Learn how to create custom transitions in After Effects.

Custom transitions with masks

Animate masks to create a custom transition.


What you learned: Create a custom transition using masks

Masks are used to hide, or reveal, specific areas of a layer.

  • To apply a mask to a layer:
    1. Select the desired layer in the timeline.
    2. Select the Pen tool or a Shape tool in the Tools panel.
    3. Draw a mask shape in the Composition panel to define the areas to hide.
  • To animate a mask:
    1. Move the Current Time Indicator (CTI) to a frame in the Timeline for the start of the transition.
    2. Press M to open the Mask Path settings.
    3. Click the stopwatch to the left of the words Mask Path to record the position of the mask path and set the first keyframe.
    4. Move the CTI down the Timeline to mark the end of the transition.
    5. Click the words Mask Path in the Timeline to select the mask path.
    6. Move each anchor point in the path to a new position or press Control+T (Windows) or Command+T (macOS) to apply transform handles to the mask path.
    7. Drag inside the mask handles to move the mask without changing the shape; drag the handles to transform the shape of the mask.
    8. Reposition the mask and press Enter on your keyboard to apply the transformation and automatically record the second keyframe for the transition.

Build graphic transitions with Shape layers

Build animated graphics using Shape layers.


What you learned: Create animated transitions 

An Adobe Illustrator layer can be converted to a Shape layer.

  • To convert an Illustrator layer to a Shape layer:
    1. Select the desired layer in the Timeline.
    2. In the main menu, select Layer > Create shapes from vector layer.
  • Shapes layers can be repeated using a Repeater:
    1. Select the Shape layer to repeat in the Timeline.
    2. Open the layer options by clicking the triangle on the left side of the layer.
    3. To the right of the Contents section on the layer, click the button to the right of the word Add and choose Repeater.
    4. Open the triangle for Repeater 1 and set the number of Copies.
    5. Open the triangle for Transform: Repeater 1 and change the settings to adjust how each shape will move when it is repeated. (The default setting will move each copy 100 pixels on the X Position.)
    6. To animate the repeated shape, keyframe the Offset for Repeater 1.

Create transparency with layers

Create transparency in a layer using a track matte.


What you learned: Create transparency in a layer 

The Alpha channel determines the transparency of an image. Anything that is 100% white is 100% opaque and anything that is 100% black is 100% transparent.

To reveal track mattes, toggle the Switches/Modes button in the bottom of the timeline and make sure Switches are hidden and Modes are revealed.

Track mattes look at the next layer directly above in the timeline to determine transparency.

There are five different settings for track mattes in the Track Matte drop-down menu:

  • No Matte: No transparency created; next layer above acts as normal layer.
  • Alpha Matte: Opaque when alpha channel pixel value is 100%.
  • Alpha Inverted Matte: Opaque when alpha channel pixel value is 0%.
  • Luma Matte: Opaque when the luminance value of a pixel is 100%.
  • Luma Inverted Matte: Opaque when the luminance value of a pixel is 0%.


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Presenter: Ian Robinson

Designer: Will Freeman

Designer: Martin Hoang

Designer: Erica Larson

Contributor: David K. Helmly

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