Issue 3

Permanent URI for this collection

https://diglib7.eg.org/handle/10.2312/91
EG 1999 Conference Proceedings

BibTeX (Issue 3)
                
@article{
10.1111:1467-8659.00319,

journal = {Computer Graphics Forum},
title = {{
The Digital Michelangelo Project}},

author = {
Levoy, Marc A.
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00319}

}
                
@article{
10.1111:1467-8659.00328,

journal = {Computer Graphics Forum},
title = {{
Multi-layered impostors for accelerated rendering}},

author = {
Decoret, Xavier
 and 
Sillion, Francois
 and 
Schaufler, Gernot
 and 
Dorsey, Julie
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00328}

}
                
@article{
10.1111:1467-8659.00329,

journal = {Computer Graphics Forum},
title = {{
Interactive Multiresolution Editing of Arbitrary Meshes}},

author = {
Lee, Seungyong
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00329}

}
                
@article{
10.1111:1467-8659.00330,

journal = {Computer Graphics Forum},
title = {{
Generalized View-Dependent Simplification}},

author = {
El-Sana, Jihad
 and 
Varshney, Amitabh
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00330}

}
                
@article{
10.1111:1467-8659.00331,

journal = {Computer Graphics Forum},
title = {{
An Information Theory Framework for the Analysis of Scene Complexity}},

author = {
Feixas, Miquel
 and 
Del Acebo, Esteve
 and 
Bekaert, Philippe
 and 
Sbert, Mateu
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00331}

}
                
@article{
10.1111:1467-8659.00332,

journal = {Computer Graphics Forum},
title = {{
A Free Form Feature Taxonomy}},

author = {
Fontana, M.
 and 
Giannini, F.
 and 
Meirana, M.
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00332}

}
                
@article{
10.1111:1467-8659.00343,

journal = {Computer Graphics Forum},
title = {{
A Practical Analysis of Clustering Strategies for Hierarchical Radiosity (Supplementary material)}},

author = {
Hasenfratz, Jean-Marc
 and 
Damez, Cyrille
 and 
Sillion, Francois
 and 
Drettakis, George
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00343}

}
                
@article{
10.1111:1467-8659.00334,

journal = {Computer Graphics Forum},
title = {{
Improved Laplacian Smoothing of Noisy Surface Meshes}},

author = {
Vollmer, J.
 and 
Mencl, R.
 and 
Muller, H.
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00334}

}
                
@article{
10.1111:1467-8659.00333,

journal = {Computer Graphics Forum},
title = {{
A Shrink Wrapping Approach to Remeshing Polygonal Surfaces}},

author = {
Kobbelt, Leif P.
 and 
Vorsatz, Jens
 and 
Labsik, Ulf and
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00333}

}
                
@article{
10.1111:1467-8659.00335,

journal = {Computer Graphics Forum},
title = {{
An Adaptive Method for Area Light Sources and Daylight in Ray Tracing}},

author = {
Zaninetti, Jacques
 and 
Boy, Pierre
 and 
Peroche, Bernard
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00335}

}
                
@article{
10.1111:1467-8659.00336,

journal = {Computer Graphics Forum},
title = {{
Adaptive Acquisition of Lumigraphs from Synthetic Scenes}},

author = {
Schirmacher, Hartmut
 and 
Heidrich,  Wolfgang
 and 
Seidel, Hans-Peter
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00336}

}
                
@article{
10.1111:1467-8659.00320,

journal = {Computer Graphics Forum},
title = {{
Perceptual Principles and Computer Graphics}},

author = {
May, Jon
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00320}

}
                
@article{
10.1111:1467-8659.00338,

journal = {Computer Graphics Forum},
title = {{
Capturing and Re-Using Rendition Styles for Non-Photorealistic Rendering}},

author = {
Hamel, J.
 and 
Strothotte, T.
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00338}

}
                
@article{
10.1111:1467-8659.00337,

journal = {Computer Graphics Forum},
title = {{
Compact Metallic Reflectance Models}},

author = {
Neumann, Laszlo
 and 
Neumannn, Attila
 and 
Szirmay-Kalos, Laszlo
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00337}

}
                
@article{
10.1111:1467-8659.00339,

journal = {Computer Graphics Forum},
title = {{
An Interactive Designing System with Virtual Sculpting and Virtual Woodcut Printing}},

author = {
Mizunoy, S.
 and 
Okadayy, M.
 and 
Toriwakiy, J.
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00339}

}
                
@article{
10.1111:1467-8659.00341,

journal = {Computer Graphics Forum},
title = {{
Weighted Multipass Methods for Global Illumination}},

author = {
Suykens, Frank
 and 
Willems, Yves D.
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00341}

}
                
@article{
10.1111:1467-8659.00340,

journal = {Computer Graphics Forum},
title = {{
Computer-Generated Graphite Pencil Rendering of 3D Polygonal Models}},

author = {
Sousa, Mario Costa
 and 
Buchanan, John W.
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00340}

}
                
@article{
10.1111:1467-8659.00342,

journal = {Computer Graphics Forum},
title = {{
A Practical Analysis of Clustering Strategies for Hierarchical Radiosity}},

author = {
Hasenfratz, Jean-Marc
 and 
Damez, Cyrille
 and 
Sillion, Francois
 and 
Drettakis, George
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00342}

}
                
@article{
10.1111:1467-8659.00344,

journal = {Computer Graphics Forum},
title = {{
Stochastic Iteration for Non-diffuse Global Illumination}},

author = {
Szirmay-Kalos, Laszlo
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00344}

}
                
@article{
10.1111:1467-8659.00345,

journal = {Computer Graphics Forum},
title = {{
Texturing 3D Models of Real World Objects from Multiple Unregistered Photographic Views}},

author = {
Neugebauer, Peter J.
 and 
Klein, Konrad
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00345}

}
                
@article{
10.1111:1467-8659.00346,

journal = {Computer Graphics Forum},
title = {{
Virtual Dunhuang Art Cave: A Cave within a CAVE}},

author = {
Lutz, B.
 and 
Weintke, M.
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00346}

}
                
@article{
10.1111:1467-8659.00347,

journal = {Computer Graphics Forum},
title = {{
A New Method of Image Mosaicking and Its Application to Cultural Heritage Representation}},

author = {
Cortelazzo, G.M.
 and 
Lucchese, L.
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00347}

}
                
@article{
10.1111:1467-8659.00321,

journal = {Computer Graphics Forum},
title = {{
Active Storytelling}},

author = {
Glassner, Andrew
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00321}

}
                
@article{
10.1111:1467-8659.00348,

journal = {Computer Graphics Forum},
title = {{
A Translucent Sketchpad for the Virtual Table Exploring Motion-based Gesture Recognition}},

author = {
Encarnacao, L. M.
 and 
Bimber, O.
 and 
Schmalstieg, D.
 and 
Chandler, S. D.
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00348}

}
                
@article{
10.1111:1467-8659.00349,

journal = {Computer Graphics Forum},
title = {{
Interactive Mechanical Design Variation for Haptics and CAD}},

author = {
Nelson, Donald D.
 and 
Cohen, Elaine
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00349}

}
                
@article{
10.1111:1467-8659.00350,

journal = {Computer Graphics Forum},
title = {{
The Hybrid World of Virtual Environments}},

author = {
Smith, Shamus
 and 
Duke, David
 and 
Massink, Mieke
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00350}

}
                
@article{
10.1111:1467-8659.00352,

journal = {Computer Graphics Forum},
title = {{
Partitioning and Handling Massive Models for Interactive Collision Detection}},

author = {
Wilson, A.
 and 
Larsen, E.
 and 
Manocha, D.
 and 
Lin, M. C.
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00352}

}
                
@article{
10.1111:1467-8659.00351,

journal = {Computer Graphics Forum},
title = {{
An Informed Environment Dedicated to the Simulation of Virtual Humans in Urban Context}},

author = {
Farenc, Nathalie
 and 
Boulic, Ronan
 and 
Thalmann, Daniel
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00351}

}
                
@article{
10.1111:1467-8659.00354,

journal = {Computer Graphics Forum},
title = {{
Image Morphing with Feature Preserving Texture}},

author = {
Tal, Ayellet
 and 
Elber, Gershon
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00354}

}
                
@article{
10.1111:1467-8659.00353,

journal = {Computer Graphics Forum},
title = {{
Seamless Integration of Databases in VR for Constructing Virtual Environments}},

author = {
Soetebier, Ingo
 and 
Dorner, Ralf
 and 
Braun, Norbert
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00353}

}
                
@article{
10.1111:1467-8659.00357,

journal = {Computer Graphics Forum},
title = {{
Fast Polyhedral Cell Sorting for Interactive Rendering of Unstructured Grids}},

author = {
Comba, Joao
 and 
Klosowsk, James T.
 and 
Max, Nelson
 and 
Mitchell, Joseph S. B.
 and 
Silva, Claudio T.
 and 
Williams, Peter L.
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00357}

}
                
@article{
10.1111:1467-8659.00355,

journal = {Computer Graphics Forum},
title = {{
Efficient and Handy Texture Mapping on 3D Surfaces}},

author = {
Matsushita, Kenji
 and 
Kaneko, Toyohisa
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00355}

}
                
@article{
10.1111:1467-8659.00356,

journal = {Computer Graphics Forum},
title = {{
Data Intermixing and Multi-volume Rendering}},

author = {
Cai, Wenli
 and 
Sakas, Georgios
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00356}

}
                
@article{
10.1111:1467-8659.00322,

journal = {Computer Graphics Forum},
title = {{
Interactive Line Art Rendering of Freeform Surfaces}},

author = {
Elber, Gershon
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00322}

}
                
@article{
10.1111:1467-8659.00358,

journal = {Computer Graphics Forum},
title = {{
Fast Lines: a Span by Span Method}},

author = {
Boyer, V.
 and 
Bourdin, J.J.
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00358}

}
                
@article{
10.1111:1467-8659.00323,

journal = {Computer Graphics Forum},
title = {{
Comprehensive Halftoning of 3D Scenes}},

author = {
Veryovka, O.
 and 
Buchanan, J.
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00323}

}
                
@article{
10.1111:1467-8659.00325,

journal = {Computer Graphics Forum},
title = {{
Interactive Cuts through 3-Dimensional Soft Tissue}},

author = {
Bielser, Daniel
 and 
Maiwald, Volker A.
 and 
Gross, Markus H.
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00325}

}
                
@article{
10.1111:1467-8659.00324,

journal = {Computer Graphics Forum},
title = {{
An Efficient and Flexible Perception Pipeline for Autonomous Agents}},

author = {
Bordeux, Christophe
 and 
Boulic, Ronan
 and 
Thalmann, Daniel
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00324}

}
                
@article{
10.1111:1467-8659.00359,

journal = {Computer Graphics Forum},
title = {{
An Efficient 2? D rendering and Compositing System}},

author = {
Froumentin, M.
 and 
Willis, P.
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00359}

}
                
@article{
10.1111:1467-8659.00326,

journal = {Computer Graphics Forum},
title = {{
Creating Architectural Models from Images}},

author = {
Liebowitz, David
 and 
Criminisi, Antonio
 and 
Zisserman, Andrew
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00326}

}
                
@article{
10.1111:1467-8659.00327,

journal = {Computer Graphics Forum},
title = {{
Occluder Shadows for Fast Walkthroughs of Urban Environments}},

author = {
Wonka, Peter
 and 
Schmalstieg, Dieter
},
year = {
1999},

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


ISSN = {1467-8659},

DOI = {
10.1111/1467-8659.00327}

}

Browse

Recent Submissions

Now showing 1 - 41 of 41
  • No Thumbnail Available
    Item
    The Digital Michelangelo Project
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Levoy, Marc A.
  • Thumbnail Image
    Item
    Multi-layered impostors for accelerated rendering
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Decoret, Xavier; Sillion, Francois; Schaufler, Gernot; Dorsey, Julie
    This paper describes the successful combination of pre-generated and dynamically updated image-based representations to accelerate the visualization of complex virtual environments. We introduce a new type of impostor, which has the desirable property of limiting de-occlusion errors to a user-specified amount. This impostor, composed of multiple layers of textured meshes, replaces the distant geometry and is much faster to draw. It captures the relevant depth complexity in the model without resorting to a complete sampling of the scene. We show that layers can be dynamically updated during visualization. This guarantees bounded scene complexity in each frame and also exploits temporal coherence to improve image quality when possible. We demonstrate the strengths of this approach in the context of city walkthroughs.
  • No Thumbnail Available
    Item
    Interactive Multiresolution Editing of Arbitrary Meshes
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Lee, Seungyong
    This paper presents a novel approach to multiresolution editing of a triangular mesh. The basic idea is to embed an editing area of a mesh onto a 2D rectangle and interpolate the user-specified editing information over the 2D rectangle. The result of the interpolation is mapped back to the editing area and then used to update the mesh. We adopt harmonic maps for the embedding and multilevel B-splines for the interpolation. The proposed mesh editing technique can handle an arbitrary mesh without any preprocessing such as remeshing. It runs fast enough to support interactive editing and produces intuitive editing results.
  • No Thumbnail Available
    Item
    Generalized View-Dependent Simplification
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) El-Sana, Jihad; Varshney, Amitabh
    We propose a technique for performing view-dependent geometry and topology simplifications for level-of-detail-based renderings of large models. The algorithm proceeds by preprocessing the input dataset into a binary tree, the view-dependence tree of general vertex-pair collapses. A subset of the Delaunay edges is used to limit the number of vertex pairs considered for topology simplification. Dependencies to avoid mesh foldovers in manifold regions of the input object are stored in the view-dependence tree in an implicit fashion. We have observed that this not only reduces the space requirements by a factor of two, it also highly localizes the memory accesses at run time. The view-dependence tree is used at run time to generate the triangles for display. We also propose a cubic-spline-based distance metric that can be used to unify the geometry and topology simplifications by considering the vertex positions and normals in an integrated manner.
  • No Thumbnail Available
    Item
    An Information Theory Framework for the Analysis of Scene Complexity
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Feixas, Miquel; Del Acebo, Esteve; Bekaert, Philippe; Sbert, Mateu
    In this paper we present a new framework for the analysis of scene visibility and radiosity complexity. We introduce a number of complexity measures from information theory quantifying how difficult it is to compute with accuracy the visibility and radiosity in a scene. We define the continuous mutual information as a complexity measure of a scene, independent of whatever discretisation, and discrete mutual information as the complexity of a discretised scene. Mutual information can be understood as the degree of correlation or dependence between all the points or patches of a scene. Thus, low complexity corresponds to low correlation and vice versa. Experiments illustrating that the best mesh of a given scene among a number of alternatives corresponds to the one with the highest discrete mutual information, indicate the feasibility of the approach. Unlike continuous mutual information, which is very cheap to compute, the computation of discrete mutual information can however be quite demanding. We will develop cheap complexity measure estimates and derive practical algorithms from this framework in future work.
  • No Thumbnail Available
    Item
    A Free Form Feature Taxonomy
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Fontana, M.; Giannini, F.; Meirana, M.
    In this paper the notion of free form feature for aesthetic design is presented. The design of industrial products constituted by free form surfaces is done by using CAD systems representing curves and surfaces by means of NURBS functions, which are usually defined by low level entities that are not intuitive and require some knowledge of the mathematical language. Similarly to the feature-based approach adopted by CAD systems for classical mechanical design, a set of high level modelling entities which provides commonly performed shape modifications has been identified. Particularly, the paper suggests a classification of the so-called detail features for an aesthetic and/or functional characterization of predefined free form surfaces. Feature types are formally described by means of an analytical definition of the surface modification through deformation and elimination laws. A topological classification is then given according to the application domain of such laws. A further sub-classification of morphological types is then suggested according to geometric properties of weak convexity and concavity for the resulting modified shape, leading to a taxonomy of simple free form features meaningful for aesthetic design.
  • No Thumbnail Available
    Item
    A Practical Analysis of Clustering Strategies for Hierarchical Radiosity (Supplementary material)
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Hasenfratz, Jean-Marc; Damez, Cyrille; Sillion, Francois; Drettakis, George
  • No Thumbnail Available
    Item
    Improved Laplacian Smoothing of Noisy Surface Meshes
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Vollmer, J.; Mencl, R.; Muller, H.
    This paper presents a technique for smoothing polygonal surface meshes that avoids the well-known problem of deformation and shrinkage caused by many smoothing methods, like e.g. the Laplacian algorithm. The basic idea is to push the vertices of the smoothed mesh back towards their previous locations. This technique can be also used in order to smooth unstructured point sets, by reconstructing a surface mesh to which the smoothing technique is applied. The key observation is that a surface mesh which is not necessarily topologically correct, but which can efficiently be reconstructed, is sufficient for that purpose.
  • No Thumbnail Available
    Item
    A Shrink Wrapping Approach to Remeshing Polygonal Surfaces
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Kobbelt, Leif P.; Vorsatz, Jens; Labsik, Ulf and
    Due to their simplicity and flexibility, polygonal meshes are about to become the standard representation for surface geometry in computer graphics applications. Some algorithms in the context of multiresolution representation and modeling can be performed much more efficiently and robustly if the underlying surface tesselations have the special subdivision connectivity. In this paper, we propose a new algorithm for converting a given unstructured triangle mesh into one having subdivision connectivity. The basic idea is to simulate the shrink wrapping process by adapting the deformable surface technique known from image processing. The resulting algorithm generates subdivision connectivity meshes whose base meshes only have a very small number of triangles. The iterative optimization process that distributes the mesh vertices over the given surface geometry guarantees low local distortion of the triangular faces. We show several examples and applications including the progressive transmission of subdivision surfaces.
  • No Thumbnail Available
    Item
    An Adaptive Method for Area Light Sources and Daylight in Ray Tracing
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Zaninetti, Jacques; Boy, Pierre; Peroche, Bernard
    This paper proposes an adaptive method for taking both (diffuse or not) planar area light sources and daylight into account in a ray tracing environment which separates the calculation of direct and indirect illumination. In a given point, direct illumination due to a light source or to natural light is represented by a vector, the direction and magnitude of which being computed through an adaptive area approach, which is driven by the solid angle according to which a part of the source is seen from the current point. In the case of unoccluded diffuse polygonal sources, an analytical formula is used which gives an exact value for this vector.
  • No Thumbnail Available
    Item
    Adaptive Acquisition of Lumigraphs from Synthetic Scenes
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Schirmacher, Hartmut; Heidrich, Wolfgang; Seidel, Hans-Peter
    Light fields and Lumigraphs are capable of rendering scenes of arbitrary geometrical or illumination complexity in real time. They are thus interesting ways of interacting with both recorded real-world and high-quality synthetic scenes.Unfortunately, both light fields and Lumigraph rely on a dense sampling of the illumination to provide a good rendering quality. This induces high costs both in terms of storage requirements and computational resources for the image acquisition. Techniques for acquiring adaptive light field and Lumigraph representations are thus mandatory for practical applications.In this paper we present a method for the adaptive acquisition of images for Lumigraphs from synthetic scenes. Using image warping to predict the potential improvement in image quality when adding a certain view, we decide which new views of the scene should be rendered and added to the light field. This a-priori error estimator accounts for both visibility problems and illumination effects such as specular highlights.
  • No Thumbnail Available
    Item
    Perceptual Principles and Computer Graphics
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) May, Jon
  • No Thumbnail Available
    Item
    Capturing and Re-Using Rendition Styles for Non-Photorealistic Rendering
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Hamel, J.; Strothotte, T.
    Rendering high-quality non-photorealistic images of a given geometric model is often associated with a considerable amount of effort on the part of a user to fine-tune the rendition. In this paper we introduce a method and tools for re-using the user's effort invested in one model for the rendering of other models.Our method uses templates to describe rendition styles. The paper gives a number of examples of the successful transfer of styles from one model to another.
  • Thumbnail Image
    Item
    Compact Metallic Reflectance Models
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Neumann, Laszlo; Neumannn, Attila; Szirmay-Kalos, Laszlo
    The paper presents simple, physically plausible, but not physically based reflectance models for metals and other specular materials. So far there has been no metallic BRDF model that is easy to compute, suitable for fast importance sampling and is physically plausible. This gap is filled by appropriate modifications of the Phong, Blinn and the Ward models. The Phong and the Blinn models are known not to have metallic characteristics. On the other hand, this paper also shows that the Cook-Torrance and the Ward models are not physically plausible, because of their behavior at grazing angles. We also compare the previous and the newly proposed models. Finally, the generated images demonstrate how the metallic impression can be provided by the new models.
  • No Thumbnail Available
    Item
    An Interactive Designing System with Virtual Sculpting and Virtual Woodcut Printing
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Mizunoy, S.; Okadayy, M.; Toriwakiy, J.
    In this paper, we propose an interactive designing method and a system based on it to create 3D objects and 2D images. This system consists of two subsystems for virtual sculpting to create a 3D shape and virtual printing to produce a picture with a printing block. In the virtual sculpting subsystem, a user can form solid objects with curved surfaces as if sculpting them. The user operates virtual chisels, and can remove or attach arbitrary shapes of ellipsoids or cubes from or to the workpiece. A 3D object generated by virtual sculpting looks like a real wooden sculpture. If using a board as a workpiece, a user can generate a virtual printing block. In the virtual printing subsystem, a user can synthesize a woodcut printing image from the virtual printing block mentioned above, a virtual paper sheet, and a printing brush. The user can synthesize a realistic woodcut print with a procedure similar to the actual woodcut printing.
  • No Thumbnail Available
    Item
    Weighted Multipass Methods for Global Illumination
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Suykens, Frank; Willems, Yves D.
    In multipass rendering, care has to be taken to include all light transport only once in the final solution. Therefore the different methods in current multipass configurations handle a perfectly disjunct part of the light transport. In this paper a Monte Carlo variance reduction technique is presented that probabilistically weights overlapping transport between different methods. A good heuristic for the weights is derived so that strengths of the respective methods are retained. The technique is applied to a combination of radiosity and bidirectional path tracing and significant improvement is obtained over the non-weighted combination. This method promises to be a very useful extension to other multipass algorithms as well.
  • No Thumbnail Available
    Item
    Computer-Generated Graphite Pencil Rendering of 3D Polygonal Models
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Sousa, Mario Costa; Buchanan, John W.
    Researchers in non-photorealistic rendering have investigated the display of three-dimensional worlds using various display models. In particular, recent work has focused on the modeling of traditional artistic media and styles such as pen-and-ink illustration and watercolor painting. By providing 3D rendering systems that use these alternative display models users can generate traditional illustration renderings of their three-dimensional worlds. In this paper we present our graphite pencil 3D renderer. We have broken the problem of simulating pencil drawing down into four fundamental parts: (1) simulating the drawing materials (graphite pencil and drawing paper, blenders and kneaded eraser), (2) modeling the drawing primitives (individual pencil strokes and mark-making to create tones and textures), (3) simulating the basic rendering techniques used by artists and illustrators familiar with pencil rendering, and (4) modeling the control of the drawing composition. Each part builds upon the others and is essential to developing the framework for higher-level rendering methods and tools. In this paper we present parts 2, 3, and 4 of our research. We present non-photorealistic graphite pencil rendering methods for outlining and shading. We also present the control of drawing steps from preparatory sketches to finished rendering results. We demonstrate the capabilities of our approach with a variety of images generated from 3D models.
  • No Thumbnail Available
    Item
    A Practical Analysis of Clustering Strategies for Hierarchical Radiosity
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Hasenfratz, Jean-Marc; Damez, Cyrille; Sillion, Francois; Drettakis, George
    The calculation of radiant energy balance in complex scenes has been made possible by hierarchical radiosity methods based on clustering mechanisms. Although clustering offers an elegant theoretical solution by reducing the asymptotic complexity of the algorithm, its practical use raises many difficulties, and may result in image artifacts or unexpected behavior. This paper proposes a detailed analysis of the expectations placed on clustering and compares the relative merits of existing, as well as newly introduced, clustering algorithms. This comparison starts from the precise definition of various clustering strategies based on a taxonomy of data structures and construction algorithms, and proceeds to an experimental study of the clustering behavior for real-world scenes. Interestingly, we observe that for some scenes light is difficult to simulate even with clustering. Our results lead to a series of observations characterizing the adequacy of clustering methods for meeting such diverse goals as progressive solution improvement, efficient ray casting acceleration, and faithful representation of object density for approximate visibility calculations.
  • Thumbnail Image
    Item
    Stochastic Iteration for Non-diffuse Global Illumination
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Szirmay-Kalos, Laszlo
    This paper presents a single-pass, view-dependent method to solve the rendering equation, using a stochastic iterational scheme where the transport operator is selected randomly in each iteration. The requirements of convergence are given for the general case. To demonstrate the basic idea, a very simple,continuous random transport operator is examined, which gives back the light tracing algorithm incorporating Russian roulette. Then, a new mixed continuous and finite-element based iteration method is proposed, which uses ray-bundles to transfer the radiance in a single random direction. The resulting algorithm is fast, it provides initial results in seconds and accurate solutions in minutes and does not suffer from the error accumulation problem and the high memory demand of other finite-element and hierarchical approaches.
  • No Thumbnail Available
    Item
    Texturing 3D Models of Real World Objects from Multiple Unregistered Photographic Views
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Neugebauer, Peter J.; Klein, Konrad
    As the efficiency of computer graphic rendering methods is increasing, generating realistic models is now becoming a limiting factor. In this paper we present a new technique to enhance already existing geometry models of real world objects with textures reconstructed from a sparse set of unregistered still photographs. The aim of the proposed technique is the generation of nearly photo-realistic models of arbitrarily shaped objects with minimal effort. In our approach, we require neither a prior calibration of the camera nor a high precision of the user's interaction. Two main problems have to be addressed of which the first is the recovery of the unknown positions and parameters of the camera. An initial estimate of the orientation is calculated from interactively selected point correspondences. Subsequently, the unknown parameters are accurately calculated by minimising a blend of objective functions in a 3D-2D projective registration approach. The key point of the proposed method of registration is a novel filtering approach which utilises the spatial information provided by the geometry model. Second, the individual images have to be combined yielding a set of consistent texture maps. We present a robust method to recover the texture from the photographs thereby preserving high spatial frequencies and eliminating artifacts, particularly specular highlights. Parts of the object not seen in any of the photographs are interpolated in the textured model. Results are shown for three complex example objects with different materials and numerous self-occlusions.
  • No Thumbnail Available
    Item
    Virtual Dunhuang Art Cave: A Cave within a CAVE
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Lutz, B.; Weintke, M.
    Virtual Reality can present historical places in a three-dimensional and interactive way, giving visitors a photorealistic impression of objects. Not only existing scenarios can be shown, but VR can also be used to rebuild scenarios that were damaged or destroyed a long time ago, giving new life to the cultural heritage. We used Virtual Reality to present the Mogao Grottos in Dunhuang. This cave site is one of the most important cultural and religious places by the ancient Silk Road. The presentation is to give visitors the impression of visiting the cave site and provide information about the caves, paintings and statues in an interesting way. To achieve this, we developed a new, intuitive interaction paradigm, which enables the user to explore the caves. To give observers a photorealistic impression of the caves and to create a feeling of immersion, innovative rendering techniques were integrated.The resulting presentation combines Virtual Reality and archaeology to give tourists a realistic experience of this cave site and to support scientists in their research work.
  • No Thumbnail Available
    Item
    A New Method of Image Mosaicking and Its Application to Cultural Heritage Representation
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Cortelazzo, G.M.; Lucchese, L.
    This paper presents an original two-step procedure for estimating projective transformations between pairs of images: first, the transformation between the images is approximated as an affine transformation; second, this estimate is refined into that of a projective transformation. This strategy for matching projective views is computationally very efficient. The proposed method can be applied both to mosaicking of high resolution images of planar textured objects (e.g., frescoes and paintings), with subpixel accuracy, and to construction of panoramic images. Practical examples of mosaicking of cultural heritage imagery obtained by using the presented procedure are discussed in the paper.
  • No Thumbnail Available
    Item
    Active Storytelling
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Glassner, Andrew
  • No Thumbnail Available
    Item
    A Translucent Sketchpad for the Virtual Table Exploring Motion-based Gesture Recognition
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Encarnacao, L. M.; Bimber, O.; Schmalstieg, D.; Chandler, S. D.
    The Virtual Table presents stereoscopic graphics to a user in a workbench-like setting. For this device, a user interface and new interaction techniques have been developed based on transparent props -a tracked hand-held pen and a pad. These props, particularly the pad, are augmented with 3D graphics from the Virtual Table's display that can serve as a palette for tools and controls as well as a window-like see-through interface, a plane-shaped and through-the-plane tool, supporting a variety of new interaction techniques. This paper reports on an extension of this user-interface design space which uses gestural input to create and control solid geometries for CAD and conceptual design. The application of gestural interfaces is a common method for interacting with virtual environments on a habitual and natural basis. The motion-based gesture recognition presented here uses Fuzzy Logic to support a predictable, flexible, and efficient learning process. This new interaction paradigm greatly increases the Virtual Table's suitability for design tasks. Traditional CAD dialogue can be combined with intuitive rapid sketching of geometry on the pad. Additionally, the resulting events and objects can be associated with scene details below the translucent tablet.
  • No Thumbnail Available
    Item
    Interactive Mechanical Design Variation for Haptics and CAD
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Nelson, Donald D.; Cohen, Elaine
    A fast design variation technique for mechanical systems is presented. It is used to interactively optimize mechanical characteristics while "self-assembling" or satisfying large systems of mechanical constraints. The high speed method is central to providing inverse dynamics force feedback in haptics and control applications. Performance advantages with the use of augmented coordinates for inverse dynamics of closed loop topologies are also noted. The interaction framework allows manipulation of complex assemblies while maintaining kinematically admissible configurations though linkage and joint limit constraints. Furthermore, design variables such as link length can be treated as free variables and optimized to meet design criteria such as assembly dexterity. Assemblies with flexible bodies fit naturally within this framework. Thus, the contribution of this paper is the advancement of techniques in augmented coordinates for the kinematic and force feedback interaction with virtual mechanical assembly design optimization at force control rates.
  • No Thumbnail Available
    Item
    The Hybrid World of Virtual Environments
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Smith, Shamus; Duke, David; Massink, Mieke
    Much of the work concerned with virtual environments has addressed the development of new rendering technologies or interaction techniques. As the technology matures and becomes adopted in a wider range of applications, there is, however, a need to better understand how this technology can be accommodated in software engineering practice. A particular challenge presented by virtual environments is the complexity of the interaction that is supported, and sometimes necessary, for a particular task. Methods such as finite-state automata which are used to represent and design dialogue components for more conventional interfaces, e.g. using direct manipulation within a desktop model, do not seem to capture adequately the style of interaction that is afforded by richer input devices and graphical models. In this paper, we suggest that virtual environments are, fundamentally, what are known as hybrid systems. Building on this insight, we demonstrate how techniques developed for modelling hybrid systems can be used to represent and understand virtual interaction in a way that can be used in the specification and design phases of software development, and which have the potential to support prototyping and analysis of virtual interfaces.
  • No Thumbnail Available
    Item
    Partitioning and Handling Massive Models for Interactive Collision Detection
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Wilson, A.; Larsen, E.; Manocha, D.; Lin, M. C.
    We describe an approach for interactive collision detection and proximity computations on massive models composed of millions of geometric primitives. We address issues related to interactive data access and processing in a large geometric database, which may not fit into main memory of typical desktop workstations or computers. We present a new algorithm using overlap graphs for localizing the "regions of interest" within a massive model, thereby reducing runtime memory requirements. The overlap graph is computed off-line, pre-processed using graph partitioning algorithms, and modified on the fly as needed. At run time, we traverse localized sub-graphs to check the corresponding geometry for proximity and pre-fetch geometry and auxiliary data structures. To perform interactive proximity queries, we use bounding-volume hierarchies and take advantage of spatial and temporal coherence. Based on the proposed algorithms, we have developed a system called IMMPACT and used it for interaction with a CAD model of a power plant consisting of over 15 million triangles. We are able to perform a number of proximity queries in real-time on such a model. In terms of model complexity and application to large models, we have improved the performance of interactive collision detection and proximity computation algorithms by an order of magnitude.
  • No Thumbnail Available
    Item
    An Informed Environment Dedicated to the Simulation of Virtual Humans in Urban Context
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Farenc, Nathalie; Boulic, Ronan; Thalmann, Daniel
    In this paper, we outline the creation of an Informed Environment, dedicated to urban life simulation.We propose methods and tools for creating and providing the information necessary for animating virtual humans in a city using an Informed Environment. The Informed Environment is based on a hierarchical decomposition of a urban scene into Environment Entities providing geometrical information as well as semantic notions, thus allowing a more realistic simulation of human behaviour. In this manner, virtual humans can integrate with a certain kind of urban knowledge.
  • No Thumbnail Available
    Item
    Image Morphing with Feature Preserving Texture
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Tal, Ayellet; Elber, Gershon
    Image metamorphosis as an animation tool has mostly been employed in the context of the entire image. This work explores the use of isolated and focused image based metamorphosis between two-dimensional objects, while capturing the features, colors, and textures of the objects. This pinpointed approach allows one to independently overlay several such dynamic shapes, without any bleeding of one shape into another. Hence, shape blending and metamorphosis of two-dimensional objects can be exploited as animated sequences of clip arts.
  • No Thumbnail Available
    Item
    Seamless Integration of Databases in VR for Constructing Virtual Environments
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Soetebier, Ingo; Dorner, Ralf; Braun, Norbert
    An approach for authoring virtual environments within the virtual environments themselves is presented, integrating a database containing arbitrary components that are used to construct the 3D scene. The issues important to a seamless integration of the database, such as multimedia data storage and database linkage are discussed, with the focus on the human-computer interaction component. A concept for a 3D database interface is described for query, presentation and usage of query results in the virtual environment. Finally, an implementation of the concept using VRML and Java is presented.
  • No Thumbnail Available
    Item
    Fast Polyhedral Cell Sorting for Interactive Rendering of Unstructured Grids
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Comba, Joao; Klosowsk, James T.; Max, Nelson; Mitchell, Joseph S. B.; Silva, Claudio T.; Williams, Peter L.
    Direct volume rendering based on projective methods works by projecting, in visibility order, the polyhedral cells of a mesh onto the image plane, and incrementally compositing the cell's color and opacity into the final image. Crucial to this method is the computation of a visibility ordering of the cells. If the mesh is "well-behaved" (acyclic and convex), then the MPVO method of Williams provides a very fast sorting algorithm; however, this method only computes an approximate ordering in general datasets, resulting in visual artifacts when rendered. A recent method of Silva et al. removed the assumption that the mesh is convex, by means of a sweep algorithm used in conjunction with the MPVO method; their algorithm is substantially faster than previous exact methods for general meshes.In this paper we propose a new technique, which we call BSP-XMPVO, which is based on a fast and simple way of using binary space partitions on the boundary elements of the mesh to augment the ordering produced by MPVO. Our results are shown to be orders of magnitude better than previous exact methods of sorting cells.
  • No Thumbnail Available
    Item
    Efficient and Handy Texture Mapping on 3D Surfaces
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Matsushita, Kenji; Kaneko, Toyohisa
    There has been a rapid technical progress in three-dimensional (3D) computer graphics. But gathering surface and texture data is yet a laborious task. This paper addresses the problem of mapping photographic images on the surface of a 3D object whose geometric data are already known. We propose an efficient and handy method for acquiring textures and mapping them precisely on the surface, employing a digital camera alone. We describe an algorithm for selecting a minimal number of camera positions that can cover the entire surface of a given object and also an algorithm to determine camera's position and direction for each photograph taken so as to paste it to the corresponding surfaces precisely. We obtained a matching accuracy within a pixel on a surface through three experimental examples, by which the practicability of our method is demonstrated.
  • No Thumbnail Available
    Item
    Data Intermixing and Multi-volume Rendering
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Cai, Wenli; Sakas, Georgios
    The main difference between multi-volume rendering and mono-volume rendering is data intermixing. In this paper, we present three levels of data intermixing and their rendering pipelines in direct multi-volume rendering, which discriminate image level intensity intermixing, accumulation level opacity intermixing, and illumination model level parameter intermixing. In the context of radiotherapy treatment planning, different data intermixing methods are applied to three volumes, including CT volume, Dose volume, and Segmentation volume, to compare the features of different data intermixing methods.
  • No Thumbnail Available
    Item
    Interactive Line Art Rendering of Freeform Surfaces
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Elber, Gershon
    In recent years, synthetically created line art renderings have reached quality levels that are aesthetically pleasing. Moreover, the sketch based approach was found to be quite capable at conveying geometrical information in an intuitive manner. While a growing interest in this type of rendering method has yielded successful and appealing results, the developed techniques were, for the most part, too slow to be embedded in real time interactive display. This paper presents a line art rendering method for freeform polynomial and rational surfaces that is capable of achieving real time and interactive display. A careful preprocessing stage that combines an a-priori construction of line art strokes with proper classification of these strokes, allows one to significantly alleviate the computational cost, in real time, of the sketch based rendering, and enables interactive line art display.
  • No Thumbnail Available
    Item
    Fast Lines: a Span by Span Method
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Boyer, V.; Bourdin, J.J.
    Straight line's scan conversion and drawing is a major field in computer graphics. Algorithm's time computation is very important. Nowadays, most of research papers suggest improvements of the DDA method that was first presented by J. Bresenham. But other approaches exist as well like combinatory analysis and linguistic methods. Both of them use multiple string copies that slow down the efficiency of the algorithms. This paper proposes a new algorithm based on a careful analysis of the line segments' properties some of them previously unused. Our algorithm is proved significantly faster than previously published ones.
  • No Thumbnail Available
    Item
    Comprehensive Halftoning of 3D Scenes
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Veryovka, O.; Buchanan, J.
    The display of images on binary output hardware requires a halftoning step. Conventional halftoning algorithms approximate image values independently from the image content and often introduce artificial texture that obscures fine details. The objective of this research is to adapt a halftoning technique to 3D scene information and thus to enhance the display of computer generated 3D scenes. Our approach is based on the control of halftoning texture by the combination of ordered dithering and error diffusion techniques. We extend our previous work and enable a user to specify the shape, scale, direction, and contrast of the halftoning texture using an external buffer. We control texture shape by constructing a dither matrix from an arbitrary image or a procedural texture. Texture direction and scale are adapted to the external information by the mapping function. Texture contrast and the accuracy of tone reproduction are varied across the image using the error diffusion process. We halftone images of 3D scenes by using the geometry, position, and illumination information to control the halftoning texture. Thus, the texture provides visual cues and can be used to enhance the viewer's comprehension of the display.
  • No Thumbnail Available
    Item
    Interactive Cuts through 3-Dimensional Soft Tissue
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Bielser, Daniel; Maiwald, Volker A.; Gross, Markus H.
    We describe a physically based framework for interactive modeling and cutting of 3-dimensional soft tissue that can be used for surgery simulation. Unlike existing approaches which are mostly designed for tensorproduct grids our methods operate on tetrahedral decompositions giving more topological and geometric flexibility for the efficient modeling of complex anatomical structures. We start from an initial tetrahedralization such as being provided by any conventional meshing method. In order to track topological changes tetrahedra intersected by the virtual scalpel are split into substructures whose connectivity follows the trajectory of the cut, which can be arbitrary. For the efficient computation of collisions between the scalpel and individual tetrahedra we devised a local collision detection algorithm. The underlying physics is approximated through masses and springs attached to each tetrahedral vertex and edge. A hierarchical Runge-Kutta iteration computes the relaxation of the system by traversing the designed data structures in a breadth-first order. The framework includes a force-feedback interface and uses real-time texture mapping to enhance the visual realism.
  • No Thumbnail Available
    Item
    An Efficient and Flexible Perception Pipeline for Autonomous Agents
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Bordeux, Christophe; Boulic, Ronan; Thalmann, Daniel
    Agents in virtual environments require a combination of perception and action to behave in an autonomous way. We extend a software architecture for the management of actions blending, called AGENTlib, with a perception mechanism. The perception system provides a uniform interface to various techniques in the field of virtual perception, including synthetic vision, database access and perception persistency. We describe the framework we designed to efficiently filter valuable information from the scene and we address concerns about computation redundancy and data propagation through multiple filtering modules.
  • No Thumbnail Available
    Item
    An Efficient 2? D rendering and Compositing System
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Froumentin, M.; Willis, P.
    We describe a method for doing image compositing using either 2D geometric shapes or raster images as input primitives. The resolution of the final image is virtually unlimited but, as no frame buffer is used, performance is much less dependant on resolution than with standard painting programs, allowing rendering very large images in reasonable time. Many standard features found in compositing programs have been implemented, like hierarchical data structures for input primitives, lighting control for each layer and filter operations (for antialiasing or defocus).
  • No Thumbnail Available
    Item
    Creating Architectural Models from Images
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Liebowitz, David; Criminisi, Antonio; Zisserman, Andrew
    We present methods for creating 3D graphical models of scenes from a limited numbers of images, i.e. one or two, in situations where no scene co-ordinate measurements are available. The methods employ constraints available from geometric relationships that are common in architectural scenes - such as parallelism and orthogonality - together with constraints available from the camera. In particular, by using the circular points of a plane simple, linear algorithms are given for computing plane rectification, plane orientation and camera calibration from a single image. Examples of image based 3D modelling are given for both single images and image pairs.
  • No Thumbnail Available
    Item
    Occluder Shadows for Fast Walkthroughs of Urban Environments
    (Blackwell Publishers Ltd and the Eurographics Association, 1999) Wonka, Peter; Schmalstieg, Dieter
    This paper describes a new algorithm that employs image-based rendering for fast occlusion culling in complex urban environments. It exploits graphics hardware to render and automatically combine a relatively large set of occluders. The algorithm is fast to calculate and therefore also useful for scenes of moderate complexity and walkthroughs with over 20 frames per second. Occlusion is calculated dynamically and does not rely on any visibility precalculation or occluder preselection. Speed-ups of one order of magnitude can be obtained.