Animation productions begin by deciding on a story. The oral or literary source material must then be converted into an animation film script, from which the storyboard is derived. The storyboard has an appearance somewhat similar to a comic book, and it shows the sequence of shots as consecutive sketches that also indicate transitions, camera angles, and framing. The images allow the animation team to plan the flow of the plot and the composition of the imagery. The storyboard artists will have regular meetings with the director and may have to redraw or "re-board" a sequence many times before it meets final approval.
Before true animation begins, a preliminary soundtrack or "scratch track" is recorded, so that the animation may be more precisely synchronized to the soundtrack. Given the slow, methodical manner in which traditional animation is produced, it is almost always easier to synchronize animation to a pre-existing soundtrack than it is to synchronize a soundtrack to pre-existing animation. A completed cartoon soundtrack will feature music, sound effects, and dialogue performed by voice actors. However, the scratch track used during animation typically contains only the voices, any vocal songs to which characters must sing along, and temporary musical score tracks; the final score and sound effects are added during post-production.
In the case of Japanese anime, as well as most pre-1930 sound animated cartoons, the sound was post-synched; that is, the soundtrack was recorded after the film elements were finished by watching the film and performing the dialogue, music, and sound effects required. Some studios, most notably Fleischer Studios, continued to post-synch their cartoons through most of the 1930s, which allowed for the presence of the "muttered ad-libs" present in many Popeye the Sailor and Betty Boop cartoons.
Often, an animatic or story reel is made after the soundtrack is created, but before full animation begins. An animatic typically consists of pictures of the storyboard synchronized with the soundtrack. This allows the animators and directors to work out any script and timing issues that may exist with the current storyboard. The storyboard and soundtrack are amended if necessary, and a new animatic may be created and reviewed with the director until the storyboard is perfected. Editing the film at the animatic stage prevents the animation of scenes that would be edited out of the film; as traditional animation is a very expensive and time-consuming process, creating scenes that will eventually be edited out of the completed cartoon is strictly avoided.
Advertising agencies today employ the use of animatics to test their commercials before they are made into full up spots. Animatics use drawn artwork, with moving pieces (for example, an arm that reaches for a product, or a head that turns). Video storyboards are similar to animatics but do not have moving pieces. Photomatics are another option when creating test spots, but instead of using drawn artwork, there is a shoot in which hundreds of digital photographs are taken. The large number of images to choose from may make the process of creating a test commercial a bit easier, as opposed to creating an animatic, because changes to drawn art take time and money. Photomatics generally cost more than animatics, as they may require a shoot and on-camera talent. However, the emergence of affordable stock photography and image editing software permits the inexpensive creation of photomatics using stock elements and photo composites.
Design and timing
Once the animatic has been approved, it and the storyboards are sent to the design departments. Character designers prepare model sheets for all important characters and props in the film; these are used to help standardize appearance, poses, and gestures. These model sheets will show how a character or object looks from a variety of angles with a variety of poses and expressions so that all artists working on the project can deliver consistent work. Sometimes, small statues known as maquettes may be produced, so that an animator can see what a character looks like in three dimensions. At the same time, the background stylists will do similar work for the settings and locations in the project, and the art directors and color stylists will determine the art style and color schemes to be used.
While design is going on, the timing director (who in many cases will be the main director) takes the animatic and analyzes exactly what poses, drawings, and lip movements will be needed on what frames. An exposure sheet (or X-sheet for short) is created; this is a printed table that breaks down the action, dialogue, and sound frame-by-frame as a guide for the animators. If a film is based more strongly in music, a bar sheet may be prepared in addition to or instead of an X-sheet. Bar sheets show the relationship between the on-screen action, the dialogue, and the actual musical notation used in the score.
Layout begins after the designs are completed and approved by the director. The layout process is the same as the blocking out of shots by a cinematographer on a live-action film. It is here that the background layout artists determine the camera angles, camera paths, lighting, and shading of the scene. Character layout artists will determine the major poses for the characters in the scene and will make a drawing to indicate each pose. For short films, character layouts are often the responsibility of the director.
The layout drawings and storyboards are then spliced, along with the audio and an animatic is formed (not to be confused with its predecessor, the leica reel). The term "animatic" was originally coined by Walt Disney Animation Studios.
Once the animatic is finally approved by the director, animation begins.
In the traditional animation process, animators will begin by drawing sequences of animation on sheets of transparent paper perforated to fit the peg bars in their desks, often using colored pencils, one picture or "frame" at a time. A peg bar is an animation tool used in traditional (cel) animation to keep the drawings in place. The pins in the peg bar match the holes in the paper. It is attached to the animation desk or light table, depending on which is being used. A key animator or lead animator will draw the key drawings in a scene, using the character layouts as a guide. The key animator draws enough of the frames to get across the major points of the action; in a sequence of a character jumping across a gap, the key animator may draw a frame of the character as he is about to leap, two or more frames as the character is flying through the air and the frame for the character landing on the other side of the gap.
Timing is important for the animators drawing these frames; each frame must match exactly what is going on in the soundtrack at the moment the frame will appear, or else the discrepancy between sound and visual will be distracting to the audience. For example, in high-budget productions, extensive effort is given in making sure a speaking character's mouth matches in shape the sound that character's actor is producing as he or she speaks.
While working on a scene, a key animator will usually prepare a pencil test of the scene. A pencil test is a preliminary version of the final animated scene; the pencil drawings are quickly photographed or scanned and synced with the necessary soundtracks. This allows the animation to be reviewed and improved upon before passing the work on to his assistant animators, who will add details and some of the missing frames in the scene. The work of the assistant animators is reviewed, pencil-tested, and corrected until the lead animator is ready to meet with the director and have his scene sweatboxed, or reviewed by the director, producer, and other key creative team members. Similar to the storyboarding stage, an animator may be required to redo a scene many times before the director will approve it.
In high-budget animated productions, often each major character will have an animator or group of animators solely dedicated to drawing that character. The group will be made up of one supervising animator, a small group of key animators, and a larger group of assistant animators. For scenes where two characters interact, the key animators for both characters will decide which character is "leading" the scene, and that character will be drawn first. The second character will be animated to react to and support the actions of the "leading" character.
Once the key animation is approved, the lead animator forwards the scene on to the clean-up department, made up of the clean-up animators and the inbetweeners. The clean-up animators take the lead and assistant animators' drawings and trace them onto a new sheet of paper, taking care in including all of the details present on the original model sheets, so that it appears that one person animated the entire film. The inbetweeners will draw in whatever frames are still missing in between the other animators' drawings. This procedure is called tweening. The resulting drawings are again pencil-tested and sweatboxed until they meet approval.
At each stage during pencil animation, approved artwork is spliced into the Leica reel.
This process is the same for both character animation and special effects animation, which on most high-budget productions are done in separate departments. Effects animators animate anything that moves and is not a character, including props, vehicles, machinery and phenomena such as fire, rain, and explosions. Sometimes, instead of drawings, a number of special processes are used to produce special effects in animated films; rain, for example, has been created in Disney animated films since the late 1930s by filming slow-motion footage of water in front of a black background, with the resulting film superimposed over the animation.
After all the drawings are cleaned up, they are then photographed on an animation camera, usually on black and white film stock. Nowadays, pencil tests can be made using a video camera and computer software.
While the animation is being done, the background artists will paint the sets over which the action of each animated sequence will take place. These backgrounds are generally done in gouache or acrylic paint, although some animated productions have used backgrounds done in watercolor or oil paint. Background artists follow very closely the work of the background layout artists and color stylists (which is usually compiled into a workbook for their use) so that the resulting backgrounds are harmonious in tone with the character designs.
Traditional ink-and-paint and camera
Once the clean-ups and in-between drawings for a sequence are completed, they are prepared for photography, a process known as ink-and-paint. Each drawing is then transferred from paper to a thin, clear sheet of plastic called a cel, a contraction of the material name celluloid (the original flammable cellulose nitrate was later replaced with the more stable cellulose acetate). The outline of the drawing is inked or photocopied onto the cel, and gouache, acrylic or a similar type of paint is used on the reverse sides of the cels to add colors in the appropriate shades. In many cases, characters will have more than one color palette assigned to them; the usage of each one depends upon the mood and lighting of each scene. The transparent quality of the cel allows for each character or object in a frame to be animated on different cels, as the cel of one character can be seen underneath the cel of another; and the opaque background will be seen beneath all of the cels.
When an entire sequence has been transferred to cels, the photography process begins. Each cel involved in a frame of a sequence is laid on top of each other, with the background at the bottom of the stack. A piece of glass is lowered onto the artwork in order to flatten any irregularities, and the composite image is then photographed by a special animation camera, also called rostrum camera. The cels are removed, and the process repeats for the next frame until each frame in the sequence has been photographed. Each cel has registration holes, small holes along the top or bottom edge of the cel, which allow the cel to be placed on corresponding peg bars before the camera to ensure that each cel aligns with the one before it; if the cels are not aligned in such a manner, the animation, when played at full speed, will appear "jittery." Sometimes, frames may need to be photographed more than once, in order to implement superimpositions and other camera effects. Pans are created by either moving the cels or backgrounds one step at a time over a succession of frames (the camera does not pan; it only zooms in and out).
A camera used for shooting traditional animation. See also Aerial image
As the scenes come out of final photography, they are spliced into the Leica reel, taking the place of the pencil animation. Once every sequence in the production has been photographed, the final film is sent for development and processing, while the final music and sound effects are added to the soundtrack. Again, editing in the traditional live-action sense is generally not done in animation, but if it is required it is done at this time, before the final print of the film is ready for duplication or broadcast.
Among the most common types of animation rostrum cameras was the Oxberry. Such cameras were always made of black anodized aluminum, and commonly had two pegbars, one at the top and one at the bottom of the lightbox. The Oxberry Master Series had four pegbars, two above and two below, and sometimes used a "floating pegbar" as well. The height of the column on which the camera was mounted determined the amount of zoom achievable on a piece of artwork. Such cameras were massive mechanical affairs which might weigh close to a ton and take hours to break down or set up.
In the later years of the animation rostrum camera, stepper motors controlled by computers were attached to the various axes of movement of the camera, thus saving many hours of hand cranking by human operators. Gradually, motion control techniques were adopted throughout the industry.
Digital ink and paint processes gradually made these traditional animation techniques and equipment obsolete.
Digital ink and paint
The current process, termed "digital ink and paint", is the same as traditional ink and paint until after the animation drawings are completed; instead of being transferred to cels, the animators' drawings are either scanned into a computer or drawn directly onto a computer monitor (such as a Wacom Cintiq tablet), where they are colored and processed using one or more of a variety of software packages. The resulting drawings are composited in the computer over their respective backgrounds, which have also been scanned into the computer (if not digitally painted), and the computer outputs the final film by either exporting a digital video file, using a video cassette recorder, or printing to film using a high-resolution output device. Use of computers allows for easier exchange of artwork between departments, studios, and even countries and continents (in most low-budget American animated productions, the bulk of the animation is actually done by animators working in other countries, including South Korea, China, Japan, Singapore, Mexico, and India). As the cost of both inking and painting new cels for animated films and TV programs and the repeated usage of older cels for newer animated TV programs and films went up and the cost of doing the same thing digitally went down, eventually, the digital ink-and-paint process became the standard for future animated movies and TV programs. Digital ink and paint has been in use at Walt Disney Feature Animation since 1989, where it was used for the final rainbow shot in The Little Mermaid. All subsequent Disney animated features were digitally inked-and-painted (starting with The Rescuers Down Under, which was also the first major feature film to entirely use digital ink and paint), using Disney's proprietary CAPS (Computer Animation Production System) technology, developed primarily by Pixar.
While Disney was the first to switch to digital inking and painting, it took the rest of the industry longer to adapt. Many filmmakers and studios did not want to shift to the digital ink-and-paint process because they felt that the digitally-colored animation would look too synthetic and would lose the aesthetic appeal of the non-computerized cel for their projects. Many animated television series were still animated in other countries by using the traditionally inked-and-painted cel process as late as 2004; though most of them switched over to the digital process at some point during their run. The last major feature film to use traditional ink and paint was Studio Ghibli's Princess Mononoke (1997); the last major animation production to use the traditional process was Cartoon Network's Ed, Edd n Eddy, which switched to digital paint in 2004. Minor productions such as Hair High (2004) by Bill Plympton have used traditional cels long after the introduction of digital techniques. Most studios today use one of a number of other high-end software packages, such as Toon Boom Harmony, Toonz Bravo!, Animo, and RETAS, or even consumer-level applications such as Adobe Flash, Toon Boom Studio, UbiArt Framework TVPaint, and Toonz Harlequin.
Computers and digital video cameras
Computers and digital video cameras can also be used as tools in traditional cel animation without affecting the film directly, assisting the animators in their work and making the whole process faster and easier. Doing the layouts on a computer is much more effective than doing it by traditional methods. Additionally, video cameras give the opportunity to see a "preview" of the scenes and how they will look when finished, enabling the animators to correct and improve upon them without having to complete them first. This can be considered a digital form of pencil testing.