CSC417/CSC2549-Physics-based Animation Fall 2021

image courtesy David Levin

Instructors

Prof. David I.W. Levin
Email: diwlevin@cs.toronto.edu
Webpage

Office Hours: Thursdays 17:00-18:00 first two weeks on Zoom Zoom link will be sent to registered students

TA

Yixin Chen

Haoda Li

Jonathan Panuelos

Email Instructor and TAs: csc417tas@cs.toronto.edu

Lectures

Thursday 15:00-17:00 first two weeks on Zoom

Tutorials

Tuesday 10:00-11:00 first two weeks on Zoom

Zoom links will be emailed to registered students

Links

Discussion board using Piazza
Hand in assignments using MarkUs.

Course Overview

This course is designed to introduce students to the field of physics-based animation by exposing them to the underlying mathematical and algorithmic techniques required to understand and develop efficient numerical simulations of physical phenomena such as rigid bodies, deformable bodies and fluids. In Physics-Based Animation we will learn how to develop algorithms that produce visually compelling representations of physical systems. We will learn the underlying continuous mathematics describing the motion of physical objects, explore how to discretize them and how to solve the resulting discrete equations quickly and robustly.

Prerequisites: C/C++ Programming, Linear Algebra, Calculus, Numerical Methods

The student is expected to read background material as necessary and should be comfortable with elementary linear algebra, geometry, and vector calculus. It is also assumed that the student is comfortable programming in basic C++.

(Strongly) Recommended preparation: Multivariable Calculus

Helpful Resources

The Variational Principles of Mechanics (Book)

Calculus of Variations

Numerical Methods for Evolutionary Differential Equations (Book)

Fluid Simulation for Graphics (Book)

Fluid Simulation for Graphics (Notes)

Real-time Collision Detection (Book)

Real Time Physics (Website)

FEM Simulation of 3D Deformable Solids (Website)

Matrix and Linear Algebra Identities (PDF)

Geometric Tools (Website)

Material Point Method SIGGRAPH Course (PDF)

Two-Minute Papers (YouTube not strictly physics, but cool)

Prof. Shinjiro Sueda's Rigid Body Mechanics Notes for Joints

Great Book on Geometric Time Integration by Hairer

libigl for geometry processing

Lecture Schedule (Due dates are day/month)

NOTE: Video and Assignment content maybe updated as the course progresses

Week Topic / Event
1 Reading
Academic Policy
Grading Scheme
Late Policy
Videos
Introduction
Slides
Research Highlight
Fast Mass-Spring Systems
Assignment 1 (1D mass-springs) bonus 24/9
2 Video
Explicit and implicit time integration
Slides
Research Highlight
Discrete Elastic Rods
Working on A1
3 Video
Mass-spring systems in three dimensions
Slides
Research Highlight
Shape Matching
Assignment 2 (3d mass-springs) bonus 1/10
4 Videos
Finite Elements for Solids I
Gradients and Hessians with MATLAB’s Symbolic Toolkit
Derivatives!
Avengers:Endgame Simulation Breakdown
Slides
Research Highlight
Position-Based Dynamics
Assignment 3 (3d FEM) bonus 15/10
5 Video
Finite Elements for Solids II
Slides
Research Highlight
Frame-Based Elastic Models
Working on A3
6 Video
Finite Elements for Simulating Cloth and Shells
Slides
Research Highlight
Homogenized Yarn-Level Cloth
Assignment 4 Finite Elements for Cloth Simulation bonus 29/10
7 No new videos but there will be class
8 Videos
Rigid body mechanics
Rotation Matrix Time Derivatives
Slides
Assignment 5 Rigid body simulation bonus 5/11
November 8 Drop date (consider if grade so far is <50%)
9 Video
Jointed Rigid Body Systems
Work on A5
10 Video
Rigid Body Collision
Slides
Research Highlight
Anisotropic Elasticity for Inversion-Safety and Element Rehabilitation
Assignment 6 (Collision Resolution) due (26/11)
11 Videos
The Material Derivative
Fluid Simulation
Slides
Research Highlight
Variational Stokes
Work on A6
12 Research Highlight
On the accurate large-scale simulation of ferrofluids

Academic Honesty (required reading)

Final Project

The final project should involve implementing one physics-simulation algorithm from a number of choices provided by the professor (coming soon). The projects will be taken from popular research papers. While the course will cover all the mathematical an technical concepts required to complete the projects, it will not cover the algorithms in detail. Projects can be done in up to groups of two (2) with no exceptions.

UPDATE: Implement an algorithm from one of these papers, more complete implementations are expected from lower degree of difficulty submissions

Difficulty (1 Easiest, 4 Hardest) Paper
1 Large Steps in Cloth Simulation
1 Stable Fluids
1 Projective Dynamics
1 Discrete Shells
1 Meshless Deformations Based on Shape Matching
1 Stable Neo-Hookean Flesh Simulation
2 Discrete Elastic Rods
2 Discrete Viscous Threads
2 FEPR: Fast Energy Projection for REal-Time Simultion of Deformable Objects
2 Velocity-based shock propagation for multibody dynamics animation
2 Position Based Fluids
2 Animating Sand as a Fluid
3 Variational Stokes: A Unified Pressure-Viscosity Solver for Accurate Viscous Liquids
3 Incremental Potential Contact: Intersection- and Inversion-free Large Deformation Dynamics
3 Linear-Time Dynamics using Lagrange Multipliers
3 High-order Differentiable Autoencoder for Nonlinear Model Reduction
3 A Fast Variational Framework for Accurate Solid-Fluid Coupling
3 The Affine Particle-In-Cell Method
3 Interactive Differentiable Dynamics
4 ADD: Analytically Differentiable Dynamics for Multi-Body Systems with Frictional Contact

Deliverable: The code for your algorithm (in Python, C++ or MATLAB) along with instructions to compile and run the implementation. A two (2) page writeup of the algorithm in the style of a short SIGGRAPH paper. A 5-minute SIGGRAPH style video showing the results of your method.

Due Date: December 21st at 11:59pm.

Example Report

Example Video

Suggested Structure

Treat your video like a 5-minute presentation of your work (in lieu of a final presentation). You don't have to show yourself in the video, but a good suggested organization is (1) Introduce the problem (2) Mention the important resources you used (3) Outline the algorithm (4) show some results.

Document Templates (use Technical Brief)

Grading

% Item
60% Assignments (top 5 of 6)
40% Final Project

Lateness Policy

Please read, this course has an involved late policy aimed at giving you maximum flexibility in scheduling your semester

Assignments are due by 11:59pm on the three due dates below.

0.007% off for every minute late.

Assignments 1,2,3,4 must be handed in by November 19th at 11:59 pm.
Assignments 5 and 6 must be handed in by December 17th at 11:59 pm.
The final project must be handed in by December 21st at 11:59 pm.

Extensions to the dates above can only be issued by the instructor.

THERE ARE NO LATE PENALTIES APPLIED TO ANY OTHER DEADLINES ASIDE FROM THE THREE (3) DEADLINES DIRECTLY ABOVE THIS TEXT.

**IMPORTANT: ** Students who hand in their assignments on the due dates in the schedule above will be awarded a five (5) percent bonus on the assignment grade up to a maximum score of one-hundred (100) percent.

Academic Honesty

Academic honesty is a very serious matter and can result in very serious consequences. Note that academic offences may be discovered and handled retroactively, even after the semester in which the course was taken for credit. This is a challenging class aimed at teaching you the fundamentals of computer graphics. You wont learn much if you cheat but you might get a good grade if you get away with it. If all you want is a good grade take an easier class where you wont have to cheat!

For purposes of this class, academic dishonesty is defined as:

  • Any attempt to pass off work on an assignment that didn't come straight out of your own head.
  • Any collaboration on written or programming assignments (its ok to share ideas on programming assignments but the code MUST be your own) in which the collaborating parties don't clearly and prominently explain exactly who did what, at turn-in time.
  • Any activity that has the effect of significantly impairing the ability of another student to learn. Examples here might include destroying the work of others, interfering with their access to resources (e.g., digital cameras), or deliberately providing them with misleading information.

Email & Bulletin Board Traffic

  • Use GitHub issues for answering questions about class subject matter or about the assignments. The TAs and the instructor will monitor the issues pages. Email sent to the instructor or TAs regarding these matters will be ignored.
  • Remark requests will be handled through MarkUs.
  • Appropriate use of issues page: clarifications on assignment, on lecture material, general concerns about the course, or other remarks that are appropriate for all students to see/participate in.
  • Do NOT broadcast pieces of your code or answers to written assignments to the issues page. Specific or general implementation questions whose answer would benefit all students in the class are appropriate.
  • Questions of the form "I cannot find the problem with my code; here it is, can you help me" are unlikely to be replied, so don't count on it.