• Adobe After Effects Expressions

  Add value to slider based on another value

  Posted by Krish Chhottra on March 3, 2018 at 10:46 pm

  So basically I have null with slider control
  with the pick whip, I connected an evolution type of effect (like the hue/saturation change which is in 360 degrees)
  I have an audio aptitude layer
  I want to add the value of the audio layer to the slider control without subtracting it after, so every frame, if the audio is at 3 the first frame and 11 at the second, the slider will go to 3 and then 14.
  Thanks to anyone who tries to help me.

  Krish Chhottra replied 8 years, 2 months ago 2 Members · 2 Replies
• 2 Replies

• 

  Dan Ebberts

  March 4, 2018 at 1:21 am

  Something like this maybe:

  
a = thisComp.layer("Audio Amplitude").effect("Both Channels")("Slider");
accum = 0;
for (i = timeToFrames(inPoint); i <= timeToFrames(time); i++){
accum += a.valueAtTime(framesToTime(i));
}
value + accum*thisComp.frameDuration


  It can be a performance hog though, because on each successive frame it has to do more and more work. If performance is an issue, it would be better to get Red Giant’s Sound Keys, which has a built-in integration mode.

  Dan
• 

  Krish Chhottra

  March 4, 2018 at 2:28 am

  Thanks for the advice, I did have sound keys. Just didn’t know it can do this so easily!

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