32-Issue 1

Permanent URI for this collection

https://diglib.eg.org/handle/10.2312/179

Editorial

[meta data] [files: ]

Efficient GPU Data Structures and Methods to Solve Sparse Linear Systems in Dynamics Applications

[meta data] [files: ]
Weber, Daniel
; 
Bender, Jan
; 
Schnoes, Markus
; 
Stork, Andre
; 
Fellner, Dieter W.

Scalable Symmetry Detection for Urban Scenes

[meta data] [files: ]
Kerber, J.
; 
Bokeloh, M.
; 
Wand, M.
; 
Seidel, H.-P.

Synthetic Controllable Turbulence Using Robust Second Vorticity Confinement

[meta data] [files: ]
He, S.
; 
Lau, R. W. H.

Vega: Non-Linear FEM Deformable Object Simulator

[meta data] [files: ]
Sin, F. S.
; 
Schroeder, D.
; 
Barbic, J.

Large and Small Eddies Matter: Animating Trees in Wind Using Coarse Fluid Simulation and Synthetic Turbulence

[meta data] [files: ]
Selino, A.
; 
Jones, M. D.

Fast Insertion-Based Optimization of Bounding Volume Hierarchies

[meta data] [files: ]
Bittner, Jiří
; 
Hapala, Michal
; 
Havran, Vlastimil

Visualization and Analysis of Second-Order Tensors: Moving Beyond the Symmetric Positive-Definite Case

[meta data] [files: ]
Kratz, A.
; 
Auer, C.
; 
Stommel, M.
; 
Hotz, I.

Just-in-Time Texture Synthesis

[meta data] [files: ]
Wang, Lili
; 
Shi, Yulong
; 
Chen, Yi
; 
Popescu, Voicu

Perceptual Metrics for Static and Dynamic Triangle Meshes

[meta data] [files: ]
Corsini, M.
; 
Larabi, M. C.
; 
Lavoué, G.
; 
Petřík, O.
; 
Váša, L.
; 
Wang, K.

Robust Image Denoising Using a Virtual Flash Image for Monte Carlo Ray Tracing

[meta data] [files: ]
Moon, Bochang
; 
Jun, Jong Yun
; 
Lee, JongHyeob
; 
Kim, Kunho
; 
Hachisuka, Toshiya
; 
Yoon, Sung-Eui

Interactive Planarization and Optimization of 3D Meshes

[meta data] [files: ]
Poranne, Roi
; 
Ovreiu, Elena
; 
Gotsman, Craig

Feature-Preserving Surface Reconstruction From Unoriented, Noisy Point Data

[meta data] [files: ]
Wang, J.
; 
Yu, Z.
; 
Zhu, W.
; 
Cao, J.

Coarse-to-Fine Isometric Shape Correspondence by Tracking Symmetric Flips

[meta data] [files: ]
SahillioÄ lu, Y.
; 
Yemez, Y.

Content-Based Colour Transfer

[meta data] [files: ]
Wu, Fuzhang
; 
Dong, Weiming
; 
Kong, Yan
; 
Mei, Xing
; 
Paul, Jean-Claude
; 
Zhang, Xiaopeng

Publisher's Note

[meta data] [files: ]

2013 Cover Image: Prism

[meta data] [files: ]
Spencer, Ben
; 
Jones, Mark W.

Simulation of Morphology Changes in Drying Leaves

[meta data] [files: ]
Jeong, SoHyeon
; 
Park, Si-Hyung
; 
Kim, Chang-Hun

Erratum

[meta data] [files: ]

BibTeX (32-Issue 1)
                
@article{
10.1111:cgf.12016,

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

author = {},
year = {
2013},

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


ISSN = {1467-8659},

DOI = {
10.1111/cgf.12016}

}
                
@article{
10.1111:j.1467-8659.2012.03227.x,

journal = {Computer Graphics Forum},
title = {{
Efficient GPU Data Structures and Methods to Solve Sparse Linear Systems in Dynamics Applications}},

author = {
Weber, Daniel
 and 
Bender, Jan
 and 
Schnoes, Markus
 and 
Stork, Andre
 and 
Fellner, Dieter W.
},
year = {
2013},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2012.03227.x}

}
                
@article{
10.1111:j.1467-8659.2012.03226.x,

journal = {Computer Graphics Forum},
title = {{
Scalable Symmetry Detection for Urban Scenes}},

author = {
Kerber, J.
 and 
Bokeloh, M.
 and 
Wand, M.
 and 
Seidel, H.-P.
},
year = {
2013},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2012.03226.x}

}
                
@article{
10.1111:j.1467-8659.2012.03228.x,

journal = {Computer Graphics Forum},
title = {{
Synthetic Controllable Turbulence Using Robust Second Vorticity Confinement}},

author = {
He, S.
 and 
Lau, R. W. H.
},
year = {
2013},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2012.03228.x}

}
                
@article{
10.1111:j.1467-8659.2012.03230.x,

journal = {Computer Graphics Forum},
title = {{
Vega: Non-Linear FEM Deformable Object Simulator}},

author = {
Sin, F. S.
 and 
Schroeder, D.
 and 
Barbic, J.
},
year = {
2013},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2012.03230.x}

}
                
@article{
10.1111:j.1467-8659.2012.03232.x,

journal = {Computer Graphics Forum},
title = {{
Large and Small Eddies Matter: Animating Trees in Wind Using Coarse Fluid Simulation and Synthetic Turbulence}},

author = {
Selino, A.
 and 
Jones, M. D.
},
year = {
2013},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2012.03232.x}

}
                
@article{
10.1111:cgf.12000,

journal = {Computer Graphics Forum},
title = {{
Fast Insertion-Based Optimization of Bounding Volume Hierarchies}},

author = {
Bittner, Jiří
 and 
Hapala, Michal
 and 
Havran, Vlastimil
},
year = {
2013},

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


ISSN = {1467-8659},

DOI = {
10.1111/cgf.12000}

}
                
@article{
10.1111:j.1467-8659.2012.03231.x,

journal = {Computer Graphics Forum},
title = {{
Visualization and Analysis of Second-Order Tensors: Moving Beyond the Symmetric Positive-Definite Case}},

author = {
Kratz, A.
 and 
Auer, C.
 and 
Stommel, M.
 and 
Hotz, I.
},
year = {
2013},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2012.03231.x}

}
                
@article{
10.1111:cgf.12003,

journal = {Computer Graphics Forum},
title = {{
Just-in-Time Texture Synthesis}},

author = {
Wang, Lili
 and 
Shi, Yulong
 and 
Chen, Yi
 and 
Popescu, Voicu
},
year = {
2013},

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


ISSN = {1467-8659},

DOI = {
10.1111/cgf.12003}

}
                
@article{
10.1111:cgf.12001,

journal = {Computer Graphics Forum},
title = {{
Perceptual Metrics for Static and Dynamic Triangle Meshes}},

author = {
Corsini, M.
 and 
Larabi, M. C.
 and 
Lavoué, G.
 and 
Petřík, O.
 and 
Váša, L.
 and 
Wang, K.
},
year = {
2013},

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


ISSN = {1467-8659},

DOI = {
10.1111/cgf.12001}

}
                
@article{
10.1111:cgf.12004,

journal = {Computer Graphics Forum},
title = {{
Robust Image Denoising Using a Virtual Flash Image for Monte Carlo Ray Tracing}},

author = {
Moon, Bochang
 and 
Jun, Jong Yun
 and 
Lee, JongHyeob
 and 
Kim, Kunho
 and 
Hachisuka, Toshiya
 and 
Yoon, Sung-Eui
},
year = {
2013},

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


ISSN = {1467-8659},

DOI = {
10.1111/cgf.12004}

}
                
@article{
10.1111:cgf.12005,

journal = {Computer Graphics Forum},
title = {{
Interactive Planarization and Optimization of 3D Meshes}},

author = {
Poranne, Roi
 and 
Ovreiu, Elena
 and 
Gotsman, Craig
},
year = {
2013},

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


ISSN = {1467-8659},

DOI = {
10.1111/cgf.12005}

}
                
@article{
10.1111:cgf.12006,

journal = {Computer Graphics Forum},
title = {{
Feature-Preserving Surface Reconstruction From Unoriented, Noisy Point Data}},

author = {
Wang, J.
 and 
Yu, Z.
 and 
Zhu, W.
 and 
Cao, J.
},
year = {
2013},

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


ISSN = {1467-8659},

DOI = {
10.1111/cgf.12006}

}
                
@article{
10.1111:cgf.12007,

journal = {Computer Graphics Forum},
title = {{
Coarse-to-Fine Isometric Shape Correspondence by Tracking Symmetric Flips}},

author = {
SahillioÄ lu, Y.
 and 
Yemez, Y.
},
year = {
2013},

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


ISSN = {1467-8659},

DOI = {
10.1111/cgf.12007}

}
                
@article{
10.1111:cgf.12008,

journal = {Computer Graphics Forum},
title = {{
Content-Based Colour Transfer}},

author = {
Wu, Fuzhang
 and 
Dong, Weiming
 and 
Kong, Yan
 and 
Mei, Xing
 and 
Paul, Jean-Claude
 and 
Zhang, Xiaopeng
},
year = {
2013},

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


ISSN = {1467-8659},

DOI = {
10.1111/cgf.12008}

}
                
@article{
10.1111:cgf.12018,

journal = {Computer Graphics Forum},
title = {{
Publisher's Note}},

author = {},
year = {
2013},

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


ISSN = {1467-8659},

DOI = {
10.1111/cgf.12018}

}
                
@article{
10.1111:cgf.12017,

journal = {Computer Graphics Forum},
title = {{
2013 Cover Image: Prism}},

author = {
Spencer, Ben
 and 
Jones, Mark W.
},
year = {
2013},

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


ISSN = {1467-8659},

DOI = {
10.1111/cgf.12017}

}
                
@article{
10.1111:cgf.12009,

journal = {Computer Graphics Forum},
title = {{
Simulation of Morphology Changes in Drying Leaves}},

author = {
Jeong, SoHyeon
 and 
Park, Si-Hyung
 and 
Kim, Chang-Hun
},
year = {
2013},

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


ISSN = {1467-8659},

DOI = {
10.1111/cgf.12009}

}
                
@article{
10.1111:cgf.12002,

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

author = {},
year = {
2013},

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


ISSN = {1467-8659},

DOI = {
10.1111/cgf.12002}

}

Browse

Recent Submissions

Now showing 1 - 19 of 19
  • No Thumbnail Available
    Item
    Editorial
    (The Eurographics Association and Blackwell Publishing Ltd., 2013) Holly Rushmeier and Oliver Deussen
  • No Thumbnail Available
    Item
    Efficient GPU Data Structures and Methods to Solve Sparse Linear Systems in Dynamics Applications
    (The Eurographics Association and Blackwell Publishing Ltd., 2013) Weber, Daniel; Bender, Jan; Schnoes, Markus; Stork, Andre; Fellner, Dieter W.; Holly Rushmeier and Oliver Deussen
    We present graphics processing unit (GPU) data structures and algorithms to efficiently solve sparse linear systems that are typically required in simulations of multi-body systems and deformable bodies. Thereby, we introduce an efficient sparse matrix data structure that can handle arbitrary sparsity patterns and outperforms current state-of-the-art implementations for sparse matrix vector multiplication. Moreover, an efficient method to construct global matrices on the GPU is presented where hundreds of thousands of individual element contributions are assembled in a few milliseconds. A finite-element-based method for the simulation of deformable solids as well as an impulse-based method for rigid bodies are introduced in order to demonstrate the advantages of the novel data structures and algorithms. These applications share the characteristic that a major computational effort consists of building and solving systems of linear equations in every time step. Our solving method results in a speed-up factor of up to 13 in comparison to other GPU methods.We present GPU data structures and algorithms to efficiently solve sparse linear systems which are typically required in simulations of multibody systems and deformable bodies. Thereby, we introduce an efficient sparse matrix data structure that can handle arbitrary sparsity patterns and outperforms current state-of-the-art implementations for sparse matrix vector multiplication. Moreover, an efficient method to construct global matrices on the GPU is presented where hundreds of thousands of individual element contributions are assembled in a few milliseconds. A finite element based method for the simulation of deformable solids as well as an impulse-based method for rigid bodies are introduced in order to demonstrate the advantages of the novel data structures and algorithms. These applications share the characteristic that a major computational effort consists of building and solving systems of linear equations in every time step. Our solving method results in a speed-up factor of up to 13 in comparison to other GPU methods.
  • No Thumbnail Available
    Item
    Scalable Symmetry Detection for Urban Scenes
    (The Eurographics Association and Blackwell Publishing Ltd., 2013) Kerber, J.; Bokeloh, M.; Wand, M.; Seidel, H.-P.; Holly Rushmeier and Oliver Deussen
    In this paper, we present a novel method for detecting partial symmetries in very large point clouds of 3D city scans. Unlike previous work, which has only been demonstrated on data sets of a few hundred megabytes maximum, our method scales to very large scenes: We map the detection problem to a nearest-eighbour problem in a low-dimensional feature space, and follow this with a cascade of tests for geometric clustering of potential matches. Our algorithm robustly handles noisy real-world scanner data, obtaining a recognition performance comparable to that of state-of-the-art methods. In practice, it scales linearly with scene size and achieves a high absolute throughput, processing half a terabyte of scanner data overnight on a dual socket commodity PC.In this paper we present a novel method for detecting partial symmetries in very large point clouds of 3D city scans. Unlike previous work, which has only been demonstrated on data sets of a few hundred megabytes maximum, our method scales to very large scenes: We map the detection problem to a nearest-eighbor problem in a lowdimensional feature space, and follow this with a cascade of tests for geometric clustering of potential matches. Our algorithm robustly handles noisy real-world scanner data, obtaining a recognition performance comparable to that of state-of-the-art methods. In practice, it scales linearly with scene size and achieves a high absolute throughput, processing half a terabyte of scanner data overnight on a dual socket commodity PC.
  • No Thumbnail Available
    Item
    Synthetic Controllable Turbulence Using Robust Second Vorticity Confinement
    (The Eurographics Association and Blackwell Publishing Ltd., 2013) He, S.; Lau, R. W. H.; Holly Rushmeier and Oliver Deussen
    Capturing fine details of turbulence on a coarse grid is one of the main tasks in real-time fluid simulation. Existing methods for doing this have various limitations. In this paper, we propose a new turbulence method that uses a refined second vorticity confinement method, referred to as robust second vorticity confinement, and a synthesis scheme to create highly turbulent effects from coarse grid. The new technique is sufficiently stable to efficiently produce highly turbulent flows, while allowing intuitive control of vortical structures. Second vorticity confinement captures and defines the vortical features of turbulence on a coarse grid. However, due to the stability problem, it cannot be used to produce highly turbulent flows. In this work, we propose a robust formulation to improve the stability problem by making the positive diffusion term to vary with helicity adaptively. In addition, we also employ our new method to procedurally synthesize the high-resolution flow fields. As shown in our results, this approach produces stable high-resolution turbulence very efficiently.Capturing fine details of turbulence on a coarse grid is one of the main tasks in real-time fluid simulation. Existing methods for doing this have various limitations. In this paper, we propose a new turbulence method that uses a refined Second Vorticity Confinement method, referred to as Robust Second Vorticity Confinement, and a synthesis scheme to create highly turbulent effects from coarse grid. The new technique is sufficiently stable to efficiently produce highly turbulent flows, while allowing intuitive control of vortical structures. Second Vorticity Confinement captures and defines the vortical features of turbulence on a coarse grid. However, due to the stability problem, it cannot be used to produce highly turbulent flows. In this work, we propose a robust formulation to improve the stability problem by making the positive diffusion term to vary with helicity adaptively. In addition, we also employ our new method to procedurally synthesize the high resolution flow fields. As shown in our results, this approach produces stable high resolution turbulence very efficiently.
  • No Thumbnail Available
    Item
    Vega: Non-Linear FEM Deformable Object Simulator
    (The Eurographics Association and Blackwell Publishing Ltd., 2013) Sin, F. S.; Schroeder, D.; Barbic, J.; Holly Rushmeier and Oliver Deussen
    This practice and experience paper describes a robust C++ implementation of several non-linear solid three-dimensional deformable object strategies commonly employed in computer graphics, named the Vega finite element method (FEM) simulation library. Deformable models supported include co-rotational linear FEM elasticity, Saint-Venant Kirchhoff FEM model, mass-spring system and invertible FEM models: neo-Hookean, Saint-Venant Kirchhoff and Mooney-Rivlin. We provide several timestepping schemes, including implicit Newmark and backward Euler integrators, and explicit central differences. The implementation of material models is separated from integration, which makes it possible to employ our code not only for simulation, but also for deformable object control and shape modelling. We extensively compare the different material models and timestepping schemes. We provide practical experience and insight gained while using our code in several computer animation and simulation research projects.This practice and experience paper describes a robust C++ implementation of several nonlinear solid 3D deformable object strategies commonly employed in computer graphics, named the Vega FEM simulation library. Deformable models supported include co-rotational linear FEM elasticity, Saint-Venant Kirchhoff FEM model, mass-spring system, and invertible FEM models: neo-Hookean, Saint-Venant Kirchhoff, and Mooney-Rivlin. We provide several timestepping schemes, including implicit Newmark and backward Euler integrators, and explicit central differences. The implementation of material models is separated from integration, which makes it possible to employ our code not only for simulation, but also for deformable object control and shape modeling. We extensively compare the different material models and timestepping schemes. We provide practical experience and insight gained while using our code in several computer animation and simulation research projects.
  • No Thumbnail Available
    Item
    Large and Small Eddies Matter: Animating Trees in Wind Using Coarse Fluid Simulation and Synthetic Turbulence
    (The Eurographics Association and Blackwell Publishing Ltd., 2013) Selino, A.; Jones, M. D.; Holly Rushmeier and Oliver Deussen
    Animating trees in wind has long been a problem in computer graphics. Progress on this problem is important for both visual effects in films and forestry biomechanics. More generally, progress on tree motion in wind may inform future work on two-way coupling between turbulent flows and deformable objects. Synthetic turbulence added to a coarse fluid simulation produces convincing animations of turbulent flows but two-way coupling between the enriched flow and objects embedded in the flow has not been investigated. Prior work on two-way coupling between fluid and deformable models lacks a subgrid resolution turbulence model. We produce realistic animations of tree motion by including motion due to both large and small eddies using synthetic subgrid turbulence and porous proxy geometry. Synthetic turbulence at the subgrid scale is modulated using turbulent kinetic energy (TKE). Adding noise after sampling the mean flow and TKE transfers energy from small eddies directly to the tree geometry. The resulting animations include both global sheltering effects and small scale leaf and branch motion. Viewers, on average, found animations, which included both coarse fluid simulation and TKE-modulated noise to be more accurate than animations generated using coarse fluid simulation or noise alone.Prior work on two-way coupling between fluid and deformable models lacks a subgrid resolution turbulence model. We produce realistic animations of tree motion by including motion due to both large and small eddies using synthetic subgrid turbulence and porous proxy geometry. Synthetic turbulence at the subgrid scale is modulated using turbulent kinetic energy (TKE). Adding noise after sampling the mean flow and TKE transfers energy from small eddies directly to the tree geometry. The resulting animations include both global sheltering effects and small scale leaf and branch motion. Viewers, on average, found animations which included both coarse fluid simulation and TKE-modulated noise to be more accurate than animations generated using coarse fluid simulation or noise alone.
  • No Thumbnail Available
    Item
    Fast Insertion-Based Optimization of Bounding Volume Hierarchies
    (The Eurographics Association and Blackwell Publishing Ltd., 2013) Bittner, Jiří; Hapala, Michal; Havran, Vlastimil; Holly Rushmeier and Oliver Deussen
    We present an algorithm for fast optimization of bounding volume hierarchies (BVH) for efficient ray tracing. We perform selective updates of the hierarchy driven by the cost model derived from the surface area heuristic. In each step, the algorithm updates a fraction of the hierarchy nodes to minimize the overall hierarchy cost. The updates are realized by simple operations on the tree nodes: removal, search and insertion. Our method can quickly reduce the cost of the hierarchy constructed by the traditional techniques, such as the surface area heuristic. We evaluate the properties of the proposed method on fourteen test scenes of different complexity including individual objects and architectural scenes. The results show that our method can improve a BVH initially constructed with the surface area heuristic by up to 27% and a BVH constructed with the spatial median split by up to 88%.We present an algorithm for fast optimization of bounding volume hierarchies (BVH) for efficient ray tracing. We perform selective updates of the hierarchy driven by the cost model derived from the surface area heuristic. In each step the algorithm updates a fraction of the hierarchy nodes in order to minimize the overall hierarchy cost. The updates are realized by simple operations on the tree nodes: removal, search, and insertion. Our method can quickly reduce the cost of the hierarchy constructed by the traditional techniques such as the surface area heuristic. We evaluate the properties of the proposed method on fourteen test scenes of different complexity including individual objects and architectural scenes. The results show that our method can improve a BVH initially constructed with the surface area heuristic by up to 27% and a BVH constructed with the spatial median split by up to 88%.
  • No Thumbnail Available
    Item
    Visualization and Analysis of Second-Order Tensors: Moving Beyond the Symmetric Positive-Definite Case
    (The Eurographics Association and Blackwell Publishing Ltd., 2013) Kratz, A.; Auer, C.; Stommel, M.; Hotz, I.; Holly Rushmeier and Oliver Deussen
    Tensors provide a powerful language to describe physical phenomena. Consequently, they have a long tradition in physics and appear in various application areas, either as the final result of simulations or as intermediate product. Due to their complexity, tensors are hard to interpret. This motivates the development of well-conceived visualization methods. As a sub-branch of scientific visualization, tensor field visualization has been especially pushed forward by diffusion tensor imaging. In this review, we focus on second-order tensors that are not diffusion tensors. Until now, these tensors, which might be neither positive-definite nor symmetric, are under-represented in visualization and existing visualization tools are often not appropriate for these tensors. Hence, we discuss the strengths and limitations of existing methods when dealing with such tensors as well as challenges introduced by them. The goal of this paper is to reveal the importance of the field and to encourage the development of new visualization methods for tensors from various application fields.Tensors provide a powerful language to describe physical phenomena. In this review, we focus on second-order tensors that are not diffusionensors. Until now, these tensors, which might be neither positive-definite nor symmetric, are underrepresented in visualization and existing visualization tools are often not appropriate for these tensors. Hence, we discuss the strengths and limitations of existing methods when dealing with such tensors as well as challenges introduced by them. The goal of this paper is to reveal the importance of the field and to encourage the development of new visualization methods for tensors from various application fields.
  • No Thumbnail Available
    Item
    Just-in-Time Texture Synthesis
    (The Eurographics Association and Blackwell Publishing Ltd., 2013) Wang, Lili; Shi, Yulong; Chen, Yi; Popescu, Voicu; Holly Rushmeier and Oliver Deussen
    Texture bombing is a texture synthesis approach that saves memory by stopping short of assembling the output texture from the arrangement of input texture patches; instead, the arrangement is used directly at run time to texture surfaces. However, several problems remain in need of better solutions. One problem is improving texture diversification. A second problem is that mipmapping cannot be used because texel data is not stored explicitly. The lack of an appropriate level-of-detail (LoD) scheme results in severe minification artefacts. We present a just-in-time texturing method that addresses these two problems. Texture diversification is achieved by modelling a texture patch as an umbrella, a versatile hybrid 3-D geometry and texture structure with parameterized appearance. The LoD is adapted continuously with a hierarchical algorithm that acts directly on the arrangement map. Results show that our method can model and render the diversity present in nature with only small texture memory requirements.We present a just-intime texturing method that addresses these two problems. Texture diversification is achieved by modeling a texture patch as an umbrella, a versatile hybrid 3-D geometry and texture structure with parameterized appearance. The LoD is adapted continuously with a hierarchical algorithm that acts directly on the arrangement map. Results show that our method can model and render the diversity present in nature with only small texture memory requirements.
  • No Thumbnail Available
    Item
    Perceptual Metrics for Static and Dynamic Triangle Meshes
    (The Eurographics Association and Blackwell Publishing Ltd., 2013) Corsini, M.; Larabi, M. C.; Lavoué, G.; Petřík, O.; Váša, L.; Wang, K.; Holly Rushmeier and Oliver Deussen
    Almost all mesh processing procedures cause some more or less visible changes in the appearance of objects represented by polygonal meshes. In many cases, such as mesh watermarking, simplification or lossy compression, the objective is to make the change in appearance negligible, or as small as possible, given some other constraints. Measuring the amount of distortion requires taking into account the final purpose of the data. In many applications, the final consumer of the data is a human observer, and therefore the perceptibility of the introduced appearance change by a human observer should be the criterion that is taken into account when designing and configuring the processing algorithms. In this review, we discuss the existing comparison metrics for static and dynamic (animated) triangle meshes. We describe the concepts used in perception-oriented metrics used for 2D image comparison, and we show how these concepts are employed in existing 3D mesh metrics. We describe the character of subjective data used for evaluation of mesh metrics and provide comparison results identifying the advantages and drawbacks of each method. Finally, we also discuss employing the perception-correlated metrics in perception-oriented mesh processing algorithms. Please use and the following text for graphical abstract: In this review, we discuss the existing comparison metrics for static and dynamic (animated) triangle meshes. We describe the concepts used in perception-oriented metrics used for 2D image comparison, and we show how these concepts are employed in existing 3D mesh metrics. We describe the character of subjective data used for evaluation of mesh metrics and provide comparison results identifying the advantages and drawbacks of each method. Finally, we also discuss employing the perception-correlated metrics in perception-oriented mesh processing algorithms.In this review, we discuss the existing comparison metrics for static and dynamic (animated) triangle meshes. We describe the concepts used in perception-oriented metrics used for 2D image comparison, and we show how these concepts are employed in existing 3D mesh metrics. We describe the character of subjective data used for evaluation of mesh metrics and provide comparison results identifying the advantages and drawbacks of each method. Finally, we also discuss employing the perception-correlated metrics in perception-oriented mesh processing algorithms.
  • No Thumbnail Available
    Item
    Robust Image Denoising Using a Virtual Flash Image for Monte Carlo Ray Tracing
    (The Eurographics Association and Blackwell Publishing Ltd., 2013) Moon, Bochang; Jun, Jong Yun; Lee, JongHyeob; Kim, Kunho; Hachisuka, Toshiya; Yoon, Sung-Eui; Holly Rushmeier and Oliver Deussen
    We propose an efficient and robust image-space denoising method for noisy images generated by Monte Carlo ray tracing methods. Our method is based on two new concepts: virtual flash images and homogeneous pixels. Inspired by recent developments in flash photography, virtual flash images emulate photographs taken with a flash, to capture various features of rendered images without taking additional samples. Using a virtual flash image as an edge-stopping function, our method can preserve image features that were not captured well only by existing edge-stopping functions such as normals and depth values. While denoising each pixel, we consider only homogeneous pixelsâ ''pixels that are statistically equivalent to each other. This makes it possible to define a stochastic error bound of our method, and this bound goes to zero as the number of ray samples goes to infinity, irrespective of denoising parameters. To highlight the benefits of our method, we apply our method to two Monte Carlo ray tracing methods, photon mapping and path tracing, with various input scenes. We demonstrate that using virtual flash images and homogeneous pixels with a standard denoising method outperforms state-of-the-art image-space denoising methods.We propose an efficient and robust image-space denoising method for noisy images generated by Monte Carlo ray tracing methods. Our method is based on two new concepts: virtual flash images and homogeneous pixels. Inspired by recent developments in flash photography, virtual flash images emulate photographs taken with a flash, to capture various features of rendered images without taking additional samples. Using a virtual flash image as an edge-stopping function, our method can preserve image features that were not captured well only by existing edge-stopping functions such as normals and depth values.
  • No Thumbnail Available
    Item
    Interactive Planarization and Optimization of 3D Meshes
    (The Eurographics Association and Blackwell Publishing Ltd., 2013) Poranne, Roi; Ovreiu, Elena; Gotsman, Craig; Holly Rushmeier and Oliver Deussen
    Constraining 3D meshes to restricted classes is necessary in architectural and industrial design, but it can be very challenging to manipulate meshes while staying within these classes. Specifically, polyhedral meshesâ ''those having planar facesâ ''are very important, but also notoriously difficult to generate and manipulate efficiently. We describe an interactive method for computing, optimizing and editing polyhedral meshes. Efficiency is achieved thanks to a numerical procedure combining an alternating least-squares approach with the penalty method. This approach is generalized to manipulate other subsets of polyhedral meshes, as defined by a variety of other constraints.Constraining 3D meshes to restricted classes is necessary in architectural and industrial design, but it can be very challenging to manipulate meshes while staying within these classes. Specifically, polyhedral meshes - those having planar faces - are very important, but also notoriously difficult to generate and manipulate efficiently. We describe an interactive method for computing, optimizing and editing polyhedral meshes. Efficiency is achieved thanks to a numerical procedure combining an alternating least-squares approach with the penalty method. This approach is generalized to manipulate other subsets of polyhedral meshes, as defined by a variety of other constraints.
  • No Thumbnail Available
    Item
    Feature-Preserving Surface Reconstruction From Unoriented, Noisy Point Data
    (The Eurographics Association and Blackwell Publishing Ltd., 2013) Wang, J.; Yu, Z.; Zhu, W.; Cao, J.; Holly Rushmeier and Oliver Deussen
    We propose a robust method for surface mesh reconstruction from unorganized, unoriented, noisy and outlier-ridden 3D point data. A kernel-based scale estimator is introduced to estimate the scale of inliers of the input data. The best tangent planes are computed for all points based on mean shift clustering and adaptive scale sample consensus, followed by detecting and removing outliers. Subsequently, we estimate the normals for the remaining points and smooth the noise using a surface fitting and projection strategy. As a result, the outliers and noise are removed and filtered, while the original sharp features are well preserved. We then adopt an existing method to reconstruct surface meshes from the processed point data. To preserve sharp features of the generated meshes that are often blurred during reconstruction, we describe a two-step approach to effectively recover original sharp features. A number of examples are presented to demonstrate the effectiveness and robustness of our method.We propose a robust method for surface mesh reconstruction from unorganized, unoriented, noisy and outlierridden 3D point data. A kernel-based scale estimator is introduced to estimate the scale of inliers of the input data. The best tangent planes are computed for all points based on mean shift clustering and adaptive scale sample consensus, followed by detecting and removing outliers. We estimate the normals for the remaining points and smooth the noise using a surface fitting and projection strategy. We then adopt an existing method to reconstruct surface meshes from the processed point data. We then describe a two-step approach to effectively recover original sharp features.
  • No Thumbnail Available
    Item
    Coarse-to-Fine Isometric Shape Correspondence by Tracking Symmetric Flips
    (The Eurographics Association and Blackwell Publishing Ltd., 2013) SahillioÄ lu, Y.; Yemez, Y.; Holly Rushmeier and Oliver Deussen
    We address the symmetric flip problem that is inherent to multi-resolution isometric shape matching algorithms. To this effect, we extend our previous work which handles the dense isometric correspondence problem in the original 3D Euclidean space via coarse-to-fine combinatorial matching. The key idea is based on keeping track of all optimal solutions, which may be more than one due to symmetry especially at coarse levels, throughout denser levels of the shape matching process. We compare the resulting dense correspondence algorithm with state-of-the-art techniques over several 3D shape benchmark datasets. The experiments show that our method, which is fast and scalable, is performance-wise better than or on a par with the best performant algorithms existing in the literature for isometric (or nearly isometric) shape correspondence. Our key idea of tracking symmetric flips can be considered as a meta-approach that can be applied to other multi-resolution shape matching algorithms, as we also demonstrate by experiments.We address the symmetric flip problem that is inherent to multiresolution isometric shape matching algorithms.To this effect, we extend our previous work which handles the dense isometric correspondence problem in the original 3D Euclidean space via coarse-to-fine combinatorial matching. The key idea is based on keeping track of all optimal solutions, which may be more than one due to symmetry especially at coarse levels, throughout denser levels of the shape matching process. We compare the resulting dense correspondence algorithm with state-of-the-art techniques over several 3D shape benchmark datasets. The experiments show that our method, which is fast and scalable, is performance-wise better than or on a par with the best performant algorithms existing in the literature for isometric (or nearly isometric) shape correspondence.
  • No Thumbnail Available
    Item
    Content-Based Colour Transfer
    (The Eurographics Association and Blackwell Publishing Ltd., 2013) Wu, Fuzhang; Dong, Weiming; Kong, Yan; Mei, Xing; Paul, Jean-Claude; Zhang, Xiaopeng; Holly Rushmeier and Oliver Deussen
    This paper presents a novel content-based method for transferring the colour patterns between images. Unlike previous methods that rely on image colour statistics, our method puts an emphasis on high-level scene content analysis. We first automatically extract the foreground subject areas and background scene layout from the scene. The semantic correspondences of the regions between source and target images are established. In the second step, the source image is re-coloured in a novel optimization framework, which incorporates the extracted content information and the spatial distributions of the target colour styles. A new progressive transfer scheme is proposed to integrate the advantages of both global and local transfer algorithms, as well as avoid the over-segmentation artefact in the result. Experiments show that with a better understanding of the scene contents, our method well preserves the spatial layout, the colour distribution and the visual coherence in the transfer process. As an interesting extension, our method can also be used to re-colour video clips with spatially-varied colour effects.This paper presents a novel content-based method for transferring the colour patterns between images. Unlike previous methods that rely on image colour statistics, our method puts an emphasis on high level scene content analysis. We first automatically extract the foreground subject areas and background scene layout from the scene. The semantic correspondences of the regions between source and target images are established. In the second step, the source image is re-coloured in a novel optimization framework, which incorporates the extracted content information and the spatial distributions of the target colour styles.
  • No Thumbnail Available
    Item
    Publisher's Note
    (The Eurographics Association and Blackwell Publishing Ltd., 2013) Holly Rushmeier and Oliver Deussen
  • No Thumbnail Available
    Item
    2013 Cover Image: Prism
    (The Eurographics Association and Blackwell Publishing Ltd., 2013) Spencer, Ben; Jones, Mark W.; Holly Rushmeier and Oliver Deussen
  • No Thumbnail Available
    Item
    Simulation of Morphology Changes in Drying Leaves
    (The Eurographics Association and Blackwell Publishing Ltd., 2013) Jeong, SoHyeon; Park, Si-Hyung; Kim, Chang-Hun; Holly Rushmeier and Oliver Deussen
    We introduce a biologically motivated simulation technique for the realistic shape deformation of drying leaves. In contrast to skeleton-based leaf deformation, our approach simulates the whole leaf surface to capture the fine details of desiccated leaves. We represent a leaf as a triangulated double-layer structure that consists of a Delaunay triangulation discretized along the vein structure and its corresponding Voronoi diagram. This structure can generate not only sharp creases along leaf veins, but also the complicated curling and crumpling on the leaf surface. The loss of water is the major factor that controls the inhomogeneous shrinkage of drying leaves. The proposed osmotic water flow successfully models the gradual changes of dehydrated regions advancing towards the veins. We demonstrate the robustness of our method by comparing a sequence of simulated morphology changes with photographs of real leaves.We introduce a biologically motivated simulation technique for the realistic shape deformation of drying leaves. In contrast to skeleton-based leaf deformation, our approach simulates the whole leaf surface to capture the fine details of desiccated leaves. We represent a leaf as a triangulated double-layer structure that consists of a Delaunay triangulation discretized along the vein structure and its corresponding Voronoi diagram. This structure can generate not only sharp creases along leaf veins, but also the complicated curling and crumpling on the leaf surface. The loss of water is the major factor that controls the inhomogeneous shrinkage of drying leaves.
  • No Thumbnail Available
    Item
    Erratum
    (The Eurographics Association and Blackwell Publishing Ltd., 2013) Holly Rushmeier and Oliver Deussen