• Adobe After Effects Expressions

  Using slider expression to control oscillating value of opacity?

  Posted by Germain Wu on June 28, 2011 at 10:29 am

  Hi!
  I’m attempting to use a expression control slider to control the frequency of a layer’s visibility but have no idea how to.
  I’ve been doing it manually but it’s a pain when I need to change the keyframes so I was wondering how I can do it with expression.

  I have a layer that turns on and off from say twice per second to the maximum keyframe I can have in the comp’s framerate usually sync to the music.
  I have done it by spacing keyframes but is there a method to do it using slider control so the frequency of switching on and off can be animated using just 2 key frames?

  Thanks

  Greg Burrus replied 14 years, 10 months ago 2 Members · 1 Reply
• 1 Reply

• 

  Greg Burrus

  June 28, 2011 at 1:23 pm

  There is actually a preset already set up to do pretty much this in a random way.

  If you look in animation presets > behaviors > Opacity flash random or just search opacity flash you will find it.

  You can use this a building block to make exactly what you need or just use as is.

  Hope this helps.

  Greg

  https://mogra.g2bproductions.com/ – Blog
  https://g2bproductions.com/ – Portfolio

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