Nadia Magnenat-thalmann | University of Geneva, Switzerland (original) (raw)

Papers by Nadia Magnenat-thalmann

The Visual Computer, Aug 13, 2008

Over the last fifteen years, research on hair simulation has made great advances in the domains o... more Over the last fifteen years, research on hair simulation has made great advances in the domains of modeling, animation and rendering, and is now moving towards more innovative interaction modalities. The combination of visual and haptic interaction within a virtual hairstyling simulation framework represents an important concept evolving in this direction. Our visuo-haptic hair interaction framework consists of two layers which handle the response to the user's interaction at a local level (around the contact area), and at a global level (on the full hairstyle). Two distinct simulation models compute individual and collective hair behavior. Our multilayered approach can be used to efficiently address the specific requirements of haptics and vision. Haptic interaction with both models has been tested with virtual hairstyling tools.

When building robotic hands, researchers are always face with two main issues of how to make robo... more When building robotic hands, researchers are always face with two main issues of how to make robotic hands look human-like and how to make robotic hands function like real hands. Most existing solutions solve these issues by manually modelling the robotic hand [10-18]. However, the design processes are long, and it is difficult to duplicate the geometry shape of a human hand. To solve these two issues, this paper presents a simple and effective method that combines 3D printing and digitization techniques to create a 3D printable cable-driven robotic hand from scanning a physical hand. The method involves segmenting the 3D scanned hand model, adding joints, and converting it into a 3D printable model. Comparing to other robotic solutions, our solution retains more than 90% geometry information of a human hand 1 , which is attained from 3D scanning. Our modelling progress takes around 15 minutes that include 10 minutes of 3D scanning and five minutes for changing the scanned model to an articulated model by running our algorithm. Compared to other articulated modelling solutions [19, 20], our solution is compatible with an actuation system which provides our robotic hand with the ability to mimic different gestures. We have also developed a way of representing hand skeletons based on the hand anthropometric. As a proof of concept, we demonstrate our robotic hand's performance in the grasping experiments.

Describes a method for creating and animating a synthetic actress. It emphasizes the methodology ... more Describes a method for creating and animating a synthetic actress. It emphasizes the methodology used to generate realistic images and motions. In particular, points which are often ignored in the literature are explained in detail: for example, the planning and preparation of models for digitizing, composition, skeleton installation and the animation process itself

Encyclopedia of Computer Graphics and Games, 2018

Mixed Reality as display technology, gamification as motivational element, storytelling as intera... more Mixed Reality as display technology, gamification as motivational element, storytelling as interaction metaphor while maintaining the feeling of Presence, are identified as key elements for defining the next generation of virtual museums.

Computer science workbench, 1985

During the period 1963–1967, a dozen computer films were made at Bell Telephone Laboratories. Apa... more During the period 1963–1967, a dozen computer films were made at Bell Telephone Laboratories. Apart from Ken Knowlton [1964,1965], the most important computer animators at Bell Labs were: E. Zajac [1966], who made the first computer-animated film Two-gyro gravity-gradient attitude control system in 1963. F. Sinden [1967], who made Force, Mass and Motion, a film that demonstrates Newton’s laws of motion; the programming language was FORTRAN. Huggins and Weiner, who made Harmonic Phasors, a film concerning the composition of complicated periodic waveforms; the film was produced by programming in PMACRO [Alexander and Huggins 1967].

Graphics Interface, 1986

Interactive systems have the great advantage of being dedicated to artists; however, computer ani... more Interactive systems have the great advantage of being dedicated to artists; however, computer animation programming language does not impose fewer limits on creativity. CINEMIRA-2 is one way of conciliating the two approaches. This is a computer animation sublanguage only designed for extending the MIRANIM animation system. Five kinds of entities may be programmed in CINEMIRA-2: procedural objects, procedural evolution laws, procedural actor transformations, procedural subactor types and animation blocks. These entities are then controlled in a user-friendly way by non-programmer animators. This paper presents an informal description of the CINEMIRA-2 sublanguage with examples.

In this chapter we introduce the Networked Virtual Park. This park consists of two parts, the con... more In this chapter we introduce the Networked Virtual Park. This park consists of two parts, the content creating Attraction Builder and the actual Network Virtual Environment System. We describe not only the basics of both systems, but also the techniques used to bring reality to such a Virtual Park, including Virtual Humans and the available interactions.

Frontiers in Computer Graphics, 1985

MIRA-SHADING is a structured graphics language that provides the programmer the way of specifying... more MIRA-SHADING is a structured graphics language that provides the programmer the way of specifying, manipulating and animating 3D shaded objects by the use of high level graphical types. The major application of MIRA-SHADING is a director-oriented 3D shaded computer animation system.

Computer Science Workbench, 1985

Computer animation is currently developing very quickly because of its usefulness for advertising... more Computer animation is currently developing very quickly because of its usefulness for advertising purposes. The three giants (NBC, CBS and ABC) of American television often use this technique to present their logos or to augment their programs. At the same time, film studios in Hollywood have become interested in computer animation because of the spectacular effects that can be created.

Creating and Animating the Virtual World, 1992

This paper presents an interactive tool dedicated to the design of walking trajectories for human... more This paper presents an interactive tool dedicated to the design of walking trajectories for human figures. It uses a global human free-walking model built from experimental data on a wide range of normalized velocities. This tool is particularly efficient in that the higher level of the ...

The Visual Computer, 1989

CGI '88 is the Official Annual Conference of the Computer Graphics Society. Since 1982, this ... more CGI '88 is the Official Annual Conference of the Computer Graphics Society. Since 1982, this Conference has been held in Tokyo. This year, it has been taking place in Geneva, Switzerland. In 1989, it will be held in Leeds, U.K., in ]990 in Singapore, in 1991 in U.S.A. and in ]992 in Montreal, Canada. The conference was organized by the Computer Graphics Society (CGS) with the cooperation of le Minist6re des Relations Internationales du Qu6bec, le Minist+re du Commerce Ext6rieur et du D6veloppement Technologique du Qu6bec, the Display group of the British Computer Society, the Swiss Computer Graphics Association (SCGA), l'Association Suisse pour l 'Automatique (ASSPA), la Soci6t6 Suisse d'Informatique M6dicale (SSIM), l'Ecole des Hautes Etudes Commerciales de Montr6al, L'Universit6 de Gen6ve, l'Ecole Polytechnique F6d6rale de Lausanne et l'Universit6 de Montr6al. In addition to CGI '88, the First Computer-generated Film Festival of Geneva has attracted over thousand people. Over 100 papers were submitted to CGI '88 and 61 papers were selected by the International Program Committee. From these 61 papers, the Program Committee decided to select 11 outstanding papers and asked the authors to prepare an expanded version of their papers. Papers have been carefully revised and newest results and pictures have been included. These papers are presented in this issue. Although papers were submitted in all areas of Computer Graphics, papers selected for The Visual Computer are only in three areas: 4 papers in Computer Animation, 5 papers in Geometric Modeling and 2 papers in Image Synthesis. The first paper in Computer Animation by Daniel Pletincks, from Barco Industries, in Belgium, describes two new methods for splining quaternions so that they can be used within a keyframe animation system. Then, K. Harada and E. Nakamae, from Hiroshima University, in Japan, focus on the application of cubic splines with chord length parametrization for design of motion in computer animation. In the third paper, B. Arnaldi, G. Dumont and G. H~gron, from IRISA/INRIA, in France, present an analysis of unified animation control processes. Finally, N. MagnenatThalmann, H.T. Minh, M. de Angelis and D. Thalmann from the University of Montreal, in Canada, discuss tools for the creation of new synthetic actors and their transformation of personalities. In geometric modeling, T. Noma, T.L. Kunii, N. Kin, E. Enomoto, E. Aso and T. Yamamoto, from '88 (CGI '88)

The Visual Computer, 2012

This paper presents an interactive multi-agent system based on a fully immersive virtual environm... more This paper presents an interactive multi-agent system based on a fully immersive virtual environment. A user can interact with the virtual characters in real time via an avatar by changing their moving behavior. Moreover, the user is allowed to select any character as the avatar to be controlled. A path planning algorithm is proposed to address the problem of dynamic navigation of individual and groups of characters in the multi-agent system. A natural interface is designed for the interaction between the user and the virtual characters, as well as the virtual environment, based on gesture recognition. To evaluate the efficiency of the dynamic navigation method, performance results are provided. The presented system has the potential to be used in the training and evaluation of emergency evacuation and other real-time applications of crowd simulation with interaction.

IEEE Computer Graphics and Applications, 1986

One of the most impressive effects in computergenerated films' is rotation around a three-dimensi... more One of the most impressive effects in computergenerated films' is rotation around a three-dimensional object or penetration of any complex solid. Although these effects are very spectacular, they are in fact quite easy to produce. Typically, they are done by simulating movement of a camera, called a virtual or synthetic camera. A single virtual camera simply consists of a pair of vector characteristics, the eye and the interest point. The virtual camera model may also include a zoom. These features are very convenient for all wireframe drawings and most shaded images. Potmesil and Chakravarty2 have introduced a more realistic camera model that approximates the lens and aperture of a real camera. It allows the generation of synthetic images which have a depth of field and can be focused on an arbitrary plane. In fact the term "virtual camera" is frequently used by

Computer Animation and Virtual Worlds, 2014

This issue contains 7 regular papers. In the first paper, Mingming Zhang, from Zhejiang Universit... more This issue contains 7 regular papers. In the first paper, Mingming Zhang, from Zhejiang University, in Hangzhou, China, presents an on-line virtual home decoration system which integrates web interaction technique into virtual home decoration. The main functions of this system include house design, house decoration and data management. For the house design, an automatic joint method of the walls is proposed, in order to design various house. For the house decoration, the author introduces the wall decoration principle corresponding to the algorithm of discretization on the walls which contains doors or windows and triangularization on the irregular floors. To variety of different textures and collage regulations, the author provides a new texture collage mapping method. The second paper, by Weitao Li, Yuanfeng Zhou, Caiming Zhang, and Xuemei Li, from Shandong University, in Jinan, China presents a new robust multilevel partition of unity (MPU) method which constructs an implicit surface from a triangular mesh via the new error metric between the mesh and the implicit surface. The new error metric employs a weighted function of inner points and vertices of a triangle to fit an implicit surface, which can control the approximation error between the surface and vertices of the triangle. Furthermore, it is applied to the MPU method by utilizing the dual graph of a triangular mesh, and the general quadric implicit surface is used for surface representation. Compared with MPU method, the new method generates fewer subdivision cells with the same approximation error, and performs more steadily especially when given triangular mesh with fewer vertices. Displaying 3D volumetric medical datasets on traditional 2D screens can present problems such as occlusion and information overload, especially when multiple data sources are present. In the third paper, Can Kirmizibayrak, MikeWakid, YenyYim,Dimitre Hristov, and JamesKHahn, from The George Washington & Stanford Universities, USA, present an interactive focus + context visualization approach that uses the volumetric Magic Lens interaction paradigm. They propose to use the Magic Lens as a volumetric brush to perform volume editing tasks, therefore combining data exploration with volumetric editing. The authors discuss the application of their methods to radiation therapy, which is an important cancer treatment modality. The fourth paper, by Chunxiao Zhang, from Beijing Institute of Space Mechanics and Electricity, China, Eric Dubois, from University of Ottawa, Canada, and Yan Zhao, from Beihang University in Beijing, China

Computer Animation and Virtual Worlds, 2013

Co-Editor-in-chief This issue contains five regular papers. Ahmad Abdul Karim, Thibaut Gaudin, Al... more Co-Editor-in-chief This issue contains five regular papers. Ahmad Abdul Karim, Thibaut Gaudin, Alexandre Meyer, Axel Buendia and Saïda Bouakaz, from Université Lyon 1 and Spir.Ops in France, present a fully procedural method capable of generating in real time a wide range of locomotion for multi-legged characters in a dynamic environment, without using any motion data. Their system consists of several independent blocks: a character controller, a gait/tempo manager, a 3D path constructor and a footprints planner. The four modules work cooperatively to calculate in real time the footprints and the 3D trajectories of the feet and the pelvis. The system can animate dozens of creatures using dedicated level of detail techniques and is totally controllable allowing the user to design a multitude of locomotion styles through a user-friendly interface. In the second paper, Amit Kumar and Aparajita Ojha, from PDPM Indian Institute of Information Technology in Jabalpur, in India, propose a new approach to natural path planning by adding wavelet noise to a path generated using subdivision-based corridor map method. Because wavelet noise is almost perfectly band-limited and provides good details with minimal aliasing effects, the resulting path becomes smoother and more natural. Moreover, by appropriately choosing the levels of down/up sampling in the wavelet noise generation algorithm, frequency of wavelet noise can be adjusted. This serves as an effective tool in bringing variations in path as per the requirement. The third paper by Yanzhen Wang, Yueshan Xiong, Kai Xu and Dong Liu, from National University of Defense Technology in Changsha, Hunan, in China, describes a surgical procedure simulation system for the training of arthroscopic ACL reconstruction involving operations such as puncturing, probing, incision and drilling. In this system, the authors employ a linear elastic finite element method and position-based dynamics for deformable modelling. Simplified vertex duplicating method and an implementation of real-time Boolean operations are proposed for the topological change of tissue

Computer Animation and Virtual Worlds, 2013

This issue is a special issue with selected papers from Motion in Games (MIG) 2012, which was hel... more This issue is a special issue with selected papers from Motion in Games (MIG) 2012, which was held during November 15–17 in Rennes, France. Five papers were selected by a review committee composed of Paul Kry, McGill University; Rachel McDonnell, Trinity College Dublin; and Arjan Egges, Utrecht University. The review committee took into account not only the manuscripts but also the presentations and the potential for impact on the motion in games area that is being nurtured by MIG. This special issue contains four out of the five selected papers. The fifth paper will appear in the next issue of Computer Animation & Virtual Worlds. The first paper on this issue is from Peter Sandilands, Myung Geol Choi and Taku Komura, from the University of Edinburgh, UK. The authors propose a technique for action motion capture that allows them to capture an object’s motion and geometry alongside a character’s movement and local environment, using a magnetic motion capture system and a RGB-D sensor. Traditional methods of actor motion capture do not give any information about the spatial relationship between objects you may interact with, or are limited to large props and motions that are not occluded during capture. The proposed method not only gives greater information when placing a character in the scene, but enables the authors to digitally recreate the scene in motion without significant animator work after capture. The second paper by Junghyun Ahn, Stephane Gobron, Daniel Thalmann, and Ronan Boulic, from Ecole Polytechnique Federale de Lausanne (EPFL), Switzerland, and NTU, Singapore, addresses emotional expressivity for embodied conversational agents by considering asymmetric facial expressions. The asymmetry of facial expressions helps to convey complex emotional feelings such as conflicting and/or hidden emotions due to social conventions. The proposed linear model can automatically drive a large number of autonomous virtual humans, or support the interactive design of complex facial expressions over time. The approach produces facial expressions for most of the emotional spectrum and it can also achieve more complex ambivalent feelings when differing emotions are applied on the left and right sides of the face. The third paper by Robert Backman and Marcelo Kallmann from the University of California, Merced, presents a system that allows non-programmers to create ge-

Proc. of Comp. Graphics Int'l (CGI 2004), 2004

AVSP, 2001

For realistic speech animation, smooth viseme and expression transitions, blending and co-articul... more For realistic speech animation, smooth viseme and expression transitions, blending and co-articulation have been so far studied and experimented widely. In this paper, we describe an approach for speech animation by smooth viseme transition. Though this method cannot form an alternative to the coarticulation phenomenon, it certainly takes us a step nearer to realistic speech animation. The approach is devised as a result of the Principal Component Analysis of facial capture data extracted using an optical tracking system. The system extracts the 3D positions of markers attached at the specific feature point locations on face to capture the facial movements of a talking person. We form a vector space representation by using the Principal Component Analysis of this data. We call this space the "viseme space". We use the viseme space to generate convincing speech animation and to make smooth transitions from one viseme to another. As the analysis and the resulting viseme space automatically consider the dynamics of and the deformation constraints on the facial movements, the resulting facial animation is very realistic.

Abstract In this paper, an interactive tool is proposed for the visualization, editing and manipu... more Abstract In this paper, an interactive tool is proposed for the visualization, editing and manipulation of multiple track sequences. A sequence is associated with an articulated figure and can integrate different motion generators such as walking, inverse kinematics, ...

The Visual Computer, Aug 13, 2008

Over the last fifteen years, research on hair simulation has made great advances in the domains o... more Over the last fifteen years, research on hair simulation has made great advances in the domains of modeling, animation and rendering, and is now moving towards more innovative interaction modalities. The combination of visual and haptic interaction within a virtual hairstyling simulation framework represents an important concept evolving in this direction. Our visuo-haptic hair interaction framework consists of two layers which handle the response to the user's interaction at a local level (around the contact area), and at a global level (on the full hairstyle). Two distinct simulation models compute individual and collective hair behavior. Our multilayered approach can be used to efficiently address the specific requirements of haptics and vision. Haptic interaction with both models has been tested with virtual hairstyling tools.

When building robotic hands, researchers are always face with two main issues of how to make robo... more When building robotic hands, researchers are always face with two main issues of how to make robotic hands look human-like and how to make robotic hands function like real hands. Most existing solutions solve these issues by manually modelling the robotic hand [10-18]. However, the design processes are long, and it is difficult to duplicate the geometry shape of a human hand. To solve these two issues, this paper presents a simple and effective method that combines 3D printing and digitization techniques to create a 3D printable cable-driven robotic hand from scanning a physical hand. The method involves segmenting the 3D scanned hand model, adding joints, and converting it into a 3D printable model. Comparing to other robotic solutions, our solution retains more than 90% geometry information of a human hand 1 , which is attained from 3D scanning. Our modelling progress takes around 15 minutes that include 10 minutes of 3D scanning and five minutes for changing the scanned model to an articulated model by running our algorithm. Compared to other articulated modelling solutions [19, 20], our solution is compatible with an actuation system which provides our robotic hand with the ability to mimic different gestures. We have also developed a way of representing hand skeletons based on the hand anthropometric. As a proof of concept, we demonstrate our robotic hand's performance in the grasping experiments.

Describes a method for creating and animating a synthetic actress. It emphasizes the methodology ... more Describes a method for creating and animating a synthetic actress. It emphasizes the methodology used to generate realistic images and motions. In particular, points which are often ignored in the literature are explained in detail: for example, the planning and preparation of models for digitizing, composition, skeleton installation and the animation process itself

Encyclopedia of Computer Graphics and Games, 2018

Mixed Reality as display technology, gamification as motivational element, storytelling as intera... more Mixed Reality as display technology, gamification as motivational element, storytelling as interaction metaphor while maintaining the feeling of Presence, are identified as key elements for defining the next generation of virtual museums.

Computer science workbench, 1985

During the period 1963–1967, a dozen computer films were made at Bell Telephone Laboratories. Apa... more During the period 1963–1967, a dozen computer films were made at Bell Telephone Laboratories. Apart from Ken Knowlton [1964,1965], the most important computer animators at Bell Labs were: E. Zajac [1966], who made the first computer-animated film Two-gyro gravity-gradient attitude control system in 1963. F. Sinden [1967], who made Force, Mass and Motion, a film that demonstrates Newton’s laws of motion; the programming language was FORTRAN. Huggins and Weiner, who made Harmonic Phasors, a film concerning the composition of complicated periodic waveforms; the film was produced by programming in PMACRO [Alexander and Huggins 1967].

Graphics Interface, 1986

Interactive systems have the great advantage of being dedicated to artists; however, computer ani... more Interactive systems have the great advantage of being dedicated to artists; however, computer animation programming language does not impose fewer limits on creativity. CINEMIRA-2 is one way of conciliating the two approaches. This is a computer animation sublanguage only designed for extending the MIRANIM animation system. Five kinds of entities may be programmed in CINEMIRA-2: procedural objects, procedural evolution laws, procedural actor transformations, procedural subactor types and animation blocks. These entities are then controlled in a user-friendly way by non-programmer animators. This paper presents an informal description of the CINEMIRA-2 sublanguage with examples.

In this chapter we introduce the Networked Virtual Park. This park consists of two parts, the con... more In this chapter we introduce the Networked Virtual Park. This park consists of two parts, the content creating Attraction Builder and the actual Network Virtual Environment System. We describe not only the basics of both systems, but also the techniques used to bring reality to such a Virtual Park, including Virtual Humans and the available interactions.

Frontiers in Computer Graphics, 1985

MIRA-SHADING is a structured graphics language that provides the programmer the way of specifying... more MIRA-SHADING is a structured graphics language that provides the programmer the way of specifying, manipulating and animating 3D shaded objects by the use of high level graphical types. The major application of MIRA-SHADING is a director-oriented 3D shaded computer animation system.

Computer Science Workbench, 1985

Computer animation is currently developing very quickly because of its usefulness for advertising... more Computer animation is currently developing very quickly because of its usefulness for advertising purposes. The three giants (NBC, CBS and ABC) of American television often use this technique to present their logos or to augment their programs. At the same time, film studios in Hollywood have become interested in computer animation because of the spectacular effects that can be created.

Creating and Animating the Virtual World, 1992

This paper presents an interactive tool dedicated to the design of walking trajectories for human... more This paper presents an interactive tool dedicated to the design of walking trajectories for human figures. It uses a global human free-walking model built from experimental data on a wide range of normalized velocities. This tool is particularly efficient in that the higher level of the ...

The Visual Computer, 1989

CGI '88 is the Official Annual Conference of the Computer Graphics Society. Since 1982, this ... more CGI '88 is the Official Annual Conference of the Computer Graphics Society. Since 1982, this Conference has been held in Tokyo. This year, it has been taking place in Geneva, Switzerland. In 1989, it will be held in Leeds, U.K., in ]990 in Singapore, in 1991 in U.S.A. and in ]992 in Montreal, Canada. The conference was organized by the Computer Graphics Society (CGS) with the cooperation of le Minist6re des Relations Internationales du Qu6bec, le Minist+re du Commerce Ext6rieur et du D6veloppement Technologique du Qu6bec, the Display group of the British Computer Society, the Swiss Computer Graphics Association (SCGA), l'Association Suisse pour l 'Automatique (ASSPA), la Soci6t6 Suisse d'Informatique M6dicale (SSIM), l'Ecole des Hautes Etudes Commerciales de Montr6al, L'Universit6 de Gen6ve, l'Ecole Polytechnique F6d6rale de Lausanne et l'Universit6 de Montr6al. In addition to CGI '88, the First Computer-generated Film Festival of Geneva has attracted over thousand people. Over 100 papers were submitted to CGI '88 and 61 papers were selected by the International Program Committee. From these 61 papers, the Program Committee decided to select 11 outstanding papers and asked the authors to prepare an expanded version of their papers. Papers have been carefully revised and newest results and pictures have been included. These papers are presented in this issue. Although papers were submitted in all areas of Computer Graphics, papers selected for The Visual Computer are only in three areas: 4 papers in Computer Animation, 5 papers in Geometric Modeling and 2 papers in Image Synthesis. The first paper in Computer Animation by Daniel Pletincks, from Barco Industries, in Belgium, describes two new methods for splining quaternions so that they can be used within a keyframe animation system. Then, K. Harada and E. Nakamae, from Hiroshima University, in Japan, focus on the application of cubic splines with chord length parametrization for design of motion in computer animation. In the third paper, B. Arnaldi, G. Dumont and G. H~gron, from IRISA/INRIA, in France, present an analysis of unified animation control processes. Finally, N. MagnenatThalmann, H.T. Minh, M. de Angelis and D. Thalmann from the University of Montreal, in Canada, discuss tools for the creation of new synthetic actors and their transformation of personalities. In geometric modeling, T. Noma, T.L. Kunii, N. Kin, E. Enomoto, E. Aso and T. Yamamoto, from '88 (CGI '88)

The Visual Computer, 2012

This paper presents an interactive multi-agent system based on a fully immersive virtual environm... more This paper presents an interactive multi-agent system based on a fully immersive virtual environment. A user can interact with the virtual characters in real time via an avatar by changing their moving behavior. Moreover, the user is allowed to select any character as the avatar to be controlled. A path planning algorithm is proposed to address the problem of dynamic navigation of individual and groups of characters in the multi-agent system. A natural interface is designed for the interaction between the user and the virtual characters, as well as the virtual environment, based on gesture recognition. To evaluate the efficiency of the dynamic navigation method, performance results are provided. The presented system has the potential to be used in the training and evaluation of emergency evacuation and other real-time applications of crowd simulation with interaction.

IEEE Computer Graphics and Applications, 1986

One of the most impressive effects in computergenerated films' is rotation around a three-dimensi... more One of the most impressive effects in computergenerated films' is rotation around a three-dimensional object or penetration of any complex solid. Although these effects are very spectacular, they are in fact quite easy to produce. Typically, they are done by simulating movement of a camera, called a virtual or synthetic camera. A single virtual camera simply consists of a pair of vector characteristics, the eye and the interest point. The virtual camera model may also include a zoom. These features are very convenient for all wireframe drawings and most shaded images. Potmesil and Chakravarty2 have introduced a more realistic camera model that approximates the lens and aperture of a real camera. It allows the generation of synthetic images which have a depth of field and can be focused on an arbitrary plane. In fact the term "virtual camera" is frequently used by

Computer Animation and Virtual Worlds, 2014

This issue contains 7 regular papers. In the first paper, Mingming Zhang, from Zhejiang Universit... more This issue contains 7 regular papers. In the first paper, Mingming Zhang, from Zhejiang University, in Hangzhou, China, presents an on-line virtual home decoration system which integrates web interaction technique into virtual home decoration. The main functions of this system include house design, house decoration and data management. For the house design, an automatic joint method of the walls is proposed, in order to design various house. For the house decoration, the author introduces the wall decoration principle corresponding to the algorithm of discretization on the walls which contains doors or windows and triangularization on the irregular floors. To variety of different textures and collage regulations, the author provides a new texture collage mapping method. The second paper, by Weitao Li, Yuanfeng Zhou, Caiming Zhang, and Xuemei Li, from Shandong University, in Jinan, China presents a new robust multilevel partition of unity (MPU) method which constructs an implicit surface from a triangular mesh via the new error metric between the mesh and the implicit surface. The new error metric employs a weighted function of inner points and vertices of a triangle to fit an implicit surface, which can control the approximation error between the surface and vertices of the triangle. Furthermore, it is applied to the MPU method by utilizing the dual graph of a triangular mesh, and the general quadric implicit surface is used for surface representation. Compared with MPU method, the new method generates fewer subdivision cells with the same approximation error, and performs more steadily especially when given triangular mesh with fewer vertices. Displaying 3D volumetric medical datasets on traditional 2D screens can present problems such as occlusion and information overload, especially when multiple data sources are present. In the third paper, Can Kirmizibayrak, MikeWakid, YenyYim,Dimitre Hristov, and JamesKHahn, from The George Washington & Stanford Universities, USA, present an interactive focus + context visualization approach that uses the volumetric Magic Lens interaction paradigm. They propose to use the Magic Lens as a volumetric brush to perform volume editing tasks, therefore combining data exploration with volumetric editing. The authors discuss the application of their methods to radiation therapy, which is an important cancer treatment modality. The fourth paper, by Chunxiao Zhang, from Beijing Institute of Space Mechanics and Electricity, China, Eric Dubois, from University of Ottawa, Canada, and Yan Zhao, from Beihang University in Beijing, China

Computer Animation and Virtual Worlds, 2013

Co-Editor-in-chief This issue contains five regular papers. Ahmad Abdul Karim, Thibaut Gaudin, Al... more Co-Editor-in-chief This issue contains five regular papers. Ahmad Abdul Karim, Thibaut Gaudin, Alexandre Meyer, Axel Buendia and Saïda Bouakaz, from Université Lyon 1 and Spir.Ops in France, present a fully procedural method capable of generating in real time a wide range of locomotion for multi-legged characters in a dynamic environment, without using any motion data. Their system consists of several independent blocks: a character controller, a gait/tempo manager, a 3D path constructor and a footprints planner. The four modules work cooperatively to calculate in real time the footprints and the 3D trajectories of the feet and the pelvis. The system can animate dozens of creatures using dedicated level of detail techniques and is totally controllable allowing the user to design a multitude of locomotion styles through a user-friendly interface. In the second paper, Amit Kumar and Aparajita Ojha, from PDPM Indian Institute of Information Technology in Jabalpur, in India, propose a new approach to natural path planning by adding wavelet noise to a path generated using subdivision-based corridor map method. Because wavelet noise is almost perfectly band-limited and provides good details with minimal aliasing effects, the resulting path becomes smoother and more natural. Moreover, by appropriately choosing the levels of down/up sampling in the wavelet noise generation algorithm, frequency of wavelet noise can be adjusted. This serves as an effective tool in bringing variations in path as per the requirement. The third paper by Yanzhen Wang, Yueshan Xiong, Kai Xu and Dong Liu, from National University of Defense Technology in Changsha, Hunan, in China, describes a surgical procedure simulation system for the training of arthroscopic ACL reconstruction involving operations such as puncturing, probing, incision and drilling. In this system, the authors employ a linear elastic finite element method and position-based dynamics for deformable modelling. Simplified vertex duplicating method and an implementation of real-time Boolean operations are proposed for the topological change of tissue

Computer Animation and Virtual Worlds, 2013

This issue is a special issue with selected papers from Motion in Games (MIG) 2012, which was hel... more This issue is a special issue with selected papers from Motion in Games (MIG) 2012, which was held during November 15–17 in Rennes, France. Five papers were selected by a review committee composed of Paul Kry, McGill University; Rachel McDonnell, Trinity College Dublin; and Arjan Egges, Utrecht University. The review committee took into account not only the manuscripts but also the presentations and the potential for impact on the motion in games area that is being nurtured by MIG. This special issue contains four out of the five selected papers. The fifth paper will appear in the next issue of Computer Animation & Virtual Worlds. The first paper on this issue is from Peter Sandilands, Myung Geol Choi and Taku Komura, from the University of Edinburgh, UK. The authors propose a technique for action motion capture that allows them to capture an object’s motion and geometry alongside a character’s movement and local environment, using a magnetic motion capture system and a RGB-D sensor. Traditional methods of actor motion capture do not give any information about the spatial relationship between objects you may interact with, or are limited to large props and motions that are not occluded during capture. The proposed method not only gives greater information when placing a character in the scene, but enables the authors to digitally recreate the scene in motion without significant animator work after capture. The second paper by Junghyun Ahn, Stephane Gobron, Daniel Thalmann, and Ronan Boulic, from Ecole Polytechnique Federale de Lausanne (EPFL), Switzerland, and NTU, Singapore, addresses emotional expressivity for embodied conversational agents by considering asymmetric facial expressions. The asymmetry of facial expressions helps to convey complex emotional feelings such as conflicting and/or hidden emotions due to social conventions. The proposed linear model can automatically drive a large number of autonomous virtual humans, or support the interactive design of complex facial expressions over time. The approach produces facial expressions for most of the emotional spectrum and it can also achieve more complex ambivalent feelings when differing emotions are applied on the left and right sides of the face. The third paper by Robert Backman and Marcelo Kallmann from the University of California, Merced, presents a system that allows non-programmers to create ge-

Proc. of Comp. Graphics Int'l (CGI 2004), 2004

AVSP, 2001

For realistic speech animation, smooth viseme and expression transitions, blending and co-articul... more For realistic speech animation, smooth viseme and expression transitions, blending and co-articulation have been so far studied and experimented widely. In this paper, we describe an approach for speech animation by smooth viseme transition. Though this method cannot form an alternative to the coarticulation phenomenon, it certainly takes us a step nearer to realistic speech animation. The approach is devised as a result of the Principal Component Analysis of facial capture data extracted using an optical tracking system. The system extracts the 3D positions of markers attached at the specific feature point locations on face to capture the facial movements of a talking person. We form a vector space representation by using the Principal Component Analysis of this data. We call this space the "viseme space". We use the viseme space to generate convincing speech animation and to make smooth transitions from one viseme to another. As the analysis and the resulting viseme space automatically consider the dynamics of and the deformation constraints on the facial movements, the resulting facial animation is very realistic.

Abstract In this paper, an interactive tool is proposed for the visualization, editing and manipu... more Abstract In this paper, an interactive tool is proposed for the visualization, editing and manipulation of multiple track sequences. A sequence is associated with an articulated figure and can integrate different motion generators such as walking, inverse kinematics, ...

During her illustrious career, she also established MIRALab in Switzerland, a ground-breaking int... more During her illustrious career, she also established MIRALab in Switzerland, a ground-breaking interdisciplinary multimedia research institute. She participated in more than 50 European research projects, helping MIRALab to develop revolutionising interdisciplinary research in computer graphics, computer animation, and virtual worlds and producing impactful work that synergises art, fashion, computer graphics. Her work is regularly displayed at museums, galleries and fashion shows. Her most recent work includes the 3D virtual patient, including a case study on visualizing the articulations of ballerinas while dancing or soccer players.