Virtual plants: The interplay between biology and computer graphics
Przemyslaw Prusinkiewicz
Department of Computer Science
University of Calgary
Canada

The first simulation models of plants were constructed to advance biological knowledge, yet subsequent progress in plant modeling has largely been fuelled by computer graphics. At present, plant modeling and rendering techniques are advancing in three directions: realistic image synthesis, from individual plant organs to entire plants and plant ecosystems; interactive plant modeling, invigorated by an influx of new ideas derived from sketch-based techniques; and the use of computer graphics in support of biological research on plant morphogenesis. A surprising discovery in this last category, integrating molecular biology data with computer simulations and visualizations, is a strong link between two of the most beautiful patterns in plants: phyllotactic patterns, which govern the spatial arrangement of organs, and leaf venation patterns. Using this result as a reference, the presentation will survey the interplay between biology and computer graphics in plant modeling, with a focus on current contributions and research directions.

Przemyslaw Prusinkiewicz is a University Professor of Computer Science at the University of Calgary. He holds M.Sc. and Ph.D. from the Technical University of Warsaw. His research is focused on the modeling, simulation and visualization of biological patterns and structures, in particular plants. His best known contributions are related to the applications of L-systems to computer graphics and biological modeling. Professor Prusinkiewicz is a recipient of the SIGGRAPH Achievement Award, and has received a doctorate honoris causa from the University of East Anglia.

Historical city tour in Petropolis

Located about 800 meters above sea level, Petrópolis is Rio de Janeiro's city most sought as mountain Resort and fourth largest commercial center. It is chiefly a monument to Dom Pedro II, emperor of Brazil from 1831 until his exile in 1889. Emperor Pedro I, who purchased land in the spectacular Serra do Mar for a projected summer palace, first time Petrópolis was idealized in the 1830's. However, it was his son, Pedro II, who actually built the palace and the quaint town surrounding it. The idea was to maintain a refreshing refuge from Rio's wilting summer heat.

The highway linking Rio and Petrópolis is an engineering marvel. Its concrete bridges soar over green valleys and the road curves around mountain walls revealing magnifics views of the horizon. We will see: Quitandinha Hotel, Imperial Museum, Sao Pedro de Alcântara Cathedral, Praça da Liberdade (Liberty Square), Palácio de Cristal (Crystal Palace), and Santos Dumont's Home. Lunch will be in a typical all-you-can-eat Brazilian restaurant, the "churrascaria". It's a meat eater's delight, where waiters bring over choice meats on skewers and cut slices of your choice.

This tutorial will present the latest techniques to create animatable bodies from scan data or measurements and simulate groups and crowds. Concepts of modeling hair and clothes will also be presented as well as real-time crowds for games and VR systems for training and simulation. The course will be illustrated with examples from real-time applications from several European Research projects as Emergency situations, Social Phobia, and Cultural Heritage.

Session 1 : modeling virtual humans from scan data or measurements. Modelling hair and clothes

Nadia Magnenat-Thalmann, MIRALab (45 minutes)

This session will focus on the fast creation of any virtual human shape from scanned data or measurements. We will also show how to define and animate hair and clothes and what is the state of the art today. Several examples will be shown coming for ongoing EU Research projects as Leapfrog, Lifeplus.

1. State of the art
2. VH interactive modeling techniques
3. Interactive modeling for hair and animation
4. Interactive modeling for clothes and animation
5. Case studies from Leapfrog and Lifeplus EU projects

Session 2: Real-time animation of humans and motion retargeting

Etienne Lyard, MIRALab (45 minutes)

This session will focus on virtual human animation in real time. It will cover the entire animation pipeline, from the initial data acquisition to the embodiment of the character in a 3D environment. The topics to be addressed include motion capture, Physics based animation and motion retargeting.

1. Introduction
2. Motion capture
3. Physics based animation
4. Skinning
5. Data driven animation
6. Motion retargeting

Session 3 : groups and crowds simulations techniques

Daniel Thalmann, EPFL, 45 minutes

This section will focus on the methods to animate a large number of virtual humans. Techniques to create various people with different animation will be presented as well as the rendering pipeline and the way of interacting with crowds.

1. State-of-the-Art
2. Crowd Variety
3. Animation variety
4. Crowd rendering
5. Crowd Interaction and Scripting
6. Applications
   Social phobia
   Cultural heritage

Session 4 : Relating Virtual Crowds with Real Crowds

Soraia Musse, PUCRS, Brazil (45 minutes)

This section describes some reflections concerning the challenge of capturing information from real crowds to relate it with virtual crowds. The main goal is to provide data to be used to simulate virtual crowds in a more realistic way. Five parts are described:

1. Introduction
2. a study undertaken on the motion and behavior of real crowds, where the goal is to identify some patterns of real people behaviors to be used subsequently in virtual crowds,
3. computer vision methods as automatic ways to capture information from real life to guide virtual crowds,
4. Crowd Simulation used in security applications, and
5. Putting together Crowd Simulation and Computer Vision.

This tutorial course will introduce Implicit Modelling Techniques. Dr. Wyvill has been working in the area of implicit modeling at University of Calgary, Canada since 1981 and published a number of journal papers on this field. Dr. Wyvill moved to the University of Victoria to take up a tier One Canada Research Chair in 2007. In the tutorial course the following topics in Implicit Modelling will be presented: Skeletons, Polygonization, Blending, Constructive Solid Geometry, The BlobTree, Speeding up rendering, Texturing, and Sketch Based Implicit Modeling.

This tutorial course will introduce the motivations behind building response models for character animation and will cover several aspects of character response to various interactions. The work draws from various research topics investigated by the presenter that describe physically based reactions as well as anticipatory responses to various conditions and stimuli: including full body reactions that can lead to a character falling over and the compliant response of the hand required for realistic grasping.