User Guide Cancel

Using expression controls

  1. After Effects User Guide
  2. Beta releases
    1. Beta Program Overview
    2. After Effects Beta Home
  3. Getting started
    1. Get started with After Effects
    2. What's new in After Effects 
    3. Release Notes | After Effects
    4. After Effects system requirements
    5. Keyboard shortcuts in After Effects
    6. Supported File formats | After Effects
    7. Hardware recommendations
    8. After Effects for Apple silicon
    9. Planning and setup
  4. Workspaces
    1. General user interface items
    2. Get to know After Effects interface
    3. Workflows
    4. Workspaces, panels, and viewers
  5. Projects and compositions
    1. Projects
    2. Composition basics
    3. Precomposing, nesting, and pre-rendering
    4. View detailed performance information with the Composition Profiler
    5. CINEMA 4D Composition Renderer
  6. Importing footage
    1. Preparing and importing still images
    2. Importing from After Effects and Adobe Premiere Pro
    3. Importing and interpreting video and audio
    4. Preparing and importing 3D image files
    5. Importing and interpreting footage items
    6. Working with footage items
    7. Detect edit points using Scene Edit Detection
    8. XMP metadata
  7. Text and Graphics
    1. Text
      1. Formatting characters and the Character panel
      2. Text effects
      3. Creating and editing text layers
      4. Formatting paragraphs and the Paragraph panel
      5. Extruding text and shape layers
      6. Animating text
      7. Examples and resources for text animation
      8. Live Text Templates
    2. Motion Graphics
      1. Work with Motion Graphics templates in After Effects
      2. Use expressions to create drop-down lists in Motion Graphics templates
      3. Work with Essential Properties to create Motion Graphics templates
      4. Replace images and videos in Motion Graphics templates and Essential Properties
      5. Animate faster and easier using the Properties panel
  8. Drawing, Painting, and Paths
    1. Overview of shape layers, paths, and vector graphics
    2. Paint tools: Brush, Clone Stamp, and Eraser
    3. Taper shape strokes
    4. Shape attributes, paint operations, and path operations for shape layers
    5. Use Offset Paths shape effect to alter shapes
    6. Creating shapes
    7. Create masks
    8. Remove objects from your videos with the Content-Aware Fill panel
    9. Roto Brush and Refine Matte
  9. Layers, Markers, and Camera
    1. Selecting and arranging layers
    2. Blending modes and layer styles
    3. 3D layers
    4. Layer properties
    5. Creating layers
    6. Managing layers
    7. Layer markers and composition markers
    8. Cameras, lights, and points of interest
  10. Animation, Keyframes, Motion Tracking, and Keying
    1. Animation
      1. Animation basics
      2. Animating with Puppet tools
      3. Managing and animating shape paths and masks
      4. Animating Sketch and Capture shapes using After Effects
      5. Assorted animation tools
      6. Work with Data-driven animation
    2. Keyframe
      1. Keyframe interpolation
      2. Setting, selecting, and deleting keyframes
      3. Editing, moving, and copying keyframes
    3. Motion tracking
      1. Tracking and stabilizing motion
      2. Face Tracking
      3. Mask Tracking
      4. Mask Reference
      5. Speed
      6. Time-stretching and time-remapping
      7. Timecode and time display units
    4. Keying
      1. Keying
      2. Keying effects
  11. Transparency and Compositing
    1. Compositing and transparency overview and resources
    2. Alpha channels and masks
    3. Track Mattes and Traveling Mattes
  12. Adjusting color
    1. Color basics
    2. Color management
    3. Color Correction effects
    4. OpenColorIO and ACES color management
  13. Effects and Animation Presets
    1. Effects and animation presets overview
    2. Effect list
    3. Effect Manager
    4. Simulation effects
    5. Stylize effects
    6. Audio effects
    7. Distort effects
    8. Perspective effects
    9. Channel effects
    10. Generate effects
    11. Transition effects
    12. The Rolling Shutter Repair effect
    13. Blur and Sharpen effects
    14. 3D Channel effects
    15. Utility effects
    16. Matte effects
    17. Noise and Grain effects
    18. Detail-preserving Upscale effect
    19. Obsolete effects
  14. Expressions and Automation
    1. Expressions
      1. Expression basics
      2. Understanding the expression language
      3. Using expression controls
      4. Syntax differences between the JavaScript and Legacy ExtendScript expression engines
      5. Editing expressions
      6. Expression errors
      7. Using the Expressions editor
      8. Use expressions to edit and access text properties
      9. Expression language reference
      10. Expression examples
    2. Automation
      1. Automation
      2. Scripts
  15. Immersive video, VR, and 3D
    1. Construct VR environments in After Effects
    2. Apply immersive video effects
    3. Compositing tools for VR/360 videos
    4. Advanced 3D Renderer
    5. Import and add 3D models to your composition
    6. Import 3D models from Creative Cloud Libraries
    7. Image-Based Lighting
    8. Extract and animate lights and cameras from 3D models
    9. Tracking 3D camera movement
    10. Cast and accept shadows
    11. Embedded 3D model animations
    12. Shadow Catcher
    13. 3D depth data extraction
    14. Modify materials properties of a 3D layer
    15. Work in 3D Design Space
    16. 3D Transform Gizmos
    17. Do more with 3D animation
    18. Preview changes to 3D designs real time with the Mercury 3D engine
    19. Add responsive design to your graphics 
  16. Views and Previews
    1. Previewing
    2. Video preview with Mercury Transmit
    3. Modifying and using views
  17. Rendering and Exporting
    1. Basics of rendering and exporting
    2. H.264 Encoding in After Effects
    3. Export an After Effects project as an Adobe Premiere Pro project
    4. Converting movies
    5. Multi-frame rendering
    6. Automated rendering and network rendering
    7. Rendering and exporting still images and still-image sequences
    8. Using the GoPro CineForm codec in After Effects
  18. Working with other applications
    1. Dynamic Link and After Effects
    2. Working with After Effects and other applications
    3. Sync Settings in After Effects
    4. Creative Cloud Libraries in After Effects
    5. Plug-ins
    6. Cinema 4D and Cineware
  19. Collaboration: Frame.io, and Team Projects
    1. Collaboration in Premiere Pro and After Effects
    2. Frame.io
      1. Install and activate Frame.io
      2. Use Frame.io with Premiere Pro and After Effects
      3. Frequently asked questions
    3. Team Projects
      1. Get Started with Team Projects
      2. Create a Team Project
      3. Collaborate with Team Projects
  20. Memory, storage, performance
    1. Memory and storage
    2. How After Effects handles low memory issues while previewing    
    3. Improve performance
    4. Preferences
    5. GPU and GPU driver requirements for After Effects
  21. Knowledge Base
    1. Known issues
    2. Fixed issues
    3. Frequently asked questions
    4. After Effects and macOS Ventura
    5. How After Effects handles low memory issues while previewing

Link your expressions to Expression Controls so you can control and keyframe their values just like you do with effects.

Using expression controls with your expressions makes them more dynamic and easier to update. Rather than always needing to modify the values inside the expression editor, you can link them to an Expression Control in the Effect Controls panel. A single control can affect several properties at once.

You can use them to control parameters within your expressions. You can add a slider that moves a layer only within certain limits, or let the user select between several options by choosing from a dropdown menu. You can add checkboxes that turn layers on or off, or change color schemes on text and graphics layers. You can add angle controls that drive the rotation of several layers, and you can add color controls that change the color of text, glows, or shapes.

The names for the Expression Control effects indicate what type of property control they provide: Angle Control, Checkbox Control, Color Control, Layer Control, Point Control, Slider Control, and Dropdown Menu Control.

Note:

If you apply an animation preset from the Animation Presets > Shapes > Backgrounds category, you can see a custom Animated Shape Control effect in the Effect Controls panel. This custom effect is a specialized expression control effect that was created specifically for these animation presets. You can copy and paste this effect to other layers, or you can save it as an animation preset itself so that you can apply it elsewhere.

Apply expression controls to layers

You apply Expression Controls effects to a layer in the same ways that you apply other effects, such as dragging the effect onto the layer from the Effects & Presets panel.

You can apply Expression Controls effects to any layer; however, it is useful to apply them to a null layer, which you can simply use as a controlling layer. You then add expressions to properties on other layers to take input from that control. For example, you can add the Slider Control effect to a null layer (Null 1), and then apply this expression to the Position properties of multiple layers:

  position+[0,10*(index-1)*thisComp.layer("Null 1").effect("Slider Control")("Slider")]

In this example, as you drag the slider, each layer with this expression moves. The layers with greater index numbers (layers toward the bottom in the Timeline panel) are shifted more than the layers with lower index numbers, at 10-pixel intervals. You can set keyframes for the slider on the null layer, and all the other layers animate accordingly.

It is often useful to rename each instance of an Expression Control effect to indicate its use. For example, renaming an instance of the Color Control effect to sky color makes it easier to tell what the effect is controlling. You can rename each instance of an Expression Control effect just as you rename any other effect: select it in the Timeline panel or Effect Controls panel and press Enter on the main keyboard (Windows) or Return (Mac OS).

Note:

To modify the range of a control, right-click (Windows) or Control-click (Mac OS) the underlined property value for the control and choose Edit Value from the context menu.

Convert an expression to keyframes

In some situations, it’s useful to convert an expression to keyframes. For example, if you want to freeze the values in an expression, you can convert the expression to keyframes and then adjust the keyframes accordingly. If an expression takes a long time to evaluate, you can convert it to keyframes so that it renders more quickly. When you convert an expression to keyframes, After Effects evaluates the expression, creating a keyframe at every frame, and then disables the expression.

In the Timeline panel, select the property on which the expression is written and choose Animation > Keyframe Assistant > Convert Expression To Keyframes. The original expression is preserved, only disabled.

More Expression resources

Now that you have understood some of the concepts behind expressions, come to the community for some real-life examples, and to share your work.

You can also check out Dan Ebberts' excellent collection of example expressions and tutorials on his MotionScript website.

The AE Enhancers forum also provides many examples and much information about expressions, as well as scripts and animation presets.

 Adobe

Get help faster and easier

New user?

Adobe MAX 2024

Adobe MAX
The Creativity Conference

Oct 14–16 Miami Beach and online

Adobe MAX

The Creativity Conference

Oct 14–16 Miami Beach and online

Adobe MAX 2024

Adobe MAX
The Creativity Conference

Oct 14–16 Miami Beach and online

Adobe MAX

The Creativity Conference

Oct 14–16 Miami Beach and online