Tweening
Encyclopedia
Inbetweening or tweening is the process of generating intermediate frames between two images to give the appearance that the first image evolves smoothly into the second image. Inbetweens are the drawings between the key frame
s which help to create the illusion of motion. Inbetweening is a key process in all types of animation
, including computer animation
.
When animating in a digital context, especially with Adobe Flash
, the shortened term tweening is commonly used. Sophisticated animation software enables one to identify specific objects in an image and define how they should move and change during the tweening process. Software may be used to manually render
or adjust transitional frames by hand or may be used to automatically render transitional frames using interpolation
of graphic parameters. In the context of Adobe Flash, inbetweening using automatic interpolation is called tweening, and the resulting sequence of frames is called a tween.
"Ease-in" and "ease-out" in digital animation typically refer to a mechanism for defining the physics of the transition between two animation states, i.e., the linearity of a tween.
The use of computers for inbetweening was pioneered by Nestor Burtnyk and Marceli Wein at the National Research Council of Canada
. They received a Technical Achievement Academy Award in 1997, for "pioneering work in the development of software techniques for computer assisted key framing for character animation".
In the inbetweening workflow of traditional hand-drawn animation
, the senior or key artist would draw the keyframes which define the movement, then, after testing and approval of the rough animation, would hand over the scene to his or her assistant. The assistant does the clean-up and the necessary inbetweens, or, in large studios, only some breakdowns which define the movement in more detail, then handing down the scene to his assistant, the inbetweener who does the rest.
(1908), widely considered the first fully animated movie, was animated on twos.
Key frame
A key frame in animation and filmmaking is a drawing that defines the starting and ending points of any smooth transition. They are called "frames" because their position in time is measured in frames on a strip of film...
s which help to create the illusion of motion. Inbetweening is a key process in all types of animation
Animation
Animation is the 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. The effect is an optical illusion of motion due to the phenomenon of persistence of vision, and can be created and demonstrated in several ways...
, including computer animation
Computer animation
Computer animation is the process used for generating animated images by using computer graphics. The more general term computer generated imagery encompasses both static scenes and dynamic images, while computer animation only refers to moving images....
.
In digital animation
Adobe Flash
Adobe Flash is a multimedia platform used to add animation, video, and interactivity to web pages. Flash is frequently used for advertisements, games and flash animations for broadcast...
, the shortened term tweening is commonly used. Sophisticated animation software enables one to identify specific objects in an image and define how they should move and change during the tweening process. Software may be used to manually render
Artistic rendering
Rendering in visual art and technical drawing means the process of creating, shading, and texturing of an image, especially a photorealistic one. It can also be used to describe the quality of execution of that process...
or adjust transitional frames by hand or may be used to automatically render transitional frames using interpolation
Interpolation
In the mathematical field of numerical analysis, interpolation is a method of constructing new data points within the range of a discrete set of known data points....
of graphic parameters. In the context of Adobe Flash, inbetweening using automatic interpolation is called tweening, and the resulting sequence of frames is called a tween.
"Ease-in" and "ease-out" in digital animation typically refer to a mechanism for defining the physics of the transition between two animation states, i.e., the linearity of a tween.
The use of computers for inbetweening was pioneered by Nestor Burtnyk and Marceli Wein at the National Research Council of Canada
National Research Council of Canada
The National Research Council is an agency of the Government of Canada which conducts scientific research and development.- History :...
. They received a Technical Achievement Academy Award in 1997, for "pioneering work in the development of software techniques for computer assisted key framing for character animation".
In traditional animation
Traditional inbetweening involves the use of light tables to draw a set of pencil-on-paper pictures.In the inbetweening workflow of traditional hand-drawn animation
Traditional animation
Traditional animation, is an animation technique where each frame is drawn by hand...
, the senior or key artist would draw the keyframes which define the movement, then, after testing and approval of the rough animation, would hand over the scene to his or her assistant. The assistant does the clean-up and the necessary inbetweens, or, in large studios, only some breakdowns which define the movement in more detail, then handing down the scene to his assistant, the inbetweener who does the rest.
Frame frequency
Typically, an animator does not draw inbetweens for all 24 frames required for one second of film. Only very fast movements require animation "on ones", as it is called. Most movements can be done with 12 drawings per second, which is called animating "on twos". Too few inbetweens distort the illusion of movement, such as in cheap TV animation series where there can be as few as 4 drawings for a second of film. Computer generated animation is usually animated on ones. The decision about the number of inbetweens is also an artistic one, as certain styles of animation require a not-so-smooth fashion of movement. Animation "on twos" dates to the dawn of animation – FantasmagorieFantasmagorie (1908 film)
Fantasmagorie is an 1908 French animated film by Émile Cohl. It is one of the earliest examples of traditional animation, and considered by film historians to be the first animated cartoon.-Description:...
(1908), widely considered the first fully animated movie, was animated on twos.
See also
- Flicker fusion thresholdFlicker fusion thresholdThe flicker fusion threshold is a concept in the psychophysics of vision. It is defined as the frequency at which an intermittent light stimulus appears to be completely steady to the observer...
- MorphingMorphingMorphing is a special effect in motion pictures and animations that changes one image into another through a seamless transition. Most often it is used to depict one person turning into another through technological means or as part of a fantasy or surreal sequence. Traditionally such a depiction...
- Onion skinningOnion skinningOnion skinning is a 2D computer graphics term for a technique used in creating animated cartoons and editing movies to see several frames at once...
- CacaniCacaniCacani, abbreviation for "Computer Assisted Cel Animation", is a 2D animation system that automatically generates in-between frames from key frames. Cacani is sometimes also written as CACAni or CACANI....
- Motion blurMotion blurMotion blur is the apparent streaking of rapidly moving objects in a still image or a sequence of images such as a movie or animation. It results when the image being recorded changes during the recording of a single frame, either due to rapid movement or long exposure.- Photography :When a camera...
- SynfigSynfigSynfig Studio is a free and open source 2D vector graphics and timeline-based computer animation program created by Robert Quattlebaum with additional contributions by Adrian Bentley....
a Free and Open Source Software (FOSSFossFoss may refer toPeople*Foss , people with the last name Foss*Foss Shanahan , New Zealand diplomat*Foss Westcott , English bishop...
) tweener