After Effects, Animation Day 5


  • Learn how to create and animate masks
  • Understand how the pen tool works and use it to create more detailed masks
  • Understand how to use the following mask properties:
    • Mask type (add, subtract, inverted)
    • Mask Path
    • Feathering
    • Expansion
  • Understand the the following track matte types and how to use them:
    • Alpha Matte
    • Alpha Inverted Matte
    • Luma Matte
    • Luma Inverted Matte

Link to files:



  • Has anyone used masks before? (In After Effects or in another program like Premiere)


  • See the Mattes and Masking Example file for the final versions of each project.
  • When teaching, don’t worry about getting to every project, focus instead on completing at least one from each objective.

—–Masking: First Project (Vehicle)—–

  • Create a new composition with the vehicle Footage
    • Create a text layer in the center of the composition
    • Create and keyframe a mask to make the car reveal the text as it drives by
      • Create a mask for desired layer by selecting the layer and then using the shape or pen tools
      • Show how to edit individual points after initial creation
      • Mask properties can be found in the masked layer in the layer panel (keyboard shortcut “M”)
      • Keyframe mask points and position with the Mask Path property
      • Adjust mask feathering (softness) and expansion if needed in the mask properties
      • Can also change the mask mode (e.g. from Add to Subtract) or invert it

—–Masking: Second Project (Soda)—–

  • Create a new composition with the soda footage
  • Create a text layer in the center of the composition
  • Create and keyframe a mask so that the text is revealed when the soda bottle is removed

Track Mattes: First Project—–

  • Setup
    • Create a new composition
    • Create a text layer in the center of the composition
      • Can animate its scale a little for demonstration purposes
    • Add two image to the composition (desert and snow) and position the layers below the text layer
  • Applying a track matte
    • If the track matte option is missing from the layer panel, click “Toggle Switches / Modes” on the bottom of the panel
    • Show the difference between alpha and alpha inverted matte
    • Show the difference between luma and luma inverted matte and how luma mattes are different from alpha mattes
      • For luma mattes, it may be helpful to add a gradient ramp effect to the text to show how the change in brightness affects the strength of the mask (see example project)

—–Track Mattes: Second Project (Lower Thirds Animation)—–

  • Setup or just show how it works using the example comp depending on time
    • Create a new composition
    • Add some text
    • Create a rectangle shape layer in front of the text (if the text is white, make sure the rectangle is black and vice versa)
  • Set the track matte of the text so that it’s masked by the rectangle
  • Position the text below the rectangle mask and keyframe it to move up until it’s visible

—–Track Mattes Example Activity (Present X-Ray)—–

  • Have students open the present example and create a circle shape layer
  • Have student use what they learned about track mattes to make the circle act as an x-ray revealing what’s inside the present
  • OPTIONAL: Let the student also practice using a mask as an x-ray


  • Recap: Today we learned
    • How to create and animate masks
    • How to use the pen tool
    • What Track Mattes are and how to use them