The process of animation is long and complex. A typical Pixar animation takes four to five years to complete. Pixar's filmmaking process is a design process, alternating iterations of planning and implementation, all centred on storytelling. Pixar's process is based on a few simple approaches. Films are visually developed, meaning their process is one that celebrates visual presentation rather than narrative. They use traditional skills, like drawing, painting, sculpture and storytelling in their planning process.
First a Pixar employee pitches their idea to other members of the development team. The real challenge is to get the audience to believe in the idea and see the possibilities in it. Next a text treatment is created. A treatment is a short document that summarises the main idea of the story. Sometime, many treatments of the same idea will be developed in order to find the right balance between solid ideas and open possibilities, which will be filled in later by development and storyboard artists. The script is written after the story idea and text treatment. Storyboards are like a hand-drawn version of the movie and serve as the blueprint for the action and dialogue. Each storyboard artist receives script pages and/or a "beat outline", a map of the characters' emotional changes that need to be seen through actions. Using these as guidelines, the artists envision their assigned sequences, draw them out and then "pitch" their work to the director.
Then, temporary "scratch" voices are recorded by pixar artists for the storyboard reels. Later, when the story and dialogue are further along, professional actors begin recording the character voices, reading from a script and improvising. Actors must record lines several different ways, and the best reading is eventually animated. Sometimes though, scratch voices are so good, they are not replaced. Next, reels are made. A reel is a videotape that allows the cleaned-up storyboard sequence to stand alone, without a pitch person to tell the story. A pitch can be successful because the storyteller is strong, so reels are an essential step to validate the sequence and are the first instance that the "timing" of the sequence is understood. Editorial uses the information to fix the length and other elements of each shot in a sequence.
Based on the initial text treatment, storyboards and their own creative brainstorming and development work, the art department creates inspirational art illustrating the world and the characters. It also designs sets, props, visual looks for surfaces and colours and "colour scripts" for lighting, which are impressionistic pastel illustrations that emphasize the light in screens. The art department designs all the characters, major set locations, props and colour palettes for the film.
Pixar's proprietary animation software, is then used to create three-dimensional computer models of characters, props and sets. These computer models describe the shape of the object as well as the motion controls that the animators use to create movement and expressions. Using the art department's model packet - a set of informational drawings - the characters, sets and props are either sculpted by hand and then scanned in three dimensionally or modelled in three-dimensions directly in the computer. Since these are 3D objects, they're modeled on the X, Y and Z axes and can be rotated and viewed from any angle. When you first begin to model an object, it doesn't have any surface color or texture. All you see on your screen is the object's skeleton -- the lines and outlines of the individual cubes, blocks and spheres that have been used to construct it. This is called a wireframe. The models are then give "avars", or hinges, which the animator will use to make the object or character move. For example, Woody has 100 avars in his face alone.
Sets are environments created for the film's story. They are the settings where the action of the film occurs. After the sets are built in three-dimensions they must be dressed with prop models, such as chairs, curtains, and toys, to create a believable world. Set dressers work closely with the director to ensure that the director's vision for the environment is being realised. The characters are then placed on the set in a process called blocking. The director and lead animators block the key character positions and camera angles for each and every shot of the movie. Translating the story into three-dimensional scenes, the layout crew choreographs the characters in the set and uses a virtual camera to create shots that capture the emotion and story point of each scene. Layout often produces multiple versions of shots to provide the editorial department with choices for cutting the scene for maximum storytelling effect. Once the seen has been cut, the final version is released to animation.
Pixar's animators neither draw nor paint the shots, as is required in traditional animation. Because the characters, models, dialogue and sound are already set up, animators are like actors or puppeteers. Using Pixar's animation software, they choreograph the movements and facial expressions in each scene. Pixar's animators choreograph the motion in each scene by defining key frames or poses. They do this by using computer controls and the character's avars to define key poses. The computer then creates the "in-between" frames, which the animator adjusts as necessary. It's common for an animator to re-do a single short animated sequence several times before the director or lead animator is satisfied. Computer programs that describe surface characteristics, including textures, finishes and colors, are added to every object in the scene. These programs, called "shaders," can simulate a wide variety of appearances, including wood, metal, fabric, glass, hair and skin. The characters and props are given surface texture and color. They're dressed with clothing that wrinkles and flows naturally with body movements, hair and fur that waves in the virtual breeze, and skin that looks real enough to touch. Using "digital light", every scene is lit in much the same manner as stage lighting. Key, fill and bounce lights and room ambience are all defined and used to enhance the mood and emotion of each scene. Lighting takes its inspiration from the colour scripts created by the art department. Animators , use ambient, omnidirectional and spotlights to create depth, shadows and moods.
Rendering is the act of translating all of the information in the files that make up the shot, (sets, colours, character movement), into a single frame of film. Pixar's RenderMan is a computer system that interprets the data. Pixar's RenderMan software "draws" the finished image by computing every pixel of the image from the model, animation, shading, and lighting information. Using powerful computers, all of the digital information that the animators have created is assembled into a single frame of film. Even with the incredible computing power of a company like Pixar, it takes an average of six hours to render one frame of an animated film. Pixar animated films are produced at a frame rate of 24 frames per second (fps). For a 90 minute film, that's nearly 130,000 frames of animation. At Pixar an individual animator is expected to produce 100 frames of animation a week.
Editorial oversees the completion and addition of the musical score and the other sound effects. Effect animation adds special effects. and the photo science department records the digital frame to film or to a form appropriate for digital production.