ANIMATION

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Introduction to Animation• To animate can be thought of as, “to bring

to life”• Animation = An illusion of movement

created by sequentially playing still image frames with different movements at the general rate of 15 - 30 fps (frames per second)

• Animation = rapid display of a sequence of images of 2-D or 3-D artwork or model positions in order to create an illusion of movement.

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How Animation Works• Animation is achieved by adding motion to still image/object.• May also be defined as the creation of moving pictures one

frame at a time.• Few types of animation▫ Layout transition▫ Process/ information transition▫ Object movement

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This animation moves at 10 frames per second.

This animation moves at 2 frames per second. At this rate, the individual frames should be discernible

Introduction to AnimationAnimation is possible because of •a biological phenomenon known as persistence of

vision ▫An object seen by human eye remains chemically mapped

on the eye’s retina for a brief time after viewing•a psychological phenomenon called phi▫Human’s mind need to conceptually complete the

perceived action i.e. translating the action

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How Animation Works

• Combination of these two (persistence of vision + phi) make it possible for a series of images that are changed very slightly and very rapidly, one after another, to seemingly blend together into a visual illusion of movement.

• E.g. a few cells or frames of rotating logo, when continuously and rapidly changed, the arrow of the compass is perceived to be spinning.

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Still images are flashed in sequence to provide the illusion of animation

How Animation Works

•Still images are flashed in sequence to provide the illusion of animation

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How Animation Works

•The speed of the image changes is called the frame rate.

•Film is typically delivered at 24 frames per second (fps)• In reality, the projector light flashes twice per frame,

thus increasing the flicker rate to 48 times per second to remove any flicker effect.

•The more interruptions per second, the more continuous the beam of light appears, the smoother the animation.

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Types of animation• Hand-drawn• Stop motion• Animatronics• Performance animation (mocap)• Virtual models• Effects

Traditional Animation Types and Techniques• Cel animation - The animation artist

draws or paints on sheets of celluloid film. The cels are layered over the background, then photographed frame by frame.

• Stop-motion animation. Stop-motion animation is a film technique that involves shooting one frame of film at a time. A stationary camera is pointed at the object or scene. Each frame of motion picture film is exposed individually. Between exposures, the object or scene is manipulated or changed.

• Rotoscoping - is the technique of re-drawing live-action images on paper in order to capture natural motion in one's illustrations.

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"The Lost World", 1925, animation by Willis O'Brien, one of the early masters of stop-motion.

Animation Technique: Cel AnimationMade famous by Disney 1) A series of progressively different graphics are used for

each frame of film2) Elements in a scene that might move, for example

Kluang man, are drawn on sheets of transparent material called ‘cel’, and laid over a background which is drawn separately (kampung scenery for example)In producing a sequence, only the moving elements on the cel need to be redrawn for each frame, the fixed part of the scene need only be made once.

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Animation Technique: Cel Animation• Animation is drawn between keyframes.

▫ Key frames identify the start and end of some action▫ The process of filling in the action is called

tweening.

• Tweening is a process which requires calculating the number of frames between keyframes and the path the action takes, and then actually sketching on to a cel the series of progressively different outlines.

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•This image shows how two transparent cells, each with a different character drawn on them, and an opaque background are photographed together to form the composite image.

Animation Techniques - Cel Animation

http://en.wikipedia.org/wiki/Traditional_animation

Animation Technique: Stop Motion• Miniatures three-dimensional sets are used (stage,

objects)• Objects are moved carefully between shots.• Objects may include articulate figures, whose limbs

can be repositioned, or solid figures whose parts are replaced, or substitute between shots, to produce an effect of gesture, walking, and so on.

• Plasticine may be used for objects, to be manipulated between shots to produce both natural movement, and otherwise impossible changes and transformations.

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http://wallbond.org/uploaded_images/PierceStopMotion-788581.jpg

Stop-motion animation

Computer Animation – Digital cel & sprite animation•Employ the same logic and procedural concept of cel

animation.•Objects are drawn using 3D modeling software•Objects and background are drawn on different

layers, which can be put on top of one another.• Layers allow you to create separate parts of a still

image, for example, a person and the background of a scene they are walking through – so that each can be altered or moved independently.

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Computer Animation – Digital cel & sprite animation•Sprite animation – animation on moving object

(sprite).•A set of images, called faces is associated with

each sprite.•Example, a walking man, can be created by

advancing the position of the sprite (the man) and cycling through the faces (walking motion), the man can be made to walk.

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Computer Animation – Key Frame Animation• Keyframes : ▫Are drawn to provide the pose a detailed characteristic of

characters at important points in the animation.▫Example, specify the start and end of a walk, the top and

bottom of the fall.• 3D modeling and animation software will do the

tweening process▫ It fill in the gaps between the keyframes and create a

smooth animation.▫You just set the value of frames per second (fps) for your

animation.

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Example of a claymation Example of a computer animationhttp://en.wikipedia.org/wiki/Image:Pyramid_of_35_spheres_animation.gifhttp://www.dbprescott.com/girlanim.gif

Animation Techniques – Claymation And Computer Animation

http://www.cadtutor.net/dd/bryce/anim/anim.html

Basic Concepts of Tweening

Computer Animation – Hybrid Animation•Mixing cel and 3D computer

animation.•May as well include life footage.

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Animation Techniques - Kinematics

• The study of motion of jointed structure (such as people)

• Realistic animation of such movement can be complex.

• Latest technology use motion capture for complex movement animation.

• Inverse kinematics is the process of linking objects, and defining their relationship and limits.

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http://dictionary.zdnet.com/definition/motion+capture.html

Animation Techniques - Morphing

•The process of transitioning from one image to another

•When morphing, few key elements (such as a nose from both images) are set to share the same location (one the final image).

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Animation File Formats•Windows Media files : .avi, .asf or .wmv•Apple QuickTime files: .qt or .mov•Motion video files : .mpeg or .mpg•Flash files : .swf•Shockwaves files : .dcr•Animated GIF : .gif

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Creating Animation•Use digital camera to capture each drawn frame.•Scan the drawn image/frame.•Video camera (connected through video capture

card) is connected directly to computer to capture each frame of animation on disk – let it be on paper, cel, constructed on 3D set or by any other techniques discussed.

•Software tool can help create object

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The 11 Principles•Developed at Disney over the 1920s and 1930s•Described by John Lasseter (Pixar) 1987•Squash-and-Stretch, Timing, Anticipation, Follow

Through and Overlapping Action, Straight Ahead Action and Pose-to-Pose Action, Slow In and Out, Arcs, Exaggeration, Secondary Action, Appeal

•Basically, principles are driven by:▫Perceptual factors, such as directing the viewer’s

attention and smoothing the motion for easier perception

▫Conveying emotion through motion

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Traditional animationFundamental principles of traditional animation (Disney):1. Squash and stretch2. Timing3. Anticipation4. Staging5. Follow through and overlapping action6. Straight ahead action and pose-to-pose action7. Slow in and out8. Arcs9. Exaggeration10. Secondary action11. Appeal

Squash and stretch• Movement shows rigidity of an object – soft objects deform more• Squashing and stretching emphasize natural movement, object rigidity and movement speed• Squash and stretch should preserve volume• Laws of physics may be broken (e.g. stretch before impact)• Squash and stretch need not deform the object

Timing• Timing is the speed of an action• Timing helps define an action (see example previous slide)• Proper timing is critical to make the audience understand an action: time the phases (anticipation/action/reaction) so that the action is understood (not too short!) without losingattention (not too long!)• Timing defines weight of objects (including characters)

Anticipation• Anticipation is the preparation for an action

Anticipation• Often anatomical necessity; no anticipation gives an unnatural movement• Prepares audience for an action - you know hat is going to happen• Draws the attention – action is not missed and can be faster

Staging• Staging is presenting an idea so that it is unmistakably clear– Actions are staged so that they are understood– A personality is staged so that they are recognizable– An expression so that it’s visible– A mood so that it affects the audience• For good staging the audience’s attention must be where it needs to be. Staging,anticipation and timing are crucial to leading the eye• Stage only one idea at a time (or it might be ‘upstaged’)• Contrast the object of interest with the rest of the scene

Staging• Staging is much clearer when done entirely in good silhouette

Follow through and overlapping action

• Follow through is the proper termination of actions• Actions rarely end suddenly• Most movements in an action are not simultaneous; there is a ‘lead’ and there are movements that follow (or drag) behind.These movements may overlap in time

Straight ahead and pose-to-pose action• The two approaches to animation:– Straight ahead: draw all the scenes in sequence from first to last• Spontaneous, creative– Pose-to-pose: draw the main poses and fill in the inbetweens later• Focus on acting, timing

Slow in and out• A movement between two extremes is usually presented best when the movement is slowest at the extremes• May not be physically correct• Allows the viewer a little more time at the (interesting) extreme poses• Implemented by non-linear timing of the inbetweens

Arcs• Movement of (parts of) objects is generally more interesting when the movement traces an arc (splines!) instead of a straight line

Exaggeration• Exaggeration of the motions that identify an emotional state makes this state easier to see• Do not arbitrarily distort object or actions, amplify only that which enhances the underlying reason for a motion

Secondary action• Actions have consequences.These should be part of the animation to enhance a realistic complexity• Should in general be kept subordinate to the main action, to avoid detracting attention.

Computer role in animation• Computer animation can assist the traditional animation process on many levels, e.g. by– Generating inbetweens– Automating cel layering– Generating images from models• Computer enables many new applications:– animations in video games or other interactive media (i.e. without fully prescripted animation),– merging of film and animated models,– etc.

Computer animation techniques• 2D– Sprite animation– Morphing– Graphic embedding• 3D, virtual world– Object model• Articulated model• Particle system• Deformable object• Hybrid– Rendering• Motion blur– Motion models• Keyframing• Kinematics• Procedural• Motion capture