[2024] Posterize Time & Wiggle After Effects Expression Tutorial

In After Effects, leverage the Posterize Time expression to control your animation's frame rate, giving it a distinct choppy feel. Simultaneously, use the Wiggle expression to introduce random movement to your layers, and when combined, these tools can craft a unique stop-motion style with a touch of randomness.

November 26, 2023
[2024] Posterize Time & Wiggle After Effects Expression Tutorial

Wiggle Posterize Time In After Effects

Posterize Time Expression

Use this to control the playback speed of your animation:

posterizeTime(12);

Wiggle Expression

Add random movement to your layers:

wiggle(3,15);

Combined Expression

Combine Posterize Time with Wiggle for a unique effect:

posterizeTime(12);
wiggle(3,15);

What it Does

Think of it as a tool that lets you control the playback speed of your animation, but not in the traditional sense. Instead of speeding up or slowing down your animation, it limits the number of frames that play every second.

For instance, let's say you're working on a 24 frames per second (fps) composition. By default, every second of your animation plays back 24 individual frames. Now, if you apply the posterizeTime function and set it to 12 fps, your animation will only show every other frame, giving it a "choppy" look.

How To Use It

How to Apply Posterize Time:

  1. Select the layer you want to apply the effect to.
  2. Press "E" on your keyboard to bring up the expressions panel.
  3. Alt-click (Option-click on Mac) on the stopwatch icon next to the property you want to affect (like position or rotation).
  4. In the expression field that appears, type posterizeTime(12); and press Enter. This sets your layer to play back at 12 fps.

Introducing the Wiggle Expression

Now, let's talk about another expression: "Wiggle." This is one of my favorites because it adds a random movement to your layers. The wiggle expression requires two main values: frequency and amplitude. Frequency determines how often your layer will "wiggle" or move, and amplitude controls how far it can move from its starting position.

Imagine you want your layer to shift slightly, giving it a natural, organic feel. You could set a frequency of 3 (meaning it will move three times every second) and an amplitude of 15 (it can move up to 15 pixels from its starting position).

How to Apply the Wiggle Expression:

  1. Select your desired layer.
  2. Press "E" to open the expressions panel.
  3. Alt-click (Option-click on Mac) on the stopwatch next to the property you want to affect.
  4. Type wiggle(3,15); in the expression field and press Enter.

Combining Posterize Time and Wiggle

When you combine Posterize Time with Wiggle, magic happens. Your layer will still have that random "wiggle" movement, but it'll appear choppy due to the reduced frame rate from Posterize Time. This combination can give your animation a unique "stop-motion" feel with a touch of randomness.

Steps to Combine Both Expressions:

  1. Select your layer.
  2. Press "E" to access the expressions panel.
  3. Alt-click (Option-click on Mac) on the stopwatch of your desired property.
  4. First, type posterizeTime(12); and on the next line, type wiggle(3,15);.

By following these steps, you've now applied both expressions to your layer. Play back your composition, and you'll see the layer moving randomly but at a controlled, choppy frame rate.