• Adobe After Effects Expressions

  making opacity binary (on or off) with expression

  Posted by Adam Browne on August 29, 2012 at 8:29 pm

  I’m trying to make an effect controlled by music, and I need to make a layer’s opacity controlled by the Audio Amplitude keyframes I converted from the audio. I think I’m 80% there with this expression on the opacity of the layer:

  transform.opacity=(thisComp.layer(“Audio Amplitude”).effect(“Both Channels”)(“Slider”))

  That’s varying the opacity, but what I need is for the layer’s opacity to be binary, either 0% or 100% depending on the “audio amplitude”. In other words, I want to be able to say, “if the amplitude is greater than X, be ON, if not, be OFF” Does that make sense? Any ideas?

  transform.opacity=(thisComp.layer("Audio Amplitude").effect("Both Channels")("Slider"))

  Adam Browne replied 13 years, 8 months ago 2 Members · 2 Replies
• 2 Replies

• 

  Anna Blume

  August 30, 2012 at 8:54 am

  Hi Adam,

  I’m also a beginner, but try the expression attached. If you connect the variable maxVal with an additional slider you can also change this value over time.

  maxVal = 80;
if (thisComp.layer("Audio Amplitude").effect("Both Channels")("Slider") >= maxVal) {
100}
else {
0}
• 

  Adam Browne

  August 30, 2012 at 5:38 pm

  That did it! Thanks! This is my first foray into expressions… so much more to learn.

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