Computer Animation is the creation of the appearance of movement by using computer-generated images or by manipulating digitally represented visual elements over time. It encompasses both two-dimensional and three-dimensional techniques and can involve entirely synthetic imagery, digitally manipulated artwork, procedural systems, motion capture, physical simulation, or combinations of these approaches.
The essential principle is temporal change: an animation system defines how an object's geometry, position, orientation, scale, colour, lighting, deformation, camera, or other properties vary from one moment to another, and a sequence of frames or continuously rendered images presents those changes to an observer. The term therefore describes a broad production discipline rather than one particular software technique. Computer Animation is used in feature films, television, games, advertising, scientific visualisation, engineering, education, simulation, interface design, virtual environments and many other contexts where controlled visual motion communicates information or creates an experience.
The development of Computer Animation is closely connected with the development of computer graphics and increasingly capable computational hardware. Early computer animation was constrained by extremely limited processing power and display technology, so researchers commonly generated simple geometric forms, wireframe imagery and mathematical demonstrations rather than the photorealistic sequences possible today. During the later twentieth century, computer-assisted animation became increasingly practical for commercial graphics, while digital compositing, keyframe systems and computer-generated imagery expanded its use in film and television.
Three-dimensional modelling and rendering subsequently enabled characters, environments, lighting and cameras to be manipulated in virtual space. Modern production may combine traditional animation principles with physically based rendering, simulation, procedural generation, motion capture and real-time graphics. The historical progression is therefore not simply a movement from two dimensions to three dimensions, but an expansion from manually specified visual changes towards increasingly sophisticated systems for representing, generating and controlling motion.
A central technique in Computer Animation is keyframe animation, in which an animator specifies important states at selected times and software calculates intermediate states through interpolation. The interpolated motion may be linear, spline-based, or controlled by curves that determine acceleration, deceleration and other aspects of timing. More sophisticated character animation uses hierarchical rigs containing joints, controls and constraints, allowing an animator to manipulate a character without directly editing every vertex.
Deformation systems can bend, stretch, twist or otherwise alter meshes, while blend shapes can represent predefined facial or anatomical configurations. Motion capture records the movement of performers or objects and transfers that information to digital characters, although captured movement frequently requires cleaning, retargeting and artistic adjustment. Procedural animation instead uses algorithms and rules to generate motion, which can be particularly effective for crowds, particles, vegetation, mechanical systems and other situations where manually specifying every movement would be inefficient.
Computer Animation can represent movement through fundamentally different computational models. Rigid-body animation treats objects as bodies whose position and rotation change while their shape remains substantially fixed, whereas deformable-body animation allows geometry to change shape. Particle systems represent large numbers of small elements and are commonly used for smoke-like effects, sparks, rain, dust and explosions, although physically accurate fluid and volumetric simulations use substantially more specialised numerical models.
Cloth simulation calculates how fabric responds to forces, constraints and collisions, while hair and fur systems model large collections of strands or fibres. Inverse kinematics calculates joint configurations required to place an end effector at a desired location, while forward kinematics determines resulting positions from specified joint transformations. These techniques may be combined within one animation, allowing a character's intentional movements, simulated clothing, physically affected hair and environmental effects to coexist within the same scene.
Timing and perception are fundamental to the effectiveness of Computer Animation. Traditional animation principles such as anticipation, squash and stretch, staging, follow-through, overlapping action, timing and spacing remain relevant even when images are generated digitally. A technically correct interpolation can appear unnatural if its timing does not communicate the intended weight, force or personality of an object.
Frame rate also affects perceived smoothness, but a higher frame rate does not automatically produce better animation because motion design, shutter simulation, interpolation and display characteristics all affect the result. Animation can be produced at a fixed frame rate, such as 24, 25, 30, 50 or 60 frames per second, or generated procedurally and sampled at an appropriate output rate. Motion blur can visually integrate rapidly changing positions across a frame, making movement appear more natural and avoiding an excessively sharp or stroboscopic appearance.
Production workflows for Computer Animation generally separate several stages even though modern software increasingly integrates them. Artists may begin with storyboards and animatics before creating models, textures, rigs, animation controls and environments. Animation is then created and reviewed, after which lighting, rendering, compositing, effects and sound may be added. A production can use low-resolution proxies during animation and replace them with detailed assets during final rendering because high-quality geometry, textures and simulations can be computationally expensive.
Asset interchange and scene-description systems are important in large productions because animation may pass between modelling, rigging, animation, effects, lighting and compositing applications. Version control, caching and deterministic simulation can also become significant when hundreds or thousands of shots must be rendered consistently. The division between animation and rendering is important: animation defines how scene properties change, while rendering converts a particular scene state into an image.
Computer Animation has applications beyond entertainment because temporal visualisation can communicate changes that are difficult to observe directly. Engineers can animate mechanical assemblies, researchers can visualise molecular or astronomical processes, medical specialists can represent anatomical motion, architects can demonstrate how spaces will be experienced, and educators can show physical or mathematical processes.
In games and interactive applications, animation must often be generated in real time and respond to user input, requiring systems that can blend motions dynamically rather than simply play predetermined sequences. Real-time character controllers may combine locomotion cycles, inverse kinematics, procedural adjustments and state machines. Simulation-based animation can also provide training environments for aviation, industrial equipment and other complex systems. In these applications, visual plausibility may be important, but so are numerical accuracy, timing, repeatability and the correct representation of underlying phenomena.
A common misconception is that Computer Animation is synonymous with cartoons or entirely artificial imagery. In practice, it includes digitally manipulating real recorded movement, generating realistic simulations, animating graphical interfaces and augmenting live-action footage. It is also distinct from rendering: an animation can exist as mathematical transformations, keyframes, motion data or simulation states before any final images are produced. Computer Animation can be deterministic, where identical inputs produce the same movement, or stochastic, where controlled randomness contributes variation.
Its principal advantages include precise control, repeatability, editability, scalability and the ability to depict events that are impossible, dangerous, expensive or impractical to film physically. Its limitations include substantial production complexity, computational cost, asset-management requirements and the difficulty of creating convincing motion when physical behaviour or human performance is visually demanding.
