Animation

Animation is creating the illusion of movement from static images, by rapidly displaying a sequence of drawings, models, or 3-D computer graphics, bringing inanimate objects and characters to life for storytelling, entertainment, and art/science.

Related techniques include traditional hand-drawn (cel) animation, computer-generated imagery (CGI) for 2-D/3-D, and stop- motion using physical objects. The core principle is designing key poses (keyframes) and creating smooth “in-between” frames to transition between them, using principles such as timing, spacing, squash & stretch, and follow-through to add realism and personality.

Animated Perspective

We can have several different kinds of animated perspective:

Hand-drawn animations: Type of animated perspective in which visual images of human/animal characters, etc., are sketched (by hand one at a time) onto single drawing/movie frames, whilst being changed slightly between frames to represent movement, and then displayed in rapid succession to evoke a real-time impression of movement.
Computer-generated images: Type of animated perspective in which visual images of human/animal characters, etc., are created by, and within, a computer model (often individually one at a time), with slight changes between frames to represent movement, and then these same images are transferred onto movie frames, which are then displayed in rapid succession to evoke a real-time impression of movement.
Stop motion animation: Type of animated perspective in which individual photographic snapshots of physical models of human/animal characters are taken one at a time with slight changes between frames to represent movement, etc., which are then transferred onto movie frames displayed in rapid succession to evoke a a real-time impression of movement.

Persistence of Vision Principle

Refers to the optical phenomenon where the human eye retains an image on the retina for a brief moment even after it has disappeared from sight, allowing the brain to perceive a series of rapidly shown still images as continuous motion when displayed in quick succession, essentially creating the illusion of movement. This principle is fundamental to animation and film technology.

Characteristics

How it works: An image briefly lingers on the retina; if replaced quickly, the brain blends
them for smooth motion.
Animation: Rapidly displaying slightly different images creates the illusion of movement.
Frame rate and perception: The eye processes 10-12 images per second, requiring at least 24 frames per second for smooth motion in film.

Beta Movement Illusion

Beta movement is a perceptual illusion described by Max Wertheimer in 1912, in which the brain combines two or more still images into perceived motion. The illusion of motion caused by animation and film is sometimes believed to rely on beta movement, an alternative to the older explanation, persistence of vision. However, the human visual system can’t distinguish between the short-range apparent motion of film and real motion, whereas the long-range apparent motion of beta movement is recognised as distinct and processed differently.

Animated Photograph

An animated photograph, also known as a cinemagraph, is a still image animated to create an illusion of movement. Coined in 1917 by Kevin Burg and Jamie Beck, the term refers to their technique of combining printed photographs with animation. Animation creates movement by rapidly displaying multiple images, which the brain perceives as a single moving image.

Motion Capture

Motion capture, also known as mocap, is a technology that records the movement of people or objects and converts it into digital data. The data is then used to create realistic animations for characters in movies, video games, and other applications.

How it works

Actors wear a suit with markers or sensors that track their movement
Cameras capture the markers and record the movement
The data is transferred to a computer program
The data is mapped to a 3-D model to create an animation

Applications

Film and TV: Motion capture creates realistic characters for movies and TV shows
Video games: Motion capture creates a library of character movements for video games
Sports: Motion capture analyses sports performance and enables 3-D training programs
Healthcare: Motion capture aided rehabilitation programs and ergonomics assessment
Biomechanics research: Motion capture is used to gain insights into human movement

Types

Magnetic: Sensors measure signals from a magnetic source
Mechanical: The performer wears an exoskeleton that tracks their movement
Optical: The performer wears a suit with markers or LED lights that are captured by cameras
Inertial: Sensors on the performer record their movement

Phenakistoscope or Fantascope

The first animation device to create a fluid illusion of motion. It is regarded as a forerunner of the motion picture and film industry. The phenakistiscope is a cardboard disc with an array of sequential pictures around its centre and evenly spaced rectangular apertures around the rim.

To view the pictures in motion, the disc is placed on a handle and spun in front of a mirror while the user looks through the slits from the back of the disc. If the disc spins quickly enough, the human visual system fuses the alternating views of the reflected image and the intervening cardboard (a phenomenon known as flicker fusion). During unnoticed gaps, each image is replaced by the next in the sequence, perceived as a single figure traversing the depicted phases of motion.

The stroboscopic view through the slits prevents motion blur in the perception of the spinning pictures – the slimmer the slits, the sharper but darker the image.

Zoetrope

A zoetrope is an early animation device consisting of a slitted cylinder with sequential images that create the illusion of movement. It is a precursor of cinema.