Animation by Adaptation
Tutorial 2: Motion Editing

Outline

Where we left off…

Why change a perfectly good motion?

The Plan…

The Challenge…

Motion Editing

Properties of Motion

What makes this walk this walk?

Quiz: Name That Motion!

A Motion Curve

Transformation Basics
Change what isn’t important, retain what is

Transformation as Constrained Optimization

What kinds of constraints

Spacetime Constraints

Spacetime Basics

“Original Spacetime”
Witkin and Kass, SIGGRAPH ‘98

Spacetime Motion Editing
Gleicher ’97, ’98

Basic Idea 1: Constraints

Basic Idea 2: Frequency Content

Retargetting Motion to New Characters

What properties to preserve?
What is “important”?

Retargetting Recipe

Retargetting Recipe

Retargetting Results

Want Better Results?
Devise Better Constraints!

Collision Constraints

Constraints don’t fix everything…

Other Editing Tricks

Wins and Losses of Spacetime

Is there an alternative?

Per-Frame IK + Filter (PFIK+F)

PFIK+F vs. Spacetime

PFIK+F vs. Spacetime

My PFIK+F solver

Downsides of PFIK+F?

The Idea

What is Path Editing?

Why Edit Paths?
(because previous work can’t do it)

How to Edit a Path

What is a Path?

Orientations

Path Editing is just…
A Moving Tile on the Floor

Path Mathematics…

Wait! Isn’t this just…

In Practice…

The Importance of Timing

Closest-point Parameterization

Details:
Arc-Length Parametrization

Details of Motions:
Constraints

Animation by Adaptation!

What’s next?
Graphics group projects

What’s next?
Graphics group projects

Thanks!