SIGGRAPH 97 Course 23

Artificial Life for Graphics, Animation, Multimedia, and Virtual Reality

Tuesday / Full Day / Intermediate

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This course investigates the increasingly important role that concepts from the field of artificial life are playing across the breadth of computer graphics, including image synthesis, modeling, animation, multimedia, and virtual reality. Attendees will be systematically introduced to techniques for realistically modeling and animating objects that are alive. They will also explore graphics techniques that emulate phenomena fundamental to biological organisms, such as biomechanics, behavior, growth, and evolution. The challenge is to develop sophisticated graphics models that are self-creating, self-evolving, self-controlling, and/or self-animating by simulating the natural mechanisms of life.

Topics include modeling and animation of plants, animals, and humans, behavioral animation, communication and interaction with synthetic characters in virtual worlds, and artificial evolution for graphics and animation.

Who Should Attend
Graphics researchers and practitioners, including animators and VR enthusiasts, seeking a close encounter with ``life'' at the leading edge of graphics modeling.



Demetri Terzopoulos, Professor
Department of Computer Science, University of Toronto
King's College Road, Toronto, ON, Canada M5S 1A4
email: dt@cs.toronto.edu


Bruce Blumberg, Professor
Media Laboratory, Massachusetts Institute of Technology
20 Ames Street, Cambridge, MA 02139
email: bruce@media.mit.edu

Przemyslaw Prusinkiewicz, Professor
Department of Computer Science, University of Calgary
University Dr. NW, Calgary, AL, Canada, T2N 1N4
email: pwp@cpsc.ucalgary.ca

Craig Reynolds, Computer Scientist
DreamWorks SKG
100 Universal Plaza, Building 601, Universal City, CA, 91608
email: cwr@anim.dreamworks.com

Karl Sims, Founder
Genetic Arts
8 Clinton Street, Cambridge, MA 02139
email: ksims@media.mit.edu

Daniel Thalmann, Professor
Computer Graphics Lab, Swiss Federal Institute of Technology
CH-1015 Lausanne, Switzerland
email: thalmann@lig.di.epfl.ch

Bios of the Instructors


Computer graphics modeling for animation, multimedia, and virtual reality has made significant advances in the last decade. The field has witnessed the transition from an earlier generation of purely geometric models to more elaborate physics-based models. We can now simulate and animate a variety of real-world objects with stunning realism. Where do we go from here?

Graphics researchers have begun to explore a new frontier--a world of objects of enormously greater complexity than is typically accessible through geometric or physical modeling alone--objects that are alive. The modeling and simulation of living systems for computer graphics resonates with the burgeoning field of scientific inquiry called Artificial Life. Conceptually, artificial life transcends the traditional boundaries of computer science and biological science. The natural synergy between computer graphics and artificial life can be potentially beneficial to both disciplines. As this course will demonstrate, potential is becoming fulfillment.

The goal of the course is to investigate the vital role that concepts from artificial life can play in the construction of advanced graphics models for animation, multimedia, and virtual reality. The course will demonstrate and elucidate new models that realistically emulate a broad variety of living things--both plants and animals--from lower animals all the way up the evolutionary ladder to humans. Typically, these models inhabit virtual worlds in which they are subject to physical laws. Consequently, they often make use of physics-based modeling techniques. More significantly, however, they must also simulate many of the natural processes that uniquely characterize living systems--such as birth and death, growth, natural selection, evolution, perception, locomotion, manipulation, adaptive behavior, learning, and intelligence. The challenge is to develop sophisticated graphics models that are self-creating, self-evolving, self-controlling, and/or self-animating by simulating the natural mechanisms fundamental to life.

The course shows how artificial life techniques are currently being exploited in graphics, animation, multimedia, and virtual reality and will progress according to the six sessions summarized below:

  1. Artificial Plants (Przemyslaw Prusinkiewicz):
    This segment of the course will show how to use formalisms inspired by biological development processes to grow highly complex and realistic graphics models of plants. We will review Lindenmayer systems, introduced as a theoretical framework for studying the development of simple multicellular organisms and subsequently applied to the study of higher plants. Geometric and stochastic plant models expressed using L-systems have been extended in a manner suitable for simulating the interaction between a developing plant and its environment, including light, nutrients, and mechanical obstacles. We will also explain how to model the response of plants to pruning, which yields realistic synthetic images of sculptured plants found in topiary gardens.

  2. Artificial Evolution for Graphics and Animation (Karl Sims):
    This segment will show how artifical evolution allows virtual entities to be created without requiring detailed design and assembly. We will show how to evolve complex genetic codes that describe the computational procedures for automatically growing entities useful in graphics and animation. Fortunately, graphics practitioners are not required to understand these codes. Instead, they simply specify which results are more and less desirable as the entities evolve. This is a form of digital Darwinism. We will demonstrate the artificial evolution of several types of graphical entities, including virtual plants, textures, animations, 3D sculptures, and virtual creatures.

  3. Behavioral Animation and Evolution of Behavior (Craig Reynolds):
    This segment will demonstrate how complex animations can emerge with minimal effort on the part of the animator from behavioral rules governing the interaction of many autonomous agents within their virtual world. We will review a classic experiment, the flocking of ``boids,'' that convincingly bridged the gap between artificial life and computer animation. We will explain how this behavioral animation technique has been used to create special effects for feature films, such as the animation of flocks of bats in Batman Returns and herds of wildebeests in The Lion King. We will also explain how to automatically evolve behaviors that allow multiple animate agents to perform useful tasks such as navigation and game playing for multimedia applications.

  4. Artificial Animals (Demetri Terzopoulos):
    This segment will show how to build highly realistic models of animals for use in animation and virtual reality. We will present a modeling approach in which we simulate the physics of the animal in its world, the animal's use of physics for locomotion, and its ability to link perception to action through adaptive behavior. As a concrete example, we will explain the details of an autonomous virtual fish model. The artificial fish has (i) a 3D body with internal muscles and functional fins which locomotes in accordance with biomechanic and hydrodynamic principles, (ii) sensors, including eyes that can image the virtual environment, and (iii) a brain with motor, perception, behavior, and learning centers. We will present a general approach to teaching artificial animals to perform complex locomotion tasks. Similar zoomimetic modeling principles are applicable to human animals. In particular, we will explore the highly automated construction of anatomically correct, functional models of people's heads from scanned data for facial animation.

  5. Artificial Humans in Virtual Worlds (Daniel Thalmann):
    This segment of the course comprises an in-depth investigation of techniques for modeling and animating the most complex living systems--human beings. In particular, we will explore the increasingly important role of perception in human modeling. Virtual humans are made aware of their virtual world by equipping them with visual, tactile, and auditory sensors. These sensors provide information to support human behavior such as visually directed locomotion, manipulation of objects, and response to sounds and utterances. We will demonstrate sensor-based navigation, game playing, walking on challenging terrain, grasping, etc. We will also explore communication between virtual humans, behavior of crowds of virtual humans, and communication between real and virtual humans. Techniques for real-time virtual humans in real scenes will also be discussed.

  6. Interactive Autonomous Agents (Bruce Blumberg):
    In the final segment of the course, we explore the design and implementation of systems that enable full-body interaction between human participants and graphical worlds inhabited by artificial life forms that people find engaging. Entertaining agents can be modeled as autonomous, behaving entities. These agents have their own goals and can sense and interpret the actions of participants and respond to them in real time. We will explore immersive, nonintrusive interaction techniques requiring no goggles, data-gloves/suits, or tethers. The general approach will be illustrated with the ALIVE (Artificial Life Interactive Video Environment) system, which many participants have experienced at SIGGRAPH exhibitions.


Time Topic Speaker
08:30 Introduction Terzopoulos
08:45 Artificial Plants Prusinkiewicz
09:45 Artificial Evolution for Graphics and Animation Sims
10:00 Break
10:15 Artificial Evolution, cont'd Sims
11:00 Behavioral Animation Reynolds
12:00 Lunch
13:30 Artificial Animals Terzopoulos
14:30 Artificial Humans in Virtual Worlds Thalmann
15:00 Break
15:15 Artificial Humans, cont'd Thalmann
15:45 Interactive Autonomous Agents for VR Blumberg
16:45 Questions & Answers
17:00 Adjourn

Movies (from the SIGGRAPH'95 version of the course)

sims.mov.gz | reynolds.mov.gz | blumberg.mov.gz | terzopoulos.mov.gz | thalmann.mov.gz