Author: Youran Wu

12 Principles of animation

ANIMATORS SURVIVAL KIT – Pages 231-244

• Pages 231-244

1.Overlapping Action

• Overlapping Action refers to when different parts of a character or object move at different speeds or times. The various parts of the motion don’t stop simultaneously, creating a natural sense of delay and fluidity.
• Overlapping Action can prevents stiff, fully synchronized movements, adding dynamic flow and layers to the overall motion.

Key Principles:

1. Primary and secondary actions are not synchronized: The core part of the movement [ most of our body action start from hips (from ANIMATORS SURVIVAL KIT, p227) ] moves first, while secondary parts (like arms, legs, clothes, or hair) lag behind and follow.
2. Gradual transmission of movement: When a motion occurs, the various parts of the body or object don’t reach their peak or stop at the same time, producing an “overlapping” effect.

e.g. like the Pendulum exercise in class:

The three balls of a Pendulum have their own hierarchy: The first ball is the first hierarchy, and will react first, and so on. The below hierarchy will not move before the top hierarchy.

• Follow Through: After the main action ends, some parts of the character or object continue to move. Because of the force of inertia, objects don’t usually stop suddenly.

How to set overlapping:

• Delayed and progressive movement: The timing of when different parts of the movement start and stop should set to create a delay in keyframe.
• Avoid complete synchronization: Avoid setting all joints start and end at the same time.

2.Counteraction

Character naturally takes counteractionto maintain balance.

One part pushes forward, the other balances by moving backward; Or one part rises and the other balances by falling.

3.Breaking of joints to give flexibility

a character’s arm moving as 3 solid piece, the movement starts at the shoulder, then the elbow follows, and finally the wrist and hand catch up.

Shoulder – the first hierarchy
The movement starts with the shoulder, which is the starting point of the entire arm movement. Before the elbow rotation, the shoulders will prepare.

Elbow – the second hierarchy
After the shoulder start, the elbow will move after it, slightly lagging behind the shoulder action.
The elbow is the main force that guides the movement throughout the whole process (“elbow leads throughout”), and the curve generated by the elbow movement is the most critical.

Wrist – the third hierarchy
Since the wrist is the most terminal joint, it is not completed until after the shoulder and elbow movements.

3. Reference Daft

4.Drag(wave principle)

The various parts of the object will be transmitted by force, and the force will be passed from the main part to the end, like the pendulum will have the effect of dragging.

Some essential animation techniques and key points I learned while creating a bouncing ball animation in Maya.

1.Setting up a Maya Project

For each project, it’s important to create a project file and place the appropriate files in the correct folders. Before starting any project, click: File > Project Window > New, then enter the project name, check the location, and click Accept.

• Scenes: This folder stores primary Maya scene files (e.g., .ma or .mb files). Any 3D model, animation, or layout. Or put reference rigging files by creating a subfolder in scene folder.

• Images: This folder can store the render images.

• Sourceimages: Store all textures, image of the output of materials, or some external image files of scene references.

• Autosave: Maya will store autosave files in this folder if the autosave function is available.

2.Import the rigging file of ball – reference

file – reference – reference editor

3. Find suitable reference and make a plan

Find reference video to observe the rules of movement, the rhythm of movement ball reflect and hit the ground.

Plan sketch 1：

Playblast 1:

During the process, I encountered some challenges, such as the speed at which the ball rotates, whether the contact with the ground affects the rotation speed. And I should reserve enough frames to adjust the squash and stretch.

In my first attempt, the result was not ideal because the number of frames from the ball’s first drop to the impact with the ground was limited, which resulted in no frames to demonstrate the gradual stretching of the ball.

Therefore, I prepared a second plan to reduce the total number of times the ball hits the ground.

Plan sketch 2 – Reduce the number of hits to the ground：

Frame 1 – 50：The ball is thrown with great force, causing it to bounce very high in this phase. At this point, the ball’s movement speed is the greatest among the three stages, and then it gradually decreases.

Frame 51 – 89：The ball’s energy has significantly decreased, which causes less variation along the y-axis, meaning the bounce height becomes lower. Additionally, as the ball’s highest point gets closer to the ground, the frequency of the ball hitting the ground increases.

Frame 90 – 100：The ball no longer bounces; it gradually rolls forward and finally stops.

Playblast 2:

In my second attempt, I aimed to minimize the number of bounces for the ball to make the most of each frame.

Review link: https://syncsketch.com/sketch/YTMyMzNiODli/