Issue 4

Permanent URI for this collection


An Efficient Method for Rendering Underwater Optical Effects Using Graphics Hardware

Iwasaki, Kei
Dobashi, Yoshinori
Nishita, Tomoyuki

An algorithm for line clipping against a polygon based on shearing transformation

Huang, Y. Q.
Liu, Y. K.

Visualizing Crowds in Real-Time

Tecchia, Franco
Loscos, Celine
Chrysanthou, Yiorgos

Adaptive Zooming in Web Cartography

Cecconi, Alesandro
Galanda, Martin

SVG Linearization and Accessibility

Herman, Ivan
Dardailler, Daniel

Towards Interactive Real-Time Crowd Behavior Simulation

Ulicny, Branislav
Thalmann, Daniel

Siggraph 2002

Laycock, Stephen D.
Laycock, Robert G.

Eurographics 2002

Scheel, Annette

Erratum: Artistic Surface Rendering Using Layout of Text

Surazhsky, Tatiana
Elber, Gershon

Hierarchical Impostors for the Flocking Algorithm in 3D

O'Hara, Noel

Eurographics Spain 11th Conference

Isern, Jordi Regincos

Eurographics Ireland 2002 Workshop

O'Sullivan, Carol

First International Symposium on 3DPVT 2002

Max, Nelson

1st Ibero-American Symposium in Computer Graphics

Marcos, Aderito
Brunet, Pere
Jorge, Joaquim
Regincos, Jordi

13th Eurographics Workshop on Rendering

Debevec, Paul
Gibson, Simon

Eurographics Italy 1st Conference

Bordegoni, Monica

Eurographics 2003 Modelling the Real World


New Eurographics Fellow


Report of the Statutory Auditors to the General Meeting of the Members of Eurographics Association Geneva


23rd Eurographics General Assembly


Join Now!


Author Index Volume 21 (2002)


Editorial

Duke, David
Scopigno, Roberto

Computer Graphics forum


Vortex Tracking and Visualisation in a Flow Past a Tapered Cylinder

Reinders, Freek
Sadarjoen, I. Ari
Vrolijk, Benjamin
Post, Frits H.

Synthetic Vision and Memory for Autonomous Virtual Humans

Peters, C.
O'Sullivan, C.

Levels of Detail for Crowds and Groups

O'Sullivan, C.
Cassell, J.
Vilhjalmsson, H.
Dingliana, J.
Dobbyn, S.
McNamee, B. and Peters, C. and Giang, T.

A Spoken Dialogue System for Navigation in Non-Immersive Virtual Environments

McNeill, M.D.J.
Sayers, H.
Wilson, S.
Mc Kevitt, P.

A Skeleton-based Approach for Detection of Perceptually Salient Features on Polygonal Surfaces

Hisada, Masayuki
Belyaev, Alexander G.
Kunii, Tosiyasu L.

Feature Model Visualization

Bronsvoort, Willem F.
Bidarra, Rafael
Noort, Alex


BibTeX (Issue 4)
                
@article{
10.1111:1467-8659.00628,
journal = {Computer Graphics Forum}, title = {{
An Efficient Method for Rendering Underwater Optical Effects Using Graphics Hardware}},
author = {
Iwasaki, Kei
 and
Dobashi, Yoshinori
 and
Nishita, Tomoyuki
}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00628}
}
                
@article{
10.1111:1467-8659.00626,
journal = {Computer Graphics Forum}, title = {{
An algorithm for line clipping against a polygon based on shearing transformation}},
author = {
Huang, Y. Q.
 and
Liu, Y. K.
}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00626}
}
                
@article{
10.1111:1467-8659.00633,
journal = {Computer Graphics Forum}, title = {{
Visualizing Crowds in Real-Time}},
author = {
Tecchia, Franco
 and
Loscos, Celine
 and
Chrysanthou, Yiorgos
}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00633}
}
                
@article{
10.1111:1467-8659.00636,
journal = {Computer Graphics Forum}, title = {{
Adaptive Zooming in Web Cartography}},
author = {
Cecconi, Alesandro
 and
Galanda, Martin
}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00636}
}
                
@article{
10.1111:1467-8659.00635,
journal = {Computer Graphics Forum}, title = {{
SVG Linearization and Accessibility}},
author = {
Herman, Ivan
 and
Dardailler, Daniel
}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00635}
}
                
@article{
10.1111:1467-8659.00634,
journal = {Computer Graphics Forum}, title = {{
Towards Interactive Real-Time Crowd Behavior Simulation}},
author = {
Ulicny, Branislav
 and
Thalmann, Daniel
}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00634}
}
                
@article{
10.1111:1467-8659.00639,
journal = {Computer Graphics Forum}, title = {{
Siggraph 2002}},
author = {
Laycock, Stephen D.
 and
Laycock, Robert G.
}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00639}
}
                
@article{
10.1111:1467-8659.00638,
journal = {Computer Graphics Forum}, title = {{
Eurographics 2002}},
author = {
Scheel, Annette
}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00638}
}
                
@article{
10.1111:1467-8659.00637,
journal = {Computer Graphics Forum}, title = {{
Erratum: Artistic Surface Rendering Using Layout of Text}},
author = {
Surazhsky, Tatiana
 and
Elber, Gershon
}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00637}
}
                
@article{
10.1111:1467-8659.00630,
journal = {Computer Graphics Forum}, title = {{
Hierarchical Impostors for the Flocking Algorithm in 3D}},
author = {
O'Hara, Noel
}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00630}
}
                
@article{
10.1111:1467-8659.00640,
journal = {Computer Graphics Forum}, title = {{
Eurographics Spain 11th Conference}},
author = {
Isern, Jordi Regincos
}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00640}
}
                
@article{
10.1111:1467-8659.00641,
journal = {Computer Graphics Forum}, title = {{
Eurographics Ireland 2002 Workshop}},
author = {
O'Sullivan, Carol
}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00641}
}
                
@article{
10.1111:1467-8659.00645,
journal = {Computer Graphics Forum}, title = {{
First International Symposium on 3DPVT 2002}},
author = {
Max, Nelson
}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00645}
}
                
@article{
10.1111:1467-8659.00643,
journal = {Computer Graphics Forum}, title = {{
1st Ibero-American Symposium in Computer Graphics}},
author = {
Marcos, Aderito
 and
Brunet, Pere
 and
Jorge, Joaquim
 and
Regincos, Jordi
}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00643}
}
                
@article{
10.1111:1467-8659.00644,
journal = {Computer Graphics Forum}, title = {{
13th Eurographics Workshop on Rendering}},
author = {
Debevec, Paul
 and
Gibson, Simon
}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00644}
}
                
@article{
10.1111:1467-8659.00642,
journal = {Computer Graphics Forum}, title = {{
Eurographics Italy 1st Conference}},
author = {
Bordegoni, Monica
}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00642}
}
                
@article{
10.1111:1467-8659.00646,
journal = {Computer Graphics Forum}, title = {{
Eurographics 2003 Modelling the Real World}},
author = {}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00646}
}
                
@article{
10.1111:1467-8659.00647,
journal = {Computer Graphics Forum}, title = {{
New Eurographics Fellow}},
author = {}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00647}
}
                
@article{
10.1111:1467-8659.00649,
journal = {Computer Graphics Forum}, title = {{
Report of the Statutory Auditors to the General Meeting of the Members of Eurographics Association Geneva}},
author = {}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00649}
}
                
@article{
10.1111:1467-8659.00648,
journal = {Computer Graphics Forum}, title = {{
23rd Eurographics General Assembly}},
author = {}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00648}
}
                
@article{
10.1111:1467-8659.00651,
journal = {Computer Graphics Forum}, title = {{
Join Now!}},
author = {}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00651}
}
                
@article{
10.1111:1467-8659.00650,
journal = {Computer Graphics Forum}, title = {{
Author Index Volume 21 (2002)}},
author = {}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00650}
}
                
@article{
10.1111:1467-8659.00545,
journal = {Computer Graphics Forum}, title = {{
Editorial}},
author = {
Duke, David
 and
Scopigno, Roberto
}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00545}
}
                
@article{
10.1111:1467-8659.00652,
journal = {Computer Graphics Forum}, title = {{
Computer Graphics forum}},
author = {}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00652}
}
                
@article{
10.1111:1467-8659.00625,
journal = {Computer Graphics Forum}, title = {{
Vortex Tracking and Visualisation in a Flow Past a Tapered Cylinder}},
author = {
Reinders, Freek
 and
Sadarjoen, I. Ari
 and
Vrolijk, Benjamin
 and
Post, Frits H.
}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00625}
}
                
@article{
10.1111:1467-8659.00632,
journal = {Computer Graphics Forum}, title = {{
Synthetic Vision and Memory for Autonomous Virtual Humans}},
author = {
Peters, C.
 and
O'Sullivan, C.
}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00632}
}
                
@article{
10.1111:1467-8659.00631,
journal = {Computer Graphics Forum}, title = {{
Levels of Detail for Crowds and Groups}},
author = {
O'Sullivan, C.
 and
Cassell, J.
 and
Vilhjalmsson, H.
 and
Dingliana, J.
 and
Dobbyn, S.
 and
McNamee, B. and Peters, C. and Giang, T.
}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00631}
}
                
@article{
10.1111:1467-8659.00629,
journal = {Computer Graphics Forum}, title = {{
A Spoken Dialogue System for Navigation in Non-Immersive Virtual Environments}},
author = {
McNeill, M.D.J.
 and
Sayers, H.
 and
Wilson, S.
 and
Mc Kevitt, P.
}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00629}
}
                
@article{
10.1111:1467-8659.00627,
journal = {Computer Graphics Forum}, title = {{
A Skeleton-based Approach for Detection of Perceptually Salient Features on Polygonal Surfaces}},
author = {
Hisada, Masayuki
 and
Belyaev, Alexander G.
 and
Kunii, Tosiyasu L.
}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00627}
}
                
@article{
10.1111:1467-8659.00624,
journal = {Computer Graphics Forum}, title = {{
Feature Model Visualization}},
author = {
Bronsvoort, Willem F.
 and
Bidarra, Rafael
 and
Noort, Alex
}, year = {
2002},
publisher = {
Blackwell Publishers, Inc and the Eurographics Association},
ISSN = {1467-8659},
DOI = {
10.1111/1467-8659.00624}
}

Browse

Recent Submissions

Now showing 1 - 30 of 30
  • Item
    An Efficient Method for Rendering Underwater Optical Effects Using Graphics Hardware
    (Blackwell Publishers, Inc and the Eurographics Association, 2002) Iwasaki, Kei; Dobashi, Yoshinori; Nishita, Tomoyuki
    The display of realistic natural scenes is one of the most important research areas in computer graphics. Therendering of water is one of the essential components. This paper proposes an efficient method for renderingimages of scenes within water. For underwater scenery, the shafts of light and caustics are attractive and importantelements. However, computing these effects is difficult and time-consuming since light refracts when passingthrough waves. To address the problem, our method makes use of graphics hardware to accelerate the computation.Our method displays the shafts of light by accumulating the intensities of streaks of light by using hardware colorblending functions. Making use of a Z-buffer and a stencil buffer accelerates the rendering of caustics. Moreover,by using a shadow mapping technique, our method can display shafts of light and caustics taking account ofshadows due to objects.ACM CSS: I. 3.1 Computer Graphics-Hardware Architecture, I. 3.7 Computer Graphics-Three-DimensionalGraphics and Realism
  • Item
    An algorithm for line clipping against a polygon based on shearing transformation
    (Blackwell Publishers, Inc and the Eurographics Association, 2002) Huang, Y. Q.; Liu, Y. K.
    Line clipping against a polygon is widely used in computer graphics such as the hidden line problem. A newline-clipping algorithm against a general polygon is presented in this paper. The basic idea of this algorithm is tochange the line to be clipped into a horizontal line by shearing transformation. Then each edge of the polygonalwindow is transformed by a shearing transformation with the same parameters as those used to the line. Eachedge of the polygon is processed against a horizontal line, which makes the clipping process simpler. The result inthis paper shows that less calculation is needed for the new algorithm with a higher speed compared to existingalgorithms.
  • Item
    Visualizing Crowds in Real-Time
    (Blackwell Publishers, Inc and the Eurographics Association, 2002) Tecchia, Franco; Loscos, Celine; Chrysanthou, Yiorgos
    Real-time crowd visualization has recently attracted quite an interest from the graphics community and, asinteractive applications become even more complex, there is a natural demand for new and unexplored applicationscenarios. However, the interactive simulation of complex environments populated by large numbers of virtualcharacters is a composite problem which poses serious difficulties even on modern computer hardware. In thispaper we look at methods to deal with various aspects of crowd visualization, ranging from collision detectionand behaviour modeling to fast rendering with shadows and quality shading. These methods make extensive useof current graphics hardware capabilities with the aim of providing scalability without compromising run-timespeed. Results from a system employing these techniques seem to suggest that simulations of reasonably complexenvironments populated with thousands of animated characters are possible in real-time.ACM CSS: I.3.7 Three-Dimensional Graphics and Realism-Animation
  • Item
    Adaptive Zooming in Web Cartography
    (Blackwell Publishers, Inc and the Eurographics Association, 2002) Cecconi, Alesandro; Galanda, Martin
    Beyond any doubt much of the current web mapping and web GIS applications lack cartographic quality. Thereasons aren't only the technical limitations related to Internet delivery, but also the neglect of one of the maincartographic principles of digital mapping, namely adaptive zooming. Adaptive zooming describes the adjustmentof a map, its contents and the symbolization to target scale in consequence of a zooming operation. The approachdescribed in this paper proposes the combination of two commonly known concepts: on the one hand levelsof detail (LoD) for those object classes, that require high computational cost for the automated generalizationprocess (e.g. buildings, road network); on the other hand an on-the-fly generalization for those object classeswhich can be generalized by less complex methods and algorithms (e.g. rivers, lakes). Realizing such interactiveand dynamic concept for web mapping requires the use of vector based visualization tools. The data format bestmeeting the criteria is the W3C standard Scalable Vector Graphics (SVG). Thus, it has been used to implementthe presented ideas in a prototype application for topographic web mapping based on the landscape modelVECTOR25 of the Swiss Federal Office of Topography.
  • Item
    SVG Linearization and Accessibility
    (Blackwell Publishers, Inc and the Eurographics Association, 2002) Herman, Ivan; Dardailler, Daniel
    The usage of SVG (Scaleable Vector Graphics) creates new possibilities as well as new challenges for theaccessibility of Web sites. This paper presents a metadata vocabulary to describe the information content ofan SVG file geared towards accessibility. When used with a suitable tool, this metadata description can helpin generating a textual ('linear') version of the content, which can be used for users with disabilities or withnon-visual devices.Although this paper concentrates on SVG, i.e. on graphics on the Web, the metadata approach and vocabularypresented below can be applied in relation to other technologies, too. Indeed, accessibility issues have a muchwider significance, and have an effect on areas like CAD, cartography, or information visualization. Hence, theexperiences of the work presented below may also be useful for practitioners in other areas.ACM CSS: I.3.4 Graphics Utilities-Graphics Packages, I.3.6 Methodology and Techniques-Graphics datastructures and data types, Standards, K.4.2 Social Issues-Assistive technologies for persons with disabilities
  • Item
    Towards Interactive Real-Time Crowd Behavior Simulation
    (Blackwell Publishers, Inc and the Eurographics Association, 2002) Ulicny, Branislav; Thalmann, Daniel
    While virtual crowds are becoming common in non-real-time applications, the real-time domain is still relativelyunexplored. In this paper we discuss the challenges involved in creating such simulations, especially the needto efficiently manage variety. We introduce the concept of levels of variety. Then we present our work oncrowd behaviour simulation aimed at interactive real-time applications such as computer games or virtualenvironments. We define a modular behavioural architecture of a multi-agent system allowing autonomous andscripted behaviour of agents supporting variety. Finally we show applications of our system in a virtual realitytraining system and a virtual heritage reconstruction.ACM CSS: I.3.7 Three-Dimensional Graphics and Realism-Animation, I.2.11 Distributed ArtificialIntelligence-Multi-agent systems
  • Item
    Siggraph 2002
    (Blackwell Publishers, Inc and the Eurographics Association, 2002) Laycock, Stephen D.; Laycock, Robert G.
  • Item
    Eurographics 2002
    (Blackwell Publishers, Inc and the Eurographics Association, 2002) Scheel, Annette
  • Item
    Erratum: Artistic Surface Rendering Using Layout of Text
    (Blackwell Publishers, Inc and the Eurographics Association, 2002) Surazhsky, Tatiana; Elber, Gershon
  • Item
    Hierarchical Impostors for the Flocking Algorithm in 3D
    (Blackwell Publishers, Inc and the Eurographics Association, 2002) O'Hara, Noel
    The availability of powerful and affordable 3D PC graphics boards has made the rendering of rich immersiveenvironments possible at interactive speeds. The scene update rate and the appropriate behaviour of objects withinthe world are central to this immersive feeling. This paper is concerned with the behaviour computations involvedin the flocking algorithm, which has been used extensively to emulate the flocking behaviour of creatures found innature. The main contribution of this paper is a new method for hierarchically combining portions of the flocksinto groups to reduce the cost of the behavioural computation, allowing far larger flocks to be updated in real-timein the world.ACM CSS: I.3.7 Three-Dimensional Graphics and Realism-Animation
  • Item
    Eurographics Spain 11th Conference
    (Blackwell Publishers, Inc and the Eurographics Association, 2002) Isern, Jordi Regincos
  • Item
    Eurographics Ireland 2002 Workshop
    (Blackwell Publishers, Inc and the Eurographics Association, 2002) O'Sullivan, Carol
  • Item
    First International Symposium on 3DPVT 2002
    (Blackwell Publishers, Inc and the Eurographics Association, 2002) Max, Nelson
  • Item
    1st Ibero-American Symposium in Computer Graphics
    (Blackwell Publishers, Inc and the Eurographics Association, 2002) Marcos, Aderito; Brunet, Pere; Jorge, Joaquim; Regincos, Jordi
  • Item
    13th Eurographics Workshop on Rendering
    (Blackwell Publishers, Inc and the Eurographics Association, 2002) Debevec, Paul; Gibson, Simon
  • Item
    Eurographics Italy 1st Conference
    (Blackwell Publishers, Inc and the Eurographics Association, 2002) Bordegoni, Monica
  • Item
    Eurographics 2003 Modelling the Real World
    (Blackwell Publishers, Inc and the Eurographics Association, 2002)
  • Item
    New Eurographics Fellow
    (Blackwell Publishers, Inc and the Eurographics Association, 2002)
  • Item
    23rd Eurographics General Assembly
    (Blackwell Publishers, Inc and the Eurographics Association, 2002)
  • Item
    Join Now!
    (Blackwell Publishers, Inc and the Eurographics Association, 2002)
  • Item
    Author Index Volume 21 (2002)
    (Blackwell Publishers, Inc and the Eurographics Association, 2002)
  • Item
    Editorial
    (Blackwell Publishers, Inc and the Eurographics Association, 2002) Duke, David; Scopigno, Roberto
  • Item
    Computer Graphics forum
    (Blackwell Publishers, Inc and the Eurographics Association, 2002)
    Eurographics and Computer Graphics forum offer a variety of services on the international networks. You can find details ofour latest events, how to prepare a paper for the conference or for the journal and much more besides. This information can beaccessed mainly through the EG website but we also offer some support for ftp and mail server access.
  • Item
    Vortex Tracking and Visualisation in a Flow Past a Tapered Cylinder
    (Blackwell Publishers, Inc and the Eurographics Association, 2002) Reinders, Freek; Sadarjoen, I. Ari; Vrolijk, Benjamin; Post, Frits H.
    In this paper we explore a novel combined application of two of our existing visualisation techniques to thetracking of 3D vortex tubes in an unsteady flow. The applied techniques are the winding-angle vortex extractiontechnique based on streamline geometry, and the attribute-based feature tracking technique. We have applied theseto the well-known case of an unsteady 3D flow past a tapered cylinder.First, 2D vortices are detected in a number of horizontal slices for each time step, by means of the winding-anglevortex extraction method. For each 2D vortex a number of attributes are calculated and stored. These vorticesare visualised by a special type of ellipse icons, showing the position, shape and rotational direction and speed ineach slice.Next, for each time step, 3D vortex tubes are constructed from the 2D vortices by applying the feature trackingprocedure in a spatial dimension to connect the corresponding vortices in adjacent slices. The result is a graphattribute set with the 2D vortex attributes in the nodes and the spatial correspondences as edges.Finally, the 3D vortex tubes are tracked in time using the same tracking procedure, for finding the correspondingtubes in successive time steps. The result is a description of the evolution of the 3D vortices. An interactive, time-dependentvisualisation is generated using the temporal correspondences of each vortex tube. This analysis revealsa number of interesting patterns.ACM CSS: I.3.8 Computer Graphics-Applications
  • Item
    Synthetic Vision and Memory for Autonomous Virtual Humans
    (Blackwell Publishers, Inc and the Eurographics Association, 2002) Peters, C.; O'Sullivan, C.
    A memory model based on 'stage theory', an influential concept of memory from the field of cognitive psychology,is presented for application to autonomous virtual humans. The virtual human senses external stimuli througha synthetic vision system. The vision system incorporates multiple modes of vision in order to accommodate aperceptual attention approach. The memory model is used to store perceived and attended object information atdifferent stages in a filtering process. The methods outlined in this paper have applications in any area wheresimulation-based agents are used: training, entertainment, ergonomics and military simulations to name but afew.ACM CSS: I. 3.7 Computer Graphics-Virtual reality
  • Item
    Levels of Detail for Crowds and Groups
    (Blackwell Publishers, Inc and the Eurographics Association, 2002) O'Sullivan, C.; Cassell, J.; Vilhjalmsson, H.; Dingliana, J.; Dobbyn, S.; McNamee, B. and Peters, C. and Giang, T.
    Work on levels of detail for human simulation has occurred mainly on a geometrical level, either by reducing the numbers of polygons representing a virtual human, or replacing them with a two-dimensional imposter. Approaches that reduce the complexity of motions generated have also been proposed. In this paper, we describe ongoing development of a framework for Adaptive Level Of Detail for Human Animation (ALOHA), which incorporates levels of detail for not only geometry and motion, but also includes a complexity gradient for natural behaviour, both conversational and social.ACM CSS: I.3.7 Three-Dimensional Graphics and Realism-Animation
  • Item
    A Spoken Dialogue System for Navigation in Non-Immersive Virtual Environments
    (Blackwell Publishers, Inc and the Eurographics Association, 2002) McNeill, M.D.J.; Sayers, H.; Wilson, S.; Mc Kevitt, P.
    Navigation is the process by which people control their movement in virtual environments and is a corefunctional requirement for all virtual environment (VE) applications. Users require the ability to move, controllingorientation, direction of movement and speed, in order to achieve a particular goal within a VE. Navigation israrely the end point in itself (which is typically interaction with the visual representations of data) but applicationsoften place a high demand on navigation skills, which in turn means that a high level of support for navigationis required from the application. On desktop systems navigation in non-immersive systems is usually supportedthrough the usual hardware devices of mouse and keyboard. Previous work by the authors shows that many usersexperience frustration when trying to perform even simple navigation tasks - users complain about getting lost,becoming disorientated and finding the interface 'difficult to use'. In this paper we report on work in progressin exploiting natural language processing (NLP) technology to support navigation in non-immersive virtualenvironments. A multi-modal system has been developed which supports a range of high-level (spoken) navigationcommands and indications are that spoken dialogue interaction is an effective alternative to mouse and keyboardinteraction for many tasks. We conclude that multi-modal interaction, combining technologies such as NLP withmouse and keyboard may offer the most effective interaction with VEs and identify a number of areas where furtherwork is necessary.ACM CSS: I.3.6 Computer Graphics Methodology and Techniques-Interaction and Techniques, I.3.7 Three-DimensionalGraphics and Realism-Virtual Reality, I.2.7 Natural Language Processing-Speech Recognitionand Synthesis
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    A Skeleton-based Approach for Detection of Perceptually Salient Features on Polygonal Surfaces
    (Blackwell Publishers, Inc and the Eurographics Association, 2002) Hisada, Masayuki; Belyaev, Alexander G.; Kunii, Tosiyasu L.
    The paper presents a skeleton-based approach for robust detection of perceptually salient shape features. Given ashape approximated by a polygonal surface, its skeleton is extracted using a three-dimensional Voronoi diagramtechnique proposed recently by Amenta et al. [3]. Shape creases, ridges and ravines, are detected as curvescorresponding to skeletal edges. Salient shape regions are extracted via skeleton decomposition into patches.The approach explores the singularity theory for ridge and ravine detection, combines several filtering methodsfor skeleton denoising and for selecting perceptually important ridges and ravines, and uses a topological analysisof the skeleton for detection of salient shape regions.ACM CSS: I.3.5 Computational Geometry and Object Modeling
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    Feature Model Visualization
    (Blackwell Publishers, Inc and the Eurographics Association, 2002) Bronsvoort, Willem F.; Bidarra, Rafael; Noort, Alex
    Feature modelling is now the predominant way of modelling products. Feature visualization is an important aspect here that can still be considerably improved. In this paper, an integrated way of visualizing feature models is presented, using new techniques for both the geometry and the structure of models. For the geometry of feature models, techniques are presented to visualize a selected subset of form features in a way that clearly distinguishes them from the rest of the model, as well as functional information such as closure faces of subtractive form features. For the structure of features models, techniques are presented to visualize several types of graphs. The different visualization techniques are used in an integrated way. Implementation of some of the techniques requires a non-manifold representation of the geometry of the feature model. This representation, and some other implementation aspects, are briefly described. Throughout the paper, numerous examples of images of feature models are given which show that the new visualization techniques can indeed improve the effectiveness of feature modelling.ACM CSS: I.3.7 Three-Dimensional Graphics and Realism-visible line/surface algorithms, J.6 Computer-AidedEngineering-feature modelling