All 3 Variations Of The After Effects Bounce Expression

Adobe After Effects Bounce Expressions

What It Does

The bounce expression in After Effects gives your layers an organic movement, akin to dropping a basketball and watching it bounce. Imagine the surprise if you dropped a basketball and it didn't bounce; something would feel off, right? Similarly, in the realm of animation, replicating movements found in the real world is crucial for conveying ideas and telling a compelling story. This is where the bounce expression shines, allowing you to give your animations the weight and mass of real-world objects.

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e = .7;
g = 5000;
nMax = 9;
    

e = 1.2;
g = 5000;
nMax = 9;
    

e = .7;
g = 7000;
nMax = 7;
    

How Do You Add A Bounce Expression In After Effects?

Now, if you're aiming to add a bounce to any layer, the bounce expression is your go-to. At first glance, it might seem intricate, but there's no need to be daunted by its complexity. Here's a breakdown of what you need to know:

1. Accessing the Expression Field: In After Effects, select the property you want to apply the bounce to. Alt-click on the stopwatch icon next to the property to open the expression field.
2. Key Components of the Bounce Expression:
3. e: This variable controls the elasticity of the bounce. Think of it as a bungee cord attached to your object. A lower value for 'e' will make the bounce stiffer. If you desire a looser bounce, simply increase this value.
4. g: This represents gravity. Just as you'd expect, a higher value makes the object feel heavier. As gravity increases, post-bounce movements speed up.
5. nMax: This determines the maximum number of bounces allowed.
6. Applying the Expression: Once you've input the expression, After Effects will use just two keyframes to create a bounce. It will gauge the velocity of your layers' movement to determine the bounce's behavior.
7. Tweaking the Bounce: The expression provides you with the flexibility to control various aspects of the bounce. For instance, you can adjust the elasticity, gravity, and the number of bounces.
8. Understanding the Real-World Analogy: To grasp the concept of elasticity, picture a bungee cord. A lower elasticity value will resemble a tight cord, resulting in a stiffer bounce. On the other hand, a higher value will give you a looser, more fluid bounce.
9. Gravity's Role: In the bounce expression, gravity operates just as you'd expect in the real world. The higher the gravity, the heavier the object feels. As the object completes its initial bounce, subsequent bounces will conclude faster.

It's essential to note that while the bounce expression is a remarkable tool, it's not a replacement for understanding the fundamentals of creating a bounce. It's perfect for layers that require a simple bounce, but mastering the art of animation goes beyond this.

Common Uses Of Bounce Expressions

1. Text Animations

Bounce expressions are widely used for animating text in creative ways:

• Title Reveals: Text can bounce into view when it scales up from zero or moves into its final position. This adds a playful and engaging touch, especially for motion graphics.
• Individual Characters: By applying bounce effects to individual characters or words, you can create dynamic, per-character animations.
• Emphasizing Action: Adding a subtle bounce to text when it lands draws attention and creates a satisfying conclusion to the movement.

Example Use: A title sequence where each word “lands” with a slight bounce as though affected by gravity.

2. UI/UX Animations

In interface animations, bounce expressions mimic real-world physics to make interactions feel more intuitive and enjoyable:

• Button Clicks: A button can "compress" slightly when clicked, then bounce back into place.
• Icons: Icons that pop or bounce when hovered over can create a responsive feel in animated app or website demos.
• Loading Animations: Bouncing dots or shapes in loading screens add liveliness while the user waits.

Example Use: In a mobile app prototype, a tap on an icon causes it to bounce and scale slightly before returning to normal.

3. Logo Animations

For logos, bounce effects can make animations look polished and memorable:

• Introductory Animations: A logo might "fall" into the center of the screen with a bounce, reinforcing brand identity with dynamic motion.
• Character Logos: For mascot-based logos, bounce effects can give life and personality to the character.

Example Use: A company’s circular logo bounces as it “drops” into view during the opening of a promotional video.

4. Object Drops

Objects like balls, boxes, or abstract shapes frequently use bounce expressions to simulate real-world physics:

• Falling Objects: A ball can fall, bounce a few times, and settle naturally. The bounce expression simulates this without manually keyframing every rebound.
• Building Scenes: Objects can appear to bounce slightly as they come into position to make transitions smoother and more interesting.

Example Use: A bouncing ball animation to demonstrate kinetic energy in an educational video.

5. Infographics and Data Visualizations

Bounce effects can make data animations more engaging:

• Bars and Graphs: Bars in a graph can "pop" upward with a bounce when animating a data set.
• Icons and Numbers: Data counters or percentage icons can bounce into place for emphasis.

Example Use: In a financial infographic, bars in a bar chart bounce slightly as they grow to their final heights.

6. Character Animations

For animating 2D or 3D characters, bounce expressions help simulate:

• Footsteps: When a character lands on a surface, their feet or body can have a slight bounce to mimic natural movement.
• Head Tilts: When a character nods or reacts, a bounce effect on the head or other body parts can add elasticity and realism.

Example Use: A cartoon character jumping with a subtle bounce upon landing to add believability.

7. Title and Transition Sequences

Bounce expressions help transitions feel more fluid:

• Scene Changes: Elements like borders or panels that slide or pop into the frame can have a bounce to soften the abruptness of the motion.
• Text Transitions: During a slide-out or fade-in, adding a bounce can make the effect more dynamic.

Example Use: A transition between video sections where sliding panels bounce slightly upon arriving in their positions.

8. Miscellaneous Creative Uses

• Props and Objects in Skits: Simulating objects like springs, trampolines, or rubber balls.
• Product Ads: Animating product packaging or text to bounce adds energy to the presentation.
• Game Design Mockups: Bouncing effects mimic physics for objects like coins, power-ups, or interactive elements.

Example Use: A coin in a game design demo bounces up and down after being collected.

Examples of Bounce Expression

Here’s a common bounce expression for Position or Scale properties:

‍amp = 50; // Amplitude of the bounce
freq = 2; // Frequency of the bounce
decay = 3; // How quickly the bounce stops

n = 0;
if (numKeys > 0) {
   n = nearestKey(time).index;
   if (key(n).time > time) {
       n--;
   }
}
if (n > 0) {
   t = time - key(n).time;
   v = velocityAtTime(key(n).time - thisComp.frameDuration / 10);
   value + v * amp * Math.sin(freq * t * Math.PI * 2) / Math.exp(decay * t);
} else {
   value;
}


• Adjustable Parameters:
  • amp: Controls how high or large the bounce is.
  • freq: Determines how fast the bounce occurs.
  • decay: Sets how quickly the bounce effect fades out.

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