Short Papers

Permanent URI for this collection


Skeleton Based Importance Sampling for Path Tracing

Biri, Venceslas
Chaussard, John

Forward+: Bringing Deferred Lighting to the Next Level

Harada, Takahiro
McKee, Jay
Yang, Jason C.

Reflective Shadow Map Clustering for Real-Time Global Illumination

Prutkin, Roman
Kaplanyan, Anton
Dachsbacher, Carsten

Hybrid CPU/GPU KD-Tree Construction for Versatile Ray Tracing

Roccia, Jean-Patrick
Paulin, Mathias
Coustet, Christophe

Growing Cell Structures Learning a Progressive Mesh During Surface Reconstruction - A Top-Down Approach

Vierjahn, Tom
Lorenz, Guido
Mostafawy, Sina
Hinrichs, Klaus

Perceptually Based Afterimage Synthesis

Mikamo, Michihiro
Slomp, Marcos
Raytchev, Bisser
Tamaki, Toru
Kaneda, Kazufumi

Robust Outlier Removal from Point Clouds Acquired with Structured Light

Köhler, Johannes
Nöll, Tobias
Reis, Gerd
Stricker, Didier

Automatic Multi-view Surface Matching

Fantoni, Simone
Castellani, Umberto
Fusiello, Andrea

Shape Reconstruction from Raw Point Clouds using Depth Carving

Guggeri, Fabio
Scateni, Riccardo
Pajarola, Renato

Variation-Factored Encoding of Facade Images

Alsisan, Suhib
Mitra, Niloy J.

Scented Sliders for Procedural Textures

Lasram, Anass
Lefebvre, Sylvain
Damez, Cyrille

Efficient Evaluation of Semi-Smooth Creases in Catmull-Clark Subdivision Surfaces

Nießner, Matthias
Loop, Charles
Greiner, Günther

Geometric Details on Skeleton-based Implicit Surfaces

Zanni, Cedric
Bares, P.
Lagae, Ares
Quiblier, M.
Cani, Marie-Paule

Example-based Road Network Synthesis

Yu, Qizhi
Steed, Anthony

Steady State Stokes Flow Interpolation for Fluid Control

Bhatacharya, Haimasree
Nielsen, Michael B.
Bridson, Robert

FTLE Computation Beyond First-Order Approximation

Üffinger, Markus
Sadlo, Filip
Kirby, Mike
Hansen, Charles
Ertl, Thomas

Solid-state Culled Discrete Element Granular Systems

Holladay, Seth R.
Egbert, Parris

Image-based Animation of Clothes

Hilsmann, Anna
Eisert, Peter

Fast Response and Quick Progressive Transitions using Body Part Motion Graphs

Fernández-Baena, Adso
Miralles, David

Improved Obstacle Relevancy, Distance, and Angle for Crowds Constrained to Arbitrary Manifolds in 3D Space

Ricks, Brian C.
Egbert, Parris K.

Automatic Line Handles for Freeform Deformation

Schemali, Leïla
Thiery, Jean-Marc
Boubekeur, Tamy

GPU based ARAP Deformation using Volumetric Lattices

Zollhöfer, Michael
Sert, Ezgi
Greiner, Günther
Süßmuth, Jochen

Physically-Based Depth of Field in Augmented Reality

Kán, Peter
Kaufmann, Hannes

Real-Time Metaball Ray Casting with Fragment Lists

Szécsi, László
Illés, Dávid

Hyperplane Culling for Stochastic Rasterization

Munkberg, Jacob
Akenine-Möller, Tomas

Incoherent Ray Tracing without Acceleration Structures

Áfra, Attila T.

S-buffer: Sparsity-aware Multi-fragment Rendering

Vasilakis, Andreas A.
Fudos, Ioannis


BibTeX (Short Papers)
@inproceedings{
10.2312:conf/EG2012/short/001-004,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
Skeleton Based Importance Sampling for Path Tracing}},
author = {
Biri, Venceslas
 and
Chaussard, John
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/001-004}
}
@inproceedings{
10.2312:conf/EG2012/short/005-008,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
Forward+: Bringing Deferred Lighting to the Next Level}},
author = {
Harada, Takahiro
 and
McKee, Jay
 and
Yang, Jason C.
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/005-008}
}
@inproceedings{
10.2312:conf/EG2012/short/009-012,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
Reflective Shadow Map Clustering for Real-Time Global Illumination}},
author = {
Prutkin, Roman
 and
Kaplanyan, Anton
 and
Dachsbacher, Carsten
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/009-012}
}
@inproceedings{
10.2312:conf/EG2012/short/013-016,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
Hybrid CPU/GPU KD-Tree Construction for Versatile Ray Tracing}},
author = {
Roccia, Jean-Patrick
 and
Paulin, Mathias
 and
Coustet, Christophe
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/013-016}
}
@inproceedings{
10.2312:conf/EG2012/short/029-032,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
Growing Cell Structures Learning a Progressive Mesh During Surface Reconstruction - A Top-Down Approach}},
author = {
Vierjahn, Tom
 and
Lorenz, Guido
 and
Mostafawy, Sina
 and
Hinrichs, Klaus
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/029-032}
}
@inproceedings{
10.2312:conf/EG2012/short/017-020,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
Perceptually Based Afterimage Synthesis}},
author = {
Mikamo, Michihiro
 and
Slomp, Marcos
 and
Raytchev, Bisser
 and
Tamaki, Toru
 and
Kaneda, Kazufumi
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/017-020}
}
@inproceedings{
10.2312:conf/EG2012/short/021-024,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
Robust Outlier Removal from Point Clouds Acquired with Structured Light}},
author = {
Köhler, Johannes
 and
Nöll, Tobias
 and
Reis, Gerd
 and
Stricker, Didier
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/021-024}
}
@inproceedings{
10.2312:conf/EG2012/short/025-028,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
Automatic Multi-view Surface Matching}},
author = {
Fantoni, Simone
 and
Castellani, Umberto
 and
Fusiello, Andrea
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/025-028}
}
@inproceedings{
10.2312:conf/EG2012/short/033-036,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
Shape Reconstruction from Raw Point Clouds using Depth Carving}},
author = {
Guggeri, Fabio
 and
Scateni, Riccardo
 and
Pajarola, Renato
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/033-036}
}
@inproceedings{
10.2312:conf/EG2012/short/037-040,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
Variation-Factored Encoding of Facade Images}},
author = {
Alsisan, Suhib
 and
Mitra, Niloy J.
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/037-040}
}
@inproceedings{
10.2312:conf/EG2012/short/045-048,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
Scented Sliders for Procedural Textures}},
author = {
Lasram, Anass
 and
Lefebvre, Sylvain
 and
Damez, Cyrille
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/045-048}
}
@inproceedings{
10.2312:conf/EG2012/short/041-044,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
Efficient Evaluation of Semi-Smooth Creases in Catmull-Clark Subdivision Surfaces}},
author = {
Nießner, Matthias
 and
Loop, Charles
 and
Greiner, Günther
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/041-044}
}
@inproceedings{
10.2312:conf/EG2012/short/049-052,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
Geometric Details on Skeleton-based Implicit Surfaces}},
author = {
Zanni, Cedric
 and
Bares, P.
 and
Lagae, Ares
 and
Quiblier, M.
 and
Cani, Marie-Paule
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/049-052}
}
@inproceedings{
10.2312:conf/EG2012/short/053-056,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
Example-based Road Network Synthesis}},
author = {
Yu, Qizhi
 and
Steed, Anthony
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/053-056}
}
@inproceedings{
10.2312:conf/EG2012/short/057-060,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
Steady State Stokes Flow Interpolation for Fluid Control}},
author = {
Bhatacharya, Haimasree
 and
Nielsen, Michael B.
 and
Bridson, Robert
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/057-060}
}
@inproceedings{
10.2312:conf/EG2012/short/061-064,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
FTLE Computation Beyond First-Order Approximation}},
author = {
Üffinger, Markus
 and
Sadlo, Filip
 and
Kirby, Mike
 and
Hansen, Charles
 and
Ertl, Thomas
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/061-064}
}
@inproceedings{
10.2312:conf/EG2012/short/065-068,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
Solid-state Culled Discrete Element Granular Systems}},
author = {
Holladay, Seth R.
 and
Egbert, Parris
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/065-068}
}
@inproceedings{
10.2312:conf/EG2012/short/069-072,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
Image-based Animation of Clothes}},
author = {
Hilsmann, Anna
 and
Eisert, Peter
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/069-072}
}
@inproceedings{
10.2312:conf/EG2012/short/077-080,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
Fast Response and Quick Progressive Transitions using Body Part Motion Graphs}},
author = {
Fernández-Baena, Adso
 and
Miralles, David
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/077-080}
}
@inproceedings{
10.2312:conf/EG2012/short/073-076,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
Improved Obstacle Relevancy, Distance, and Angle for Crowds Constrained to Arbitrary Manifolds in 3D Space}},
author = {
Ricks, Brian C.
 and
Egbert, Parris K.
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/073-076}
}
@inproceedings{
10.2312:conf/EG2012/short/081-084,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
Automatic Line Handles for Freeform Deformation}},
author = {
Schemali, Leïla
 and
Thiery, Jean-Marc
 and
Boubekeur, Tamy
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/081-084}
}
@inproceedings{
10.2312:conf/EG2012/short/085-088,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
GPU based ARAP Deformation using Volumetric Lattices}},
author = {
Zollhöfer, Michael
 and
Sert, Ezgi
 and
Greiner, Günther
 and
Süßmuth, Jochen
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/085-088}
}
@inproceedings{
10.2312:conf/EG2012/short/089-092,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
Physically-Based Depth of Field in Augmented Reality}},
author = {
Kán, Peter
 and
Kaufmann, Hannes
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/089-092}
}
@inproceedings{
10.2312:conf/EG2012/short/093-096,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
Real-Time Metaball Ray Casting with Fragment Lists}},
author = {
Szécsi, László
 and
Illés, Dávid
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/093-096}
}
@inproceedings{
10.2312:conf/EG2012/short/105-108,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
Hyperplane Culling for Stochastic Rasterization}},
author = {
Munkberg, Jacob
 and
Akenine-Möller, Tomas
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/105-108}
}
@inproceedings{
10.2312:conf/EG2012/short/097-100,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
Incoherent Ray Tracing without Acceleration Structures}},
author = {
Áfra, Attila T.
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/097-100}
}
@inproceedings{
10.2312:conf/EG2012/short/101-104,
booktitle = {
Eurographics 2012 - Short Papers},
editor = {
Carlos Andujar and Enrico Puppo
}, title = {{
S-buffer: Sparsity-aware Multi-fragment Rendering}},
author = {
Vasilakis, Andreas A.
 and
Fudos, Ioannis
}, year = {
2012},
publisher = {
The Eurographics Association},
ISSN = {1017-4656},
DOI = {
10.2312/conf/EG2012/short/101-104}
}

Browse

Recent Submissions

Now showing 1 - 27 of 27
  • Item
    Skeleton Based Importance Sampling for Path Tracing
    (The Eurographics Association, 2012) Biri, Venceslas; Chaussard, John; Carlos Andujar and Enrico Puppo
    When working with large and complex scenes, situations arise where light flux takes complex paths to reach the observer. In such cases, traditional stochastic algorithms, like ray tracing algorithms, will have difficulties to compute noise-free images. Our present research aims to solve this problem using the 3d scene skeleton as a coarse representation. Indeed, curvilinear skeletons can be used to find light paths with higher energy. This article presents our research to use these skeletons for any ray tracing algorithm, allowing a knowledge-based choice when choosing light paths. Our method adds little computation time while producing a more accurate image.
  • Item
    Forward+: Bringing Deferred Lighting to the Next Level
    (The Eurographics Association, 2012) Harada, Takahiro; McKee, Jay; Yang, Jason C.; Carlos Andujar and Enrico Puppo
    This paper presents Forward+, a method of rendering many lights by culling and storing only lights that contribute to the pixel. Forward+ is an extension to traditional forward rendering. Light culling, implemented using the compute capability of the GPU, is added to the pipeline to create lists of lights; that list is passed to the final rendering shader, which can access all information about the lights. Although Forward+ increases workload to the final shader, it theoretically requires less memory traffic compared to compute-based deferred lighting. Furthermore, it removes the major drawback of deferred techniques, which is a restriction of materials and lighting models. Experiments are performed to compare the performance of Forward+ and deferred lighting.
  • Item
    Reflective Shadow Map Clustering for Real-Time Global Illumination
    (The Eurographics Association, 2012) Prutkin, Roman; Kaplanyan, Anton; Dachsbacher, Carsten; Carlos Andujar and Enrico Puppo
    We present a method for real-time clustering of VPLs obtained from Reflective Shadow Maps (RSM). The clusters are treated as area light sources and used to approximate indirect illumination. The spatial extent of a cluster is used to deduce the shape and size of the respective area light source. Our method is fully GPU-based and avoids flickering by temporally coherent reinitialization of the clustering. It also incorporates importance sampling for view-dependent clustering. We show visually indistinguishable results of indirect illumination with only a fraction of secondary light sources.
  • Item
    Hybrid CPU/GPU KD-Tree Construction for Versatile Ray Tracing
    (The Eurographics Association, 2012) Roccia, Jean-Patrick; Paulin, Mathias; Coustet, Christophe; Carlos Andujar and Enrico Puppo
    We propose an hybrid CPU-GPU ray-tracing implementation based on an optimal Kd-Tree as acceleration structure. The construction and traversal of this KD-tree takes benefit from both the CPU and the GPU to achieve high-performance ray-tracing on mainstream hardware. Our approach, flexible enough to use only a single computing unit (CPU or GPU), is able to efficiently distribute workload between CPUs and GPUs for fast KD-tree construction and traversal.
  • Item
    Growing Cell Structures Learning a Progressive Mesh During Surface Reconstruction - A Top-Down Approach
    (The Eurographics Association, 2012) Vierjahn, Tom; Lorenz, Guido; Mostafawy, Sina; Hinrichs, Klaus; Carlos Andujar and Enrico Puppo
    Growing Cell Structures (GCS) have been proven to be suitable for surface reconstruction from unstructured point clouds. The reconstructed triangle mesh can be represented compactly as a progressive mesh with integrated level of detail by storing only vertex split operations. However, half-edge collapse operations are used for GCS. In this paper, we present an improvement to a GCS-based surface reconstruction technique by converting a halfedge collapse to a more general vertex removal to create a progressive mesh. We have evaluated the new technique with respect to running time overhead and mesh quality. Results indicate that this technique can be used for efficient surface reconstruction. We will use the presented findings as basis for future research.
  • Item
    Perceptually Based Afterimage Synthesis
    (The Eurographics Association, 2012) Mikamo, Michihiro; Slomp, Marcos; Raytchev, Bisser; Tamaki, Toru; Kaneda, Kazufumi; Carlos Andujar and Enrico Puppo
    Afterimages comprise a common, recurring perceptual phenomenon experienced in a daily-basis. Afterimages are best realized when staring at some high intensity light source (i.e., a light bulb) and then shifting the ocular focus to other less luminous portions of the scene: a temporary “ghost” image of that strong intensity remains imprinted on the retina. During the time the afterimage stays active, several exquisite color gradations appear and fade. Although research on the topic has been moderately active in ophthalmology and vision domains, no definitive model has been devised. Furthermore, no afterimage simulation seems to have yet been investigated in computer graphics. In this paper we attempt to introduce the topic to the field and therefore widen the research spectrum of computer graphics. The proposed technique is based on psychophysical and physiological evidence, addressing the color transitions and the duration of the effect. The method is also fast and suitable for real-time applications. Our stance towards afterimages is more than just curiosity on this peculiar effect: we believe that its understanding and proper simulation can assist on relevant tasks such as urban and road engineering for safer pedestrian and vehicle mobility at adverse lighting conditions.
  • Item
    Robust Outlier Removal from Point Clouds Acquired with Structured Light
    (The Eurographics Association, 2012) Köhler, Johannes; Nöll, Tobias; Reis, Gerd; Stricker, Didier; Carlos Andujar and Enrico Puppo
    We present a method for automatic, robust identification of outliers in point clouds acquired with structured light. In contrast to most state of the art methods, we consider available 2D information instead of operating on the points only. Our method performs robust even for complex, glossy surfaces, where illumination artifacts introduce ghost geometry or outliers that seamlessly blend into the correct surface. The key idea of our algorithm is to only use cameras for reconstruction and the projector for a separate consistency check. We use encoding by phase shifting to obtain per pixel correspondences for the cameras and subpixel accuracy for the projector. The method requires at least 2 cameras, a projector and a precise calibration of all devices.
  • Item
    Automatic Multi-view Surface Matching
    (The Eurographics Association, 2012) Fantoni, Simone; Castellani, Umberto; Fusiello, Andrea; Carlos Andujar and Enrico Puppo
    In this paper we tackle the problem of automatically aligning an unordered set of range views. We propose a full pipeline that goes from the scans to the complete 3D model. The emphasis is on the automation no manual intervention is require and on the fact that no knowledge on the acquisition sequence is assumed. The contribution is twofold: in the pre-alignment phase a voting scheme is proposed that discovers the overlapping relationship among views; in the final refinement step we extend the Levenberg Marquardt-ICP to work with multiple views, in order to solve for the absolute pose of all images simultaneously.
  • Item
    Shape Reconstruction from Raw Point Clouds using Depth Carving
    (The Eurographics Association, 2012) Guggeri, Fabio; Scateni, Riccardo; Pajarola, Renato; Carlos Andujar and Enrico Puppo
    Shape reconstruction from raw point sets is a hot research topic. Point sets are increasingly available as primary input source, since low-cost acquisition methods are largely accessible nowadays, and these sets are more noisy than used to be. Standard reconstruction methods rely on normals or signed distance functions, and thus many methods aim at estimating these features. Human vision can however easily discern between the inside and the outside of a dense cloud even without the support of fancy measures. We propose, here, a perceptual method for estimating an indicator function for the shape, inspired from image-based methods. The resulting function nicely approximates the shape, is robust to noise, and can be used for direct isosurface extraction or as an input for other accurate reconstruction methods.
  • Item
    Variation-Factored Encoding of Facade Images
    (The Eurographics Association, 2012) Alsisan, Suhib; Mitra, Niloy J.; Carlos Andujar and Enrico Puppo
    Urban facades contain large-scale repetitions in the form of windows, doors, etc. Such elements often are in different configurations (e.g., open or closed) obscuring their regular arrangements to any direct low-level pixel matching based repetition detection.We propose a variation-factored representation for facade images by progressively favoring larger repeated structures while allowing relabeling using candidate element types. We formulate the problem as a Markov Random Field (MRF) based optimization, and evaluate the algorithm on a large number of benchmark facade images. Such a facade encoding is very compact and can be used for rapid generation of realistic 3D models with variations suitable for online map viewers or mobile navigation aids.
  • Item
    Scented Sliders for Procedural Textures
    (The Eurographics Association, 2012) Lasram, Anass; Lefebvre, Sylvain; Damez, Cyrille; Carlos Andujar and Enrico Puppo
    Procedural textures often expose a set of parameters controlling their final appearance. This lets end users tune the final look and feel, typically through a set of sliders. However, it is difficult to predict the changes introduced by a given slider, especially as sliders interact in non–trivial ways. We augment the sliders controlling parameters with visual previews revealing the changes that will be introduced upon manipulation. These previews are constantly refreshed to reflect changes with respect to the current settings. The main challenge is to generate the visual sliders in a very limited pixel space and at an interactive rate. This is done by synthesizing the visual slider from a small set of patches ordered in accordance with the slider. These patches are chosen so as to reveal as much as possible the visual variations induced by the slider. The selection and ordering are achieved by using the seam–carving algorithm to carve patches with low visual impact. The obtained patches are then stitched together using patch-based texture synthesis to form the final visual slider.
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    Efficient Evaluation of Semi-Smooth Creases in Catmull-Clark Subdivision Surfaces
    (The Eurographics Association, 2012) Nießner, Matthias; Loop, Charles; Greiner, Günther; Carlos Andujar and Enrico Puppo
    We present a novel method to evaluate semi-smooth creases in Catmull-Clark subdivision surfaces. Our algorithm supports both integer and fractional crease tags corresponding to the RenderMan (Pixar) specification. In order to perform fast and efficient surface evaluations, we obtain a polynomial surface representation given by the semismooth subdivision rules. While direct surface evaluation is applied for regular patches, we perform adaptive subdivision around extraordinary vertices. In the end, we are able to efficently handle high-order sharpness tags at very low cost. Compared to the state-of-the art, both render time and memory consumption are reduced from exponential to linear complexity. Furthermore, we integrate our algorithm in the hardware tessellation pipeline of modern GPUs. Our method is ideally suited to real-time applications such as games or authoring tools.
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    Geometric Details on Skeleton-based Implicit Surfaces
    (The Eurographics Association, 2012) Zanni, Cedric; Bares, P.; Lagae, Ares; Quiblier, M.; Cani, Marie-Paule; Carlos Andujar and Enrico Puppo
    We present a modeling technique to enhance implicit surfaces with procedural geometric details. The details are based on Gabor noise, which enables us to seamlessly handle anisotropy. The orientation of details can be defined with respect to the orientation of the main shape features, which reduces the amount of user input. The method extends to complex details that are tilted with respect to the normal of the input surface. Lastly, our method allows the blending of the resulting enhanced implicit primitives without causing the details to blur.
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    Example-based Road Network Synthesis
    (The Eurographics Association, 2012) Yu, Qizhi; Steed, Anthony; Carlos Andujar and Enrico Puppo
    We present a novel method for automatically synthesizing road networks that are perceptually similar to given example road networks. Our algorithm can grow a new road network from an initial node or expand an existing network. For an unfinished node in the network, we search a set of candidate nodes in the example road networks that have similar node topology, and then find a best one by neighborhood edge matching. Rather than simply copy edges incident to the best matched node, we consider the local constraints including obstacle avoidance and relationships to existing roads. Our results demonstrate that the method produces good results for various typical street patterns. Furthermore, we can blend styles of road networks in an intuitive and easy to control manner.
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    Steady State Stokes Flow Interpolation for Fluid Control
    (The Eurographics Association, 2012) Bhatacharya, Haimasree; Nielsen, Michael B.; Bridson, Robert; Carlos Andujar and Enrico Puppo
    Fluid control methods often require surface velocities interpolated throughout the interior of a shape to use the velocity as a feedback force or as a boundary condition. Prior methods for interpolation in computer graphics velocity extrapolation in the normal direction and potential flow suffer from a common problem. They fail to capture the rotational components of the velocity field, although extrapolation in the normal direction does consider the tangential component. We address this problem by casting the interpolation as a steady state Stokes flow. This type of flow captures the rotational components and is suitable for controlling liquid animations where tangential motion is pronounced, such as in a breaking wave.
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    FTLE Computation Beyond First-Order Approximation
    (The Eurographics Association, 2012) Üffinger, Markus; Sadlo, Filip; Kirby, Mike; Hansen, Charles; Ertl, Thomas; Carlos Andujar and Enrico Puppo
    We present a framework for different approaches to finite-time Lyapunov exponent (FTLE) computation for 2D vector fields, based on the advection of seeding circles. On the one hand it unifies the popular flow map approach with techniques based on the evaluation of distinguished trajectories, such as renormalization. On the other hand it allows for the exploration of their order of approximation (first-order approximation representing the flow map gradient). Using this framework, we derive a measure for nonlinearity of the flow map, that brings us to the definition of a new FTLE approach. We also show how the nonlinearity measure can be used as a criterion for flow map refinement for more accurate FTLE computation, and we demonstrate that ridge extraction in supersampled FTLE leads to superior ridge quality.
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    Solid-state Culled Discrete Element Granular Systems
    (The Eurographics Association, 2012) Holladay, Seth R.; Egbert, Parris; Carlos Andujar and Enrico Puppo
    Dry granular materials are common in computer animations, such as when a character drags a finger through sand or grabs a handful of wheat. However, simulating hundreds of thousands to millions of interacting particulates can take several minutes per frame or longer. More efficient granular material algorithms compromise visual accuracy due to granules complex behavior and detail. To shorten simulation times without sacrificing visual fidelity, we simulate individual granules close to the material s surface and use implicit surfaces and constructive solid geometry boolean functions to cull away solid-state granules beneath the surface and only replace them where the simulation requires. This surface dynamically updates in response to collisions or exposure from the surface granules. Our technique selectively removes the majority of granules for significant speedups, while staying flexible enough to cull out and repopulate granules to respond to multiple external forces.
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    Image-based Animation of Clothes
    (The Eurographics Association, 2012) Hilsmann, Anna; Eisert, Peter; Carlos Andujar and Enrico Puppo
    We propose a pose-dependent image-based rendering approach for the visualization of clothes with very high rendering quality. Our representation combines body-pose-dependent geometry and appearance. A geometric model accounts for low-resolution shape adaptation, e.g. animation and view interpolation, while small details as well as complex shading/reflection properties are accounted for through numerous images. Information on shading, texture distortion and silhouette at fine wrinkles are extracted from the images to allow later texture replacement. The image-based representations are estimated in advance from real samples of clothes captured in an offline process, thus shifting computational complexity into the training phase. For rendering, pose dependent geometry and appearance are interpolated and merged from the stored representations.
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    Fast Response and Quick Progressive Transitions using Body Part Motion Graphs
    (The Eurographics Association, 2012) Fernández-Baena, Adso; Miralles, David; Carlos Andujar and Enrico Puppo
    Interactive applications where 3D character animation plays an important role need avatars ready to perform different activities. This objective has been accomplished in different works [LCR*02] [ZS09] that look for transition points in motion capture clips to allow transitions between them. These works ensure realism and smoothness but their responses and transition durations depend on transition points. Working with partial motions, such as body part motions, allows finding specific transition points for each part in order to optimize whole body transitions in a progressive way. This can be achieved with body part motion graphs (BPMG’s) [FBM11]. In this work we want to show that progressive transitions generated by BPMG’s have fast response and quick execution. In order to demonstrate this we have compared BPMG’s transitions against standard motion graphs (SMG) transitions. The results we have obtained show that our method allows more reaction velocity and execution. Moreover BPMG’s transitions are smoother than SMG transitions.
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    Improved Obstacle Relevancy, Distance, and Angle for Crowds Constrained to Arbitrary Manifolds in 3D Space
    (The Eurographics Association, 2012) Ricks, Brian C.; Egbert, Parris K.; Carlos Andujar and Enrico Puppo
    Recent work has proposed crowd simulation algorithms on arbitrary manifolds in 3D space. These algorithms simulate crowds on far more realistic surfaces than previously possible, including multi-story structures, science fiction scenarios, and habitats for insects and other animals that can walk on walls. However, current implementations can have distinct artifacts, including collision false positives and false negatives. Also, current implementations fail to account for the cylindrical shape of the characters being simulated. The resulting crowds move unnaturally and have obvious collisions. After identifying the cause of these artifacts, we propose an algorithm that does not struggle from these false positives or false negatives and correctly accounts for the non-spherical shape of agents. The resulting crowds move on large surfaces (over 100k triangles) running with a thousand agents in real-time.
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    Automatic Line Handles for Freeform Deformation
    (The Eurographics Association, 2012) Schemali, Leïla; Thiery, Jean-Marc; Boubekeur, Tamy; Carlos Andujar and Enrico Puppo
    Interactive freeform surface deformation methods allow to explore the space of possible shapes using simple control structures. While recent advances in variational editing provide high quality deformations, designing control structures remains a time-consuming manual process. We propose a new automatic control structure generation based on the observation that the most salient visual structures of a surface, such as the one exploited in Line Drawing methods, are tightly linked to the potential deformations it may undergo. Our basic idea is to build control structures from those lines in order to provide users with an automatic set of deformation handles to grab and manipulate, avoiding the tedious task of region selection and handle positioning. The resulting interface inherits view-dependency and adaptivity from line definitions, reduces significantly the modeling session time in a number of scenarii, and remains fully compatible with classical handle-based deformations.
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    GPU based ARAP Deformation using Volumetric Lattices
    (The Eurographics Association, 2012) Zollhöfer, Michael; Sert, Ezgi; Greiner, Günther; Süßmuth, Jochen; Carlos Andujar and Enrico Puppo
    We present a novel lattice based direct manipulation paradigm (LARAP) for mesh editing that decouples the runtime complexity from the mesh’s geometric complexity. Since our non-linear optimization is based on the ARAP paradigm, it is very fast and can be easily implemented. Our proxy geometry automatically introduces volumeawareness into the optimization problem, leading to more natural deformations. Since we compute how the space surrounding an object has to be deformed to satisfy a set of user-constraints, we can even handle models with disconnected parts. We analyze the bottlenecks of the presented approach and propose a data-parallel multiresolution implementation on the GPU, which allows to pose even high-quality meshes consisting of millions of triangles in real-time.
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    Physically-Based Depth of Field in Augmented Reality
    (The Eurographics Association, 2012) Kán, Peter; Kaufmann, Hannes; Carlos Andujar and Enrico Puppo
    We present a novel method for rendering and compositing video in augmented reality. We focus on calculating the physically correct result of the depth of field caused by a lens with finite sized aperture. In order to correctly simulate light transport, ray-tracing is used and in a single pass combined with differential rendering to compose the final augmented video. The image is fully rendered on GPUs, therefore an augmented video can be produced at interactive frame rates in high quality. Our method runs on the fly, no video postprocessing is needed. In addition we evaluated the user experiences with our rendering system with the hypothesis that a depth of field effect in augmented reality increases the realistic look of composited video. Results with 30 users show that 90% perceive videos with a depth of field considerably more realistic.
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    Real-Time Metaball Ray Casting with Fragment Lists
    (The Eurographics Association, 2012) Szécsi, László; Illés, Dávid; Carlos Andujar and Enrico Puppo
    In this paper we describe a method for rendering particle-based medium representations. The algorithm builds per-pixel lists of relevant metaballs, then incrementally constructs a piecewise polynomial approximation of summed metaball densities along rays, and finds intersections with the isosurface using those. This new approach scales well for a high number of particles, it can handle local extremities of depth complexity robustly, and it does not suffer from the inaccuracies and limitations of screen-space filtering approximation methods.
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    Hyperplane Culling for Stochastic Rasterization
    (The Eurographics Association, 2012) Munkberg, Jacob; Akenine-Möller, Tomas; Carlos Andujar and Enrico Puppo
    We present two novel culling tests for rasterization of simultaneous depth of field and motion blur. These tests efficiently reduce the set of xyuvt samples that need to be coverage tested within a screen space tile. The first test finds linear bounds in ut- and vt-space using a separating line algorithm. We also derive a hyperplane in xyuvtspace for each triangle edge, and all samples outside of these planes are culled in our second test. Based on these tests, we present an efficient stochastic rasterizer, which has substantially higher sample test efficiency and lower arithmetic cost than previous tile-based stochastic rasterizers.
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    Incoherent Ray Tracing without Acceleration Structures
    (The Eurographics Association, 2012) Áfra, Attila T.; Carlos Andujar and Enrico Puppo
    Recently, a new family of dynamic ray tracing algorithms, called divide-and-conquer ray tracing, has been introduced. This approach partitions the primitives on-the-fly during ray traversal, which eliminates the need for an acceleration structure. We present a new ray traversal method based on this principle, which efficiently handles incoherent rays, and takes advantage of the SSE and AVX instruction sets of the CPU. Our algorithm offers notable performance improvements over similar existing solutions, and it is competitive with powerful static ray tracers.
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    S-buffer: Sparsity-aware Multi-fragment Rendering
    (The Eurographics Association, 2012) Vasilakis, Andreas A.; Fudos, Ioannis; Carlos Andujar and Enrico Puppo
    This work introduces S-buffer, an efficient and memory-friendly gpu-accelerated A-buffer architecture for multifragment rendering. Memory is organized into variable contiguous regions for each pixel, thus avoiding limitations set in linked-lists and fixed-array techniques. S-buffer exploits fragment distribution for precise allocation of the needed storage and pixel sparsity (empty pixel ratio) for computing the memory offsets for each pixel in a parallel fashion. An experimental comparative evaluation of our technique over previous multi-fragment rendering approaches in terms of memory and performance is provided.