The earliest animation devices were zoetropes: spinning cylinders with evenly spaced vertical slots through which a viewer could see a succession of images on the opposite inside wall of the cylinder. These images changed position slightly as the cylinder turned and thus appeared to be in motion. This invention has been dated back as far as second-century China but became popular in the West only as late as the mid-19th century.
Flip books, in which readers riffle the pages so that a sequence of drawings appears to move, were invented in England around this same time, made possible partly by the development of cheap paper. Whereas zoetropes were circular and therefore best suited to repetitious, cyclical motions such as the galloping of a horse, flip books could portray a linear sequence.
Some of the earliest creators of motion pictures, at the turn of the 20th century, experimented with animation. The French filmmaker Georges Méliès discovered stop-motion animation by accident when objects changed position in a scene he was shooting while the camera was halted by a malfunction. Another French filmmaker, Émile Cohl, pioneered drawn animation shortly afterward with his film Fantasmagorie (1908), which consisted mostly of simple drawings of human figures, animals, and other objects doing fanciful things. During the following decade, drawn animations grew more sophisticated, became known as cartoons, and began to be shown regularly in movie theaters.
The period from 1930 to 1960 is considered the golden age of hand-drawn animation. Soundtracks had become fully integrated with the visual images, moviegoers had come to expect cartoon shorts alongside feature films, and many series were built upon popular cartoon characters such as Felix the Cat, Mickey Mouse, Betty Boop, and Popeye the Sailor. After success with Mickey Mouse and a transition to color images, Walt Disney began to plan what became the first feature-length animation to be released in the United States, Snow White and the Seven Dwarfs (1938). The production almost bankrupted Disney's studio, but the finished film was a huge commercial and critical success, to be followed by Pinocchio, Fantasia, Bambi, and other releases.
Television created a new outlet for animation, but animators who wanted to create enough material to fill a weekly series were hampered by the slow, labor-intensive nature of hand-drawn animation. The animation directors William Hanna and Joseph Barbera, after success in the movies with Tom and Jerry cartoons, solved this problem by using partial animation, in which most of the drawings remained static and only essential parts needed to change from one frame to the next. Their characters, such as The Flintstones and The Jetsons, had muzzle-like mouths so that the rest of the face (except the eyes) could remain stationary while they talked.
Television was an early adopter of computer-generated animation for applications such as title sequences and dynamic weather maps.
Computer-generated animations began appearing in feature films in the 1970s. One of the first instances was in Westworld (1973), where they were used to show the point of view of a robotic character. In the original Star Wars film (1977), they were displayed as part of a training exercise for the attack on the Death Star. In the 1980s, the technology was advanced enough to render computer-generated images (CGI) to represent real objects rather than schematics. For example, the spaceships that appeared in The Last Starfighter (1984) were all rendered by CGI. In the 1990s, CGI was able to represent human body movements and even skin texture with considerable realism.
In the first decade of the 21st century, some animators adopted a new technique, motion capture, to render body movements with greater realism than was possible with purely computer-generated images. To use this technique, the animator films a live actor in motion, usually covered in a black suit dotted with white balls. The computer tracks the motion of the balls in the film and then reassigns these movements to the corresponding locations on the body of an artistic creation, such as a monster. The Polar Express (2004) was the first entirely computer-animated 3-D film to use motion capture.
Animation has been important in video games since the late 1970s, when the games moved beyond purely geometrical images (as in Pong) and began to depict aliens, asteroids, and angry gorillas. At first, only arcade game machines had sufficient computing power to render the sophisticated graphics of the most detailed and fastest paced animations, but beefed-up home consoles eventually lured dedicated gamers away from the arcades.
When desktop computers shifted from text-based to graphic interfaces in the 1980s, they improved on simple animations, such as hourglasses, and began to use more sophisticated animations to represent common operations, such as files being copied from one drive to another. Personal computers have also made it possible for amateurs to create complex animations and share them on sites such as YouTube. Animation continues to improve every year. Today's video games, such as Fortnite (2017) and Apex Legends (2019), feature characters with complex physical movements and facial expressions that are the most realistic and lifelike yet.