Animation
Techniques

Animation Techniques

Keys, Breakdowns & In-Betweens

This is the foundational animation concept that every animator starts with. A character moves from position A (extreme 1) to position B (extreme 5). The positions at A and B are called extremes, while positions 2, 3, and 4 between them are called in-betweens. The line connecting A and B is called the Path of Action.

A Breakdown pose is a critical intermediate pose inserted between two extremes to guide the natural arc of movement. Without a breakdown, in-betweens are calculated mechanically by the software, resulting in incorrect — often linear — motion. Adding a breakdown corrects this.

Animation Techniques

Path of Action

The Path of Action is the imaginary line that indicates the suggested movement of an element or object during animation. It is a planning tool that allows an animator to visualize movements in advance and correct any flaws before production begins.

A clear path of action prevents the most common beginner mistake: letting software interpolate positions along a straight line when the real motion should arc. Whether it’s a bouncing ball, a swinging arm, or a turning head — the path of action is always a curve, never a straight line.

Animation Techniques

Timing, Spacing & Ease-in / Ease-out

Time is the essence of animation. The speed of real-world objects varies at the beginning, middle, and end of a movement. Getting an object to convey a sense of weight depends entirely on how it moves — and natural movement depends on correct timing and spacing of animated poses.

Uniform spacing between frames creates mechanical, unnatural movement. The solution is Ease-in / Ease-out: frames are clustered closer together at the start and end of a motion (slow-in, slow-out) and spread farther apart in the middle (faster movement).

Animation Techniques

Bouncing Ball Animation

The bouncing ball is a classic beginner exercise that reveals many important animation concepts at once. The ball rises and falls in parabolic curves. Due to gravity, the height of each curve gradually reduces until the ball comes to a halt.

The key insight: the ball does not move at uniform speed. At the top of each arc it slows (ease-in) and as it falls and rises it moves faster. This speed variation must be represented by adjusting the spacing between frames — frames spaced farther apart at the peak (slow) and closer together on the way down and up (fast).

To complete the exercise, add Stretch and Squash: the ball squashes flat when hitting the floor and stretches vertically when in fast motion. This makes the animation look far more natural and elastic.

Animation Techniques

Stretch & Squash

Flexible materials like rubber squash their shape when they hit a harder surface. When they move fast, they slightly elongate in the direction of movement. This principle — known as Stretch and Squash — is one of the classic 12 principles of animation and can be applied across many situations beyond just rubber balls.

Stretch and squash can be applied to character faces (cheeks stretching on a fast turn), full bodies (exaggerated crouching before a jump), and props. The key rule is that volume must remain consistent — when an object squashes wider, it becomes shorter; when it stretches taller, it becomes narrower.

Animation Techniques

Head Turns & Turnarounds

The head turn is one of the most frequently used animation movements. The number of in-betweens controls the speed: more in-betweens create a slower, more deliberate turn; fewer in-betweens produce a quicker snap.

For Turnaround Animation, a full 360° rotation requires drawing eight distinct views: Front, ¾ front right, Profile right, ¾ back right, Back, ¾ back left, Profile left, and ¾ front left. All body parts and facial features must be carefully aligned across views to avoid jitters. More intermediate drawings produce a smoother turnaround but significantly increase workload.

Animation Techniques

ARC Principle & Solid Drawing

Movements of living beings generally follow an arc path rather than a linear (straight) path. This concept is fundamental to creating more natural action. The arc path is visible in a head turn from side to side, the swing of arms, and the movement of fingers — all follow curved trajectories, never straight lines.

The Solid Drawing principle addresses a key challenge of 2D animation: simulating a three-dimensional space with two-dimensional objects. Characters must look real and volumetric when they move — not like flat cutouts. When body parts on left and right sides are perfectly symmetrical and identical, the result looks stiff and artificial. Varying each side slightly creates a much more natural, three-dimensional appearance.

Animation Techniques

Lip Synching & Facial Animation

Creating convincing lip movements for dialogue is a core animation skill. Dialogue can demand hundreds of mouth positions to match a voice track. Traditional animators developed an elegant solution: Preston Blair’s nine phoneme positions can substitute convincingly for any spoken dialogue.

Study these sounds in front of a mirror. Note that speech is phonetic — words are not pronounced letter by letter, so match mouth shapes to the way words actually sound when spoken naturally. Modify the style of each phoneme to suit your character’s design and store them as a mouth symbol in Flash’s library.

For Facial Animation, convert each facial feature — eyes, eyebrows, nose, mouth, jaw — into individual symbols placed in separate layers. Animate them independently by inserting keyframes at required intervals to change expressions.

Animation Techniques

Animating with Bone Tools (IK)

Flash’s Bone Tool works on the concept of Inverse Kinematics (IK). IK is a method of animating objects using a chain of bones — when one bone moves, all connected bones move in relation to it. By specifying start and end positions of bones on the timeline, Flash automatically interpolates the in-betweens.

Animation Techniques

Walk, Run & Fly Cycles

Cyclic animation is playing a repeated sequential movement in a looping manner. This is achieved by converting repeated movements into an animated symbol that loops endlessly. Walk, run, and fly cycles are the most common applications.

Walk Cycle — Four Key Poses

The four stages are repeated for the opposite leg and arm, making 8 total stages for a full traditional walk cycle. In Flash, the tweening method simplifies this to 4 stages (Poses A–D plus a return to Pose A as Pose E), using Classic tweens between each stage.

The Fly cycle uses 8 stages. In drawings 2–4, the bird raises wings upward to prepare to catch more air. In drawings 6–8, the bird pushes air downward by spreading the wings fully. The cycle loops to create continuous flight.