Modeling and Simulating Bodies and Garments (eBook)

Professor Nadia Magnenat-Thalmann is currently Professor at the University of Geneva in Switzerland and Director of the research lab MIRALab. After having obtained several diplomas in various disciplines (Psychology, Biology, Chemistry, Computer Science and a PhD in Quantum Physics, all from University of Geneva), she moved to Canada in 1977 where she became subsequently assistant, associate and full Professor at the University of Montreal. During these years, she pioneered the field of Virtual Humans and received 7 artistic awards for her participation to the film “Dreamflight”. This film won an award at the conference On-Line in London, in front of Disney's film "Tron" in 1982. She further developed a strong agenda of interdisciplinary research that was considered by the scientific community as a very early innovation. In 1987, she was nominated Woman of the Year by the greater Montreal Association for her exceptional achievement in Sciences and Art. In 1988, she received a one year grant from the Council of Arts of Canada for her co-direction of the film “Rendez-vous in Montreal” that allows her to show her work on Virtual Marilyn at the Modern Art Museum in New York along with young Canadian promising artists. Back in Switzerland in 1988, she has initiated and developed several programs of intensive research that have been awarded by the European Commission and the Swiss National Foundation. She has obtained more than 45 European projects that makes her group the most EU funded lab in Switzerland. During the nineties and 2000, she has received continuously scientific and artistic awards. Among the most cited awards are the Golden Camera Award at the Golden Camera Ceremony in Berlin (shown at TV with 16 million viewers), a ZDF program dedicated to "die virtuelle Marilyn, die Welt von Nadia Thalmann", more recently her selection in the electronic Wall of Fame in the Heinz Nixdorf Museum in Germany and the best paper of the International Journal of Virtual Reality for the year 2007 (award obtained by vote of the readers). She is regularly invited by the European Commission to contribute to the writing of white papers, particularly for the Networked Media Unit dealing with the 3D internet as she is coordinating a Network of excellence in Network Virtual Realities (intermedia.miralab.ch). She recently directed the research and the production of a new awarded film, High Fashion in Equations, that was shown at the Museum of Yverdon and at the electronic theatre in SIGGRAPH 2007, film selected among 1000 submissions, most of them from Disney, Pixar and DreamWorks and other major production houses. The film has received since then two artistic awards in 2007 and 2008. Professor Nadia Magnenat-Thalmann has contributed, along with her students, to the publication of more than 480 scientific papers, written more than 40 books and produced more than 25 virtual reality interactive shows. Professor Nadia Magnenat-Thalmann is Editor-in-chief of several scientific journals, among them, the Visual Computer published by Springer and the Computer Animation Virtual Worlds Journal published by Wiley. She is also associate Editor of several others, as for example, the IEEE Transactions Journal on Multimedia. She has been invited to present and discuss the impact of her work at the World Economic Forum in Davos from 1999 to 2001.

Preface 6
Contents 8
List of Figures 12
Chapter 1: Modeling Bodies 20
1.1 Introduction 20
1.2 Geometric Modeling 21
1.2.1 Basic Geometric Deformations 22
1.2.2 Free Form Deformation 23
1.3 Physically Based Modeling 31
1.4 Anatomic and Anthropometric Body Modeling Techniques 33
1.5 Data Acquisition 43
1.5.1 Data Acquisition and Reconstruction Pipeline 44
1.5.2 Data Resolution and Data Format 46
1.5.3 Scan Data Based Modeling Approaches 47
References 48
Chapter 2: Character Based Adaptation 50
2.1 Introduction 50
2.1.1 Character Animation 50
2.2 Previous Works 52
2.3 A Footskate Removal Method for Simplified Characters 54
2.3.1 Feet Motion Analysis 55
2.3.1.1 Foot Selection 55
2.3.1.2 Vertex Selection 56
2.4 Root Translation Correction 57
2.4.1 Horizontal Correction 57
2.4.2 Vertical Correction 59
2.5 Character Movements Adaptation 61
2.5.1 Introduction 61
2.5.2 Skeleton Design 63
2.5.2.1 Limbs Simplification 64
2.5.2.2 Vertex/Cylinder Allocation 66
2.5.2.3 Penetration Calculation 67
2.5.3 Arms Adaptation 68
2.5.3.1 Penetration Removal 68
Objective Function 69
2.5.3.2 Forearm Orientation Correction 70
2.5.4 Legs Adaptation 72
2.5.5 General Purpose Collisions Removal 74
2.5.6 Balance Correction 74
2.5.6.1 Character Setup 75
Weights Estimation 75
Threshold Distances Calculation 76
2.5.6.2 Balance Optimization 77
2.5.6.3 Runtime System 79
Radial Basis Functions 81
Data Pre-processing 83
Skeleton Adaptation 84
A Growing Body 85
Joints Translation 87
References 87
Chapter 3: Cloth Modeling and Simulation 90
3.1 A Brief History on Garment Simulation 90
3.2 Measuring Physical Parameters 94
3.2.1 Introduction 94
3.2.2 The Concept of Fabric Hand 94
3.2.2.1 Subjective Fabric Hand Assessment 96
3.2.2.2 Objective Hand Measurements 97
Fundamental Research 97
Kawabata (KES-f) (Kawabata 1980) 102
Other Measurement Systems 108
3.2.3 Fabric Drape 108
3.2.4 Mechanical and Physical Fabric Properties in Virtual Simulation Systems 110
3.3 Physical Simulation of Cloth 111
3.3.1 Introduction 111
3.3.2 Physical Properties of Cloth Materials 112
3.3.3 Simulation Models 114
3.3.3.1 Generalities on Mechanical Simulation 114
3.3.3.2 State-of-the-Art in Cloth Simulation Techniques 115
3.3.4 A Simple Method for Accurate Simulation of Nonlinear Cloth Materials 118
3.3.5 Numerical Integration 122
3.3.5.1 Explicit Integration Methods 122
3.3.5.2 Implicit Integration Methods 124
3.3.6 Collision Processing 125
3.3.6.1 Techniques for Collision Detection on Cloth Objects 127
3.3.6.2 Collision Response 129
3.3.6.3 Repairing Collisions 130
3.3.7 Real-Time Garment Animation 131
3.3.7.1 Real-Time Garment Animation on a Virtual Character 132
3.4 Touching Virtual Textiles 134
3.4.1 Haptic Interaction with Virtual Textiles: The Problems to Solve 135
3.4.1.1 Abstraction of the Real World Scenario 136
3.4.1.2 Development of Physically Based Simulation Techniques to Render the Cloth Behavior According to the Specified Fabric 136
3.4.1.3 Design and Realization of a Haptic Interface Able to Provide Both Tactile and Kinesthetic Stimuli 137
3.4.1.4 Cross-Modal Validation of the Complete System 137
3.4.2 The Sense of Touch 137
3.4.2.1 The Tactile Sense 138
3.4.2.2 The Kinesthetic Sense 138
3.4.3 Rendering Touch Signals 139
3.4.3.1 The Haptic Interaction Process 139
3.4.3.2 Tactile Rendering 140
3.4.3.3 Force Rendering 141
3.4.4 Haptic Interfaces 142
3.4.4.1 Commercial Devices 143
3.4.4.2 Tactile Actuators 143
3.4.4.3 Multipoint Force-Feedback Devices 145
3.4.4.4 Integration and Synchronization 145
3.4.5 The EU Project HAPTEX: Concepts and Solutions 147
3.4.5.1 Validation 147
3.4.5.2 Results 149
Textile Simulation 149
Fabric Measurements 149
Force-Feedback and Tactile Rendering 150
Whole Haptic Interface 150
Milestones 151
References 151
Chapter 4: Designing and Animating Patterns and Clothes 158
4.1 Introduction 158
4.2 Pattern Design 159
4.2.1 Digitalization 159
4.2.2 Import from CAD Software 159
4.2.3 Extraction of the Outer Shell Pattern Pieces 160
4.3 Pattern Placement 161
4.4 Seaming 162
4.5 Fabric Properties 162
4.6 Garment Fitting 163
4.7 Comparison of Real and Virtual Fitting Processes 164
4.7.1 Physical Precision of the Simulation Result 166
4.8 The Making of the Award Winning Film: High Fashion in Equations 168
4.8.1 Introduction 168
4.8.2 Robert Piguet 169
4.8.3 Inspiration 170
4.8.4 Design and Implementation 171
4.8.4.1 Unlimited Parameters for Virtual Representations 171
4.8.4.2 Design of 2D Patterns 173
4.8.4.3 Fabric Material 173
4.8.4.4 Intended Aesthetic 175
4.8.4.5 Animation 176
4.8.4.6 Final Composition 176
4.8.5 Result 177
References 178
Chapter 5: Virtual Prototyping and Collaboration in the Clothing Industry 180
5.1 Introduction 180
5.2 The New Market Trend 182
5.3 Virtual Prototyping of Garments 182
5.3.1 Current Design and Manufacturing Paradigms 183
5.3.2 Current Online Garment Customization 185
5.3.3 MIRALab’s Virtual Try On 186
5.4 Collaboration in Virtual Clothing 190
5.4.1 Distinction Between PDM and PLM 190
5.4.2 PDM/PLM in the Apparel Industry: Current Solutions/Examples and Their Benefits 192
5.5 Future Challenge: Co-design 192
5.6 Towards a Co-design Virtual Garments Platform 193
5.6.1 Related Work 194
5.6.2 Design Considerations 196
5.6.3 Communication Architecture 196
5.6.4 User Membership Management 198
5.6.5 Content Transmission Scheme 199
5.6.6 Event Management 200
5.6.7 Proposed Architecture 200
5.6.8 Overall Architecture 201
5.6.8.1 Application Stub 202
5.6.8.2 Node Manager 203
5.6.8.3 Event Manager 203
5.6.8.4 Communication Manager 204
References 204