Animation: History, Techniques, and Applications

Part of film history from the beginning, animation techniques have been constantly developed and are still in use today. In the process, each technique has produced its own aesthetic. Today, the decision for a certain animation technique is made mainly from a commercial point of view, which means that the majority of all animated productions are either cartoons or 3D computer animation, because these two techniques are best suited for industrial production with many specialized workflows. All other techniques are mainly used in short films, commercials, and film schools. They also require more of an artistic approach and a central person in the workflow.

Stop motion or object animation

In the stop-motion technique, objects are animated by changing them only ever so slightly for each individual frame of the film. A distinction is made in this area:

• Brick movies, where all the characters and sets are assembled from Lego bricks;
• Pixilation, in which actors are photographed frame by frame just as objects are;
• Collage films in which arbitrary materials are assembled under the camera to form moving images;
• Claymation (so-called clay figure films);
• Puppet animation films. However, puppet films and hand puppet films do not belong to the latter, as the film runs continuously.

2D animation

Cartoon

The source material of the individual images are many drawings that differ from each other frame by frame and, shot on film in the right order, create a fluid movement. Nowadays, these are usually scanned and digitally processed. However, the drawings can also be taken directly from the camera, and not only can pencil be used to draw on paper, but any drawing or painting technique is possible. In the simplest version these are stick figures, as they are often used for flip-books. As "Stick Figure Theatre" stick figure parodies of cinema classics were part of the 80s MTV show Liquid Television, today they are often created as vector animation in Flash or other programs.

Sand on Glass Animation

Sand is scattered on a light table, which appears black in the picture. With the hand or with tools, the sand is moved frame by frame, which creates very soft shapes and movements and is particularly suitable for morphing.

Examples: Films by Ferenc Cakó, Alla Churikova, or Caroline Leaf.

Needleboard animation

This special technique was developed by Alexandre Alexeieff. Thousands of needles stuck close together in a board can be pushed in or pulled out. Illuminated from the side, their shadows create an image similar to an engraving.

Oil on Glass Animation

Similar to the sand on glass animation is worked on a light table. Oil paint is used to paint directly onto the glass. The paint remains soft for a long time, can be wiped away, painted over and worked on with tools. The results are hardly inferior to real oil paintings in their color effect.

Examples: Films by Alexander Petrov or Jochen Kuhn.

Drawing or scratching directly on film

With a foil pen or paint, drawings are made directly on blank film material or scratched onto black film material with a needle or knife. The results are usually very rough and wobbly. The sound strip can also be worked on directly, which leads to scratching and crackling noises.

Examples: Norman McLaren's Blinkity Blank or Lines Vertical, scenes from Hideaki Anno's Neon Genesis Evangelion.

Kinoxing or rotoscoping

Existing real film material is projected onto a matt screen and copied frame by frame.

Example: films by Max Fleischer (Gulliver), Georges Schwizgebel or Richard Linklater.

Flat figure film (also called lay figure film)

Cut-out shapes, usually body parts (as in a jumping jack), are placed under the camera.

Examples: Quirino Cristiani's films and Terry Gilliam's animations in the Monty Python films.

Silhouette animation

A special form of flat figure film in which the elements are only recognizable as dark silhouettes, as in shadow play.

Examples: the films of Lotte Reiniger.

Experimental animation

This includes all other techniques, such as time manipulation (slow motion and fast motion), the creation of animations from existing, recycled film material (found footage), a large part of abstract film, but also (as yet) nameless trends and fashions in motion graphics, such as those currently playing a major role in advertising and TV design. Many forms of artistic expression also fall into this area.

Drawing techniques

The predominant techniques of classical animation are the pose-to-pose and the straight-ahead method. In the pose-to-pose technique, the animator first creates so-called extremes, which represent the extreme phases of the movement, usually the start and end points. Breakdowns are then created between the extreme phases, which define the path from extreme to extreme in more detail. Finally, to make the movement fluid, intermediate phases (inbetweens) are inserted between the extremes and the breakdowns. This step is generally not done by the animator, but by an assistant or inbetweener assigned to him.

The pose-to-pose method gives artists the greatest possible control over the timing, movement, and detail of figures, and its division of tasks makes it a particularly economical way to work. However, it has a mechanical element that can lead to stiff, lifeless animation for inexperienced artists.

In the Straight Ahead method, the animator draws all frames in sequential order. This makes it possible to create particularly fast movements with eccentric frames that fall out of the movement pattern and create a dynamic overall impression. However, the design, detail, and timing of the figure drawn in this way are more difficult to control, and errors tend to add up or worsen as the scene progresses. Therefore, in the Straight Ahead method, the assistant's main task is to maintain the visual continuity of the animator's rough drawings.

In general, professional draughtsmen tend to use and sometimes mix both techniques. The methods require a great understanding of drawing as well as the ability to assess the effect of different numbers of individual images for the representation of movement. Both methods are also used in 3D animation, but the computer takes over the tasks of assistant and intermediate phase draughtsman.

Principles of animation

In 1981, Ollie Johnston and Frank Thomas published the book The Illusion of Life: Disney Animation. In this book, they summarized the experiences of leading animators of The Walt Disney Company, which arose since the 1930s to create believable animations. From this they derived twelve principles that are essential for creating the illusion of living characters and worlds.

1. squash & stretch (squeeze & stretch)

The shapes of the figures are compressed or stretched in length, but the overall volume of the shapes must be maintained. This serves to represent weight or external forces acting on the figure.

2. anticipation (to anticipate or anticipate)

The main movement of a figure is introduced by a counter movement, such as the lunge before a throw or the run-up before a jump. This makes the actual movements easier to read and more natural.

3. staging (staging of the poses)

Concerns both the arrangement of the figures within the scene and the design of unmistakably recognizable poses. The silhouette of the figure serves as a control here. Ideally, the body expression should be understandable even if one could only see the outline of the figure.

4. straight ahead & pose-to-pose

Creating frames sequentially and constructing animation around motion-defining extreme phases. Straight Ahead Animation is more dynamic, Pose-to-Pose Animation more controlled.

5. follow through & overlapping action (continuing and overlapping movement)

Follow Through is often applied to describe how inanimate elements of figures (e.g. hair or worn fabric) follow the main movement with a time lag when the limbs move violently, then shoot past the end point of that movement and only then fall back to their resting position. Overlapping action describes the fact that not all limbs necessarily perform or complete a movement at the same time. The definitional boundaries between Follow Through and Overlapping Action are often fluid.

6. slow in & slow out (acceleration and deceleration)

A principle that describes that natural movements usually start slowly, then speed up and slow down again towards the end. In concrete terms, this means that more frames are used at the beginning and end of a movement than in the middle.

7. arcs (arcs of movement)

Limbs generally rotate around a joint. Therefore, their movements are arced rather than linear. The animator must define these arcs of motion within individual movements and provide a harmonious transition between movements.

8. secondary action (secondary or supporting movement)

Simultaneous movements of a character that support the main movement, such as swinging arms while walking or gestures that accentuate dialogue.

9. timing (duration of movement)

Describes both the duration of movements and the time between movements. This aspect is highly dependent on the character of the figure depicted and relies on the experience of the draftsman. One must be aware of how fast or slow a figure can move based on its body, how fast or slow it will do so based on its internal attitude, and how many frames are needed to represent the time period.

10. exaggeration (caricature)

To make the poses and movements of drawn characters particularly clear, it is often necessary to exaggerate their appearance and movements. Here it is important to check that the exaggeration does not make the movement too hectic or too imprecise and that it is appropriate to the message of the scene.

11. solid drawing (solid drawing)

Describes a draftsman's basic ability to draw consistent figures. They should be properly proportioned and correct in perspective, and should not lose these qualities even when in motion.

12. appeal (charisma, charm and allure)

Describes that the appearance and design of the characters as well as their poses and movements should be pleasing and appropriate to the character of the character. Here, too, there is room for interpretation: an evil figure can appear beautiful but reveal its true character through its acting, while an ugly figure can also be endearing through its appearance. Appeal does not automatically mean beauty, but effectively portraying the inner qualities of characters.

Nowadays, aesthetics and production methods are no longer as firmly linked as they used to be. For this reason, many 2D animations are created entirely or partially in the computer using special software, or the material recorded in the classical manner is digitized and further processed in the computer. Since around 1980, when it was possible to scan in originals and the resulting data volumes became technically manageable, this technology has experienced rapid development and commercial success. The CGI technology, which developed from CAD, finally made it possible to do without any digitized artwork and to generate all image objects completely in the computer. The basis is often vector data of the objects in two or three dimensions. Information about the appearance and movements of all objects are combined until finally every necessary individual image can be calculated and rendered in the desired image resolution.

Since the Oscar win of the film Happy Feet, there has been a dispute among experts as to whether films in which the movements of their characters were generated in part by means of motion capture are considered animated films at all, or rather belong to puppet and hand puppet films. However, alternative input methods for movements of CGI characters have long been in use, preferably those derived from puppetry.

In the context of animation on the computer, a basic distinction is made between three techniques: keyframe animation, action-based animation and frame-by-frame animation.

Keyframe animation In keyframe animation, the values of the object properties to be animated are defined at specific points in time in the animation software (= keyframes). Each object or scene state thus receives an entry on a time axis. As the length of the animation and the number of animation events increases, the time-object diagram expands. The object values for the time points lying between the keyframes are calculated by the animation software using mathematical interpolation.

Action-based animation Action-based animation takes an object-oriented approach and encapsulates the time aspect in individual animation actions. As in MS Powerpoint or 3D animation tools, for example, the animations are defined by a list of actions that are executed one after the other during the sequence. Parallel sequences (temporal synchronization) can also be defined, with the objects concerned being specially marked.

Frame-by-frame animation In this animation concept, the individual frames are created one by one, as in a flipbook.