AnimationAnimation is the rapid display of a sequence ofimages of 2-D or 3-D artwork or model positionsin order to create an illusion of movement. It isan optical illusion of motion due to thephenomenon of persistence of vision, and canbe created and demonstrated in a number ofways. The most common method of presentinganimation is as a motion picture or videoprogram, although several other forms ofpresenting animation also exist
Traditional AnimationTraditional animation (also called cel animation or hand-drawnanimation) was the process used for most animated films of the20th century. The individual frames of a traditionally animatedfilm are photographs of drawings, which are first drawn onpaper. To create the illusion of movement, each drawing differsslightly from the one before it. The animators drawings aretraced or photocopied onto transparent acetate sheets called“cels”, which are filled in with paints in assigned colors or toneson the side opposite the line drawings. The completed charactercels are photographed one-by-one onto motion picture filmagainst a painted background by a rostrum camera.
The traditional cel animation process became obsoleteby the beginning of the 21st century. Today, animatorsdrawings and the backgrounds are either scanned intoor drawn directly into a computer system. Varioussoftware programs are used to color the drawings andsimulate camera movement and effects. The finalanimated piece is output to one of several deliverymedia, including traditional 35 mm film and newermedia such as digital video. The "look" of traditional celanimation is still preserved, and the characteranimators work has remained essentially the sameover the past 70 years.
Full animation refers to the process of producing high-quality traditionally animated films, which regularly usedetailed drawings and plausible movement. Fullyanimated films can be done in a variety of styles, frommore realistically animated works such as thoseproduced by the Walt Disney studio (Beauty and theBeast, Aladdin, Lion King) to the more "cartoony" stylesof those produced by the Warner Bros. animationstudio (Iron Giant, Quest for Camelot, Cats DontDance). Many of the Disney animated features areexamples of full animation, as are non-Disney workssuch as The Secret of NIMH (US, 1982) and The IronGiant (US, 1999), Nocturna (Spain, 2007)
Limited animation involves the use of less detailedand/or more stylized drawings and methods ofmovement. Pioneered by the artists at the Americanstudio United Productions of America, limitedanimation can be used as a method of stylized artisticexpression, as in Gerald McBoing Boing (US, 1951),Yellow Submarine (UK, 1968), and much of the animeproduced in Japan. Its primary use, however, has beenin producing cost-effective animated content for mediasuch as television (the work of Hanna-Barbera,Filmation, and other TV animation studios) and laterthe Internet (web cartoons). Some examples are;Spongebob Squarepants (USA, 1999–present), TheFairly OddParents (USA, 2001–present) and Invader Zim(USA, 2001–2006).
Rotoscoping is a technique, patented by MaxFleischer in 1917, where animators trace live-action movement, frame by frame. The sourcefilm can be directly copied from actors outlinesinto animated drawings, as in The Lord of theRings (US, 1978), used as a basis and inspirationfor character animation, as in most Disney films,or used in a stylized and expressive manner, asin Waking Life (US, 2001) and A Scanner Darkly(US, 2006). Some other examples are: Fire andIce (USA, 1983) and Heavy Metal (1981).
Live-action/animation is a technique, when combining hand-drawn characters into live action shots. One of the earlier uses of it was Koko theClown when Koko was drawn over liveaction footage. Other examples would include Who Framed Roger Rabbit? (USA, 1988), Space Jam (USA, 1996) and Osmosis Jones (USA, 2002).
Stop MotionStop-motion animation is used to describe animationcreated by physically manipulating real-world objectsand photographing them one frame of film at a time tocreate the illusion of movement. There are manydifferent types of stop-motion animation, usuallynamed after the type of media used to create theanimation. Computer software is widely available tocreate this type of animation. Puppet animation typically involves stop-motionpuppet figures interacting with each other in aconstructed environment, in contrast to the real-worldinteraction in model animation. The puppets generally
have an armature inside of them to keep them still and steady as well as constraining them to move at particular joints. Examples include The Tale of the Fox(France, 1937), Nightmare Before Christmas (US, 1993), Corpse Bride (US, 2005), Coraline (US, 2009), the filmsof Jiří Trnka and the TV series Robot Chicken (US, 2005– present). Puppetoon, created using techniques developed by George Pal, are puppet-animated films which typicallyuse a different version of a puppet for different frames, rather than simply manipulating one existing puppet.
Clay animation, or Plasticine animation often abbreviated asclaymation, uses figures made of clay or a similar malleablematerial to create stop-motion animation. The figures may havean armature or wire frame inside of them, similar to the relatedpuppet animation (below), that can be manipulated in order topose the figures. Alternatively, the figures may be made entirelyof clay, such as in the films of Bruce Bickford, where claycreatures morph into a variety of different shapes. Examples ofclay-animated works include The Gumby Show (US, 1957–1967)Morph shorts (UK, 1977–2000), Wallace and Gromit shorts (UK,as of 1989), Jan Švankmajers Dimensions of Dialogue(Czechoslovakia, 1982), The Trap Door (UK, 1984). Films includeWallace and Gromit: Curse of the Were-Rabbit, Chicken Run andThe Adventures of Mark Twain
Computer AnimationSome typical applications of computer-generatedanimation are entertainment (motion pictures andcartoons),advertising,scientific and engineeringstudies,and training and education.although we tend tothink of animation as implying object motions,the term“computer animation” generally refers to any timesequence of visual changes in a scene.In addition to changing object position withtranslations or rotations,a computer-generatedanimation could display time variations in objectsize,color,transparency, or surface texture.Advertising
animations often transition one objectshape into another,for example,transforming a can of motor oil into anautomobile engine.Computer animationscan also be generated by changing cameraparameters, such as, position, orientation,and focal length and we can producecomputer animations by changing lightingeffects or other parameters
In general,an animation sequence is designed with thefollowing steps:1. Storyboard layout.2. Object definitions.3. Key-frame specifications.4. Generation of in-between frames.The “storyboard” is an outline of the action.It definesthe motion sequence as a set of basic events that areto take place.Depending on the type of animation to beproduced,the storyboard could consist of a set of roughsketches or it could be a list of the basic ideas for themotion.
An “object definition” is given for each participant inthe action.Objects can be defined in terms of basicshapes,such as polygons or splines.In addition,theassociated movements for each object are specifiedalong with the shape. A “key-frame” is a detailed drawing of the scene at acertain time in the animation sequence.Within eachkey-frame,each object is positioned according to thetime for that frame.Some key frames are chosen at
extreme positions in the action; others are spaced sothat time interval between key frames is not too great.More key frames are specified for intricate motionsthan for simple, slowly varying motions.“In-betweens” are the intermediate frames betweenthe key frames.The number of in-betweens needed isdetermined by the media to be used to display theanimation.Film requires 24 frames per second, andgraphic terminals are refreshed at the rate of 30 to 60frames per second. Typically, the time intervals for themotion are set up so that there are from three to five
in-betweens for each pair of keyframes.Depending on the speed specified forthe motion, some key frames can be duplicated.For a 1-minute film sequence with noduplication, we would need 1440 frames.Withfive in-betweens for each pair of key frames,wewould need 288 key frames.If the motion is nottoo complicated,we could space the key framesa little farther apart.