#### Department of Computer Science College of Arts and Sciences The University of North Carolina at Chapel Hill

COMP259: Physically-Based Modeling, Simulation and Animation

# COMP 259: Physically-Based Modeling, Simulation and Animation

## Instructor: Ming C. Lin

Time and Place: MW 2:00-3:15pm, SN115
Office Hours: MW 3:15-4:15pm, SN223
TA: Michael Henson, SN313
Prerequisites: Math 191 or COMP250 AND COMP136 or COMP235 (Images, Graphics and Vision) OR Instructor's approval
Textbook: Course Notes and In-Class Handouts

## CHECK OUT THESE VIDEO CLIPS !!!

• Course Overview
• Lectures and Approximate Schedule
• Assignments and Projects
• WEBS of Physically-Based Modeling & Animation
• Geometric Algorithms & Software Available on the Web
• Conferences in Related Areas
• ### COURSE OVERVIEW:

Physically-based modeling and simulation attempts to map a natural phenomena to a computer simulation program. There are two basic processes in this mapping: mathematical modeling and numerical solution. The goal of this course is to understand both of them. The mathematical modeling concerns the description of natural phenomena by mathematical equations. Differential equations that govern dynamics and geometric representation of objects are typical ingredients of the mathematical model. The numerical solution involves computing an efficient and accurate solution of the mathematical equations. Finite precision of numbers, limited computational power and memory forces us to approximate the mathematical model with simple procedures.

In this course, we will study various techniques to simulate the physical and mechanical behavior of objects in a graphical simulation or a virtual environment. Students will learn about implementation of basic simulation programs that produce interesting results and verify its correctness. The course will cover three basic components in physically-based modeling and simulation:

• Geometry
• Collision Detection
• Computing Contact Manifolds
• Mechanics
• Particle Dynamics
• Rigid Body Dynamics
• Non-Rigid Body Dynamics
• Numerical Computing
• Initial Value Problems
• Boundary Value Problems
• Constraints & Differential-Algebraic Equations
• The goal of this class is to get students an appreciation of computational methods for modeling of motions in the physical and virtual world. We will discuss various considerations and tradeoffs used in designing simulation methodologies (e.g. time, space, robustness, and generality). This will include data structures, algorithms, computational methods and simulation techniques, their complexity and implementation. The lectures will also cover some applications of physically-based modeling and simulation to the following areas:
• Computer Animation
• Virtual Environments
• Rapid Prototyping
• Haptic Rendering
• Computer Game Dynamics
• Robotics and Automation
• Medical Simulation and Analysis
• Depending on the interests of the students, we may also cover geometric-based simulation techniques, such as constraint-based systems, inverse dynamics, kinematics of motions, motion planning, synethesis and generation of autonomous agents.

### LECTURES AND APPROXIMATE SCHEDULE

Here is a list of TENTATIVE lecture topics (subject to changes). Schedule and information on each topic (e.g. readings, web pointers) will be added during the semester before each class.

• Overview (Wed, Jan 7, 2004)
• Basics of Motion Generations for Animation (Mon, Jan 12, 2004)
• Inverse Kinematics (Wed, Jan 14, 2004)
• MLK, NO CLASS (Mon, Jan 19, 2004)
• ODE Basics: Initial Value Problem (Wed, Jan 28, 2004)
• ODE & Particle System Dynamics (Mon, Feb 2, 2004)
• Particle System Dynamics (Wed, Feb 4, 2004)
• Constrained Dynamics (Mon, Feb 9, 2004)
• Implicit Methods (Wed, Feb 11, 2004)
• In-Class Demos (Mon, Feb 16, 2004)
• Free-Form Deformation (Mon, Feb 16, 2004)
• Cloth Simulation and Hair Simulation (Wed, Feb 18, 2004)
• Collision Detection: Basics & Convex Polyhedra and Review on Comp Geom (Mon, Feb 23, 2004)
• Collision Detection: BVHs & Spatial Partitioning (Wed, Feb 25, 2004)
• Rigid Body Dynamics (I) (Mon, Mar 1, 2004)
• Rigid Body Dynamics (II) (Wed, Mar 3, 2004)
• SPRING BREAK (March 8-12, 2004)
• Project Proposal (Mon, Mar 15, 2004)
• Continuous Collision Detection (Wed, Mar 17, 2004)
• Human Motion Synthesis (I) and Human Motion Synthesis (II) (Mon, Mar 22, 2004)
• Human Motion Synthesis (II) and Motion Capture (I) (Wed, Mar 24, 2004)
• Motion Capture (II) and Articulated Body Dynamics (Mon, Mar 29, 2004)
• Haptic Rendering (Wed, Mar 31, 2004)
• In-Class Demos (Mon, Apr 5, 2004)
• Modeling of Non-Rigid Bodies (Mon, Apr 5, 2004)
• Facial Animation Synthesis (Wed, Apr 7, 2004)
• Muscle-based Facial Animation and Introduction to Fluid Dynamics & Applications (Mon, Apr 12, 2004)
• Introduction to Fluid Dynamics & Applications and Animating Explosion (Wed, Apr 14, 2004)
• Modeling and Animating Fire and Modeling Air Flow using Lattice Boltzmann's Model (Mon, Apr 19, 2004)
• Modeling Air Flow using Lattice Boltzmann's Model and Physically-based Simulations on GPUs (Wed, Apr 21, 2004)

### Reference Papers Used in Lectures:

• SIGGRAPH Course Notes on Physically-Based Modeling
• Reading List for the Class (updated throughout the semester)

• ### ASSIGNMENTS AND PROJECTS

The class grade of each student is determined by
• Homework (30%)
• Class Presentation (20%)
• Final Project (50%)

### SELECTED RESEARCH GROUPS:

• UNC Research Group on Geometric Algorithms for Modeling, Motion and Animation
• UNC Interactive Collision Detection and Proximity Queries Packages
• Simlab: Computer Tools for Analysis and Simulation (Cornell)
• iMAGIS (GRAVIR / IMAG research lab / INRIA)
• Center for Human Modeling and Simulation(UPENN)
• MIRALab (University of Geneva)
• Rutgers Computational Biomedicine Imaging and Modeling (Rutgers)
• University of Aukland, Bioengineering Research Group
• ### RESEARCHERS:

• David Baraff (now at Pixar)
• David Breen
• Chris Bregler
• Marie-Paule Cani
• Jessica Hodgins
• Michael Gleicher
• Dimitris Metaxas
• Brian Mirtich (now at Cognex)
• Richard Parent
• Daniel Thalmann
• Demetri Terzopoulos
• Michiel van de Panne
• Andy Witkin's Gallery (now at Pixar)
• ### INDUSTRY

• Boston Dynamics Inc.
• Chris Hecker's Corner (Definition Six, Inc.)
• GamaNetwork
• Havok
• Immersion Corporation
• MAYA (Alias|Wavefront)
• MSC.Working Knowledge
• Pixar Animation Studios
• Rhythm & Hues Studios
• SensAble Technology
• Telekinesys
• ### GEOMETRIC ALGORITHMS AND SOFTWARES AVAILABLE ON THE WEB:

Here are just some possible locations to find geometric software/libraries and algorithmic toolkits you may need:
• Internet Finite Element Resources
• A comprehensive collection of geometric software
• CGAL: Computational Geometry Algorithms Library (in C++)
• LEDA: Library of Efficient Datatypes and Algorithms (in C++)
• The Stony Brook Algorithm Repository: Implementation in C, C++, Pascal and Fortran
• CMU's Computer Vision Homepage
• Finite element mesh generation and More
• Machine learning resources

### Other Reference Books in Computer Animation:

• Making Them Move: Mechanics, Control and Animation of Articulated Figures, by Badler, Barsky and Zelter, Morgan Kaufmann Publishers, 1991.
• Advanced Animation and Rendering Techniques: Theory and Practice, by A. Watt and M. Watt, 1992.
• Computer Animation: Algorithms and Techniques, by Rick Parent, 1999.
• ### Other Reference Books in Mechanics:

• Concepts and Applications of Finite Element Analysis, by R. D. Cook, D. S. Malkus and M. E. Plesha, John Wiley & Sons, 1989.
• Finite Element Procedures, by K.-J. Bathe, Prentice Hall, 1996.
• First Course in Continuum Mechanics, by Y.C. Fung, Prentice Hall, 1993.
• ### Other Reference Books in Numerical Methods:

• Numerical Recipes, by Press, Flanner, Teukolsky and Vetterling, Cambridge University Press.
• Handbook of Numerical Analysis, edited by Ciarlet and Lions, Vol. I - VI, North-Holland, 1994.
• ### Other Reference Books in Robotics:

• Robot Motion Planning, by Latombe, Kluwer Academic Publishers, 1991.
• Robot Manipulators: Mathematics, Programming, and Control, by R. P. Paul, MIT Press, 1981.
• ### Other Reference Books in Geometry:

• Computational Geometry (Algorithms and Applications), by de Berg, van Kreveld, Overmars and Schwarzkofp, Springer-Verlag, 1997.
• Computational Geometry In C (Second Edition), by O'Rourke, Cambridge University Press, 1998.
• Handbook on Discrete and Computational Geometry, by Goodman and O'Rourke (eds), CRC Press LLC, 1997.
• Applied Computational Geometry: Toward Geometric Engineering, by Lin and Manocha (eds), Springer-Verlag, 1996.
• Algorithms in Combinatorial Geometry, by Edelsbrunner, Springer-Verlag, 1987.
• Computational Geometry (An Introduction), by Preparata and Shamos, Springer-Verlag, 1985.