria, Lawrence
 and 
Lindstrom, Peter
 and 
Rossignac, Jarek
 and 
Szymczak, Andrzej
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00681}

}
                
@article{
10.1111:1467-8659.00688,

journal = {Computer Graphics Forum},
title = {{
Animating Hair with Loosely Connected Particles}},

author = {
Bando, Yosuke
 and 
Chen, Bing-Yu
 and 
Nishita, Tomoyuki
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00688}

}
                
@article{
10.1111:1467-8659.00689,

journal = {Computer Graphics Forum},
title = {{
Adaptive Logarithmic Mapping For Displaying High Contrast Scenes}},

author = {
Drago, F.
 and 
Myszkowski, K.
 and 
Annen, T.
 and 
Chiba, N.
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00689}

}
                
@article{
10.1111:1467-8659.00691,

journal = {Computer Graphics Forum},
title = {{
Shadow Volumes on Programmable Graphics Hardware}},

author = {
Brabec, Stefan
 and 
Seidel, Hans-Peter
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00691}

}
                
@article{
10.1111:1467-8659.00690,

journal = {Computer Graphics Forum},
title = {{
Image Categorization using Color Blobs in a Mobile Environment}},

author = {
Gavilan Ruiz, David
 and 
Takahashi, Hiroki
 and 
Nakajima, Masayuki
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00690}

}
                
@article{
10.1111:1467-8659.00693,

journal = {Computer Graphics Forum},
title = {{
Automatic texture atlas generation from trimmed NURBS models}},

author = {
Guthe, M.
 and 
Klein, R.
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00693}

}
                
@article{
10.1111:1467-8659.00692,

journal = {Computer Graphics Forum},
title = {{
Solving Geometric Optimization Problems using Graphics Hardware}},

author = {
Denny, Markus
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00692}

}
                
@article{
10.1111:1467-8659.00694,

journal = {Computer Graphics Forum},
title = {{
Interactive Rendering with Bidirectional Texture Functions}},

author = {
Suykens, Frank
 and 
Berge, Karl
 and 
Lagae, Ares
 and 
Dutre, Philip
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00694}

}
                
@article{
10.1111:1467-8659.00695,

journal = {Computer Graphics Forum},
title = {{
Planned Sampling of Spatially Varying BRDFs}},

author = {
Lensch, Hendrik P.A.
 and 
Lang, Jochen
 and 
Sa, Asla M.
 and 
Seidel, Hans-Peter
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00695}

}
                
@article{
10.1111:1467-8659.00669,

journal = {Computer Graphics Forum},
title = {{
On Visual Similarity Based 3D Model Retrieval}},

author = {
Chen, Ding-Yun
 and 
Tian, Xiao-Pei
 and 
Shen, Yu-Te
 and 
Ouhyoung, Ming
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00669}

}
                
@article{
10.1111:1467-8659.00697,

journal = {Computer Graphics Forum},
title = {{
Progressive Simplification of Tetrahedral Meshes Preserving All Isosurface Topologies}},

author = {
Chiang, Yi-Jen
 and 
Lu, Xiang
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00697}

}
                
@article{
10.1111:1467-8659.00696,

journal = {Computer Graphics Forum},
title = {{
Multiresolution Surface Representation Based on Displacement Volumes}},

author = {
Botsch, Mario
 and 
Kobbelt, Leif
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00696}

}
                
@article{
10.1111:1467-8659.00699,

journal = {Computer Graphics Forum},
title = {{
Beyond Stippling - Methods for Distributing Objects on the Plane}},

author = {
Hiller, Stefan
 and 
Hellwig, Heino
 and 
Deussen, Oliver
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00699}

}
                
@article{
10.1111:1467-8659.00698,

journal = {Computer Graphics Forum},
title = {{
BDAM - Batched Dynamic Adaptive Meshes for High Performance Terrain Visualization}},

author = {
Cignoni, P.
 and 
Ganovelli, F.
 and 
Gobbetti, E.
 and 
Marton, F.
 and 
Ponchio, F.
 and 
Scopigno, R.
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00698}

}
                
@article{
10.1111:1467-8659.t01-3-00700,

journal = {Computer Graphics Forum},
title = {{
Interactive Cutaway Illustrations}},

author = {
Diepstraten, J.
 and 
Weiskopf, D.
 and 
Ertl, T.
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.t01-3-00700}

}
                
@article{
10.1111:1467-8659.t01-2-00703,

journal = {Computer Graphics Forum},
title = {{
Adaptive Ray Tracing of Subdivision Surfaces}},

author = {
Müller, Kerstin
 and 
Techmann, Torsten
 and 
Fellner, Dieter W.
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.t01-2-00703}

}
                
@article{
10.1111:1467-8659.t01-2-00701,

journal = {Computer Graphics Forum},
title = {{
Advanced Design for a Realistic Virtual Brush}},

author = {
Xu, Songhua
 and 
Lau, Francis C.M.
 and 
Tang, Feng
 and 
Pan, Yunhe
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.t01-2-00701}

}
                
@article{
10.1111:1467-8659.00666,

journal = {Computer Graphics Forum},
title = {{
Volumetric Filtering, Modeling and Visualization for Nano-Medicine}},

author = {
Bajaj, Chandrajit
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00666}

}
                
@article{
10.1111:1467-8659.t01-1-00702,

journal = {Computer Graphics Forum},
title = {{
Ray Differentials and Multiresolution Geometry Caching for Distribution Ray Tracing in Complex Scenes}},

author = {
Christensen, Per H.
 and 
Laur, David M.
 and 
Fong, Julian
 and 
Wooten, Wayne L.
 and 
Batali, Dana
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.t01-1-00702}

}
                
@article{
10.1111:1467-8659.t01-1-00704,

journal = {Computer Graphics Forum},
title = {{
Hierarchical Higher Order Face Cluster Radiosity for Global Illumination Walkthroughs of Complex Non-Diffuse Environments}},

author = {
Gobbetti, Enrico
 and 
Spano, Leonardo
 and 
Agus, Marco
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.t01-1-00704}

}
                
@article{
10.1111:1467-8659.t01-1-00706,

journal = {Computer Graphics Forum},
title = {{
The Stringed Haptic Workbench: a New Haptic Workbench Solution}},

author = {
Tarrin, N.
 and 
Coquillart, S.
 and 
Hasegawa, S.
 and 
Bouguila, L.
 and 
Sato, M.
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.t01-1-00706}

}
                
@article{
10.1111:1467-8659.t01-2-00705,

journal = {Computer Graphics Forum},
title = {{
Image Based Interactive Rendering with View Dependent Geometry}},

author = {
Evers-Senne, J.-F.
 and 
Koch, R.
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.t01-2-00705}

}
                
@article{
10.1111:1467-8659.t01-2-00709,

journal = {Computer Graphics Forum},
title = {{
Real-Time Caustics}},

author = {
Wand, M.
 and 
Strasser, W.
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.t01-2-00709}

}
                
@article{
10.1111:1467-8659.t01-2-00707,

journal = {Computer Graphics Forum},
title = {{
Interactive Design of Bonsai Tree Models}},

author = {
Boudon, Frederic
 and 
Prusinkiewicz, Przemyslaw
 and 
Federl, Pavol
 and 
Godin, Christophe
 and 
Karwowski, Radoslaw
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.t01-2-00707}

}
                
@article{
10.1111:1467-8659.t01-2-00708,

journal = {Computer Graphics Forum},
title = {{
A Fast Rendering Method for Refractive and Reflective Caustics Due to Water Surfaces}},

author = {
Iwasaki, Kei
 and 
Dobashi, Yoshinori
 and 
Nishita, Tomoyuki
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.t01-2-00708}

}
                
@article{
10.1111:1467-8659.t01-2-00710,

journal = {Computer Graphics Forum},
title = {{
A Scalable Approach to Interactive Global Illumination}},

author = {
Benthin, Carsten
 and 
Wald, Ingo
 and 
Slusallek, Philipp
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.t01-2-00710}

}
                
@article{
10.1111:1467-8659.t01-2-00711,

journal = {Computer Graphics Forum},
title = {{
Visyllable Based Speech Animation}},

author = {
Kshirsagar, Sumedha
 and 
Magnenat-Thalmann, Nadia
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.t01-2-00711}

}
                
@article{
10.1111:1467-8659.t01-1-00712,

journal = {Computer Graphics Forum},
title = {{
Reanimating Faces in Images and Video}},

author = {
Blanz, V.
 and 
Basso, C.
 and 
Poggio, T.
 and 
Vetter, T.
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.t01-1-00712}

}
                
@article{
10.1111:1467-8659.t01-2-00713,

journal = {Computer Graphics Forum},
title = {{
Narrative Use of Sign Language by a Virtual Character for the Hearing Impaired}},

author = {
Rieger, Thomas
 and 
Braun, Norbert
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.t01-2-00713}

}
                
@article{
10.1111:1467-8659.00676,

journal = {Computer Graphics Forum},
title = {{
ShieldTester: Cell-to-Cell Visibility Test for Surface Occluders}},

author = {
Navazo, I.
 and 
Rossignac, J.
 and 
Jou, J.
 and 
Shariff, R.
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00676}

}
                
@article{
10.1111:1467-8659.00674,

journal = {Computer Graphics Forum},
title = {{
Sub-Voxel Topology Control for Level-Set Surfaces}},

author = {
Bischoff, Stephan
 and 
Kobbelt, Leif
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00674}

}
                
@article{
10.1111:1467-8659.00685,

journal = {Computer Graphics Forum},
title = {{
A Few Good Lines: Suggestive Drawing of 3D Models}},

author = {
Sousa, Mario Costa
 and 
Prusinkiewicz, Przemyslaw
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00685}

}
                
@article{
10.1111:1467-8659.00672,

journal = {Computer Graphics Forum},
title = {{
Animation of Bubbles in Liquid}},

author = {
Hong, Jeong-Mo
 and 
Kim, Chang-Hun
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00672}

}
                
@article{
10.1111:1467-8659.00667,

journal = {Computer Graphics Forum},
title = {{
Freeform Shape Representations for Efficient Geometry Processing}},

author = {
Kobbelt, Leif
},
year = {
2003},

publisher = {
Blackwell Publishers, Inc and the Eurographics Association},


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00667}

}

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Now showing 1 - 49 of 49
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    Table of Contents CGF 22-3
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Fellner, Dieter W.; Brunet, Pere
    -
  • No Thumbnail Available
    Item
    Field Functions for Blending Range Controls on Soft Objects
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Hsu, P. C.; Lee, C.
    This paper proposes new field functions that have adjustable inner radius and outer radius of influence. Incorporatingthe proposed field functions with soft object modeling, soft blending, Ricci's super-ellipsoid blends, Perlin'sset operations, and R-functions, etc. can have blending range controls by adjusting the inner and the outer radiiof influence of given field functions. As a result, the sizes of the resulting blending surfaces on soft objects willnot be restricted by the sizes of the blended primitive soft objects and can be enlarged and shrunk freely withoutdeforming the overall shapes of blended primitive soft objects. In addition, a small soft object can have a largeblending region, and a large one can have a small blending regionCategories and Subject Descriptors (according to ACM CCS): I.3.5 [Computer Graphics]: Computational Geometry and Object Modeling - Curve, surface, solid and object representations
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    Planning Collision-Free Reaching Motions for Interactive Object Manipulation and Grasping
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Kallmann, Marcelo; Aubel, Amaury; Abaci, Tolga; Thalmann, Daniel
    We present new techniques that use motion planning algorithms based on probabilistic roadmaps to control 22 degrees of freedom (DOFs) of human-like characters in interactive applications. Our main purpose is the automatic synthesis of collision-free reaching motions for both arms, with automatic column control and leg flexion. Generated motions are collision-free, in equilibrium, and respect articulation range limits. In order to deal with the high (22) dimension of our configuration space, we bias the random distribution of configurations to favor postures most useful for reaching and grasping. In addition, extensions are presented in order to interactively generate object manipulation sequences: a probabilistic inverse kinematics solver for proposing goal postures matching pre-designed grasps; dynamic update of roadmaps when obstacles change position; online planning of object location transfer; and an automatic stepping control to enlarge the character's reachable space. This is, to our knowledge, the first time probabilistic planning techniques are used to automatically generate collision-free reaching motions involving the entire body of a human-like character at interactive frame rates.Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism
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    Multi-scale Feature Extraction on Point-Sampled Surfaces
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Pauly, Mark; Keiser, Richard; Gross, Markus
    We present a new technique for extracting line-type features on point-sampled geometry. Given an unstructuredpoint cloud as input, our method first applies principal component analysis on local neighborhoods toclassify points according to the likelihood that they belong to a feature. Using hysteresis thresholding, we thencompute a minimum spanning graph as an initial approximation of the feature lines. To smooth out the featureswhile maintaining a close connection to the underlying surface, we use an adaptation of active contour models.Central to our method is a multi-scale classification operator that allows feature analysis at multiplescales, using the size of the local neighborhoods as a discrete scale parameter. This significantly improves thereliability of the detection phase and makes our method more robust in the presence of noise. To illustrate theusefulness of our method, we have implemented a non-photorealistic point renderer to visualize point-sampledsurfaces as line drawings of their extracted feature curves.
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    Compression of 2D Vector Fields Under Guaranteed Topology Preservation
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Theisel, H.; Rossl, Ch.; Seidel, H.-P.
    In this paper we introduce a new compression technique for 2D vector fields which preserves the complete topology, i.e., the critical points and the connectivity of the separatrices. As the theoretical foundation of the algorithm, we show in a theorem that for local modifications of a vector field, it is possible to decide entirely by a local analysis whether or not the global topology is preserved. This result is applied in a compression algorithm which is based on a repeated local modification of the vector field - namely a repeated edge collapse of the underlying piecewise linear domain. We apply the compression technique to a number of data sets with a complex topology and obtain significantly improved compression ratios in comparison to pre-existing topology-preserving techniques.
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    Open Issues in Photo-realistic Rendering
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Purgathofer, Werner
    For more than two decades Computer graphics researchers have tried to achieve photo-realism in their images as reliable as possible, mainly by simulating the physical laws of light and adding one effect after the other. The recent years have brought a change of efforts towards real-time methods, easy-to-use systems, integration with vision, modelling tools and the like. The quality of images is mostly accepted as sufficient for real world applications, but where are we really? There are still numerous problems to be solved, and there is notable progress in these areas. No question, the plug-in philosophy of some commercial products has enabled several of these new techniques to be distributed quite fast. But unfortunately, many other of these developments happen in isolated systems for the pure purpose of publication, and never make it into commercial software. This presentation wants to make people more aware of such activities, and evaluate the steps we still have to go towards perfect photo-realism.The talk will start with an attempt to give a brief overview of the rendering history, highlighting the main research directions at different times. It will explain the driving forces of the developments, which are complexity, speed, and accuracy, and maybe also expression in recent years. Solved and unsolved areas are examined, and compared to practically solved but theoretically incomplete topics such as translucency, tone mapping, light source and BTF descriptions, and error metrics for image quality evaluation. The difference lies mainly in the difference between believable, correct, and predictive images. Also, for really realistic images modelling complexity is still an issue. Finally, some recent work on polarization and fluorescence is presented.
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    Cloth Motion Capture
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Pritchard, D.; Heidrich, W.
    Recent years have seen an increased interest in motion capture systems. Current systems, however, are limitedto only a few degrees of freedom, so that effectively only the motion of linked rigid bodies can be acquired. Wepresent a system for the capture of deformable surfaces, most notably moving cloth, including both geometry andparameterisation. We recover geometry using stereo correspondence, and use the Scale Invariant Feature Transform(SIFT) to identify an arbitrary pattern printed on the cloth, even in the presence of fast motion. We describea novel seed-and-grow approach to adapt the SIFT algorithm to deformable geometry. Finally, we interpolatefeature points to parameterise the complete geometry.Categories and Subject Descriptors (according to ACM CCS): I.3.5 [Computer Graphics]: Physically based modelingI.4.8 [Image Processing and Computer Vision]: Scene analysis
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    Fast Photo-Realistic Rendering of Trees in Daylight
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Qin, Xueying; Nakamae, Eihachiro; Tadamura, Katsumi; Nagai, Yasuo
    We propose a fast approach for photo-realistic rendering of trees under various kinds of daylight, which is particularlyuseful for the environmental assessment of landscapes. In our approach the 3D tree models are transformedto a quasi-3D tree database registering geometrical and shading information of tree surfaces, i.e. their normalvectors, relative depth, and shadowing of direct sunlight and skylight, by using a combination of 2D buffers.Thus the rendering speed of quasi-3D trees depends on their display sizes only, regardless of the complexity oftheir original 3D tree models. By utilizing a two-step shadowing algorithm, our proposed method can create highquality forest scenes illuminated by both sunlight and skylight at a low cost. It can generate both umbrae andpenumbrae on a tree cast by other trees and any other objects such as buildings or clouds. Transparency, specularreflection and inter-reflection of leaves, which influence the delicate shading effects of trees, can also be simulatedwith verisimilitude.Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Three dimensional Graphics and Realism
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    Particle-Based Simulation of Fluids
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Premzoe, Simon; Tasdizen, Tolga; Bigler, James; Lefohn, Aaron; Whitaker, Ross T.
    Due to our familiarity with how fluids move and interact, as well as their complexity, plausible animation of fluidsremains a challenging problem. We present a particle interaction method for simulating fluids. The underlyingequations of fluid motion are discretized using moving particles and their interactions. The method allows simulationand modeling of mixing fluids with different physical properties, fluid interactions with stationary objects, andfluids that exhibit significant interface breakup and fragmentation. The gridless computational method is suitedfor medium scale problems since computational elements exist only where needed. The method fits well into thecurrent user interaction paradigm and allows easy user control over the desired fluid motion.
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    Rendering and Affect
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Duke, D.J.; Barnard, P.J.; Halper, N.; Mellin, M.
    Previous studies at the intersection between rendering and psychology have concentrated on issues such as realismand acuity. Although such results have been useful in informing development of realistic rendering techniques,studies have shown that the interpretation of images is influenced by factors that have little to do with realism. Inthis paper, we summarize a series of experiments, the most recent of which are reported in a separate paper, thatinvestigate affective (emotive) qualities of images. These demonstrate significant effects that can be utilized withininteractive graphics, particularly via non-photorealistic rendering (NPR). We explain how the interpretation ofthese results requires a high-level model of cognitive information processing, and use such a model to account forrecent empirical results on rendering and judgement.Categories and Subject Descriptors (according to ACM CCS): I.3.m [Computer Graphics]: Miscellaneous
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    Hierarchical Context-based Pixel Ordering
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Bar-Joseph, Ziv; Cohen-Or, Daniel
    We present a context-based scanning algorithm which reorders the input image using a hierarchical representationof the image. Our algorithm optimally orders (permutes) the leaves corresponding to the pixels, by minimizing thesum of distances between neighboring pixels. The reordering results in an improved autocorrelation betweennearby pixels which leads to a smoother image. This allows us, for the first time, to improve image compressionrates using context-based scans. The results presented in this paper greatly improve upon previous work in bothcompression rate and running time.Categories and Subject Descriptors (according to ACM CCS): I.3.5 [Computer Graphics]: Computational Geometryand Object Modeling I.3.6 [Computer Graphics]: Methodology and Techniques
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    Volumetric cell-and-portal generation
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Haumont, D.; Debeir, O.; Sillion, F.
    We present an algorithm to generate a cell-and-portal decomposition of general indoor scenes. The method is an adaptation of the 3D watershed transform, computed on a distance-to-geometry sampled field. The watershed is processed using a flooding analogy in the distance field space. Flooding originates from local minima, each minimum producing a region. Portals are built as needed to avoid the merging of regions during their growth. As a result, the cell-and-portal decomposition is closely linked to the structure of the models. In a building, the algorithm finds all the rooms, doors and windows. To restrict the memory load, a hierarchical implementation of the algorithm is presented. We also explain how to handle possible model degeneracies -such as cracks, holes and interpenetrating geometries- using a pre-voxelisation step. The hierarchical algorithm, preceded when necessary by the pre-voxelisation, was tested on a large range of models. We show that it is able to deal with classical architectural models, as well as cave-like environments and large mixed indoor/outdoor scenes. Thanks to the intermediate distance field representation, the algorithm can be used regardless of the way the model is represented: it deals with parametric curves, implicit surfaces, volumetric data and polygon soups in a unified way.
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    Precise Ink Drawing of 3D Models
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Sousa, Mario Costa; Foster, Kevin; Wyvill, Brian; Samavati, Faramarz
    Drawings made with precise pen strokes accurately reveal the geometric forms that give subjects their characteristicshape. We present a system for non-photorealistic rendering of precise drawing strokes over dense 3Dtriangle meshes with arbitrary topology. During an automatic pre-process, we construct an extended version ofthe edge-buffer data structure to allow the calculation of shape measures at each mesh edge, by adapting numericalmethods used in geomorphology. At runtime, feature edges related to shape measures are extracted andrendered as strokes with varying thickness and pen marking styles. Stroke thickness is automatically adjusted byconsidering surface curvature. Pen marking styles and visual effects of ink distribution are both controlled by theuser. We demonstrate precise drawing strokes over complex meshes revealing a variety of shape characteristics.
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    Hierarchical and Heterogenous Reactive Agents for Real-Time Applications
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Niederberger, C.; Gross, M.
    We present a generic concept for autonomous agents with reactive behavior based on situation recognition in real-time environments. Our approach facilitates behavior development through specialization of existing behavior types or weighted multiple inheritance in order to create new types. Additionally, the system allows for the simultaneous generation of hierarchical and semi-individual group organizations using specification and recursive or modulo-based patterns. Our framework is designed to support the creation of large numbers of secondary characters with individual and group behavior in simulation environments such as game engines. The engine allows for the specification of a maximal time-per-run in order to guarantee a minimal and constant frame-rate. We demonstrate the usefulness of our approach by various examples with up to hundreds of individuals.Categories and Subject Descriptors (according to ACM CCS): 1.2.11 [Distributed Artificial Intelligence]: Multiagent systems, I.6.7 [Simulation Support Systems]: Environments
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    Realistic Animation of Fluid with Splash and Foam
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Takahashi, Tsunemi; Fujii, Hiroko; Kunimatsu, Atsushi; Hiwada, Kazuhiro; Saito, Takahiro and Tanaka, Ken and Ueki, Heihachi
    In this paper we describe a method for modeling and rendering dynamic behavior of fluids withsplashes and foam. A particle system is built into a fluid simulation system to represent an ocean wavecresting and spraying over another object. We use the Cubic Interpolated Propagation (CIP) method asthe fluid solver. The CIP method can solve liquid and gas together in the framework of fluid dynamicsand has high accuracy in the case of relatively coarse grids. This enables us to simulate the fluids in ashort time and describe the motion of splashes in the air that is associated with the liquid motion well.The foam floating on the water also can be described using the particle system. We integrate the rigidbody simulation with the fluid and particle system to create sophisticated scenes including splashes andfoam. We construct state change rules that are used with the particle system. This controls the generation,vanishing and transition rule of splashes and foam. The transition rule makes the seamless connection betweena splash and foam. We employed a fast volume rendering method with scattering effect for particles.One of the important features of our method is the combination of fast simulation and rendering techniques,which provides dynamic and realistic scenes in a short time.
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    Out-of-core compression and decompression of large n-dimensional scalar fields
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Ibarria, Lawrence; Lindstrom, Peter; Rossignac, Jarek; Szymczak, Andrzej
    We present a simple method for compressing very large and regularly sampled scalar fields. Our method is particularlyattractive when the entire data set does not fit in memory and when the sampling rate is high relative to thefeature size of the scalar field in all dimensions. Although we report results foranddata sets, the proposedapproach may be applied to higher dimensions. The method is based on the new Lorenzo predictor, introducedhere, which estimates the value of the scalar field at each sample from the values at processed neighbors. The predictedvalues are exact when the n-dimensional scalar field is an implicit polynomial of degreen? 1. Surprisingly,when the residuals (differences between the actual and predicted values) are encoded using arithmetic coding,the proposed method often outperforms wavelet compression in anL?sense. The proposed approach may beused both for lossy and lossless compression and is well suited for out-of-core compression and decompression,because a trivial implementation, which sweeps through the data set reading it once, requires maintaining only asmall buffer in core memory, whose size barely exceeds a single (n?1)-dimensional slice of the data.Categories and Subject Descriptors (according to ACM CCS): I.3.5 [Computer Graphics]: Compression, scalar fields,out-of-core.
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    Animating Hair with Loosely Connected Particles
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Bando, Yosuke; Chen, Bing-Yu; Nishita, Tomoyuki
    This paper presents a practical approach to the animation of hair at an interactive frame rate. In our approach,we model the hair as a set of particles that serve as sampling points for the volume of the hair, which covers thewhole region where hair is present. The dynamics of the hair, including hair-hair interactions, is simulated usingthe interacting particles. The novelty of this approach is that, as opposed to the traditional way of modeling hair,we release the particles from tight structures that are usually used to represent hair strands or clusters. Therefore,by making the connections between the particles loose while maintaining their overall stiffness, the hair can bedynamically split and merged during lateral motion without losing its lengthwise coherence.Categories and Subject Descriptions (according to ACM CCS): I.3.7 [Computer Graphics]: Three-DimensionalGraphics and Realism, I.3.3 [Computer Graphics]: Picture/Image Generation
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    Adaptive Logarithmic Mapping For Displaying High Contrast Scenes
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Drago, F.; Myszkowski, K.; Annen, T.; Chiba, N.
    We propose a fast, high quality tone mapping technique to display high contrast images on devices with limited dynamicrange of luminance values. The method is based on logarithmic compression of luminance values, imitatingthe human response to light. A bias power function is introduced to adaptively vary logarithmic bases, resultingin good preservation of details and contrast. To improve contrast in dark areas, changes to the gamma correctionprocedure are proposed. Our adaptive logarithmic mapping technique is capable of producing perceptually tunedimages with high dynamic content and works at interactive speed. We demonstrate a successful application of ourtone mapping technique with a high dynamic range video player enabling to adjust optimal viewing conditions forany kind of display while taking into account user preference concerning brightness, contrast compression, anddetail reproduction.Categories and Subject Descriptors (according to ACM CCS): I.3.3 [Image Processing and Computer Vision]: Image Representation
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    Shadow Volumes on Programmable Graphics Hardware
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Brabec, Stefan; Seidel, Hans-Peter
    One of the best choices for fast, high quality shadows is the shadow volume algorithm. However, for real timeapplications the extraction of silhouette edges can significantly burden the CPU, especially with highly tessellatedinput geometry or when complex geometry shaders are applied.In this paper we show how this last, expensive part of the shadow volume method can be implemented on programmablegraphics hardware. This way, the originally hybrid shadow volumes algorithm can now be reformulatedas a purely hardware-accelerated approach.The benefits of this implementation is not only the increase in speed. Firstly, all computations now run on thesame hardware resulting in consistent precision within all steps of the algorithm. Secondly, programmable vertextransformations are no longer problematic when applied to shadow casting objects.Categories and Subject Descriptors (according to ACM CCS): I.3.1 [Computer Graphics]: Hardware Architecture;I.3.3 [Computer Graphics]: Picture/Image Generation; I.3.7 [Computer Graphics]: Three-Dimensional Graphicsand Realism
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    Image Categorization using Color Blobs in a Mobile Environment
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Gavilan Ruiz, David; Takahashi, Hiroki; Nakajima, Masayuki
    This paper generalizes the basic idea of blobs in preattentive perception using color information. This is usedas the base of a basic classification of low resolution pictures taken with mobile phones. This classification, theblob-like representation of the image and other information in user's context, such as GPS information, can beused in the presented framework as the basis of a new graphical interface for HCI (Human Computer Interaction).Similar systems whether they work with global properties of the image, which leads to inaccurate results, or withcomplex segmentation process that fails to capture expected objects in the scene. Most of those systems do notpay attention on other information involved in the creation of the image, such as time or location. We describe asystem which uses geographical information associated with a picture in a mobile phone terminal, and with a fastsegmentation based on color categorization.
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    Automatic texture atlas generation from trimmed NURBS models
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Guthe, M.; Klein, R.
    A Texture Atlas is a two dimensional representation of a 3D model usable for paint systems or as a sewing pattern.The field of texture atlas generation from polygonal models has been well exploited in the recent years. The developedalgorithms work on piecewise linear surface representations, but not on parametric surfaces like NURBS,that are still the main surface representation in CAD systems. If a texture atlas is generated from a triangulatedNURBS model, the result cannot be edited further in a CAD system, since the separation into charts is not basedon the separate NURBS patches of the original model. We present a method for automatic generation of a textureatlas directly from trimmed NURBS models, while preserving the original NURBS representation. The resultingtexture atlas is build of several charts, each consisting of the original NURBS patches sewn together.Categories and Subject Descriptors (according to ACM CCS): I.3.3 [Computer Graphics]: Picture/Image Generation;I.3.5 [Computer Graphics]: Computational Geometry and Object Modeling; I.3.7 [Computer Graphics]: Three-DimensionalGraphics and Realism - Color, Shading and Texture; J.6 [Computer-aided Engineering]: Computer-aideddesign (CAD)
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    Solving Geometric Optimization Problems using Graphics Hardware
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Denny, Markus
    We show how to use graphics hardware for tackling optimization problems arising in the field of computationalgeometry. We exemplarily discuss three problems, where combinatorial algorithms are inefficient or hard to implement.Given a set S of n point in the plane, the first two problems are to determine the smallest homotheticscaling of a star shaped polygon P enclosing S and to find the largest empty homothetic scaling of P completelycontained inside an arbitrary polygonal region. Pixel-exact solutions for both problems are computed in real-time.The third problem is a facility location problem and more difficult to solve. Given the Voronoi diagram VoD(S) ofthe n points, we try to position another point p in the plane, such that the resulting Voronoi region of p has maximalarea. As far as we know there exists no traditional solution for this problem for which we present pixel-exactsolutions.Categories and Subject Descriptors (according to ACM CCS): I.3.5 [Computer Graphics]: Geometric algorithms,languages, and systems I.3.3 [Computer Graphics]: Display algorithms
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    Interactive Rendering with Bidirectional Texture Functions
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Suykens, Frank; Berge, Karl; Lagae, Ares; Dutre, Philip
    We propose a new technique for efficiently rendering bidirectional texture functions (BTFs). A 6D BTF describesthe appearance of a material as a texture that depends on the lighting and viewing directions. As such, a BTFaccommodates self-shadowing, interreflection, and masking effects of a complex material without needing anexplicit representation of the small scale geometry. Our method represents the BTF as a set of spatially varyingapparent BRDFs, that each encode the reflectance field of a single pixel in the BTF. Each apparent BRDF isdecomposed into a product of three or more two-dimensional positive factors using a novel factorization technique,which we call chained matrix factorization (CMF). The proposed factorization technique is fully automatic andsuitable for both BRDFs and apparent BRDFs (which typically exhibit off-specular peaks and non-reciprocity).The main benefit of CMF is that it delivers factors well suited for the limited dynamic range of conventionaltexture maps. After factorization, an efficient representation of the BTF is obtained by clustering the factors intoa compact set of 2D textures. With this compact representation, BTFs can be rendered on recent consumer levelhardware with arbitrary viewing and lighting directions at interactive rates.Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Three-DimensionalGraphics and Realism
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    Planned Sampling of Spatially Varying BRDFs
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Lensch, Hendrik P.A.; Lang, Jochen; Sa, Asla M.; Seidel, Hans-Peter
    Measuring reflection properties of a 3D object involves capturing images for numerous viewing and lightingdirections. We present a method to select advantageous measurement directions based on analyzing the estimationof the bi-directional reflectance distribution function (BRDF). The selected directions minimize the uncertaintyin the estimated parameters of the BRDF. As a result, few measurements suffice to produce models that describethe reflectance behavior well. Moreover, the uncertainty measure can be computed fast on modern graphics cardsby exploiting their capability to render into a floating-point frame buffer. This forms the basis of an acquisitionplanner capable of guiding experts and non-experts alike through the BRDF acquisition process. We demonstratethat spatially varying reflection properties can be captured more efficiently for real-world applications using ouracquisition planner.Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Three-DimensionalGraphics and Realism Virtual Reality I.4.1 [Computer Vision]: Digitization and Image Capture, Reflectance
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    On Visual Similarity Based 3D Model Retrieval
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Chen, Ding-Yun; Tian, Xiao-Pei; Shen, Yu-Te; Ouhyoung, Ming
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    Progressive Simplification of Tetrahedral Meshes Preserving All Isosurface Topologies
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Chiang, Yi-Jen; Lu, Xiang
    In this paper, we propose a novel technique for constructing multiple levels of a tetrahedral volume dataset whilepreserving the topologies of all isosurfaces embedded in the data. Our simplification technique has two majorphases. In the segmentation phase, we segment the volume data into topological-equivalence regions, that is, thesub-volumes within each of which all isosurfaces have the same topology. In the simplification phase, we simplifyeach topological-equivalence region independently, one by one, by collapsing edges from the smallest to the largesterrors (within the user-specified error tolerance, for a given error metrics), and ensure that we do not collapseedges that may cause an isosurface-topology change. We also avoid creating a tetrahedral cell of negative volume(i.e., avoid the fold-over problem). In this way, we guarantee to preserve all isosurface topologies in the entiresimplification process, with a controlled geometric error bound. Our method also involves several additionalnovel ideas, including using the Morse theory and the implicit fully augmented contour tree, identifying typesof edges that are not allowed to be collapsed, and developing efficient techniques to avoid many unnecessary orexpensive checkings, all in an integrated manner. The experiments show that all the resulting isosurfaces preservethe topologies, and have good accuracies in their geometric shapes. Moreover, we obtain nice data-reductionrates, with competitively fast running times.
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    Multiresolution Surface Representation Based on Displacement Volumes
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Botsch, Mario; Kobbelt, Leif
    We propose a new representation for multiresolution models which uses volume elements enclosed between thedifferent resolution levels to encode the detail information. Keeping these displacement volumes locally constantduring a deformation of the base surface leads to a natural behaviour of the detail features. The correspondingreconstruction operator can be implemented efficiently by a hierarchical iterative relaxation scheme, providingclose to interactive response times for moderately complex models.Based on this representation we implement a multiresolution editing tool for irregular polygon meshes that allowsthe designer to freely edit the base surface of a multiresolution model without having to care about self-intersectionsin the respective detailed surface. We demonstrate the effectiveness and robustness of the reconstructionby several examples with real-world data.
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    Beyond Stippling - Methods for Distributing Objects on the Plane
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Hiller, Stefan; Hellwig, Heino; Deussen, Oliver
    Conventionally, stippling is an effective technique for representing surfaces in pen-and-ink. We present new efficientmethods for stipple drawings by computer. In contrast to already existing techniques, arbitrary shapes canbe used in place of dots. An extension of Lloyd's Method enables us to position small objects on a plane in a visuallypleasing form. This allows us to generate new illustration styles. Similar methods can be used for positioningobjects in other applications.
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    BDAM - Batched Dynamic Adaptive Meshes for High Performance Terrain Visualization
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Cignoni, P.; Ganovelli, F.; Gobbetti, E.; Marton, F.; Ponchio, F.; Scopigno, R.
    This paper describes an efficient technique for out-of-core rendering and management of large textured terrainsurfaces. The technique, called Batched Dynamic Adaptive Meshes (BDAM), is based on a paired tree structure:a tiled quadtree for texture data and a pair of bintrees of small triangular patches for the geometry. These smallpatches are TINs and are constructed and optimized off-line with high quality simplification and tristrippingalgorithms. Hierarchical view frustum culling and view-dependent texture and geometry refinement is performedat each frame through a stateless traversal algorithm. Thanks to the batched CPU/GPU communication model,the proposed technique is not processor intensive and fully harnesses the power of current graphics hardware.Both preprocessing and rendering exploit out-of-core techniques to be fully scalable and to manage large terraindatasets.Categories and Subject Descriptors (according to ACM CCS): I.3.3 [Computer Graphics]: Picture and Image Generation;I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism.
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    Interactive Cutaway Illustrations
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Diepstraten, J.; Weiskopf, D.; Ertl, T.
    In this paper we discuss different approaches to generate cutaway illustrations. The purpose of such a drawingis to allow the viewer to have a look into an otherwise solid opaque object. Traditional methods to draw thesekinds of illustrations are evaluated to extract a small and effective set of rules for a computer-based renderingof cutaway illustrations. We show that our approaches are not limited to a specific rendering style but can besuccessfully combined with a great variety of well-known artistic or technical illustration techniques. All methodsof this paper make use of modern graphics hardware functionality to achieve interactive frame rates.
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    Adaptive Ray Tracing of Subdivision Surfaces
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Müller, Kerstin; Techmann, Torsten; Fellner, Dieter W.
    Subdivision Surfaces as well as (interactive) ray tracing have become an important issue in computer graphics.But ray tracing of subdivision surfaces has received only little attention. We present a new approach for raytracing of subdivision surfaces. The algorithm uses a projection of the ray onto the surface and works mainly intwo dimensions along this projection. While proceeding from patch to patch, we examine the bounding volume oftheir borders: the lower the distance between ray and subdivision surface, the more refinement steps are adaptivelyapplied to the surface but only along the projection of the ray. The adaptive refinement of a patch is controlled bycurvature, size, its membership to the silhouette, and its potential contribution to the light transport. The algorithmis simple and mainly consists of elementary geometric computations. Hence it is fast and easy to implementwithout the need for elaborate preprocessing. The algorithm is robust in the sense that it deals with all features ofsubdivision surfaces like creases and corners.Categories and Subject Descripters (according to ACM CCS): I.3.7 [Computer Graphics]: Raytracing
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    Advanced Design for a Realistic Virtual Brush
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Xu, Songhua; Lau, Francis C.M.; Tang, Feng; Pan, Yunhe
    This paper proposes a novel algorithmic framework for an advanced virtual brush to be used in interactive digitalpainting. The framework comprises the following components: a geometry model of the brush using a hierarchicalrepresentation that leads to substantial savings in every step of the painting process; fast online brush motionsimulation assisted by offline calibration that guarantees an accurate and stable simulation of the brush's dynamicbehavior; a new pigment model based on a diffusion process of random molecules that considers delicateand complex pigment behavior at dipping time as well as during painting; and a user-adaptation component thatenables the system to cater for the personal painting habits of different users. A prototype system has been implementedbased on this framework. Compared with other virtual brushes, this new system is designed to presenta realistic brush in the sense that the system accurately and stably simulates the complex painting functionalityof a running brush, and therefore is capable of creating high-quality digital paintings with minute aesthetic detailsthat can rival the real artwork. The advanced features also give rise to a high degree of expressiveness ofthe virtual brush that the user can comfortably manipulate. http://www.csis.hku.hk/songhuale-brush/ providessupplementary materials for this paper.Categories and Subject Descriptors (according to ACM CCS): I.3.6 [Methodology and Techniques]: Interactiontechniques; I.3.5 [Computational Geometry and Object Modeling]: Physically based modeling; I.3.4 [GraphicsUtilities]: Paint systems;
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    Volumetric Filtering, Modeling and Visualization for Nano-Medicine
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Bajaj, Chandrajit
    The 3D structures of individual proteins or small complexes, such as most of the Protein Data Bank entries, are still unable to yield the 'full picture' of a functional biological complex. The study of large macromolecular complexes, such as viruses, ion channels, the ribosome and other macromolecular machines of various types, offer more complete structural and functional description of the nano-machinery of life.In addition to x-ray crystallography. NMR spectroscopy, electron cryomicroscopy (cryoEM) imaging of single particles, and in-vivo molecular tomographic imaging has become indispensable at revealing the structures of large macromolecular complexes at subnanometer resolutions.In this talk, I shall describe some of the recent computational advances in filtering, modeling, analysis and visualization, that have propelled structure determination by cryoEM and tomographic imaging, to steadily increasing accuracy.
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    Ray Differentials and Multiresolution Geometry Caching for Distribution Ray Tracing in Complex Scenes
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Christensen, Per H.; Laur, David M.; Fong, Julian; Wooten, Wayne L.; Batali, Dana
    When rendering only directly visible objects, ray tracing a few levels of specular reflection from large, low-curvaturesurfaces, and ray tracing shadows from point-like light sources, the accessed geometry is coherentand a geometry cache performs well. But in many other cases, the accessed geometry is incoherent and a standardgeometry cache performs poorly: ray tracing of specular reflection from highly curved surfaces, tracing rays thatare many reflection levels deep, and distribution ray tracing for wide glossy reflection, global illumination, widesoft shadows, and ambient occlusion. Fortunately, less geometric accuracy is necessary in the incoherent cases.This observation can be formalized by looking at the ray differentials for different types of scattering: coherentrays have small differentials, while incoherent rays have large differentials. We utilize this observation to obtainefficient multiresolution caching of geometry and textures (including displacement maps) for classic and distributionray tracing in complex scenes. We use an existing multiresolution caching scheme (originally developed forscanline rendering) for textures and displacement maps, and introduce a multiresolution geometry caching schemefor tessellated surfaces. The multiresolution geometry caching scheme makes it possible to efficiently render scenesthat, if fully tessellated, would use 100 times more memory than the geometry cache size.
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    Hierarchical Higher Order Face Cluster Radiosity for Global Illumination Walkthroughs of Complex Non-Diffuse Environments
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Gobbetti, Enrico; Spano, Leonardo; Agus, Marco
    We present an algorithm for simulating global illumination in scenes composed of highly tessellated objects withdiffuse or moderately glossy reflectance. The solution method is a higher order extension of the face cluster radiositytechnique. It combines face clustering, multiresolution visibility, vector radiosity, and higher order baseswith a modified progressive shooting iteration to rapidly produce visually continuous solutions with limited memoryrequirements. The output of the method is a vector irradiance map that partitions input models into areaswhere global illumination is well approximated using the selected basis. The programming capabilities of moderncommodity graphics architectures are exploited to render illuminated models directly from the vector irradiancemap, exploiting hardware acceleration for approximating view dependent illumination during interactive walkthroughs.Using this algorithm, visually compelling global illumination solutions for scenes of over one millioninput polygons can be computed in minutes and examined interactively on common graphics personal computers.Categories and Subject Descriptors (according to ACM CCS): I.3.3 [Computer Graphics]: Picture and Image Generation; I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism.
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    The Stringed Haptic Workbench: a New Haptic Workbench Solution
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Tarrin, N.; Coquillart, S.; Hasegawa, S.; Bouguila, L.; Sato, M.
    The workbench is an interesting semi-immersive configuration for interactive tasks. However, haptic feedback, i.e.force and tactile feedback, is one important cue which is missing. To the authors' knowledge, the sole proposedsolution consists in installing an arm force feedback device on one-screen workbenches. This solution, however,has several drawbacks. The arm can perturb the stereoscopic display, cross virtual objects or hide parts of thevisualization space. Furthermore, the interaction space is limited by the size of the arm, which may also damagethe screen or perturb the electromagnetic tracking system. Some of these difficulties may even be worth with a two-screenworkbench. This paper discusses an alternative solution, which consists in integrating a stringed hapticdevice on a workbench. This approach is less invasive, more flexible and well-suited to a two-screen workbench.
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    Image Based Interactive Rendering with View Dependent Geometry
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Evers-Senne, J.-F.; Koch, R.
    In this paper we present a novel approach for interactive rendering of virtual views from real image sequences.Combining the concepts of light fields, depth-compensated image warping and view dependent texture mapping,this plenoptic modeling approach can handle large and complex scenes. A portable, handheld multi-camera systemhas been developed that allows to record multiple image streams by simply walking around the scene. Theseimage streams are automatically calibrated and depth maps for all views are generated as input to the renderingstage. For rendering a view dependent warping surface is constructed on the fly and depth-compensated imageinterpolation is applied with view-dependent texture mapping. Rendering quality is scalable to allow fast previewand to achieve high-end quality with the same approach. The system can handle large and geometrically complexscenes with hundreds of real images at interactive rates.Categories and Subject Descriptors (according to ACM CCS): I.3.3 [Computer Graphics]: Viewing algorithms, I.4.1[Image Processing and Computer Vision]: Digitization and Image Capture, I.4.8 [Image Processing and ComputerVision]: Scene Analysis
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    Real-Time Caustics
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Wand, M.; Strasser, W.
    We present a new algorithm to render caustics. The algorithm discretizes the specular surfaces into samplepoints. Each of the sample points is treated as a pinhole camera that projects an image of the incoming lightonto the diffuse receiver surfaces. Anti-aliasing is performed by considering the local surface curvature at thesample points to filter the projected images. The algorithm can be implemented using programmable texturemapping hardware. It allows to render caustics in fully dynamic scenes in real-time on current PC hardware.Categories and Subject Descriptors: I.3.3 [Computer Graphics]: Picture/Image Generation - Display Algorithms;I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism
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    Interactive Design of Bonsai Tree Models
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Boudon, Frederic; Prusinkiewicz, Przemyslaw; Federl, Pavol; Godin, Christophe; Karwowski, Radoslaw
    Because of their complexity, plant models used in computer graphics are commonly created with proceduralmethods. A difficult problem is the user control of these models: a small number of parameters is insufficient tospecify plant characteristics in detail, while large numbers of parameters are tedious to manipulate and difficultto comprehend. To address this problem, we propose a method for managing parameters involved in plant modelmanipulation. Specifically, we introduce decomposition graphs as multiscale representations of plant structuresand present interactive tools for designing trees that operate on decomposition graphs. The supported operationsinclude browsing of the parameter space, editing of generalized parameters (scalars, functions, and branchingsystem silhouettes), and the definition of dependencies between parameters. We illustrate our method by creatingmodels of bonsai trees.Categories and Subject Descriptors (according to ACM CCS): I.3.6 [Computer Graphics]: Methodology and Techniques
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    A Fast Rendering Method for Refractive and Reflective Caustics Due to Water Surfaces
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Iwasaki, Kei; Dobashi, Yoshinori; Nishita, Tomoyuki
    In order to synthesize realistic images of scenes that include water surfaces, the rendering of optical effectscaused by waves on the water surface, such as caustics and reflection, is necessary. However, rendering causticsis quite complex and time-consuming. In recent years, the performance of graphics hardware has made significantprogress. This fact encourages researchers to study the acceleration of realistic image synthesis. We present herea method for the fast rendering of refractive and reflective caustics due to water surfaces. In the proposed method,an object is expressed by a set of texture mapped slices. We calculate the intensities of the caustics on the objectby using the slices and store the intensities as textures. This makes it possible to render caustics at interactive rateby using graphics hardware. Moreover, we render objects that are reflected and refracted due to the water surfaceby using reflection/refraction mapping of these slices.Categories and Subject Descriptors (according to ACM CCS): I.3.1 [Computer Graphics]: Hardware Architecture I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism
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    A Scalable Approach to Interactive Global Illumination
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Benthin, Carsten; Wald, Ingo; Slusallek, Philipp
    The addition of global illumination can dramatically increase the realism achievable when rendering virtual environments.In particular with interactive applications we expect the environment to reflect changes in the scenedue to global lighting effects instead of it being just a static backdrop. However, a sufficiently fast and accuratecomputation of global illumination at interactive rates has been difficult even with recent approaches based onrealtime ray tracing.In this paper we present a highly scalable approach to interactive global illumination. It fully recomputes a high-qualitysolution for each frame and thus offers immediate feedback even for dynamic scenes, achieving more than20 fps for simple scenes. Compared to previous systems we increased the raw performance by a factor of up toeight and removed the bottlenecks that were limiting scalability. The system now scales linearly in quality andavailable computing resources, tested with up to 48 CPUs in a commodity PC-cluster. Due to its logarithmicscaling property with respect to scene complexity it even supports lighting simulation in complex scenes with morethan 50 million triangles. This scalability allows applications to perform flexible performance trade-offs. We alsoargue that the realism achievable through interactive global illumination will make it a standard feature of future3D graphics systems once the required computing resources are readily available.
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    Visyllable Based Speech Animation
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Kshirsagar, Sumedha; Magnenat-Thalmann, Nadia
    Visemes are visual counterpart of phonemes. Traditionally, the speech animation of 3D synthetic faces involvesextraction of visemes from input speech followed by the application of co-articulation rules to generate realisticanimation. In this paper, we take a novel approach for speech animation - using visyllables, the visual counterpartof syllables. The approach results into a concatenative visyllable based speech animation system. The key contributionof this paper lies in two main areas. Firstly, we define a set of visyllable units for spoken English along withthe associated phonological rules for valid syllables. Based on these rules, we have implemented a syllabificationalgorithm that allows segmentation of a given phoneme stream into syllables and subsequently visyllables. Secondly,we have recorded the database of visyllables using a facial motion capture system. The recorded visyllableunits are post-processed semi-automatically to ensure continuity at the vowel boundaries of the visyllables. We defineeach visyllable in terms of the Facial Movement Parameters (FMP). The FMPs are obtained as a result of thestatistical analysis of the facial motion capture data. The FMPs allow a compact representation of the visyllables.Further, the FMPs also facilitate the formulation of rules for boundary matching and smoothing after concatenatingthe visyllables units. Ours is the first visyllable based speech animation system. The proposed technique iseasy to implement, effective for real-time as well as non real-time applications and results into realistic speechanimation.Categories and Subject Descriptors (according to ACM CCS): 1.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism
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    Reanimating Faces in Images and Video
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Blanz, V.; Basso, C.; Poggio, T.; Vetter, T.
    This paper presents a method for photo-realistic animation that can be applied to any face shown in a single imageor a video. The technique does not require example data of the person's mouth movements, and the image to beanimated is not restricted in pose or illumination. Video reanimation allows for head rotations and speech in theoriginal sequence, but neither of these motions is required.In order to animate novel faces, the system transfers mouth movements and expressions across individuals, basedon a common representation of different faces and facial expressions in a vector space of 3D shapes and textures.This space is computed from 3D scans of neutral faces, and scans of facial expressions.The 3D model's versatility with respect to pose and illumination is conveyed to photo-realistic image and videoprocessing by a framework of analysis and synthesis algorithms: The system automatically estimates 3D shape andall relevant rendering parameters, such as pose, from single images. In video, head pose and mouth movements aretracked automatically. Reanimated with new mouth movements, the 3D face is rendered into the original images.Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Animation
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    Narrative Use of Sign Language by a Virtual Character for the Hearing Impaired
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Rieger, Thomas; Braun, Norbert
    This paper describes the concept and control of a 3d virtual character system with facial expressions and gesturesas a conversational user interface with narrative expressiveness for the hearing impaired. The gestures and facialexpressions are based on morphing techniques. The system allows the generation of sign language and mouthmotion in real time from text at the level of lip reading quality. The concept of Narrative Extended Speech Acts(NESA) is introduced, based on Interactive Storytelling techniques and the concepts of Narrative Conflict andSuspense Progression. We define a choice of annotation tags to be used with NESAs. We use the NESAs to classifyconversation fragments and to enhance computer generated sign language. We note, how the sign language gesturesare generated and show the possibilities for editing sign language gestures. Furthermore, we give details onhow the NESAs are mapped to gestures. We show the possibilities of controlling the virtual character's behaviourand gestures in a human-oriented way and provide an outlook on future work.Categories and Subject Descriptors (according to ACM CCS): 1.3.6 [Computer Graphics]: Methodology and Techniques
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    ShieldTester: Cell-to-Cell Visibility Test for Surface Occluders
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Navazo, I.; Rossignac, J.; Jou, J.; Shariff, R.
    We present a novel Cell-To-Cell Visibility (C2CV) algorithm, which given two polyhedra, AandBand a connectedand oriented manifold triangle mesh, S offers a simple, fast and conservative test for detecting when A and B areoccluded from each other by S. Previously disclosed C2CV algorithms either relied on costly occlusion fusion orwere restricted to convex or "apparently convex" occluders, which makes them inappropriate for scenes wherepotential occluders are arbitrary triangulated surfaces, such as the body of a car or a portion of a terrain. Thesimplicity of our C2CV algorithm, named ShieldTester, stems from a new Occlusion Theorem, introduced herewhich permits to establish occlusion by computing the intersection of S with a single ray from a vertex ofAtoa vertex ofB. ShieldTester may be used to establish that pairs of cells in a subdivision of space are hidden fromeach other by a relatively large surface occluder, so that when the viewer is in one cell, the objects in the othercell need not be displayed.Categories and Subject Descriptors (according to ACM CCS): I.3.3 [Computer Graphics]: Computational Geometryand Object Modeling: Occlussion Culling, Visibility Test, Triangle Meshes
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    Sub-Voxel Topology Control for Level-Set Surfaces
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Bischoff, Stephan; Kobbelt, Leif
    Active contour models are an efficient, accurate, and robust tool for the segmentation of 2D and 3D image data.In particular, geometric deformable models (GDM) that represent an active contour as the level set of an implicitfunction have proven to be very effective. GDMs, however, do not provide any topology control, i.e. contours maymerge or split arbitrarily and hence change the genus of the reconstructed surface. This behavior is inadequate insettings like the segmentation of organic tissue or other objects whose genus is known beforehand. In this paperwe describe a novel method to overcome this limitation while still preserving the favorable properties of the GDMsetup. We achieve this by adding (sparse) topological information to the volume representation at locations whereit is necessary to locally resolve topological ambiguities. Since the sparse topology information is attached to theedges of the voxel grid, we can reconstruct the interfaces where the deformable surface touches itself at sub-voxelaccuracy. We also demonstrate the efficiency and robustness of our method.
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    A Few Good Lines: Suggestive Drawing of 3D Models
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Sousa, Mario Costa; Prusinkiewicz, Przemyslaw
    We present a method for rendering 3D models in the traditionalline-drawing style used in artistic and scientificillustrations. The goal is to suggest the 3D shape of the objectsusing a small number of lines drawn with carefullychosen line qualities. The system combines several known techniquesinto a simple yet effective non-photorealisticline renderer. Feature edges related to the outline and interiorof a given 3D mesh are extracted, segmented, andsmoothed, yielding chains of lines with varying path, length, thickness,gaps, and enclosures. The paper includessample renderings obtained for a variety of models.
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    Animation of Bubbles in Liquid
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Hong, Jeong-Mo; Kim, Chang-Hun
    We present a new fluid animation technique in which liquid and gas interact with each other, using the exampleof bubbles rising in water. In contrast to previous studies which only focused on one fluid, our system considersboth the liquid and the gas simultaneously. In addition to the flowing motion, the interactions between liquid andgas cause buoyancy, surface tension, deformation and movement of the bubbles. For the natural manipulationof topological changes and the removal of the numerical diffusion, we combine the volume-of-fluid method andthe front-tracking method developed in the field of computational fluid dynamics. Our minimum-stress surfacetension method enables this complementary combination. The interfaces are constructed using the marching cubesalgorithm. Optical effects are rendered using vertex shader techniques.Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Animation
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    Freeform Shape Representations for Efficient Geometry Processing
    (Blackwell Publishers, Inc and the Eurographics Association, 2003) Kobbelt, Leif
    The most important concepts for the handling and storage of freeform shapes in geometry processing applications are parametric representations and volumetric representations. Both have their specific advantages and drawbacks. While the algebraic complexity of volumetric representations is independent from the shape complexity, the domain of a parametric representation usually has to have the same structure as the surface itself (which sometimes makes it necessary to update the domain when the surface is modified).On the other hand, the topology of a parametrically defined surface can be controlled explicitly while in a volumetric representation, the surface topology can change accidentally during deformation. A volumetric representation reduces distance queries or inside/outside tests to mere function evaluations but the geodesic neighborhood relation between surface points is difficult to resolve. As a consequence, it seems promising to combine parametric and volumetric representations to effectively exploit both advantages.In this talk, a number of projects are presented and discussed in which such a combination leads to efficient and numerically stable algorithms for the solution of various geometry processing tasks. Applications include global error control for mesh decimation and smoothing, topology control for level-set surfaces, and shape modeling with unstructured point clouds.