10.02 Animation
Animation can be broadly separated into to categories: 2D Animation and 3D Animation. Although these approaches use different tools and workflows, both rely on the same core idea of creating the illusion of movement by displaying a sequence of images over time.
2D Animation
2D animation is created on a flat, two-dimensional substrate. It can be as simple as a hand-drawn flip book, where each page contains a slightly different drawing, or as advanced as a fully digital workflow created with animation software.
Traditional 2D animation is often drawn frame by frame, with each drawing representing a small change in motion. Lead animators would draw key poses, or major moments in the action. Junior animators would then draw the in-between frames, often called tweening.
In digital 2D animation, software can assist and automate tweening by interpolating motion between important poses using keyframes and generating the in-between frames.
2D animation includes a wide range of approaches, such as:
- hand-drawn character animation
- cut-out or puppet style animation
- motion graphics and title sequences
- experimental and abstract animation
- drawing on film strips
2D animation often emphasizes shape, silhouette, line quality, composition, and stylized movement.
3D Animation
3D animation is created in a digital three-dimensional space using 3D modeling software such as Blender or Maya. In 3D animation, artists build virtual objects and characters that have volume, depth, and position in space.
A typical 3D animation workflow includes modeling objects, applying materials and textures, setting up a skeleton or control system called a rig, posing the character or object, and then animating those poses over time. Similar to 2D animation, 3D animation commonly relies on keyframes, but the movement is calculated within a 3D environment. This makes it possible to animate cameras, lights, characters, simulations, and physical effects within the same scene.
3D animation is widely used in:
- film
- television
- video games
- visual effects
- architectural visualization
- motion design
- Virtual Production and interactive media
Because 3D objects exist in virtual space, animators must think carefully about camera placement, lighting, weight, physics, and how motion reads from multiple angles.
Principles of Animation
Frank Thomas and Ollie Johnston worked as animators at Disney and contributed to the 1981 book The Illusion of Life: Disney Animation which contains “The 12 Basic Principles of Animation” based on studio practices of themselves and other disney animators striving to make realistic and lifelike animations.1 The principles were written in a time dominated by hand drawn animation but the general concepts hold true in 2D and 3D computer animation.
Many of the principles help animators make sequences that convincingly follow laws of motion and physics such as gravity, momentum, and inertia. At the same time, animation is not only about realism. Simply having a “realistic” animation is not enough to engage an audience so the principles also cover creative animation components such as composition, timing, and basic character design.
Squash and Stretch
Although we intuitively know a ball compresses when it hits a hard surface before bouncing away, it happens too fast in real life to notice. Exaggerating how objects or characters compress or extend during movement, helps the animated elements feel less rigid and more alive.
Movement follows arcs and curves
If you throw a ball, your arm moves in an arc pivoting from your shoulder. The ball also follows an arcing path as it accelerates and decelerates from wind resistance and gravity. Motion in real life often follows curved paths rather than perfectly straight lines. Using arcs makes movement feel smoother and more believable.
Follow through
If you run and then try to stop instantly, you will likely need to wave your arms to try to keep your balance as your torso continues to move above your feet. Showing how different parts of a body or object continue moving after the main action stops helps communicate a sense of momentum and flexibility.
Anticipation
It is much easier to jump by bending your knees before leaping, rather than jumping from a straight leg standing position. Showing small preparatory movements before a larger action helps the viewer understand what is about to happen in the animated movement.
Exaggeration
Remember that animation is not only about realism. Pushing extreme poses, movement timing, or motion paths slightly beyond realism can make animation clearer, more energetic, and more expressive.
Ease In and Ease Out
The concept of easing is so fundamental that most software uses these terms to label tools in their respective programs. Most movement does not begin or end abruptly. Objects usually accelerate into motion and decelerate before stopping. Ease controls the rate of change in the beginning and ending of a movement.
Secondary Actions
If the wind is blowing and you are walking down the street, your hair will follow your head but it will also move around from the wind. Smaller supporting movements such as wind blown hair can compliment reinforce the main action as a way to add visual richness to the animation.
Staging
Composition and framing are important. The action should be presented clearly so the audience knows where to look and what is important in the scene.
Timing
The number of frames used for an action affects how fast, heavy, or forceful that action feels when animated.
Solid Drawing
In traditional animation, this refers to drawing with an understanding form, volume, anatomy, balance, and perspective. In 3D animation, the same idea applies through strong posing, proportions, and spatial awareness.
Appeal
Characters, objects, and motions should be engaging and readable. Appeal does not mean likeable or cute, it means visually compelling and interesting.
Straight Ahead vs Pose to Pose
Straight ahead animation is created by drawing in sequence from one drawing or frame to the next, often producing spontaneous, fluid, and often unstructured motion.
Pose to pose animation is built by planning key poses or moments first and then filling in the in between frames, giving more control over structure and timing.