Physics of Animation

(Art/Physics 123)

Prof. Alejandro GarciaSpring 2010

My Contact Info

• Office: Science Bldg. Room 245• Office Phone: (408) 924-5244• Office Hours:

Mon. 2:00-3:00pm & Wed., 1:00-2:00pmand also available by appointment.

• E-mail: algarcia@algarcia.org• WWW: www.algarcia.org• Course website:

http://artphysics123.pbworks.com

Course Website

ArtPhysics123.pbworks.com

Course OverviewPhysics of Animation is an introduction to the principles and concepts of physics relevant to animation and special effects.

Course Outline

• Basic Animation• Character Animation• Effects Animation• Lighting and Rendering

Prerequisites

Physics of Animation is an Area R course

Course prerequisites are completion of core GE, satisfaction of WST, and upper division standing.

For students who begin continuous enrollment Fall 2005 or later, courses used to satisfy Areas R, S, and V must be taken from three separate SJSU departments or other distinct academic units.

Note that these prerequisites apply to any "SJSU Studies" course

Who Should Take This Course?

This course is most interesting for: Animation / Illustration art majors (ideally concurrent with Art 114); Film majors; non-science majors interested in animation and special-effects.

This course is less interesting for:Science and engineering majors will probably not find this course to be useful because they cover the same physics in their required courses.

Grades

• Two Term Papers (100 points each)• Homework (200 points)• Class Participation (50 points)• Final Exam (50 points)

There will also be several opportunities for extra credit.

Points Grade

500 – 401 A

400 – 301 B

300 – 201 C

200 – 101 D

100 – 0 F

Homework

• Homework will be assigned weekly; see course website for the schedule.

• Assignments will include: Shooting video reference; analyzing video using tracking software; creating stop-motion animation; and working with computer animation programs.

• You will “turn in” your homework by uploading it to your personal blog.

First Homework Assignment

Your first assignment is to set up a personal blog for this course.

You may use any system you prefer but I recommend using Blogger, which I will be using (go to artphysics123.blogspot.com).

If you already have a personal blog then I want you set up a separate blog exclusively for this course; in Blogger it's very easy to manage multiple blogs.

First Homework Assignment

Please use your real name on the blog. It will also be helpful to me if you include a recognizable photo of yourself in your profile.

This course blog will mainly be used for posting your homework assignments but you can also post other comments. It's your blog.

You are encouraged to read each others blogs, especially if you give each other helpful comments and advice.

First Homework Assignment

Once your blog has been set up, create a post entitled "The First Post"; write anything in that first post, it's just a place holder showing me that you're able to use the blog.

When your blog is set up, send me an e-mail (algarcia@algarcia.org) with the link.

5 points (First 10 persons to send me their blog get double points.)

Special Topics

Textbook / SuppliesNo textbook. Need a digital camera that can shoot video for homework. Also need a computer on which you can install programs.

DisabilitiesContact me if you’ve any special needs.

EmergenciesIf we need to leave the room, please take your stuff with you.

Cheating

• Don’t.

Demos

• Frequent in-class demos to illustrate physics and animation concepts.

• Welcome volunteers• Safety comes first• No magic tricks, just physics

Class Demo: Vampire Stake

Introduction to Animation

Three basic types of animation:

Traditional Computer Stop-motion

Animated Feature FilmsThree of the top ten films (by domestic

gross) of 2009 were animated feature films.

Combined domestic gross of nearly $700 million

Live-Action FilmsAnimation is also important in creating

special effects for live action films.

Top two grossing movies of 2009 In 2010?

CompositingAnimation is blended into live action films by compositing, which combines two or more separate images into a frame of film.

For example, all the green pixels in the left image are replaced with a computer-generated weather map.

Sin City (2005)

http://www.youtube.com/watch?v=91SiTspiFoc

King KongAnimation compositing has advanced enormously from the original King Kong to the remakes.

1933

1976

2005

Diversity in Animation

Animation is more than just

Hollywood CG blockbusters

Video GamesThe gaming industry is even bigger than

Hollywood and animation is very important.

Modern Warfare 2 grossed $300 million in first 24 hours.

Good Animation is Hard

Even with modern software tools it is difficult to create high quality animation.

Something as simple as a bouncing ball isn’t easy to animate believably.

Simple Ball Bounce Animation

This is an example of a good ball bounce animation.http://www.youtube.com/watch?v=AL6i_gHsC2E

RotoscopingAnimation is hard so producers have tried

alternatives, such as rotoscoping.

Scene is filmed and animators trace the images.

Used when the motion is too difficult for animators to capture effectively.

Patent drawing for Max Fleischer's original rotoscope (1915).

Rotoscoping in FilmsRotoscoped animation is very noticeable

so typically it’s used sparingly in films.

Rotoscope painters in modern films are mainly used to “white out” elements in a frame so that CG animation can be composited in.

A Scanner Darkly (2006)Cinderella (1950)

Waking Life (2001)

http://www.youtube.com/watch?v=_VxQuPBX1_U

Motion CaptureMotion capture is a modern tool in animation.

Scene is acted out and data from sensor points is used to assist in creating computer graphics images.

Beowulf (2007)

ILM’s motion capture system (iMoCap) was developed for the characters in the Pirates of the Caribbean sequel, Dead Man’s Chest.

Motion capture technology continues to advance because directors want to capture actors’ performances.

In-Camera Motion Capture (iMoCap)

Final Fantasy: Spirits Within (2001)

Compare the facial animation of this film …

http://www.youtube.com/watch?v=GnE64DbnUzY

Avatar (2009)…with facial animation using motion capture.

http://www.youtube.com/watch?v=cRdxXPV9GNQ

Good News, Bad News

Although rotoscoping and motion capture are useful for things like facial animation, they simply can’t match the work of a good animator.That’s the good news.

Creating good animation is hard!That’s the bad news.

How could it be made easier and better?

Physics and AnimationTo create realistic animations, animators

need to understand principles of mechanics.

Surgeons and Illustrators

Surgeons and artists learn anatomy, but for very different purposes.

Leonardo da VinciThomas Eakins

Architects and ArtistsA perspective drawing by an architect needs to be highly accurate, with precise measurements.Artists, on the other hand, usually don’t need such mathematical precision. It just has to look right.

Engineers and AnimatorsAn engineer’s calculation of motion needs to be highly accurate, with precise measurements.Animators, on the other hand, don’t need mathematical precision. But the motion has to look believable.

Real World & Animated World

Understanding the real world helps in creating interesting animated worlds.

"Animation follows the laws of physics — unless it is funnier otherwise.“Art Babbitt, Disney animator, director, and creator of Goofy

Physics EnginesAnimation and gaming software, such as

Maya, have sophisticated physics “engines” that use the laws of physics to compute motion.

Easier to use these tools knowing physics.

Four ‘A’s of Animation

In his book, Animation, The Mechanics of Motion, Chris Webster lists the following four levels for animated motion:

•Activity (arbitrary movement)•Action (physical motion)•Animation (purposeful motion)•Acting (motion with personality)

These categories are best understood by considering specific examples.

Activity (Level 1)

The opening sequence in the Star War’s movies is a good example of activity, the lowest level of animated motion.

The motion is arbitrary, without constraint of physical laws.

“Activity” (Level 1) Example

http://www.youtube.com/watch?v=Xbv8ECWEsu0

Action (Level 2)

Action is the level of animation when objects move according to physical laws, such as a bouncing ball or a waving flag.

A good “drop test” has this level of animation.

“Action” (Level 2) Example

http://www.youtube.com/watch?v=zwHFJy8X3po

Animation (Level 3)

At this level the motion not only follows the physical laws but is also intentional, such as a bird flapping its wings or a human jumping.

A walk cycle or a jump test are at this level.

“Animation” (Level 3) Example

http://www.youtube.com/watch?v=jwerYsdE9Xs

Acting (Level 4)

At this highest level not only is the motion intentional but it also conveys personality.

Curiosity Surprise Panic

“Acting” (Level 4) Example

http://www.youtube.com/watch?v=d2iqgf-YYtU

Four ‘A’s of Animation (again)1 - Activity (arbitrary movement)2 - Action (physical motion)3 - Animation (purposeful motion)4 - Acting (motion with personality)

Understanding physics helps animators achieve the second and third levels.The highest level, “Acting”, cannot be achieved without first creating animated motion that’s believable.

Next LecturePhysics of Falling

By Monday:Complete the 1st homework

(Create a personal blog for the course)