28-Issue 7

Permanent URI for this collection

https://diglib.eg.org/handle/10.2312/149
Pacific Graphics Proceedings

BibTeX (28-Issue 7)
                
@article{
10.1111:j.1467-8659.2009.01550.x,

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

author = {},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01550.x}

}
                
@article{
10.1111:j.1467-8659.2009.01550.x,

journal = {Computer Graphics Forum},
title = {{
SecondSkin: An interactive method for appearance transfer}},

author = {
Van Den Hengely, A.
 and 
Sale, D.
 and 
Dick, A. R.
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01550.x}

}
                
@article{
10.1111:j.1467-8659.2009.01551.x,

journal = {Computer Graphics Forum},
title = {{
Live Video Montage with a Rotating Camera}},

author = {
Dong, Zilong
 and 
Jiang, Lei
 and 
Zhang, Guofeng
 and 
Wang, Qing
 and 
Bao, Hujun
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01551.x}

}
                
@article{
10.1111:j.1467-8659.2009.01552.x,

journal = {Computer Graphics Forum},
title = {{
Image-to-Geometry Registration: a Mutual Information Method exploiting Illumination-related Geometric Properties}},

author = {
Corsini, Massimiliano
 and 
Dellepiane, Matteo
 and 
Ponchio, Federico
 and 
Scopigno, Roberto
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01552.x}

}
                
@article{
10.1111:j.1467-8659.2009.01553.x,

journal = {Computer Graphics Forum},
title = {{
An Intuitive Interface for Interactive High Quality Image-Based Modeling}},

author = {
Habbecke, Martin
 and 
Kobbelt, Leif
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01553.x}

}
                
@article{
10.1111:j.1467-8659.2009.01555.x,

journal = {Computer Graphics Forum},
title = {{
Approximate on-Surface Distance Computation using Quasi-Developable Charts}},

author = {
Torchelsen, Rafael P.
 and 
Pinto, Francisco
 and 
Bastos, Rui
 and 
Comba, Joao L. D.
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01555.x}

}
                
@article{
10.1111:j.1467-8659.2009.01554.x,

journal = {Computer Graphics Forum},
title = {{
Linkless Octree Using Multi-Level Perfect Hashing}},

author = {
Choi, Myung Geol
 and 
Ju, Eunjung
 and 
Chang, Jung-Woo
 and 
Lee, Jehee
 and 
Kim, Young J.
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01554.x}

}
                
@article{
10.1111:j.1467-8659.2009.01556.x,

journal = {Computer Graphics Forum},
title = {{
HPCCD: Hybrid Parallel Continuous Collision Detection using CPUs and GPUs}},

author = {
Kim, Duksu
 and 
Heo, Jae-Pil
 and 
Huh, Jaehyuk
 and 
Kim, John
 and 
Yoon, Sung-eui
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01556.x}

}
                
@article{
10.1111:j.1467-8659.2009.01558.x,

journal = {Computer Graphics Forum},
title = {{
Affective Modelling: Profiling Geometrical Models with Human Emotional Responses}},

author = {
Lo, Cheng-Hung
 and 
Chu, Chih-Hsing
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01558.x}

}
                
@article{
10.1111:j.1467-8659.2009.01557.x,

journal = {Computer Graphics Forum},
title = {{
Procedural Generation of Rock Piles using Aperiodic Tiling}},

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

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01557.x}

}
                
@article{
10.1111:j.1467-8659.2009.01559.x,

journal = {Computer Graphics Forum},
title = {{
ProcDef: Local-to-global Deformation for Skeleton-free Character Animation}},

author = {
Ijiri, Takashi
 and 
Takayama, Kenshi
 and 
Yokota, Hideo
 and 
Igarashi, Takeo
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01559.x}

}
                
@article{
10.1111:j.1467-8659.2009.01560.x,

journal = {Computer Graphics Forum},
title = {{
Expression Synthesis and Transfer in Parameter Spaces}},

author = {
Shin, Hyun Joon
 and 
Lee, Yunjin
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01560.x}

}
                
@article{
10.1111:j.1467-8659.2009.01561.x,

journal = {Computer Graphics Forum},
title = {{
Simulation of Tearing Cloth with Frayed Edges}},

author = {
Metaaphanon, Napaporn
 and 
Bando, Yosuke
 and 
Chen, Bing-Yu
 and 
Nishita, Tomoyuki
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01561.x}

}
                
@article{
10.1111:j.1467-8659.2009.01562.x,

journal = {Computer Graphics Forum},
title = {{
Simulating Gaseous Fluids with Low and High Speeds}},

author = {
Gao, Yue
 and 
Li, Chen-Feng
 and 
Hu, Shi-Min
 and 
Barsky, Brian A.
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01562.x}

}
                
@article{
10.1111:j.1467-8659.2009.01563.x,

journal = {Computer Graphics Forum},
title = {{
Procedural Synthesis using Vortex Particle Method for Fluid Simulation}},

author = {
Yoon, Jong-Chul
 and 
Kam, Hyeong Ryeol
 and 
Hong, Jeong-Mo
 and 
Kang, Shin Jin
 and 
Kim, Chang-Hun
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01563.x}

}
                
@article{
10.1111:j.1467-8659.2009.01564.x,

journal = {Computer Graphics Forum},
title = {{
Automatic Correction of Saturated Regions in Photographs using Cross-Channel Correlation}},

author = {
Masood, Syed Z.
 and 
Zhu, Jiejie
 and 
Tappen, Marshall F.
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01564.x}

}
                
@article{
10.1111:j.1467-8659.2009.01565.x,

journal = {Computer Graphics Forum},
title = {{
Edit Propagation on Bidirectional Texture Functions}},

author = {
Xu, Kun
 and 
Wang, Jiaping
 and 
Tong, Xin
 and 
Hu, Shi-Min
 and 
Guo, Baining
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01565.x}

}
                
@article{
10.1111:j.1467-8659.2009.01566.x,

journal = {Computer Graphics Forum},
title = {{
Gradient-Preserving Color Transfer}},

author = {
Xiao, Xuezhong
 and 
Ma, Lizhuang
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01566.x}

}
                
@article{
10.1111:j.1467-8659.2009.01567.x,

journal = {Computer Graphics Forum},
title = {{
Optimizing Structure Preserving Embedded Deformation for Resizing Images and Vector Art}},

author = {
Huang, Qi-xing
 and 
Mech, Radomir
 and 
Carr, Nathan
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01567.x}

}
                
@article{
10.1111:j.1467-8659.2009.01568.x,

journal = {Computer Graphics Forum},
title = {{
A Shape-Preserving Approach to Image Resizing}},

author = {
Zhang, Guo-Xin
 and 
Cheng, Ming-Ming
 and 
Hu, Shi-Min
 and 
Martin, Ralph R.
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01568.x}

}
                
@article{
10.1111:j.1467-8659.2009.01569.x,

journal = {Computer Graphics Forum},
title = {{
Texture Splicing}},

author = {
Liu, Yiming
 and 
Wang, Jiaping
 and 
Xue, Su
 and 
Tong, Xin
 and 
Kang, Sing Bing
 and 
Guo, Baining
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01569.x}

}
                
@article{
10.1111:j.1467-8659.2009.01570.x,

journal = {Computer Graphics Forum},
title = {{
The Dual-microfacet Model for Capturing Thin Transparent Slabs}},

author = {
Dai, Qiang
 and 
Wang, Jiaping
 and 
Liu, Yiming
 and 
Snyder, John
 and 
Wu, Enhua
 and 
Guo, Baining
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01570.x}

}
                
@article{
10.1111:j.1467-8659.2009.01571.x,

journal = {Computer Graphics Forum},
title = {{
Fast, Sub-pixel Antialiased Shadow Maps}},

author = {
Pan, Minghao
 and 
Wang, Rui
 and 
Chen, Weifeng
 and 
Zhou, Kun
 and 
Bao, Hujun
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01571.x}

}
                
@article{
10.1111:j.1467-8659.2009.01572.x,

journal = {Computer Graphics Forum},
title = {{
Interactive Rendering of Interior Scenes with Dynamic Environment Illumination}},

author = {
Yue, Yonghao
 and 
Iwasaki, Kei
 and 
Chen, Bing-Yu
 and 
Dobashi, Yoshinori
 and 
Nishita, Tomoyuki
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01572.x}

}
                
@article{
10.1111:j.1467-8659.2009.01573.x,

journal = {Computer Graphics Forum},
title = {{
Textures on Rank-1 Lattices}},

author = {
Dammertz, Sabrina
 and 
Dammertz, Holger
 and 
Keller, Alexander
 and 
Lensch, Hendrik P. A.
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01573.x}

}
                
@article{
10.1111:j.1467-8659.2009.01574.x,

journal = {Computer Graphics Forum},
title = {{
Image and Video Abstraction by Anisotropic Kuwahara Filtering}},

author = {
Kyprianidis, Jan Eric
 and 
Kang, Henry
 and 
Doellner, Juergen
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01574.x}

}
                
@article{
10.1111:j.1467-8659.2009.01575.x,

journal = {Computer Graphics Forum},
title = {{
Interactive Cover Design Considering Physical Constraints}},

author = {
Igarashi, Yuki
 and 
Igarashi, Takeo
 and 
Suzuki, Hiromasa
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01575.x}

}
                
@article{
10.1111:j.1467-8659.2009.01576.x,

journal = {Computer Graphics Forum},
title = {{
Flow-Based Automatic Generation of Hybrid Picture Mazes}},

author = {
Wong, Fernando J.
 and 
Takahashi, Shigeo
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01576.x}

}
                
@article{
10.1111:j.1467-8659.2009.01577.x,

journal = {Computer Graphics Forum},
title = {{
Variational Surface Approximation and Model Selection}},

author = {
Li, Bao
 and 
Schnabel, Ruwen
 and 
Jin, Shiyao
 and 
Klein, Reinhard
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01577.x}

}
                
@article{
10.1111:j.1467-8659.2009.01578.x,

journal = {Computer Graphics Forum},
title = {{
Mesh Segmentation Refinement}},

author = {
Kaplansky, Lotan
 and 
Tal, Ayellet
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01578.x}

}
                
@article{
10.1111:j.1467-8659.2009.01579.x,

journal = {Computer Graphics Forum},
title = {{
Generalized Discrete Ricci Flow}},

author = {
Yang, Yong-Liang
 and 
Guo, Ren
 and 
Luo, Feng
 and 
Hu, Shi-Min
 and 
Gu, Xianfeng
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01579.x}

}
                
@article{
10.1111:j.1467-8659.2009.01580.x,

journal = {Computer Graphics Forum},
title = {{
Curvature Aware Fundamental Cycles}},

author = {
Diaz-Gutierrez, P.
 and 
Eppstein, D.
 and 
Gopi, M.
},
year = {
2009},

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


ISSN = {1467-8659},

DOI = {
10.1111/j.1467-8659.2009.01580.x}

}

Browse

Recent Submissions

Now showing 1 - 32 of 32
  • No Thumbnail Available
    Item
    Frontmatter and Cover
    (The Eurographics Association and Blackwell Publishing Ltd, 2009)
  • No Thumbnail Available
    Item
    SecondSkin: An interactive method for appearance transfer
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Van Den Hengely, A.; Sale, D.; Dick, A. R.
    SecondSkin estimates an appearance model for an object visible in a video sequence, without the need for complex interaction or any calibration apparatus. This model can then be transferred to other objects, allowing a non-expert user to insert a synthetic object into a real video sequence so that its appearance matches that of an existing object, and changes appropriately throughout the sequence. As the method does not require any prior knowledge about the scene, the lighting conditions, or the camera, it is applicable to video which was not captured with this purpose in mind. However, this lack of prior knowledge precludes the recovery of separate lighting and surface reflectance information. The SecondSkin appearance model therefore combines these factors. The appearance model does require a dominant light-source direction, which we estimate via a novel process involving a small amount of user interaction. The resulting model estimate provides exactly the information required to transfer the appearance of the original object to new geometry composited into the same video sequence.
  • No Thumbnail Available
    Item
    Live Video Montage with a Rotating Camera
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Dong, Zilong; Jiang, Lei; Zhang, Guofeng; Wang, Qing; Bao, Hujun
    High-quality video editing usually requires accurate layer separation in order to resolve occlusions. However, most of the existing bilayer segmentation algorithms require either considerable user intervention or a simple stationary camera configuration with known background, which is difficult to meet for many real world online applications. This paper demonstrates that various visually appealing montage effects can be online created from a live video captured by a rotating camera, by accurately retrieving the camera state and segmenting out the dynamic foreground. The key contribution is that a novel fast bilayer segmentation method is proposed which can effectively extract the dynamic foreground under rotational camera configuration, and is robust to imperfect background estimation and complex background colors. Our system can create a variety of live visual effects, including but not limited to, realistic virtual object insertion, background substitution and blurring, non-photorealistic rendering and camouflage effect. A variety of challenging examples demonstrate the effectiveness of our method.
  • No Thumbnail Available
    Item
    Image-to-Geometry Registration: a Mutual Information Method exploiting Illumination-related Geometric Properties
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Corsini, Massimiliano; Dellepiane, Matteo; Ponchio, Federico; Scopigno, Roberto
    This work concerns a novel study in the field of image-to-geometry registration. Our approach takes inspiration from medical imaging, in particular from multi-modal image registration. Most of the algorithms developed in this domain, where the images to register come from different sensors (CT, X-ray, PET), are based on Mutual Information, a statistical measure of non-linear correlation between two data sources. The main idea is to use mutual information as a similarity measure between the image to be registered and renderings of the model geometry, in order to drive the registration in an iterative optimization framework. We demonstrate that some illumination-related geometric properties, such as surface normals, ambient occlusion and reflection directions can be used for this purpose. After a comprehensive analysis of such properties we propose a way to combine these sources of information in order to improve the performance of our automatic registration algorithm. The proposed approach can robustly cover a wide range of real cases and can be easily extended.
  • No Thumbnail Available
    Item
    An Intuitive Interface for Interactive High Quality Image-Based Modeling
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Habbecke, Martin; Kobbelt, Leif
    We present the design of an interactive image-based modeling tool that enables a user to quickly generate detailed 3D models with texture from a set of calibrated input images. Our main contribution is an intuitive user interface that is entirely based on simple 2D painting operations and does not require any technical expertise by the user or difficult pre-processing of the input images. One central component of our tool is a GPU-based multi-view stereo reconstruction scheme, which is implemented by an incremental algorithm, that runs in the background during user interaction so that the user does not notice any significant response delay.
  • No Thumbnail Available
    Item
    Approximate on-Surface Distance Computation using Quasi-Developable Charts
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Torchelsen, Rafael P.; Pinto, Francisco; Bastos, Rui; Comba, Joao L. D.
    There is a vast number of applications that require distance field computation over triangular meshes. State-of-the-art algorithms have quadratic or sub-quadratic worst-case complexity, making them impractical for interactive applications. While most of the research on this subject has been focused on reducing the computation complexity of the algorithms, in this work we propose an approximate algorithm that achieves similar results working in lower resolutions of the input meshes. The creation of lower resolution meshes is the essence of our proposal. The idea is to identify regions on the input mesh that can be unfolded into planar regions with minimal area distortion (i.e. quasi-developable charts). Once charts are computed, their interior is re-triangulated to reduce the number of triangles, which results in a collection of simplified charts that we call a base mesh. Due to the properties of quasi-developable regions, we are able to compute distance fields over the base mesh instead of over the input mesh. This reduces the memory footprint and data processed for distance computations, which is the bottleneck of these algorithms. We present results that are one order of magnitude faster than current exact solutions, with low approximation errors.
  • No Thumbnail Available
    Item
    Linkless Octree Using Multi-Level Perfect Hashing
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Choi, Myung Geol; Ju, Eunjung; Chang, Jung-Woo; Lee, Jehee; Kim, Young J.
    The standard C/C++ implementation of a spatial partitioning data structure, such as octree and quadtree, is often inefficient in terms of storage requirements particularly when the memory overhead for maintaining parent-to-child pointers is significant with respect to the amount of actual data in each tree node. In this work, we present a novel data structure that implements uniform spatial partitioning without storing explicit parent-to-child pointer links. Our linkless tree encodes the storage locations of subdivided nodes using perfect hashing while retaining important properties of uniform spatial partitioning trees, such as coarse-to-fine hierarchical representation, efficient storage usage, and efficient random accessibility. We demonstrate the performance of our linkless trees using image compression and path planning examples.
  • No Thumbnail Available
    Item
    HPCCD: Hybrid Parallel Continuous Collision Detection using CPUs and GPUs
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Kim, Duksu; Heo, Jae-Pil; Huh, Jaehyuk; Kim, John; Yoon, Sung-eui
    We present a novel, hybrid parallel continuous collision detection (HPCCD) method that exploits the availability of multi-core CPU and GPU architectures. HPCCD is based on a bounding volume hierarchy (BVH) and selectively performs lazy reconstructions. Our method works with a wide variety of deforming models and supports self-collision detection. HPCCD takes advantage of hybrid multi-core architectures - using the general-purpose CPUs to perform the BVH traversal and culling while GPUs are used to perform elementary tests that reduce to solving cubic equations. We propose a novel task decomposition method that leads to a lock-free parallel algorithm in the main loop of our BVH-based collision detection to create a highly scalable algorithm. By exploiting the availability of hybrid, multi-core CPU and GPU architectures, our proposed method achieves more than an order of magnitude improvement in performance using four CPU-cores and two GPUs, compared to using a single CPU-core. This improvement results in an interactive performance, up to 148 fps, for various deforming benchmarks consisting of tens or hundreds of thousand triangles.
  • No Thumbnail Available
    Item
    Affective Modelling: Profiling Geometrical Models with Human Emotional Responses
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Lo, Cheng-Hung; Chu, Chih-Hsing
    In this paper, a novel concept, Affective Modelling, is introduced to encapsulate the idea of creating 3D models based on the emotional responses that they may invoke. Research on perceptually-related issues in Computer Graphics focuses mostly on the rendering aspect. Low-level perceptual criteria taken from established Psychology theories or identified by purposefully-designed experiments are utilised to reduce rendering effort or derive quality evaluation schemes. For modelling, similar ideas have been applied to optimise the level of geometrical details. High-level cognitive responses such as emotions/feelings are less addressed in graphics literatures. This paper investigates the possibility of incorporating emotional/affective factors for 3D model creations. Using a glasses frame model as our test case, we demonstrate a methodological framework to build the links between human emotional responses and geometrical features. We design and carry out a factorial experiment to systematically analyse how certain shape factors individually and interactively influence the viewer s impression of the shape of glasses frames. The findings serve as a basis for establishing computational models that facilitate emotionally-guided 3D modelling.
  • Thumbnail Image
    Item
    Procedural Generation of Rock Piles using Aperiodic Tiling
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Peytavie, A.; Galin, E.; Grosjean, J.; Merillou, S.
    In this paper, we present a tiling method for generating piles of rocks without any computationally demanding physically-based simulation. Previous techniques rely on a periodic tiling of rocks and generate unrealistic repetitive patterns. In contrast, our approach relies on a modified corner cube algorithm to generate a set of aperiodic tiles. We generalize the construction method so that the geometry of rocks should straddle corner cubes with a view to avoiding unrealistic gaps in the arrangement of rocks. Moreover, we propose an original technique to control the shape of rocks into contact by computing the Voronoi cells using a parameterized anisotropic distance. Our method has been successfully used to generate landscapes and stone huts and walls with thousands of rocks piled together.
  • No Thumbnail Available
    Item
    ProcDef: Local-to-global Deformation for Skeleton-free Character Animation
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Ijiri, Takashi; Takayama, Kenshi; Yokota, Hideo; Igarashi, Takeo
    Animations of characters with flexible bodies such as jellyfish, snails, and, hearts are difficult to design using traditional skeleton-based approaches. A standard approach is keyframing, but adjusting the shape of the flexible body for each key frame is tedious. In addition, the character cannot dynamically adjust its motion to respond to the environment or user input. This paper introduces a new procedural deformation framework (ProcDef) for designing and driving animations of such flexible objects. Our approach is to synthesize global motions procedurally by integrating local deformations. ProcDef provides an efficient design scheme for local deformation patterns; the user can control the orientation and magnitude of local deformations as well as the propagation of deformation signals by specifying line charts and volumetric fields. We also present a fast and robust deformation algorithm based on shape-matching dynamics and show some example animations to illustrate the feasibility of our framework.
  • No Thumbnail Available
    Item
    Expression Synthesis and Transfer in Parameter Spaces
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Shin, Hyun Joon; Lee, Yunjin
    In this paper, we introduce a novel framework that allows users to synthesize the expression of a 3D character by providing a intuitive set of parametric controls. Assuming that human face movements are formed by a set of basis actuation, we analyze a set of real expressions to extract this set together with skin deformation due to the actuation of face. To do this, we first decompose the movement of each marker into a set of distinctive movements. Independent component analysis technique is then adopted to find a independent set of actuations. Our simple and efficient skin deformation model are learned to reproduce the realistic movements of facial parts due to the actuations. In this framework, users can animate characters faces by controlling the amount actuation or by directly manipulating the face geometry. In addition, the proposed method can be applied to expression transfer which reproduces one character s expression in another character s face. Experimental results demonstrate that our method can produce realistic expression efficiently.
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    Simulation of Tearing Cloth with Frayed Edges
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Metaaphanon, Napaporn; Bando, Yosuke; Chen, Bing-Yu; Nishita, Tomoyuki
    Woven cloth can commonly be seen in daily life and also in animation. Unless prevented in some way, woven cloth usually frays at the edges. However, in computer graphics, woven cloth is typically modeled as a continuum sheet, which is not suitable for representing frays. This paper proposes a model that allows yarn movement and slippage during cloth tearing. Drawing upon techniques from textile and mechanical engineering fields, we model cloth as woven yarn crossings where each yarn can be independently torn when the strain limit is reached. To make the model practical for graphics applications, we simulate only tearing part of cloth with a yarn-level model using a simple constrained mass-spring system for computational efficiency. We designed conditions for switching from a standard continuum sheet model to our yarn-level model, so that frays can be initiated and propagated along the torn lines. Results show that our method can achieve plausible tearing cloth animation with frayed edges.
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    Simulating Gaseous Fluids with Low and High Speeds
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Gao, Yue; Li, Chen-Feng; Hu, Shi-Min; Barsky, Brian A.
    Gaseous fluids may move slowly, as smoke does, or at high speed, such as occurs with explosions. High-speed gas flow is always accompanied by low-speed gas flow, which produces rich visual details in the fluid motion. Realistic visualization involves a complex dynamic flow field with both low and high speed fluid behavior. In computer graphics, algorithms to simulate gaseous fluids address either the low speed case or the high speed case, but no algorithm handles both efficiently. With the aim of providing visually pleasing results, we present a hybrid algorithm that efficiently captures the essential physics of both low- and high-speed gaseous fluids. We model the low speed gaseous fluids by a grid approach and use a particle approach for the high speed gaseous fluids. In addition, we propose a physically sound method to connect the particle model to the grid model. By exploiting complementary strengths and avoiding weaknesses of the grid and particle approaches, we produce some animation examples and analyze their computational performance to demonstrate the effectiveness of the new hybrid method.
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    Procedural Synthesis using Vortex Particle Method for Fluid Simulation
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Yoon, Jong-Chul; Kam, Hyeong Ryeol; Hong, Jeong-Mo; Kang, Shin Jin; Kim, Chang-Hun
    We propose a fast and effective technique to improve sub-grid visual details of the grid based fluid simulation. Our method procedurally synthesizes the flow fields coming from the incompressible Navier-Stokes solver and the vorticity fields generated by vortex particle method for sub-grid turbulence. We are able to efficiently animate smoke which is highly turbulent and swirling with small scale details. Since this technique does not solve the linear system in high-resolution grids, it can perform fluid simulation more rapidly. We can easily estimate the influence of turbulent and swirling effect to the fluid flow.
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    Automatic Correction of Saturated Regions in Photographs using Cross-Channel Correlation
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Masood, Syed Z.; Zhu, Jiejie; Tappen, Marshall F.
    Incorrectly setting the camera s exposure can have a significant negative effect on a photograph. Over-exposing photographs causes pixels to exhibit unpleasant artifacts due to saturation of the sensor. Saturation removal typically involves user intervention to adjust the color values, which is tedious and time-consuming. This paper discusses how saturation can be automatically removed without compromising the essential details of the image. Our method is based on a smoothness prior: neighboring pixels have similar channel ratios and color values. We demonstrate that high quality saturation-free photos can be obtained from a simple but effective approach.
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    Edit Propagation on Bidirectional Texture Functions
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Xu, Kun; Wang, Jiaping; Tong, Xin; Hu, Shi-Min; Guo, Baining
    We propose an efficient method for editing bidirectional texture functions (BTFs) based on edit propagation scheme. In our approach, users specify sparse edits on a certain slice of BTF. An edit propagation scheme is then applied to propagate edits to the whole BTF data. The consistency of the BTF data is maintained by propagating similar edits to points with similar underlying geometry/reflectance. For this purpose, we propose to use view independent features including normals and reflectance features reconstructed from each view to guide the propagation process. We also propose an adaptive sampling scheme for speeding up the propagation process. Since our method needn t any accurate geometry and reflectance information, it allows users to edit complex BTFs with interactive feedback.
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    Gradient-Preserving Color Transfer
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Xiao, Xuezhong; Ma, Lizhuang
    Color transfer is an image processing technique which can produce a new image combining one source image s contents with another image s color style. While being able to produce convincing results, however, Reinhard et al. s pioneering work has two problems-mixing up of colors in different regions and the fidelity problem. Many local color transfer algorithms have been proposed to resolve the first problem, but the second problem was paid few attentions.In this paper, a novel color transfer algorithm is presented to resolve the fidelity problem of color transfer in terms of scene details and colors. It s well known that human visual system is more sensitive to local intensity differences than to intensity itself. We thus consider that preserving the color gradient is necessary for scene fidelity. We formulate the color transfer problem as an optimization problem and solve it in two steps-histogram matching and a gradient-preserving optimization. Following the idea of the fidelity in terms of color and gradient, we also propose a metric for objectively evaluating the performance of example-based color transfer algorithms. The experimental results show the validity and high fidelity of our algorithm and that it can be used to deal with local color transfer.
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    Optimizing Structure Preserving Embedded Deformation for Resizing Images and Vector Art
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Huang, Qi-xing; Mech, Radomir; Carr, Nathan
    Smart deformation and warping tools play an important part in modern day geometric modeling systems. They allow existing content to be stretched or scaled while preserving visually salient information. To date, these techniques have primarily focused on preserving local shape details, not taking into account important global structures such as symmetry and line features. In this work we present a novel framework that can be used to preserve the global structure in images and vector art. Such structures include symmetries and the spatial relations in shapes and line features in an image. Central to our method is a new formulation of preserving structure as an optimization problem. We use novel optimization strategies to achieve the interactive performance required by modern day modeling applications. We demonstrate the effectiveness of our framework by performing structure preservation deformation of images and complex vector art at interactive rates.
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    A Shape-Preserving Approach to Image Resizing
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Zhang, Guo-Xin; Cheng, Ming-Ming; Hu, Shi-Min; Martin, Ralph R.
    We present a novel image resizing method which attempts to ensure that important local regions undergo a geometric similarity transformation, and at the same time, to preserve image edge structure. To accomplish this, we define handles to describe both local regions and image edges, and assign a weight for each handle based on an importance map for the source image. Inspired by conformal energy, which is widely used in geometry processing, we construct a novel quadratic distortion energy to measure the shape distortion for each handle. The resizing result is obtained by minimizing the weighted sum of the quadratic distortion energies of all handles. Compared to previous methods, our method allows distortion to be diffused better in all directions, and important image edges are well-preserved. The method is efficient, and offers a closed form solution.
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    Texture Splicing
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Liu, Yiming; Wang, Jiaping; Xue, Su; Tong, Xin; Kang, Sing Bing; Guo, Baining
    We propose a new texture editing operation called texture splicing. For this operation, we regard a texture as having repetitive elements (textons) seamlessly distributed in a particular pattern. Taking two textures as input, texture splicing generates a new texture by selecting the texton appearance from one texture and distribution from the other. Texture splicing involves self-similarity search to extract the distribution, distribution warping, context-dependent warping, and finally, texture refinement to preserve overall appearance. We show a variety of results to illustrate this operation.
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    The Dual-microfacet Model for Capturing Thin Transparent Slabs
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Dai, Qiang; Wang, Jiaping; Liu, Yiming; Snyder, John; Wu, Enhua; Guo, Baining
    We present a new model, called the dual-microfacet, for those materials such as paper and plastic formed by a thin, transparent slab lying between two surfaces of spatially varying roughness. Light transmission through the slab is represented by a microfacet-based BTDF which tabulates the microfacet s normal distribution (NDF) as a function of surface location. Though the material is bounded by two surfaces of different roughness, we approximate light transmission through it by a virtual slab determined by a single spatially-varying NDF. This enables efficient capturing of spatially variant transparent slices. We describe a device for measuring this model over a flat sample by shining light from a CRT behind it and capturing a sequence of images from a single view. Our method captures both angular and spatial variation in the BTDF and provides a good match to measured materials.
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    Fast, Sub-pixel Antialiased Shadow Maps
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Pan, Minghao; Wang, Rui; Chen, Weifeng; Zhou, Kun; Bao, Hujun
    Solving aliasing artifacts is an essential problem in shadow mapping approaches. Many works have been proposed, however, most of them focused on removing the texel-level aliasing that results from the limited resolution of shadow maps. Little work has been done to solve the pixel-level shadow aliasing that is produced by the rasterization on the screen plane. In this paper, we propose a fast, sub-pixel antialiased shadowing algorithm to solve the pixel aliasing problem. Our work is based on the alias-free shadow maps, which is capable of computing accurate per-pixel shadow, and only incurs little cost to extend to sub-pixel accuracy. Instead of direct supersampling the screen space, we take facets to approximate pixels in shadow testing. The shadowed area of one facet is rapidly evaluated by projecting blocker geometry onto a supersampled 2D occlusion mask with bitmasks fusion. It provides a sub-pixel occlusion sampling so as to capture fine shadow details and features. Furthermore, we introduce the silhouette mask map that limits visibility evaluation to pixels only on the silhouette, which greatly reduces the computation cost. Our algorithm runs entirely on the GPU, achieving real-time performance and is an order of magnitude faster than the brute-force supersampling method to produce comparable 32x antialiased shadows.
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    Interactive Rendering of Interior Scenes with Dynamic Environment Illumination
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Yue, Yonghao; Iwasaki, Kei; Chen, Bing-Yu; Dobashi, Yoshinori; Nishita, Tomoyuki
    A rendering system for interior scenes is proposed in this paper. The light reaches the interior scene, usually through small regions, such as windows or abat-jours, which we call portals. To provide a solution, suitable for rendering interior scenes with portals, we extend the traditional precomputed radiance transfer approaches. In our approach, a bounding sphere, which we call a shell, of the interior, centered at each portal, is created and the light transferred from the shell towards the interior through the portal is precomputed. Each shell acts as an environment light source and its intensity distribution is determined by rendering images of the scene, viewed from the center of the shell. By updating the intensity distribution of the shell at each frame, we are able to handle dynamic objects outside the shells. The material of the portals can also be modified at run time (e.g. changing from transparent glass to frosted glass). Several applications are shown, including the illumination of a cathedral, lit by skylight at different times of a day, and a car, running in a town, at interactive frame rates, with a dynamic viewpoint.
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    Textures on Rank-1 Lattices
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Dammertz, Sabrina; Dammertz, Holger; Keller, Alexander; Lensch, Hendrik P. A.
    Storing textures on orthogonal tensor product lattices is predominant in computer graphics, although it is known that their sampling efficiency is not optimal. In two dimensions, the hexagonal lattice provides the maximum sampling efficiency. However, handling these lattices is difficult, because they are not able to tile an arbitrary rectangular region and have an irrational basis. By storing textures on rank-1 lattices, we resolve both problems: Rank-1 lattices can closely approximate hexagonal lattices, while all coordinates of the lattice points remain integer. At identical memory footprint texture quality is improved as compared to traditional orthogonal tensor product lattices due to the higher sampling efficiency. We introduce the basic theory of rank-1 lattice textures and present an algorithmic framework which easily can be integrated into existing off-line and real-time rendering systems.
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    Image and Video Abstraction by Anisotropic Kuwahara Filtering
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Kyprianidis, Jan Eric; Kang, Henry; Doellner, Juergen
    We present a non-photorealistic rendering technique to transform color images and videos into painterly abstractions. It is based on a generalization of the Kuwahara filter that is adapted to the local shape of features, derived from the smoothed structure tensor. Contrary to conventional edge-preserving filters, our filter generates a painting-like flattening effect along the local feature directions while preserving shape boundaries. As opposed to conventional painting algorithms, it produces temporally coherent video abstraction without extra processing. The GPU implementation of our method processes video in real-time. The results have the clearness of cartoon illustrations but also exhibit directional information as found in oil paintings.
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    Interactive Cover Design Considering Physical Constraints
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Igarashi, Yuki; Igarashi, Takeo; Suzuki, Hiromasa
    We developed an interactive system to design a customized cover for a given three-dimensional (3D) object such as a camera, teapot, or car. The system first computes the convex hull of the input geometry. The user segments it into several cloth patches by drawing on the 3D surface. This paper provides two technical contributions. First, it introduces a specialized flattening algorithm for cover patches. It makes each two-dimensional edge in the flattened pattern equal to or longer than the original 3D edge; a smaller patch would fail to cover the object, and a larger patch would result in extra wrinkles. Second, it introduces a mechanism to verify that the user-specified opening would be large enough for the object to be removed. Starting with the initial configuration, the system virtually pulls the object out of the cover while avoiding excessive stretching of cloth patches. We used the system to design real covers and confirmed that it functions as intended.
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    Flow-Based Automatic Generation of Hybrid Picture Mazes
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Wong, Fernando J.; Takahashi, Shigeo
    A method for automatically generating a picture maze from two different images is introduced throughout this paper. The process begins with the extraction of salient contours and edge tangent flow information from the primary image in order to build the overall maze. Thus, mazes with passages flowing in the main edge directions and walls that effectively represent an abstract version of the primary image can be successfully created. Furthermore, our proposed approach makes possible the use of their solution path as a means of illustrating the main features of the secondary image, while attempting to keep its image motif concealed until the maze has been finally solved. The contour features and intensity of the secondary image are also incorporated into our method in order to determine the areas of the maze to be shaded by allowing the solution path to go through them. Moreover, an experiment has been conducted to confirm that solution paths can be successfully hidden from the participants in the mazes generated using our method.
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    Variational Surface Approximation and Model Selection
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Li, Bao; Schnabel, Ruwen; Jin, Shiyao; Klein, Reinhard
    We consider the problem of approximating an arbitrary generic surface with a given set of simple surface primitives. In contrast to previous approaches based on variational surface approximation, which are primarily concerned with finding an optimal partitioning of the input geometry, we propose to integrate a model selection step into the algorithm in order to also optimize the type of primitive for each proxy. Our method is a joint global optimization of both the partitioning of the input surface as well as the types and number of used shape proxies. Thus, our method performs an automatic trade-off between representation complexity and approximation error without relying on a user supplied predetermined number of shape proxies. This way concise surface representations are found that better exploit the full approximative power of the employed primitive types.
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    Mesh Segmentation Refinement
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Kaplansky, Lotan; Tal, Ayellet
    This paper proposes a method for refining existing mesh segmentations, employing a novel extension of the active contour approach to meshes. Given a segmentation, produced either by an automatic segmentation method or interactively, our algorithm propagates the segment boundaries to more appropriate locations. In addition, unlike most segmentation algorithms, our method allows the boundaries to pass through the mesh faces, resulting in smoother curves, particularly visible on coarse meshes. The method is also capable of changing the number of segments, by enabling splitting and merging of boundary curves during the process. Finally, by changing the propagation rules, it is possible to segment the mesh by a variety of criteria, for instance geometric-meaningful segmentations, texture-based segmentations, or constriction-based segmentations.
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    Generalized Discrete Ricci Flow
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Yang, Yong-Liang; Guo, Ren; Luo, Feng; Hu, Shi-Min; Gu, Xianfeng
    Surface Ricci flow is a powerful tool to design Riemannian metrics by user defined curvatures. Discrete surface Ricci flow has been broadly applied for surface parameterization, shape analysis, and computational topology. Conventional discrete Ricci flow has limitations. For meshes with low quality triangulations, if high conformality is required, the flow may get stuck at the local optimum of the Ricci energy. If convergence to the global optimum is enforced, the conformality may be sacrificed.This work introduces a novel method to generalize the traditional discrete Ricci flow. The generalized Ricci flow is more flexible, more robust and conformal for meshes with low quality triangulations. Conventional method is based on circle packing, which requires two circles on an edge intersect each other at an acute angle. Generalized method allows the two circles either intersect or separate from each other. This greatly improves the flexibility and robustness of the method. Furthermore, the generalized Ricci flow preserves the convexity of the Ricci energy, this ensures the uniqueness of the global optimum. Therefore the algorithm won t get stuck at the local optimum.Generalized discrete Ricci flow algorithms are explained in details for triangle meshes with both Euclidean and hyperbolic background geometries. Its advantages are demonstrated by theoretic proofs and practical applications in graphics, especially surface parameterization.
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    Curvature Aware Fundamental Cycles
    (The Eurographics Association and Blackwell Publishing Ltd, 2009) Diaz-Gutierrez, P.; Eppstein, D.; Gopi, M.
    We present a graph algorithm to find fundamental cycles aligned with the principal curvature directions of a surface. Specifically, we use the tree-cotree decomposition of graphs embedded in manifolds, guided with edge weights, in order to produce these cycles. Our algorithm is very quick compared to existing methods, with a worst case running time of O(n log n+gn) where n is the number of faces and g is the surface genus. Further, its flexibility to accommodate different weighting functions and to handle boundaries may be used to produce cycles suitable for a variety of applications and models.