Adobe After Effects Expressions and Scripting

Question 1

How do you add an expression to a property in After Effects?

Accepted Answer

Alt+click (Option+click on Mac) the stopwatch icon of the property

Answer

Right-click the property and choose Add Expression

Answer

Click the property name and press E

Answer

Drag from the Expression Picker onto the property

Question 2

What does the `wiggle()` expression function do in After Effects?

Accepted Answer

Creates random oscillation of a property's value over time with controllable frequency and amplitude

Answer

Applies the Wiggle effect to the layer automatically

Answer

Randomly shuffles the order of keyframes on the property

Answer

Generates a wiggling motion path for the layer's position

Question 3

What does `thisComp.layer("Layer Name").transform.position` do in an After Effects expression?

Accepted Answer

Returns the current position value of a named layer in the same composition

Answer

Moves the current layer to the position of the named layer

Answer

Links the composition's output position to the named layer

Answer

Reads the position property from a layer in a different composition

Question 4

What does the `time` expression variable represent in After Effects?

Accepted Answer

The current time of the composition in seconds at the current frame

Answer

The total duration of the composition in seconds

Answer

The frame number of the current frame

Answer

The elapsed CPU processing time for the current render

Question 5

What does `loopOut('cycle')` do in an After Effects expression?

Accepted Answer

Repeats the keyframe animation after the last keyframe by cycling back to the first keyframe

Answer

Loops the layer's timeline after it ends

Answer

Repeats the layer in the composition render queue

Answer

Creates a pre-comp loop of the layer animation

Question 6

What is the Expression Language in After Effects based on?

Accepted Answer

JavaScript (specifically the ECMAScript standard)

Answer

Python scripting syntax

Answer

Lua scripting language

Answer

C++ with simplified syntax