25-Issue 3

Permanent URI for this collection

EG 2006 Conference Proceedings

BibTeX (25-Issue 3)
                
@article{
-,
journal = {Computer Graphics Forum}, title = {{
Preface}},
author = {}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
-}
}
                
@article{
10.1111:j.1467-8659.2006.00942.x,
journal = {Computer Graphics Forum}, title = {{
A Primer on Topological Persistence}},
author = {
Edelsbrunner, Herbert
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00942.x}
}
                
@article{
10.1111:j.1467-8659.2006.00944.x,
journal = {Computer Graphics Forum}, title = {{
Towards a Unified Dynamical Solver for Computer Graphics}},
author = {
Stam, Jos
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00944.x}
}
                
@article{
10.1111:j.1467-8659.2006.00943.x,
journal = {Computer Graphics Forum}, title = {{
Data Preparation for Real-time High Quality Rendering of Complex Models}},
author = {
Klein, Reinhard
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00943.x}
}
                
@article{
10.1111:j.1467-8659.2006.00945.x,
journal = {Computer Graphics Forum}, title = {{
Tuning Subdivision by Minimising Gaussian Curvature Variation Near Extraordinary Vertices}},
author = {
Augsdoerfer, U.H.
and
Dodgson, N.A.
and
Sabin, M.A.
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00945.x}
}
                
@article{
10.1111:j.1467-8659.2006.00946.x,
journal = {Computer Graphics Forum}, title = {{
Silhouette Extraction in Hough Space}},
author = {
Olson, Matt
and
Zhang , Hao
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00946.x}
}
                
@article{
10.1111:j.1467-8659.2006.00947.x,
journal = {Computer Graphics Forum}, title = {{
Easy Mesh Cutting}},
author = {
Ji, Zhongping
and
Liu, Ligang
and
Chen, Zhonggui
and
Wang, Guojin
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00947.x}
}
                
@article{
10.1111:j.1467-8659.2006.00948.x,
journal = {Computer Graphics Forum}, title = {{
Accurate Specular Reflections in Real-Time}},
author = {
Roger, David
and
Holzschuch, Nicolas
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00948.x}
}
                
@article{
10.1111:j.1467-8659.2006.00949.x,
journal = {Computer Graphics Forum}, title = {{
An Improved Physically-Based Soft Shadow Volume Algorithm}},
author = {
Lehtinen, Jaakko
and
Laine, Samuli
and
Aila, Timo
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00949.x}
}
                
@article{
10.1111:j.1467-8659.2006.00950.x,
journal = {Computer Graphics Forum}, title = {{
Reflected-Scene Impostors for Realistic Reflections at Interactive Rates}},
author = {
Popescu, Voicu
and
Mei, Chunhui
and
Dauble, Jordan
and
Sacks, Elisha
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00950.x}
}
                
@article{
10.1111:j.1467-8659.2006.00952.x,
journal = {Computer Graphics Forum}, title = {{
C-BDAM - Compressed Batched Dynamic Adaptive Meshes for Terrain Rendering}},
author = {
Gobbetti, E.
and
Marton, F.
and
Cignoni, P.
and
Di Benedetto, M.
and
Ganovelli, F.
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00952.x}
}
                
@article{
10.1111:j.1467-8659.2006.00951.x,
journal = {Computer Graphics Forum}, title = {{
Multiresolution Random Accessible Mesh Compression}},
author = {
Kim, Junho
and
Choe, Sungyul
and
Lee, Seungyong
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00951.x}
}
                
@article{
10.1111:j.1467-8659.2006.00953.x,
journal = {Computer Graphics Forum}, title = {{
Texture Adaptation for Progressive Meshes}},
author = {
Chen, Chih-Chun
and
Chuang, Jung-Hong
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00953.x}
}
                
@article{
10.1111:j.1467-8659.2006.00954.x,
journal = {Computer Graphics Forum}, title = {{
Optimizing Control Variate Estimators for Rendering}},
author = {
Fan, Shaohua
and
Chenney, Stephen
and
Hu, Bo
and
Tsui, Kam-Wah
and
Lai, Yu-chi
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00954.x}
}
                
@article{
10.1111:j.1467-8659.2006.00955.x,
journal = {Computer Graphics Forum}, title = {{
A Predictive Light Transport Model for the Human Iris}},
author = {
W.Y. Lam, Michael
and
V.G. Baranoski, Gladimir
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00955.x}
}
                
@article{
10.1111:j.1467-8659.2006.00956.x,
journal = {Computer Graphics Forum}, title = {{
Data-driven Local Coordinate Systems for Image-Based Rendering}},
author = {
Mueller, Gero
and
Sarlette, Ralf
and
Klein, Reinhard
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00956.x}
}
                
@article{
10.1111:j.1467-8659.2006.00957.x,
journal = {Computer Graphics Forum}, title = {{
Bayesian Point Cloud Reconstruction}},
author = {
Jenke, P.
and
Wand, M.
and
Bokeloh, M.
and
Schilling, A.
and
Strasser, W.
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00957.x}
}
                
@article{
10.1111:j.1467-8659.2006.00958.x,
journal = {Computer Graphics Forum}, title = {{
Competing Fronts for Coarse-to-Fine Surface Reconstruction}},
author = {
Sharf, Andrei
and
Lewiner, Thomas
and
Shamir, Ariel
and
Kobbelt, Leif
and
Cohen-Or, Daniel
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00958.x}
}
                
@article{
10.1111:j.1467-8659.2006.00960.x,
journal = {Computer Graphics Forum}, title = {{
Semantic Photo Synthesis}},
author = {
Johnson, M.
and
Brostow, G. J.
and
Shotton, J.
and
Arandjelovic, O.
and
Kwatra, V.
and
Cipolla, R.
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00960.x}
}
                
@article{
10.1111:j.1467-8659.2006.00959.x,
journal = {Computer Graphics Forum}, title = {{
Volume-Surface Trees}},
author = {
Boubekeur, Tamy
and
Heidrich, Wolfgang
and
Granier, Xavier
and
Schlick, Christophe
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00959.x}
}
                
@article{
10.1111:j.1467-8659.2006.00962.x,
journal = {Computer Graphics Forum}, title = {{
Beyond Tone Mapping: Enhanced Depiction of Tone Mapped HDR Images}},
author = {
Smith, Kaleigh
and
Krawczyk, Grzegorz
and
Myszkowski, Karol
and
Seidel, Hans-Peter
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00962.x}
}
                
@article{
10.1111:j.1467-8659.2006.00961.x,
journal = {Computer Graphics Forum}, title = {{
Analysis of Reproducing Real-World Appearance on Displays of Varying Dynamic Range}},
author = {
Yoshida, Akiko
and
Mantiuk, Rafal
and
Myszkowski, Karol
and
Seidel, Hans-Peter
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00961.x}
}
                
@article{
10.1111:j.1467-8659.2006.00963.x,
journal = {Computer Graphics Forum}, title = {{
Real-Time Weighted Pose-Space Deformation on the GPU}},
author = {
Rhee, Taehyun
and
Lewis, J.P.
and
Neumann, Ulrich
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00963.x}
}
                
@article{
10.1111:j.1467-8659.2006.00965.x,
journal = {Computer Graphics Forum}, title = {{
Splicing Upper-Body Actions with Locomotion}},
author = {
Heck, Rachel
and
Kovar, Lucas
and
Gleicher, Michael
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00965.x}
}
                
@article{
10.1111:j.1467-8659.2006.00964.x,
journal = {Computer Graphics Forum}, title = {{
Dancing-to-Music Character Animation}},
author = {
Shiratori, Takaaki
and
Nakazawa, Atsushi
and
Ikeuchi, Katsushi
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00964.x}
}
                
@article{
10.1111:j.1467-8659.2006.00966.x,
journal = {Computer Graphics Forum}, title = {{
Wrinkling Coarse Meshes on the GPU}},
author = {
Loviscach, J.
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00966.x}
}
                
@article{
10.1111:j.1467-8659.2006.00967.x,
journal = {Computer Graphics Forum}, title = {{
Latent Doodle Space}},
author = {
Baxter, William
and
Anjyo, Ken-ichi
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00967.x}
}
                
@article{
10.1111:j.1467-8659.2006.00968.x,
journal = {Computer Graphics Forum}, title = {{
Sweep-based Freeform Deformations}},
author = {
Yoon, Seung-Hyun
and
Kim, Myung-Soo
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00968.x}
}
                
@article{
10.1111:j.1467-8659.2006.00969.x,
journal = {Computer Graphics Forum}, title = {{
GPU-based Collision Detection for Deformable Parameterized Surfaces}},
author = {
Gress, Alexander
and
Guthe, Michael
and
Klein, Reinhard
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00969.x}
}
                
@article{
10.1111:j.1467-8659.2006.00970.x,
journal = {Computer Graphics Forum}, title = {{
Cache-Efficient Layouts of Bounding Volume Hierarchies}},
author = {
Yoon, Sung-Eui
and
Manocha, Dinesh
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00970.x}
}
                
@article{
10.1111:j.1467-8659.2006.00971.x,
journal = {Computer Graphics Forum}, title = {{
Ray Tracing Animated Scenes using Motion Decomposition}},
author = {
Guenther, Johannes
and
Friedrich, Heiko
and
Wald, Ingo
and
Seidel, Hans-Peter
and
Slusallek, Philipp
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00971.x}
}
                
@article{
10.1111:j.1467-8659.2006.00972.x,
journal = {Computer Graphics Forum}, title = {{
Direct (Re)Meshing for Efficient Surface Processing}},
author = {
Schreiner, John
and
Scheidegger, Carlos E.
and
Fleishman, Shachar
and
Silva, Claudio T.
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00972.x}
}
                
@article{
10.1111:j.1467-8659.2006.00973.x,
journal = {Computer Graphics Forum}, title = {{
A Robust Two-Step Procedure for Quad-Dominant Remeshing}},
author = {
Marinov, Martin
and
Kobbelt, Leif
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00973.x}
}
                
@article{
10.1111:j.1467-8659.2006.00975.x,
journal = {Computer Graphics Forum}, title = {{
Projective Alpha Colour}},
author = {
Willis, Philip
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00975.x}
}
                
@article{
10.1111:j.1467-8659.2006.00974.x,
journal = {Computer Graphics Forum}, title = {{
Computing discrete shape operators on general meshes}},
author = {
Grinspun, Eitan
and
Gingold, Yotam
and
Reisman, Jason
and
Zorin, Denis
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00974.x}
}
                
@article{
10.1111:j.1467-8659.2006.00976.x,
journal = {Computer Graphics Forum}, title = {{
Easy Matting - A Stroke Based Approach for Continuous Image Matting}},
author = {
Guan, Yu
and
Chen, Wei
and
Liang, Xiao
and
Ding, Ziang
and
Peng, Qunsheng
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00976.x}
}
                
@article{
10.1111:j.1467-8659.2006.00977.x,
journal = {Computer Graphics Forum}, title = {{
Cross Dissolve Without Cross Fade: Preserving Contrast, Color and Salience in Image Compositing}},
author = {
Grundland, Mark
and
Vohra, Rahul
and
Williams, Gareth P.
and
Dodgson, Neil A.
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00977.x}
}
                
@article{
10.1111:j.1467-8659.2006.00978.x,
journal = {Computer Graphics Forum}, title = {{
Enhancing the Interactive Visualization of Procedurally Encoded Multifield Data with Ellipsoidal Basis Functions}},
author = {
Jang, Yun
and
Botchen, Ralf P.
and
Lauser, Andreas
and
Ebert, David S.
and
Gaither, Kelly P.
and
Ertl, Thomas
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00978.x}
}
                
@article{
10.1111:j.1467-8659.2006.00979.x,
journal = {Computer Graphics Forum}, title = {{
Opacity Peeling for Direct Volume Rendering}},
author = {
Rezk-Salama, Christof
and
Kolb, Andreas
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00979.x}
}
                
@article{
10.1111:j.1467-8659.2006.00980.x,
journal = {Computer Graphics Forum}, title = {{
Topological Structures in Two-Parameter-Dependent 2D Vector Fields}},
author = {
Weinkauf, T.
and
Theisel, H.
and
Hege, H.-C.
and
Seidel, H.-P.
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00980.x}
}
                
@article{
10.1111:j.1467-8659.2006.00981.x,
journal = {Computer Graphics Forum}, title = {{
Seamless Integration of Initial Sketching and Subsequent Detail Editing in Flower Modeling}},
author = {
Ijiri, T.
and
Owada, S.
and
Igarashi, T.
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00981.x}
}
                
@article{
10.1111:j.1467-8659.2006.00982.x,
journal = {Computer Graphics Forum}, title = {{
Virtual Garments: A Fully Geometric Approach for Clothing Design}},
author = {
Decaudin, Philippe
and
Julius, Dan
and
Wither, Jamie
and
Boissieux, Laurence
and
Sheffer, Alla
and
Cani, Marie-Paule
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00982.x}
}
                
@article{
10.1111:j.1467-8659.2006.00983.x,
journal = {Computer Graphics Forum}, title = {{
Implicit Surface Modelling with a Globally Regularised Basis of Compact Support}},
author = {
Walder, C.
and
Schoelkopf, B.
and
Chapelle, O.
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00983.x}
}
                
@article{
10.1111:j.1467-8659.2006.00984.x,
journal = {Computer Graphics Forum}, title = {{
Creating Face Models from Vague Mental Images}},
author = {
Blanz, V.
and
Albrecht, I.
and
Haber, J.
and
Seidel, H.-P.
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00984.x}
}
                
@article{
10.1111:j.1467-8659.2006.00985.x,
journal = {Computer Graphics Forum}, title = {{
Efficient Large Scale Acquisition of Building Interiors}},
author = {
Bahmutov, Gleb
and
Popescu, Voicu
and
Mudure, Mihai
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00985.x}
}
                
@article{
10.1111:j.1467-8659.2006.00986.x,
journal = {Computer Graphics Forum}, title = {{
Stroke Pattern Analysis and Synthesis}},
author = {
Barla, Pascal
and
Breslav, Simon
and
Thollot, Joelle
and
Sillion, Francois
and
Markosian, Lee
}, year = {
2006},
publisher = {
The Eurographics Association and Blackwell Publishing, Inc},
ISSN = {1467-8659},
DOI = {
10.1111/j.1467-8659.2006.00986.x}
}

Browse

Recent Submissions

Now showing 1 - 46 of 46
  • Item
    Preface
    (The Eurographics Association and Blackwell Publishing, Inc, 2006)
  • Item
    A Primer on Topological Persistence
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Edelsbrunner, Herbert
    The idea of topological persistence is to look at homological features that persist along a nested sequence of topo-logical spaces. As a typical example, we may take the sequence of sublevel sets of a function. The combinatorial characterization of persistence in terms of pairs of critical values and fast algorithms computing these pairs make this idea practical and useful in dealing with the pervasive phenomenon of noise in geometric and visual data. This talk will1. recall the relatively short history of persistence and some of its older roots;2. introduce the concept intuitively while pointing out where algebra is needed to solidify the more difficult steps;3. discuss a few applications to give a feeling of the potential of the method in dealing with noise and scale.Besides the initial concept, the talk will touch upon recent extensions and their motivation.
  • Item
    Towards a Unified Dynamical Solver for Computer Graphics
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Stam, Jos
    In this talk I will present some research I have done over the past few years in developing a unified dynamical solver for computer graphics. Currently many solvers are specialized for a given phenomenon such as fluid flow, cloth, rigid bodies, hair, etc. Having these different solvers interact is sometimes problematic. We propose to model all matter as a linked particle system having the topology of a simplicial complex. The dynamical complex evolves due to external forces like gravity and constraints such as collisions and internal deformation energies. We use a solution scheme that iteratively updates the velocities to achieve all constraints. Key to the stability of our system is to interleave the solve for the different constraints. The talk will cover the main ideas and ingredients of our solver and will be accompanied with live demonstrations.
  • Item
    Data Preparation for Real-time High Quality Rendering of Complex Models
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Klein, Reinhard
    The capability of current 3D acquisition systems to digitize the geometry reflection behaviour of objects as well as the sophisticated application of CAD techniques lead to rapidly growing digital models which pose new challenges for interaction and visualization. Due to the sheer size of the geometry as well as the texture and reflection data which are often in the range of several gigabytes, efficient techniques for analyzing, compressing and rendering are needed. In this talk I will present some of the research we did in our graphics group over the past years motivated by industrial partners in order to automate the data preparation step and allow for real-time high quality rendering e.g. in the context of VR-applications. Strength and limitations of the different techniques will be discussed and future challenges will be identified. The presentation will go along with live demonstrations.
  • Item
    Tuning Subdivision by Minimising Gaussian Curvature Variation Near Extraordinary Vertices
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Augsdoerfer, U.H.; Dodgson, N.A.; Sabin, M.A.
    We present a method for tuning primal stationary subdivision schemes to give the best possible behaviour near extraordinary vertices with respect to curvature variation.Current schemes lead to a limit surface around extraordinary vertices for which the Gaussian curvature diverges, as demonstrated by Karciauskas et al. [KPR04]. Even when coefficients are chosen such that the subsubdominant eigenvalues, , equal the square of the subdominant eigenvalue,, of the subdivision matrix [DS78] there is still variation in the curvature of the subdivision surface around the extraordinary vertex as shown in recent work by Peters and Reif [PR04] illustrated by Karciauskas et al. [KPR04].In our tuning method we optimise within the space of subdivision schemes with bounded curvature to minimise this variation in curvature around the extraordinary vertex. To demonstrate our method we present results for the Catmull-Clark [CC78], 4-8 [Vel01, VZ01] and 4-3 [PS03] subdivision schemes. We compare our results to previous work on the tuning of these schemes and show that the coefficients derived with this method give a significantly smaller curvature variation around extraordinary vertices.Categories and Subject Descriptors (according to ACM CCS): I.3.5 [Computer Graphics]: Computational Geometry and Object Modeling, I.3.6 [Computer Graphics]: Methodology and Techniques
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    Silhouette Extraction in Hough Space
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Olson, Matt; Zhang , Hao
    Object-space silhouette extraction is an important problem in fields ranging from non-photorealistic computer graphics to medical robotics. We present an efficient silhouette extractor for triangle meshes under perspective projection and make three contributions. First, we describe a novel application of 3D Hough transforms, which allows us to organize mesh data more effectively for silhouette computations than the traditional dual transform. Next, we introduce an incremental silhouette update algorithm which operates on an octree augmented with neighbour information and optimized for efficient low-level traversal. Finally, we present a method for initial extraction of silhouette, using the same data structure, whose performance is linear in the size of the extracted silhouette. We demonstrate significant performance improvements given by our approach over the current state of the art.Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Three-Dimensional Graphics and Realism]: Visible line/surface algorithms
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    Easy Mesh Cutting
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Ji, Zhongping; Liu, Ligang; Chen, Zhonggui; Wang, Guojin
    We present Easy Mesh Cutting, an intuitive and easy-to-use mesh cutout tool. Users can cut meaningful components from meshes by simply drawing freehand sketches on the mesh. Our system provides instant visual feedback to obtain the cutting results based on an improved region growing algorithm using a feature sensitive metric. The cutting boundary can be automatically optimized or easily edited by users. Extensive experimentation shows that our approach produces good cutting results while requiring little skill or effort from the user and provides a good user experience. Based on the easy mesh cutting framework, we introduce two applications including sketch-based mesh editing and mesh merging for geometry processing.Categories and Subject Descriptors (according to ACM CCS): I.3.5 [Computer Graphics]: Geometric algorithms, languages, and systems
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    Accurate Specular Reflections in Real-Time
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Roger, David; Holzschuch, Nicolas
    Specular reflections provide many important visual cues in our daily environment. They inform us of the shape of objects, of the material they are made of, of their relative positions, etc. Specular reflections on curved objects are usually approximated using environment maps. In this paper, we present a new algorithm for real-time computation of specular reflections on curved objects, based on an exact computation for the reflection of each scene vertex. Our method exhibits all the required parallax effects and can handle arbitrary proximity between the reflector and the reflected objects.Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism
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    An Improved Physically-Based Soft Shadow Volume Algorithm
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Lehtinen, Jaakko; Laine, Samuli; Aila, Timo
    We identify and analyze several performance problems in a state-of-the-art physically-based soft shadow volume algorithm, and present an improved method that alleviates these problems by replacing an overly conservative spatial acceleration structure by a more efficient one. The new technique consistently outperforms both the previous method and a ray tracing-based reference solution in several realistic situations while retaining the correctness of the solution and other desirable characteristics of the previous method. These include the unintrusiveness of the original algorithm, meaning that our method can be used as a black-box shadow solver in any offline renderer without requiring multiple passes over the image or other special accommodation. We achieve speedup factors from 1.6 to 12.3 when compared to the previous method.Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Three-Dimensional Graphics and Realism]: Shadowing
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    Reflected-Scene Impostors for Realistic Reflections at Interactive Rates
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Popescu, Voicu; Mei, Chunhui; Dauble, Jordan; Sacks, Elisha
    We present a technique for rendering reflections on complex reflectors at interactive rates based on approximating the geometry of the reflected scene with impostors. The reflections correctly convey the distance to the reflector surface and provide motion parallax. Two types of impostors are adapted to the reflections framework: billboards and depth maps. Billboards remove most of the problems of environment mapped reflections at only a small additional cost. Second order reflections are supported by introducing reflective billboards. Higher quality reflections that provide motion parallax within a reflected object are obtained by approximating the reflective geometry with depth maps. The computation of the intersection between a reflected ray and a depth map is accelerated by leveraging epipolar constraints. Like environment mapping, our technique does not pose any restriction on the geometry of the reflector, supports dynamic scenes, and runs at interactive rates with the help of graphics hardware.Categories and Subject Descriptors (ACM CCS): I.3.3. [Computer Graphics]-Three-Dimensional Graphics and Realism.
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    C-BDAM - Compressed Batched Dynamic Adaptive Meshes for Terrain Rendering
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Gobbetti, E.; Marton, F.; Cignoni, P.; Di Benedetto, M.; Ganovelli, F.
    We describe a compressed multiresolution representation for supporting interactive rendering of very large planar and spherical terrain surfaces. The technique, called Compressed Batched Dynamic Adaptive Meshes (C-BDAM), is an extension of the BDAM and P-BDAM chunked level-of-detail hierarchy. In the C-BDAM approach, all patches share the same regular triangulation connectivity and incrementally encode their vertex attributes using a quantized representation of the difference with respect to values predicted from the coarser level. The structure provides a number of benefits: simplicity of data structures, overall geometric continuity for planar and spherical domains, support for variable resolution input data, management of multiple vertex attributes, efficient compression and fast construction times, ability to support maximum-error metrics, real-time decompression and shaded rendering with configurable variable level-of-detail extraction, and runtime detail synthesis. The efficiency of the approach and the achieved compression rates are demonstrated on a number of test cases, including the interactive visualization of a 29 gigasample reconstruction of the whole planet Earth created from high resolution SRTM data.Categories and Subject Descriptors (according toACMCCS): I.3.3 [Computer Graphics]: Picture and Image Generation; I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism.
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    Multiresolution Random Accessible Mesh Compression
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Kim, Junho; Choe, Sungyul; Lee, Seungyong
    This paper presents a novel approach for mesh compression, which we call multiresolution random accessible mesh compression. In contrast to previous mesh compression techniques, the approach enables us to progressively decompress an arbitrary portion of a mesh without decoding other non-interesting parts. This simultaneous support of random accessibility and progressiveness is accomplished by adapting selective refinement of a multiresolution mesh to the mesh compression domain. We present a theoretical analysis of our connectivity coding scheme and provide several experimental results. The performance of our coder is about 11 bits for connectivity and 21 bits for geometry with 12-bit quantization, which can be considered reasonably good under the constraint that no fixed neighborhood information can be used for coding to support decompression in a random order.Categories and Subject Descriptors (according to ACM CCS): I.3.5 [Computer Graphics]: Computational Geometry and Object Modeling
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    Texture Adaptation for Progressive Meshes
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Chen, Chih-Chun; Chuang, Jung-Hong
    Level-of-detail modeling is a vital representation for real-time applications. To support texture mapping progressive meshes (PM), we usually allow the whole PM sequence to share a common texture map. Although such a common texture map can be derived by using appropriate mesh parameterizations that consider the minimization of geometry stretch, texture stretch, or even the texture deviation introduced by edge collapses, we have found that even with a well parameterized texture map, the texture mapped PM still reveals apparent texture distortion due to geometry changes and the nature of linear interpolation used by texture mapping hardware. In this paper, we propose a novel, simple, and efficient approach that adapts texture content for each edge collapse, aiming to eliminate texture distortion. A texture adaptation and its inverse are local and incremental operations that can be fully supported by texture mapping hardware, the render-to-texture feature, and the fragment shader. Once the necessary correspondence in the partition of texture space is built during the course of PM construction, the texture adaptation or its inverse can be applied on the fly before rendering the simplified or refined model with texture map. We also propose the mechanism of indexing mapping to reduce blurred artifacts due to under-sampling that might be introduced by texture adaptation.Keywords: texture mapping progressive meshes, mesh simplification, mesh parameterization, texture distortion Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism Color, shading, shadowing, and texture
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    Optimizing Control Variate Estimators for Rendering
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Fan, Shaohua; Chenney, Stephen; Hu, Bo; Tsui, Kam-Wah; Lai, Yu-chi
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    A Predictive Light Transport Model for the Human Iris
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) W.Y. Lam, Michael; V.G. Baranoski, Gladimir
    Recently, light interactions with organic matter have become the object of detailed investigations by image synthesis researchers. Besides allowing these materials to be rendered in a more intuitive manner, these efforts aim to extend the scope of computer graphics applications to areas such as applied optics and biomedical imaging. There are, however, organic materials that still lack predictive simulation solutions. Among these, the ocular tissues, especially those forming the human iris, pose the most challenging modeling problems which are often associated with data scarcity. In this paper, we describe the first biophysically-based light transport model for the human iris ever presented in the scientific literature. The proposed model algorithmically simulates the light scattering and absorption processes occurring within the iridal tissues, and computes the spectral radiometric responses of these tissues. Its design is based on the current scientific understanding of the iridal morphological and optical characteristics, and it is controlled by parameters directly related to these biophysical attributes. The accuracy and predictability of the spectral results provided by the model are evaluated through comparisons with actual measured iridal data, and its integration into rendering frameworks is illustrated through the generation of images depicting iridal chromatic variations.Categories and Subject Descriptors (according to ACM CCS): I.3.8 [Computer Graphics]: Applications
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    Data-driven Local Coordinate Systems for Image-Based Rendering
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Mueller, Gero; Sarlette, Ralf; Klein, Reinhard
    Image-based representations of an object profit from known geometry. The more accurate this geometry is known, the better corresponding pixels in the different images can be aligned, which leads to less artifacts and better compression performance. For opaque objects the per-pixel data can then be interpreted as a sampling of the BRDF at the respective surface point. In order to parameterize this sampled data a coordinate frame has to be defined. In previous work this coordinate frame was either the global frame or a local frame derived from the base geometry. Both approaches lead to misalignments between sample vectors: Features of basically very similar BRDFs will be shifted to different regions in the sample vector leading to poor compression performance. In order to improve alignment between the sampled BRDFs in image-based rendering, we propose an optimization algorithm which determines consistent coordinate frames for every sample point on the object surface. This way we efficiently align the features even of anisotropic reflection functions and reconstruct approximate local coordinate frames without performing an explicit 3D-reconstruction. The optimization is calculated efficiently by exploiting the Fourier-shift theorem for spherical harmonics. In order to deal with different materials in a scene, the technique is combined with a clustering algorithm. We demonstrate the utility of our method by applying it to BTFs and 6D surface reflectance fields.Categories and Subject Descriptors (according to ACM CCS): I.3.3 [Picture/Image Generation]: Digitizing and scanning I.3.7 [Three-Dimensional Graphics and Realism]: Color, shading, shadowing, and texture
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    Bayesian Point Cloud Reconstruction
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Jenke, P.; Wand, M.; Bokeloh, M.; Schilling, A.; Strasser, W.
    In this paper, we propose a novel surface reconstruction technique based on Bayesian statistics: The measurement process as well as prior assumptions on the measured objects are modeled as probability distributions and Bayes rule is used to infer a reconstruction of maximum probability. The key idea of this paper is to define both measurements and reconstructions as point clouds and describe all statistical assumptions in terms of this finite dimensional representation. This yields a discretization of the problem that can be solved using numerical optimization techniques. The resulting algorithm reconstructs both topology and geometry in form of a well-sampled point cloud with noise removed. In a final step, this representation is then converted into a triangle mesh. The proposed approach is conceptually simple and easy to extend. We apply the approach to reconstruct piecewise-smooth surfaces with sharp features and examine the performance of the algorithm on different synthetic and real-world data sets.Categories and Subject Descriptors (according to ACM CCS): I.5.1 [Models]: Statistical; I.3.5 [Computer Graphics]: Curve, surface, solid and object representations
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    Competing Fronts for Coarse-to-Fine Surface Reconstruction
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Sharf, Andrei; Lewiner, Thomas; Shamir, Ariel; Kobbelt, Leif; Cohen-Or, Daniel
    We present a deformable model to reconstruct a surface from a point cloud. The model is based on an explicit mesh representation composed of multiple competing evolving fronts. These fronts adapt to the local feature size of the target shape in a coarse-to-fine manner. Hence, they approach towards the finer (local) features of the target shape only after the reconstruction of the coarse (global) features has been completed. This conservative approach leads to a better control and interpretation of the reconstructed topology. The use of an explicit representation for the deformable model guarantees water-tightness and simple tracking of topological events. Furthermore, the coarse-to-fine nature of reconstruction enables adaptive handling of non-homogenous sample density, including robustness to missing data in defected areas.Categories and Subject Descriptors (according to ACM CCS): I.3.3 [Computer Graphics]: Digitizing and scanning.Keywords: surface reconstruction, deformable models
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    Semantic Photo Synthesis
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Johnson, M.; Brostow, G. J.; Shotton, J.; Arandjelovic, O.; Kwatra, V.; Cipolla, R.
    Composite images are synthesized from existing photographs by artists who make concept art, e.g., storyboards for movies or architectural planning. Current techniques allow an artist to fabricate such an image by digitally splicing parts of stock photographs. While these images serve mainly to quickly convey how a scene should look, their production is laborious. We propose a technique that allows a person to design a new photograph with substantially less effort. This paper presents a method that generates a composite image when a user types in nouns, such as boat and sand. The artist can optionally design an intended image by specifying other constraints. Our algorithm formulates the constraints as queries to search an automatically annotated image database. The desired photograph, not a collage, is then synthesized using graph-cut optimization, optionally allowing for further user interaction to edit or choose among alternative generated photos. An implementation of our approach, shown in the associated video, demonstrates our contributions of (1) a method for creating specific images with minimal human effort, and (2) a combined algorithm for automatically building an image library with semantic annotations from any photo collection.
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    Volume-Surface Trees
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Boubekeur, Tamy; Heidrich, Wolfgang; Granier, Xavier; Schlick, Christophe
    Many algorithms in computer graphics improve their efficiency by using Hierarchical Space Subdivision Schemes (HS3), such as octrees, kD-trees or BSP trees. Such HS3 usually provide an axis-aligned subdivision of the 3D space embedding a scene or an object. However, the purely volume-based behavior of these schemes often leads to strongly imbalanced surface clustering. In this article, we introduce the VS-Tree, an alternative HS3 providing efficient and accurate surface-based hierarchical clustering via a combination of a global 3D decomposition at coarse subdivision levels, and a local 2D decomposition at fine levels near the surface. First, we show how to efficiently construct VS-Trees over meshes and point-based surfaces, and analyze the improvement it offers for cluster-based surface simplification methods. Then we propose a new surface reconstruction algorithm based on the volume-surface classification of the VS-Tree. This new algorithm is faster than state-of-the-art reconstruction methods and provides a final semi-regular mesh comparable to the output of remeshing algorithms.
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    Beyond Tone Mapping: Enhanced Depiction of Tone Mapped HDR Images
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Smith, Kaleigh; Krawczyk, Grzegorz; Myszkowski, Karol; Seidel, Hans-Peter
    High Dynamic Range (HDR) images capture the full range of luminance present in real world scenes, and unlike Low Dynamic Range (LDR) images, can simultaneously contain detailed information in the deepest of shadows and the brightest of light sources. For display or aesthetic purposes, it is often necessary to perform tone mapping, which creates LDR depictions of HDR images at the cost of contrast information loss. The purpose of this work is two-fold: to analyze a displayed LDR image against its original HDR counterpart in terms of perceived contrast distortion, and to enhance the LDR depiction with perceptually driven colour adjustments to restore the original HDR contrast information. For analysis, we present a novel algorithm for the characterization of tone mapping distortion in terms of observed loss of global contrast, and loss of contour and texture details. We classify existing tone mapping operators accordingly. We measure both distortions with perceptual metrics that enable the automatic and meaningful enhancement of LDR depictions. For image enhancement, we identify artistic and photographic colour techniques from which we derive adjustments that create contrast with colour. The enhanced LDR image is an improved depiction of the original HDR image with restored contrast information.Categories and Subject Descriptors (according to ACM CCS): I.3.3 [Computer Graphics]: Picture/Image Generation I.4.0 [Image Processing and Computer Vision]: GeneralImage processing software
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    Analysis of Reproducing Real-World Appearance on Displays of Varying Dynamic Range
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Yoshida, Akiko; Mantiuk, Rafal; Myszkowski, Karol; Seidel, Hans-Peter
    We conduct a series of experiments to investigate the desired properties of a tone mapping operator (TMO) and to design such an operator based on subjective data. We propose a novel approach to the tone mapping problem, in which the tone mapping parameters are determined based on the data from subjective experiments, rather than an image processing algorithm or a visual model. To collect this data, a series of experiments are conducted in which the subjects adjust three generic TMO parameters: brightness, contrast and color saturation. In two experiments, the subjects are to find a) the most preferred image without a reference image (preference task) and b) the closest image to the real-world scene which the subjects are confronted with (fidelity task). We analyze subjects choice of parameters to provide more intuitive control over the parameters of a tone mapping operator. Unlike most of the researched TMOs that focus on rendering for standard low dynamic range monitors, we consider a broad range of potential displays, each offering different dynamic range and brightness. We simulate capabilities of such displays on a high dynamic range (HDR) display. This allows us to address the question of how tone mapping needs to be adjusted to accommodate displays with drastically different dynamic ranges.Categories and Subject Descriptors (according to ACM CCS): I.3.8 [Computer Graphics]: High dynamic range images, Visual perception, Tone mapping
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    Real-Time Weighted Pose-Space Deformation on the GPU
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Rhee, Taehyun; Lewis, J.P.; Neumann, Ulrich
    WPSD (Weighted Pose Space Deformation) is an example based skinning method for articulated body animation. The per-vertex computation required in WPSD can be parallelized in a SIMD (Single Instruction Multiple Data) manner and implemented on a GPU. While such vertex-parallel computation is often done on the GPU vertex processors, further parallelism can potentially be obtained by using the fragment processors. In this paper, we develop a parallel deformation method using the GPU fragment processors. Joint weights for each vertex are automatically calculated from sample poses, thereby reducing manual effort and enhancing the quality of WPSD as well as SSD (Skeletal Subspace Deformation). We show sufficient speed-up of SSD, PSD (Pose Space Deformation) and WPSD to make them suitable for real-time applications.Categories and Subject Descriptors (according to ACM CCS): I.3.1 [Computer Graphics]: Hardware Architecture-Parallel processing, I.3.5 [Computer Graphics]: Computational Geometry and Object Modeling-Curve, surface, solid and object modeling, I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism-Animation.
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    Splicing Upper-Body Actions with Locomotion
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Heck, Rachel; Kovar, Lucas; Gleicher, Michael
    This paper presents a simple and efficient technique for synthesizing high-fidelity motions by attaching, or splicing, the upper-body action of one motion example to the lower-body locomotion of another. Existing splicing algorithms do little more than copy degrees of freedom (DOFs) from one motion onto another. This naive DOF replacement can produce unrealistic results because it ignores both physical and stylistic correlations between various joints in the body. Our approach uses spatial and temporal relationships found within the example motions to retain the overall posture of the upper-body action while adding secondary motion details appropriate to the timing and configuration of the lower body. By decoupling upper-body action from lower-body locomotion, our motion synthesis technique allows example motions to be captured independently and later combined to create new natural looking motions.Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Animation
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    Dancing-to-Music Character Animation
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Shiratori, Takaaki; Nakazawa, Atsushi; Ikeuchi, Katsushi
    In computer graphics, considerable research has been conducted on realistic human motion synthesis. However, most research does not consider human emotional aspects, which often strongly affect human motion. This paper presents a new approach for synthesizing dance performance matched to input music, based on the emotional aspects of dance performance. Our method consists of a motion analysis, a music analysis, and a motion synthesis based on the extracted features. In the analysis steps, motion and music feature vectors are acquired. Motion vectors are derived from motion rhythm and intensity, while music vectors are derived from musical rhythm, structure, and intensity. For synthesizing dance performance, we first find candidate motion segments whose rhythm features are matched to those of each music segment, and then we find the motion segment set whose intensity is similar to that of music segments. Additionally, our system supports having animators control the synthesis process by assigning desired motion segments to the specified music segments. The experimental results indicate that our method actually creates dance performance as if a character was listening and expressively dancing to the music.Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism Animation; J.5 [Arts and Humanities]: Performing Arts Music
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    Wrinkling Coarse Meshes on the GPU
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Loviscach, J.
    The simulation of complex layers of folds of cloth can be handled through algorithms which take the physical dynamics into account. In many cases, however, it is sufficient to generate wrinkles on a piece of garment which mostly appears spread out. This paper presents a corresponding fully GPU-based, easy-to-control, and robust method to generate and render plausible and detailed folds. This simulation is generated from an animated mesh. A relaxation step ensures that the behavior remains globally consistent. The resulting wrinkle field controls the lighting and distorts the texture in a way which closely simulates an actually deformed surface. No highly tessellated mesh is required to compute the position of the folds or to render them. Furthermore, the solution provides a 3D paint interface through which the user may bias the computation in such a way that folds already appear in the rest pose.Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Animation, I.3.7 [Computer Graphics]: Color, shading, shadowing, and texture
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    Latent Doodle Space
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Baxter, William; Anjyo, Ken-ichi
    We propose the concept of a latent doodle space, a low-dimensional space derived from a set of input doodles, or simple line drawings. The latent space provides a foundation for generating new drawings that are similar, but not identical to, the input examples. The two key components of this technique are 1) a heuristic algorithm for finding stroke correspondences between the drawings, and 2) the use of latent variable methods to automatically extract a low-dimensional latent doodle space from the inputs. We present two practical applications that demonstrate the utility of this idea: first, a randomized stamp tool that creates a different image on every usage; and second, personalized probabilistic fonts, a handwriting synthesis technique that mimics the idiosyncrasies of one s own handwriting.Keywords: sketch, by-example, style learning, scattered data interpolation, principal component analysis, radial basis functions, Gaussian processes, digital in-betweening, handwriting synthesis
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    Sweep-based Freeform Deformations
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Yoon, Seung-Hyun; Kim, Myung-Soo
    We propose a sweep-based approach to the freeform deformation of three-dimensional objects. Instead of using a volume enclosing the whole object, we approximate only its deformable parts using sweep surfaces. The vertices on the object boundary are bound to the sweep surfaces and follow their deformation. Several sweep surfaces can be organized into a hierarchy so that they interact with each other in a controlled manner. Thus we can support intuitively plausible shape deformation of objects of arbitrary topology with multiple control handles. A sweep-based approach also provides important advantages such as volume preservation. We demonstrate the effectiveness of our technique in several examples.Categories and Subject Descriptors (according to ACM CCS): I.3.5 [Computational Geometry and Object Modeling]: Curve, surface, solid, and object representations
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    GPU-based Collision Detection for Deformable Parameterized Surfaces
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Gress, Alexander; Guthe, Michael; Klein, Reinhard
    Based on the potential of current programmable GPUs, recently several approaches were developed that use the GPU to calculate deformations of surfaces like the folding of cloth or to convert higher level geometry to renderable primitives like NURBS or subdivision surfaces. These algorithms are realized as a per-frame operation and take advantage of the parallel processing power of the GPU. Unfortunately, an efficient accurate collision detection, that is necessary for the simulation itself or for the interaction with and editing of the objects, can currently not be integrated seamlessly into these GPU-based approaches without switching back to the CPU. In this paper we describe a novel GPU-based collision detection method for deformable parameterized surfaces that can easily be combined with the aforementioned approaches. Representing the individual parameterized surfaces by stenciled geometry images allows to generate GPU-optimized bounding volume hierarchies in real-time that serve as a basis for an optimized GPU-based hierarchical collision detection algorithm. As a test case we applied our algorithm to the collision detection of deformable trimmed NURBS models, which is an important problem in industry. For the trimming and tessellation of the NURBS on the GPU we used a recent approach [GBK05] and combined it with our collision detection algorithm. This way we are able to render and check collisions for deformable models consisting of several thousands of trimmed NURBS patches in real-time.Categories and Subject Descriptors (according to ACM CCS): I.3.5 [Computer Graphics]: Computational Geometry and Object Modeling-Geometric algorithms, languages, and systems; Splines; I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism-Virtual reality
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    Cache-Efficient Layouts of Bounding Volume Hierarchies
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Yoon, Sung-Eui; Manocha, Dinesh
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    Ray Tracing Animated Scenes using Motion Decomposition
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Guenther, Johannes; Friedrich, Heiko; Wald, Ingo; Seidel, Hans-Peter; Slusallek, Philipp
    Though ray tracing has recently become interactive, its high precomputation time for building spatial indices usually limits its applications to walkthroughs of static scenes. This is a major limitation, as most applications demand support for dynamically animated models. In this paper, we present a new approach to ray trace a special but important class of dynamic scenes, namely models whose connectivity does not change over time and for which all possible poses are known in advance.We support these kinds of models by introducing two new concepts: motion decomposition, and fuzzy kd-trees. We analyze the animation and break the model down into submeshes with similar motion. For each of these submeshes and for every time step, we calculate a best affine transformation through a least square approach. Any residual motion is then captured in a single "fuzzy kd-tree" for the entire animation.Together, these techniques allow for ray tracing animations without rebuilding the spatial index structures for the submeshes, resulting in interactive frame rates of 5 to 15 fps even on a single CPU.Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Ray tracing I.3.6 [Methodology and Techniques]: Graphics data structures and data types
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    Direct (Re)Meshing for Efficient Surface Processing
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Schreiner, John; Scheidegger, Carlos E.; Fleishman, Shachar; Silva, Claudio T.
    We propose a novel surface remeshing algorithm. While many remeshing algorithms are based on global parametrization or local mesh optimization, our algorithm is closely related to surface reconstruction techniques and it requires no explicit parameterization. Our approach is based on the advancing-front paradigm, and it can be used to both incrementally remesh the complete surface, or simply to remesh a portion of it with a high-quality mesh. It is accurate, fast, robust, and suitable for use with interactive mesh processing applications that require local remeshing. We show a number of applications, including matching the resolution of meshes when doing Boolean operations such as unions and intersections. We also show how to adapt the algorithm to blend and merge mixed-mode objects - for example, to compute the union of a point-set surface and a triangle mesh.
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    A Robust Two-Step Procedure for Quad-Dominant Remeshing
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Marinov, Martin; Kobbelt, Leif
    We propose a new technique for quad-dominant remeshing which separates the local regularity requirements from the global alignment requirements by working in two steps. In the first step, we apply a slight variant of variational shape approximation in order to segment the input mesh into patches which capture the global structure of the processed object. Then we compute an optimized quad-mesh for every patch by generating a finite set of candidate curves and applying a combinatorial optimization procedure. Since the optimization is performed independently for each patch, we can afford more complex operations while keeping the overall computation times at a reasonable level. Our quad-meshing technique is robust even for noisy meshes and meshes with isotropic or flat regions since it does not rely on the generation of curves by integration along estimated principal curvature directions. Instead we compute a conformal parametrization for each patch and generate the quad-mesh from curves with minimum bending energy in the 2D parameter domain. Mesh consistency between patches is guaranteed by simply using the same set of sample points along the common boundary curve. The resulting quad-meshes are of high-quality locally (shape of the quads) as well as globally (global alignment) which allows us to even generate fairly coarse quad-meshes that can be used as Catmull-Clark control meshes.Categories and Subject Descriptors (according to ACM CCS): I.3.5 [Computer Graphics]: Geometric algorithms, languages, and systems
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    Projective Alpha Colour
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Willis, Philip
    Alpha colours were introduced for image compositing, using a pixel coverage model. Algebraically they resemble homogeneous coordinates, widely used in projective geometry calculations. We show why this is the case. This allows us to extend alpha beyond compositing, to all colour calculations regardless of whether pixels are involved and without the need for a coverage model. Our approach includes multi-channel spectral calculations and removes the need for 7 channel and 6 channel alpha colour operations. It provides a unified explanation of pre-multiplied and non pre-multiplied colours, including negative coordinates and infinite points in colour space. It permits filter and illumination operations. It unifies the three existing significant compositing models in a single framework. It achieves this with a physically-plausible energy basis.Keywords: projective geometry, homogeneous coordinates, image compositing, alpha blending, alpha compositing, colour representation, filtering, spectral colour, projective alpha colour
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    Computing discrete shape operators on general meshes
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Grinspun, Eitan; Gingold, Yotam; Reisman, Jason; Zorin, Denis
    Discrete curvature and shape operators, which capture complete information about directional curvatures at a point, are essential in a variety of applications: simulation of deformable two-dimensional objects, variational modeling and geometric data processing. In many of these applications, objects are represented by meshes. Currently, a spectrum of approaches for formulating curvature operators for meshes exists, ranging from highly accurate but computationally expensive methods used in engineering applications to efficient but less accurate techniques popular in simulation for computer graphics.We propose a simple and efficient formulation for the shape operator for variational problems on general meshes, using degrees of freedom associated with normals. On the one hand, it is similar in its simplicity to some of the discrete curvature operators commonly used in graphics; on the other hand, it passes a number of important convergence tests and produces consistent results for different types of meshes and mesh refinement.
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    Easy Matting - A Stroke Based Approach for Continuous Image Matting
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Guan, Yu; Chen, Wei; Liang, Xiao; Ding, Ziang; Peng, Qunsheng
    We propose an iterative energy minimization framework for interactive image matting. Our approach is easy in the sense that it is fast and requires only few user-specified strokes for marking the foreground and background. Beginning with the known region, we model the unknown region as a Markov Random Field (MRF) and formulate its energy in each iteration as the combination of one data term and one smoothness term. By automatically adjusting the weights of both terms during the iterations, the first-order continuous and feature-preserving result is rapidly obtained with several iterations. The energy optimization can be further performed in selected local regions for refined results. We demonstrate that our energy-driven scheme can be extended to video matting, with which the spatio-temporal smoothness is faithfully preserved. We show that the proposed approach outperforms previous methods in terms of both the quality and performance for quite challenging examples.
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    Cross Dissolve Without Cross Fade: Preserving Contrast, Color and Salience in Image Compositing
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Grundland, Mark; Vohra, Rahul; Williams, Gareth P.; Dodgson, Neil A.
    Linear interpolation is the standard image blending method used in image compositing. By averaging in the dynamic range, it reduces contrast and visibly degrades the quality of composite imagery. We demonstrate how to correct linear interpolation to resolve this longstanding problem. To provide visually meaningful, high level control over the compositing process, we introduce three novel image blending operators that are designed to preserve key visual characteristics of their inputs. Our contrast preserving method applies a linear color mapping to recover the contrast lost due to linear interpolation. Our salience preserving method retains the most informative regions of the input images by balancing their relative opacity with their relative saliency. Our color preserving method extends homomorphic image processing by establishing an isomorphism between the image colors and the real numbers, allowing any mathematical operation defined on real numbers to be applied to colors without losing its algebraic properties or mapping colors out of gamut. These approaches to image blending have artistic uses in image editing and video production as well as technical applications such as image morphing and mipmapping.Categories and Subject Descriptors (according to ACM CCS): I.3.3 [Computer Graphics]: Picture/Image Generation
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    Enhancing the Interactive Visualization of Procedurally Encoded Multifield Data with Ellipsoidal Basis Functions
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Jang, Yun; Botchen, Ralf P.; Lauser, Andreas; Ebert, David S.; Gaither, Kelly P.; Ertl, Thomas
    Functional approximation of scattered data is a popular technique for compactly representing various types of datasets in computer graphics, including surface, volume, and vector datasets. Typically, sums of Gaussians or similar radial basis functions are used in the functional approximation and PC graphics hardware is used to quickly evaluate and render these datasets. Previously, researchers presented techniques for spatially-limited spherical Gaussian radial basis function encoding and visualization of volumetric scalar, vector, and multifield datasets. While truncated radially symmetric basis functions are quick to evaluate and simple for encoding optimization, they are not the most appropriate choice for data that is not radially symmetric and are especially problematic for representing linear, planar, and many non-spherical structures. Therefore, we have developed a volumetric approximation and visualization system using ellipsoidal Gaussian functions which provides greater compression, and visually more accurate encodings of volumetric scattered datasets. In this paper, we extend previous work to use ellipsoidal Gaussians as basis functions, create a rendering system to adapt these basis functions to graphics hardware rendering, and evaluate the encoding effectiveness and performance for both spherical Gaussians and ellipsoidal Gaussians.Categories and Subject Descriptors (according to ACMCCS): I.3.3 [Computer Graphics]: Scientific Visualization, Ellipsoidal Basis Functions, Functional Approximation, Texture Advection
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    Opacity Peeling for Direct Volume Rendering
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Rezk-Salama, Christof; Kolb, Andreas
    The most important technique to visualize 3D scalar data, as they arise e.g. in medicine from tomographic measurement, is direct volume rendering. A transfer function maps the scalar values to optical properties which are used to solve the integral of light transport in participating media. Many medical data sets, especially MRI data, however, are difficult to visualize due to different tissue types being represented by the same scalar value. The main problem is that interesting structures will be occluded by less important structures because they share the same range of data values. Occlusion, however, is a view-dependent problem and cannot be solved easily by transfer function design. This paper proposes a new method to display different entities inside the volume data in a single rendering pass. The proposed opacity peeling technique reveals structures in the data set that cannot be visualized directly by one-or multi-dimensional transfer functions without explicit segmentation. We also demonstrate real-time implementations using texture mapping and multiple render targets.Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism
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    Topological Structures in Two-Parameter-Dependent 2D Vector Fields
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Weinkauf, T.; Theisel, H.; Hege, H.-C.; Seidel, H.-P.
    In this paper we extract and visualize the topological skeleton of two-parameter-dependent vector fields. This kind of vector data depends on two parameter dimensions, for instance physical time and a scale parameter. We show that two important classes of local bifurcations - fold and Hopf bifurcations - build line structures for which we present an approach to extract them. Furthermore we show that new kinds of structurally stable local bifurcations exist for this data, namely fold-fold and Hopf-fold bifurcations. We present a complete classification of them. We apply our topological extraction method to analyze a number of two-parameter-dependent vector fields with different physical interpretations of the two additional dimensions.Categories and Subject Descriptors (according to ACM CCS): I.3.3 [Computer Graphics]: Line and Curve Generation I.3.3 [Computer Graphics]: Picture/Image Generation
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    Seamless Integration of Initial Sketching and Subsequent Detail Editing in Flower Modeling
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Ijiri, T.; Owada, S.; Igarashi, T.
    We present an interactive modeling system for flower composition that supports seamless transformation from an initial sketch to a detailed three-dimensional (3D) model. To begin, the user quickly sketches the overall appearance of the desired model as a collection of two-dimensional (2D) strokes on hierarchical billboards. Then the user iteratively replaces the coarse sketch with a detailed 3D model referring to the initial sketch as a guide. Since a flower model consists of many repetitive components, the system helps the user to reuse 3D components to facilitate the modeling process. The global view of the entire model is always shown in a separate window to visualize how local modifications affect the global appearance. Our system helps the user make appropriate design decisions to keep the model consistent with the initial design, which is difficult in traditional bottom-up plant modeling systems in which the global view only emerges after all of the details are specified.Categories and Subject Descriptors (according to ACM CCS): I.3.6 [Computer Graphics]: Methodology and Techniques - Interaction Techniques.
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    Virtual Garments: A Fully Geometric Approach for Clothing Design
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Decaudin, Philippe; Julius, Dan; Wither, Jamie; Boissieux, Laurence; Sheffer, Alla; Cani, Marie-Paule
    Modeling dressed characters is known as a very tedious process. It usually requires specifying 2D fabric patterns, positioning and assembling the min 3D, and then performing a physically-based simulation. The latter accounts for gravity and collisions to compute the rest shape of the garment, with the adequate folds and wrinkles.This paper presents a more intuitive way to design virtual clothing. We start with a 2D sketching system in which the user draws the contours and seam-lines of the garment directly on a virtual mannequin. Our system then converts the sketch into an initial 3D surface using an existing method based on a precomputed distance field around the mannequin. The system then splits the created surface into different panels delimited by the seam-lines. The generated panels are typically not developable. However, the panels of a realistic garment must be developable, since each panel must unfold into a 2D sewing pattern. Therefore our system automatically approximates each panel with a developable surface, while keeping them assembled along the seams. This process allows us to output the corresponding sewing patterns.The last step of our method computes a natural rest shape for the 3D garment, including the folds due to the collisions with the body and gravity. The folds are generated using procedural modeling of the buckling phenomena observed in real fabric. The result of our algorithm consists of a realistic looking 3D mannequin dressed in the designed garment and the 2D patterns which can be used for distortion free texture mapping. The patterns we create also allow us to sew real replicas of the virtual garments.Keywords: Geometric modeling of garments, developable surfaces, procedural models, buckling.Categories and Subject Descriptors (according to ACM CCS): I.3.5 [Computing Methodologies/Computer Graphics]: Surface representations, I.3.7 [Computing Methodologies/Computer Graphics]: Three-dimensional graphics and realism
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    Implicit Surface Modelling with a Globally Regularised Basis of Compact Support
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Walder, C.; Schoelkopf, B.; Chapelle, O.
    We consider the problem of constructing a globally smooth analytic function that represents a surface implicitly by way of its zero set, given sample points with surface normal vectors.The contributions of the paper include a novel means of regularising multi-scale compactly supported basis functions that leads to the desirable interpolation properties previously only associated with fully supported bases. We also provide a regularisation framework for simpler and more direct treatment of surface normals, along with a corresponding generalisation of the representer theorem lying at the core of kernel-based machine learning methods.We demonstrate the techniques on 3D problems of up to 14 million data points, as well as 4D time series data and four-dimensional interpolation between three-dimensional shapes.Categories and Subject Descriptors (according to ACM CCS): I.3.5 [Computer Graphics]: Curve, surface, solid, and object representations
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    Creating Face Models from Vague Mental Images
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Blanz, V.; Albrecht, I.; Haber, J.; Seidel, H.-P.
    We present a novel approach to create plausible 3D face models from vague recollections or incomplete descriptions. This task plays an important role in police work, where composite facial images of suspects need to be created from vague descriptions given by the eyewitnesses of an incident.Our approach is based on a morphable model of 3D faces and takes into account correlations among facial features based on human anatomy and ethnicity. Using these correlations, unspecified parts of the target face are automatically completed to yield a coherent face model. The system uses a novel paradigm for navigating face space and provides high-level control of facial attributes as well as the possibility to import facial features from a database. In addition, the user can specify a set of attribute constraints that are used to restrict the target face to a residual subspace. These constraints can also be enforced on the example faces in the database, bringing their appearance closer to the mental image of the user, and thus avoiding confusing exposure to entirely different faces. We also propose a novel approach for adapting the system to local populations based on additional image databases that are converted into our 3D representation by automated shape reconstruction.We demonstrate the applicability of our system in a simulated forensic scenario and compare our results with those obtained by a professional forensic artist using state-of-the-art software for creating composite images in police work.Categories and Subject Descriptors (according to ACM CCS): I.3.6 [Computer Graphics]: Methodology and Techniques-Interaction techniques I.4.10 [Image Processing and Computer Vision]: Image Representation-Hierarchical, Multidimensional, Statistical J.m [Computer Applications]: Miscellaneous-Forensic Sciences
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    Efficient Large Scale Acquisition of Building Interiors
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Bahmutov, Gleb; Popescu, Voicu; Mudure, Mihai
    We describe a system for the rapid acquisition of building interiors. In 40 hours, a two member team with a single acquisition device captured a model of the corridors and 20 individual rooms spanning 6 floors of a large building. Our custom acquisition device operates at interactive rates. The system provides immediate feedback to the operator. The operator guides the acquisition device in realtime and trivially avoids over sampling the planar parts of the scene such as floors, ceilings, walls, or doors. Most of the acquisition time budget is spent on the parts of the scene with complex geometry. A corridor section is modeled by acquiring a depth enhanced panorama (DEP) a teach one of its two ends and by fitting proxy geometry to the two DEPs. A room is acquired with a single DEP and proxy geometry is fitted to the planar parts. A room or a corridor section is acquired in less than 15 minutes. The acquisition device acquires high quality color intrinsically registered with the depth data. The resulting model is a texture mapped triangle mesh that supports photo realistic interactive rendering an dissuitable for applications such as virtual training and simulation.Categories and Subject Descriptors (ACM CCS): I.3.5 [Computer Graphics]: Computational Geometry and Object Modeling.
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    Stroke Pattern Analysis and Synthesis
    (The Eurographics Association and Blackwell Publishing, Inc, 2006) Barla, Pascal; Breslav, Simon; Thollot, Joelle; Sillion, Francois; Markosian, Lee
    We present a synthesis technique that can automatically generate stroke patterns based on a user-specified reference pattern. Our method is an extension of texture synthesis techniques to vector-based patterns. Such an extension requires (a) an analysis of the pattern properties to extract meaningful pattern elements (defined as clusters of strokes) and (b) a synthesis algorithm based on similarities in the detected stroke clusters. Our method is based on results from human vision research concerning perceptual organization. The resulting synthesized patterns effectively reproduce the properties of the input patterns, and can be used to fill both 1D paths and 2D regions.Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Color, shading, shadowing, and texture I.3.4 [Computer Graphics]: Paint systems