Introduction to Character Animation

Karan SinghKaran Singh

Lecture 1: CSC 2529Lecture 1: CSC 2529

Karan SinghKaran Singh

Lecture 1: CSC 2529Lecture 1: CSC 2529

Readings• Lasseter, “Principles of Traditional Animation Applied to 3D Computer

Animation”. CG paper version of chapter from "The Illusion of Life. http://doi.acm.org/10.1145/37401.37407

• Resource for early animation is the page at the Library of Congress. Quicktime movies of many famous, early films!

• History of animation timeline: Dan McLaughlin. http://animation.filmtv.ucla.edu/program/anihist.html

• Mike Gleicher's principles of animation lecture.

• Cartoon Laws of Physics

• Lasseter, “Principles of Traditional Animation Applied to 3D Computer Animation”. CG paper version of chapter from "The Illusion of Life. http://doi.acm.org/10.1145/37401.37407

• Resource for early animation is the page at the Library of Congress. Quicktime movies of many famous, early films!

• History of animation timeline: Dan McLaughlin. http://animation.filmtv.ucla.edu/program/anihist.html

• Mike Gleicher's principles of animation lecture.

• Cartoon Laws of Physics

Early Animation1908: Emile Cohl (1857-1938) France, makes his first film, "FANTASMAGORIE." This

film is considered by many to be the first animated film.

1911: Winsor McCay (1867- Spring Lake, Ohio -1934) makes his first film, LITTLE NEMO. McCay, who was already famous for his comic strips, used this film in his vaudeville act. His advice on animation was:

" Any idiot that wants to make a couple of thousand drawings for a hundred feet of film is welcome to join the club.“

1920:1920: 19 year old Walter Disney (1901-1966) started working in animation at the 19 year old Walter Disney (1901-1966) started working in animation at the Kansas City Slide Company.Kansas City Slide Company.

1928: Disney creates Mickey Mouse. 1928: Disney creates Mickey Mouse.

1974: First Computer animated film “Faim” from NFB nominated for an Oscar.1974: First Computer animated film “Faim” from NFB nominated for an Oscar.

1908: Emile Cohl (1857-1938) France, makes his first film, "FANTASMAGORIE." This film is considered by many to be the first animated film.

1911: Winsor McCay (1867- Spring Lake, Ohio -1934) makes his first film, LITTLE NEMO. McCay, who was already famous for his comic strips, used this film in his vaudeville act. His advice on animation was:

" Any idiot that wants to make a couple of thousand drawings for a hundred feet of film is welcome to join the club.“

1920:1920: 19 year old Walter Disney (1901-1966) started working in animation at the 19 year old Walter Disney (1901-1966) started working in animation at the Kansas City Slide Company.Kansas City Slide Company.

1928: Disney creates Mickey Mouse. 1928: Disney creates Mickey Mouse.

1974: First Computer animated film “Faim” from NFB nominated for an Oscar.1974: First Computer animated film “Faim” from NFB nominated for an Oscar.

The flour sack

Animation Principles

•Squash and StretchSquash and Stretch

•TimingTiming

•AnticipationAnticipation

•StagingStaging

•Follow-Through and Secondary Follow-Through and Secondary MotionMotion

•Overlapping Action and AsymmetryOverlapping Action and Asymmetry

•Squash and StretchSquash and Stretch

•TimingTiming

•AnticipationAnticipation

•StagingStaging

•Follow-Through and Secondary Follow-Through and Secondary MotionMotion

•Overlapping Action and AsymmetryOverlapping Action and Asymmetry

•Slow In and Slow OutSlow In and Slow Out

•ArcsArcs

•ExaggerationExaggeration

•AppealAppeal

•Straight-Ahead and Pose-to-Straight-Ahead and Pose-to-PosePose

•Slow In and Slow OutSlow In and Slow Out

•ArcsArcs

•ExaggerationExaggeration

•AppealAppeal

•Straight-Ahead and Pose-to-Straight-Ahead and Pose-to-PosePose

Squash and StretchRigid objects look robotic: deformations make motion naturalRigid objects look robotic: deformations make motion natural

Accounts for physics of deformationAccounts for physics of deformation

• Think squishy ball…Think squishy ball…

• Communicates to viewerCommunicates to viewerwhat the object is made of,what the object is made of,how heavy it is, …how heavy it is, …

• Usually large deformations conserve volume: if you squash one dimension, stretch in Usually large deformations conserve volume: if you squash one dimension, stretch in another to keep mass constantanother to keep mass constant

Also accounts for persistence of visionAlso accounts for persistence of vision

• Fast moving objects leave an elongated streak on our retinasFast moving objects leave an elongated streak on our retinas

Rigid objects look robotic: deformations make motion naturalRigid objects look robotic: deformations make motion natural

Accounts for physics of deformationAccounts for physics of deformation

• Think squishy ball…Think squishy ball…

• Communicates to viewerCommunicates to viewerwhat the object is made of,what the object is made of,how heavy it is, …how heavy it is, …

• Usually large deformations conserve volume: if you squash one dimension, stretch in Usually large deformations conserve volume: if you squash one dimension, stretch in another to keep mass constantanother to keep mass constant

Also accounts for persistence of visionAlso accounts for persistence of vision

• Fast moving objects leave an elongated streak on our retinasFast moving objects leave an elongated streak on our retinas

Timing

Pay careful attention to how long an action takes -- how many Pay careful attention to how long an action takes -- how many framesframes

How something moves --- not how it looks --- defines its weight How something moves --- not how it looks --- defines its weight and mood to the audienceand mood to the audience

Also think dramatically: give the audience time to understand one Also think dramatically: give the audience time to understand one event before going to the next, but don’t bore themevent before going to the next, but don’t bore them

Pay careful attention to how long an action takes -- how many Pay careful attention to how long an action takes -- how many framesframes

How something moves --- not how it looks --- defines its weight How something moves --- not how it looks --- defines its weight and mood to the audienceand mood to the audience

Also think dramatically: give the audience time to understand one Also think dramatically: give the audience time to understand one event before going to the next, but don’t bore themevent before going to the next, but don’t bore them

AnticipationThe preparation before a motionThe preparation before a motion

• E.g. crouching before jumping, pitcher E.g. crouching before jumping, pitcher winding up to throw a ballwinding up to throw a ball

Often physically necessary, and indicates Often physically necessary, and indicates how much effort a character is makinghow much effort a character is making

Also essential for controlling the audience’s Also essential for controlling the audience’s attention, to make sure they don’t miss the attention, to make sure they don’t miss the actionaction

• Signals something is about to happen, and Signals something is about to happen, and where it is going to happenwhere it is going to happen

The preparation before a motionThe preparation before a motion

• E.g. crouching before jumping, pitcher E.g. crouching before jumping, pitcher winding up to throw a ballwinding up to throw a ball

Often physically necessary, and indicates Often physically necessary, and indicates how much effort a character is makinghow much effort a character is making

Also essential for controlling the audience’s Also essential for controlling the audience’s attention, to make sure they don’t miss the attention, to make sure they don’t miss the actionaction

• Signals something is about to happen, and Signals something is about to happen, and where it is going to happenwhere it is going to happen

Staging

Make the action clearMake the action clear

Avoid confusing the audience by having two or more things Avoid confusing the audience by having two or more things happen at the same timehappen at the same time

Create anticipation through other objects in sceneCreate anticipation through other objects in scene

Select a camera viewpoint, and pose the characters, so that Select a camera viewpoint, and pose the characters, so that visually you can’t mistake what is going onvisually you can’t mistake what is going on

• Clear enough you can tell what’s happening just from the Clear enough you can tell what’s happening just from the silhouettes (highest contrast)silhouettes (highest contrast)

Make the action clearMake the action clear

Avoid confusing the audience by having two or more things Avoid confusing the audience by having two or more things happen at the same timehappen at the same time

Create anticipation through other objects in sceneCreate anticipation through other objects in scene

Select a camera viewpoint, and pose the characters, so that Select a camera viewpoint, and pose the characters, so that visually you can’t mistake what is going onvisually you can’t mistake what is going on

• Clear enough you can tell what’s happening just from the Clear enough you can tell what’s happening just from the silhouettes (highest contrast)silhouettes (highest contrast)

Follow-Through andSecondary MotionAgain, physics demands follow-through -- the inertia that’s carried over Again, physics demands follow-through -- the inertia that’s carried over after an actionafter an action

• E.g. knees bending after a jump to define weight, rigidity, etc.E.g. knees bending after a jump to define weight, rigidity, etc.

Secondary motion is movement that’s not part of the main action, but is Secondary motion is movement that’s not part of the main action, but is physically necessary to support itphysically necessary to support it

• E.g. arms swinging in jumpE.g. arms swinging in jump

Almost everything should always be in motion - “moving hold”Almost everything should always be in motion - “moving hold”

Again, physics demands follow-through -- the inertia that’s carried over Again, physics demands follow-through -- the inertia that’s carried over after an actionafter an action

• E.g. knees bending after a jump to define weight, rigidity, etc.E.g. knees bending after a jump to define weight, rigidity, etc.

Secondary motion is movement that’s not part of the main action, but is Secondary motion is movement that’s not part of the main action, but is physically necessary to support itphysically necessary to support it

• E.g. arms swinging in jumpE.g. arms swinging in jump

Almost everything should always be in motion - “moving hold”Almost everything should always be in motion - “moving hold”

Overlapping Action and AsymmetryOverlapping action: start the next action before the current one Overlapping action: start the next action before the current one finishesfinishes

• Otherwise looks scripted and robotic instead of natural and fluidOtherwise looks scripted and robotic instead of natural and fluid

Asymmetry: natural motion is rarely exactly the same on both Asymmetry: natural motion is rarely exactly the same on both sides of the body, or for 2+ characterssides of the body, or for 2+ characters

• People very good at spotting “twins”, synchronization, etc.People very good at spotting “twins”, synchronization, etc.

• Break up symmetries to avoid scripted or robotic feelBreak up symmetries to avoid scripted or robotic feel

Overlapping action: start the next action before the current one Overlapping action: start the next action before the current one finishesfinishes

• Otherwise looks scripted and robotic instead of natural and fluidOtherwise looks scripted and robotic instead of natural and fluid

Asymmetry: natural motion is rarely exactly the same on both Asymmetry: natural motion is rarely exactly the same on both sides of the body, or for 2+ characterssides of the body, or for 2+ characters

• People very good at spotting “twins”, synchronization, etc.People very good at spotting “twins”, synchronization, etc.

• Break up symmetries to avoid scripted or robotic feelBreak up symmetries to avoid scripted or robotic feel

Slow In and OutAlso called “easing in” and “easing out”Also called “easing in” and “easing out”

More physics: objects generally smoothly accelerate and More physics: objects generally smoothly accelerate and decelerate, depending on mass and forcesdecelerate, depending on mass and forces

Just how gradual it is helps define weight, mood, etc.Just how gradual it is helps define weight, mood, etc.

Also helpful in emphasizing the key frames, the most important or Also helpful in emphasizing the key frames, the most important or “extreme” poses“extreme” poses

• Character spends more time near those poses, and less time in the Character spends more time near those poses, and less time in the transitiontransition

• Audience gets better understanding of what’s going onAudience gets better understanding of what’s going on

Also called “easing in” and “easing out”Also called “easing in” and “easing out”

More physics: objects generally smoothly accelerate and More physics: objects generally smoothly accelerate and decelerate, depending on mass and forcesdecelerate, depending on mass and forces

Just how gradual it is helps define weight, mood, etc.Just how gradual it is helps define weight, mood, etc.

Also helpful in emphasizing the key frames, the most important or Also helpful in emphasizing the key frames, the most important or “extreme” poses“extreme” poses

• Character spends more time near those poses, and less time in the Character spends more time near those poses, and less time in the transitiontransition

• Audience gets better understanding of what’s going onAudience gets better understanding of what’s going on

ArcsNatural motions tend not to be in straight lines, instead should be Natural motions tend not to be in straight lines, instead should be curved arcscurved arcs

• Just doing straight-line interpolation gives robotic, weird movementJust doing straight-line interpolation gives robotic, weird movement

Also part of physicsAlso part of physics

• gravity causes parabolic trajectoriesgravity causes parabolic trajectories

• joints cause circular motionsjoints cause circular motions

Keep motion smooth and interestingKeep motion smooth and interesting

Natural motions tend not to be in straight lines, instead should be Natural motions tend not to be in straight lines, instead should be curved arcscurved arcs

• Just doing straight-line interpolation gives robotic, weird movementJust doing straight-line interpolation gives robotic, weird movement

Also part of physicsAlso part of physics

• gravity causes parabolic trajectoriesgravity causes parabolic trajectories

• joints cause circular motionsjoints cause circular motions

Keep motion smooth and interestingKeep motion smooth and interesting

ExaggerationObvious in the old Loony Tunes cartoonsObvious in the old Loony Tunes cartoons

Not so obvious but necessary ingredient in photo-realistic special Not so obvious but necessary ingredient in photo-realistic special effectseffects

If you’re too subtle, even if that is accurate, the audience will If you’re too subtle, even if that is accurate, the audience will miss it: confusing and boringmiss it: confusing and boring

Think of stage make-up, movie lighting, and other “photo Think of stage make-up, movie lighting, and other “photo surrealistic” techniquessurrealistic” techniques

Don’t worry about being physically accurate: convey the correct Don’t worry about being physically accurate: convey the correct psychological impression as effectively as possiblepsychological impression as effectively as possible

Obvious in the old Loony Tunes cartoonsObvious in the old Loony Tunes cartoons

Not so obvious but necessary ingredient in photo-realistic special Not so obvious but necessary ingredient in photo-realistic special effectseffects

If you’re too subtle, even if that is accurate, the audience will If you’re too subtle, even if that is accurate, the audience will miss it: confusing and boringmiss it: confusing and boring

Think of stage make-up, movie lighting, and other “photo Think of stage make-up, movie lighting, and other “photo surrealistic” techniquessurrealistic” techniques

Don’t worry about being physically accurate: convey the correct Don’t worry about being physically accurate: convey the correct psychological impression as effectively as possiblepsychological impression as effectively as possible

AppealMake animations that people enjoy watchingMake animations that people enjoy watching

Appealing characters aren’t necessarily attractive, just well Appealing characters aren’t necessarily attractive, just well designed and rendereddesigned and rendered

• All the principles of art still apply to each still frameAll the principles of art still apply to each still frame

• E.g. controlling symmetry - avoid “twins”, avoid needless E.g. controlling symmetry - avoid “twins”, avoid needless complexitycomplexity

Present scenes that are clear and communicate the story Present scenes that are clear and communicate the story effectivelyeffectively

Make animations that people enjoy watchingMake animations that people enjoy watching

Appealing characters aren’t necessarily attractive, just well Appealing characters aren’t necessarily attractive, just well designed and rendereddesigned and rendered

• All the principles of art still apply to each still frameAll the principles of art still apply to each still frame

• E.g. controlling symmetry - avoid “twins”, avoid needless E.g. controlling symmetry - avoid “twins”, avoid needless complexitycomplexity

Present scenes that are clear and communicate the story Present scenes that are clear and communicate the story effectivelyeffectively

Straight Ahead vs.Pose-to-Pose

The two basic methods for animatingThe two basic methods for animating

Straight Ahead means making one frame after the otherStraight Ahead means making one frame after the other

• Especially suited for rapid, unpredictable motionEspecially suited for rapid, unpredictable motion

Pose-to-Pose means planning it out, making “key frames” of the Pose-to-Pose means planning it out, making “key frames” of the most important poses, then interpolating the frames in between most important poses, then interpolating the frames in between laterlater

• The typical approach for most scenesThe typical approach for most scenes

The two basic methods for animatingThe two basic methods for animating

Straight Ahead means making one frame after the otherStraight Ahead means making one frame after the other

• Especially suited for rapid, unpredictable motionEspecially suited for rapid, unpredictable motion

Pose-to-Pose means planning it out, making “key frames” of the Pose-to-Pose means planning it out, making “key frames” of the most important poses, then interpolating the frames in between most important poses, then interpolating the frames in between laterlater

• The typical approach for most scenesThe typical approach for most scenes

ExtremesKeyframes are also called extremes, since they usually define the extreme positions of Keyframes are also called extremes, since they usually define the extreme positions of a character (key, extreme, breakdown).a character (key, extreme, breakdown).

• E.g. for a jump:E.g. for a jump:

– the startthe start

– the lowest crouchthe lowest crouch

– the lift-offthe lift-off

– the highest partthe highest part

– the touch-downthe touch-down

– the lowest follow-throughthe lowest follow-through

• The frames in between (“inbetweens”) introduce nothing new---watching the keyframes The frames in between (“inbetweens”) introduce nothing new---watching the keyframes shows it allshows it all

• May add additional keyframes to add some interest, better control the interpolated motionMay add additional keyframes to add some interest, better control the interpolated motion

Keyframes are also called extremes, since they usually define the extreme positions of Keyframes are also called extremes, since they usually define the extreme positions of a character (key, extreme, breakdown).a character (key, extreme, breakdown).

• E.g. for a jump:E.g. for a jump:

– the startthe start

– the lowest crouchthe lowest crouch

– the lift-offthe lift-off

– the highest partthe highest part

– the touch-downthe touch-down

– the lowest follow-throughthe lowest follow-through

• The frames in between (“inbetweens”) introduce nothing new---watching the keyframes The frames in between (“inbetweens”) introduce nothing new---watching the keyframes shows it allshows it all

• May add additional keyframes to add some interest, better control the interpolated motionMay add additional keyframes to add some interest, better control the interpolated motion

Computer Animation

The task boils down to setting various animation parameters (e.g. The task boils down to setting various animation parameters (e.g. positions, angles, sizes, …) in each framepositions, angles, sizes, …) in each frame

Straight-ahead: set all variables in frame 0, then frame 1, frame 2, … in Straight-ahead: set all variables in frame 0, then frame 1, frame 2, … in orderorder

Pose-to-pose: set the variables at keyframes, let the computer smoothly Pose-to-pose: set the variables at keyframes, let the computer smoothly interpolate values for frames in betweeninterpolate values for frames in between

Can mix the methods:Can mix the methods:

• Keyframe some variables (maybe at different frames), do others straight-Keyframe some variables (maybe at different frames), do others straight-aheadahead

The task boils down to setting various animation parameters (e.g. The task boils down to setting various animation parameters (e.g. positions, angles, sizes, …) in each framepositions, angles, sizes, …) in each frame

Straight-ahead: set all variables in frame 0, then frame 1, frame 2, … in Straight-ahead: set all variables in frame 0, then frame 1, frame 2, … in orderorder

Pose-to-pose: set the variables at keyframes, let the computer smoothly Pose-to-pose: set the variables at keyframes, let the computer smoothly interpolate values for frames in betweeninterpolate values for frames in between

Can mix the methods:Can mix the methods:

• Keyframe some variables (maybe at different frames), do others straight-Keyframe some variables (maybe at different frames), do others straight-aheadahead

Layering

Work out the big picture firstWork out the big picture first

• E.g. where the characters need to be whenE.g. where the characters need to be when

Then layer by layer add more detailsThen layer by layer add more details

• Which way the characters faceWhich way the characters face

• Move their limbs and headMove their limbs and head

• Move their fingers and faceMove their fingers and face

• Add small details like wrinkles in clothing, hair, …Add small details like wrinkles in clothing, hair, …

Work out the big picture firstWork out the big picture first

• E.g. where the characters need to be whenE.g. where the characters need to be when

Then layer by layer add more detailsThen layer by layer add more details

• Which way the characters faceWhich way the characters face

• Move their limbs and headMove their limbs and head

• Move their fingers and faceMove their fingers and face

• Add small details like wrinkles in clothing, hair, …Add small details like wrinkles in clothing, hair, …

Cartoons laws of physics

Cartoon Law IAny body suspended in space will remain in space until made aware of its situation. Daffy Duck steps off a

cliff, expecting further pastureland. He loiters in midair, soliloquizing flippantly, until he chances to look down. At this point, the familiar principle of 32 feet per second per second takes over.

Cartoon Law IIAny body in motion will tend to remain in motion until solid matter intervenes suddenly. Whether shot from a cannon or in hot pursuit on foot, cartoon characters are so absolute in their momentum that only a telephone

pole or an outsize boulder retards their forward motion absolutely. Sir Isaac Newton called this sudden termination of motion the stooge's surcease.

……

Cartoon Law Amendment CCartoon Law Amendment CExplosive weapons cannot cause fatal injuries. They merely turn characters temporarily black and smoky. Explosive weapons cannot cause fatal injuries. They merely turn characters temporarily black and smoky.

Production pipeline

ScriptScript

CharacterCharactersketchessketches

StoryboardStoryboard 2D animatic2D animatic

Character setupCharacter setupMotion testsMotion tests 3D animatic3D animatic

AnimationAnimationLighting,Lighting,RenderingRendering

CompositingCompositing

Post productionPost production