• Adobe After Effects Expressions

  Incrementing position of a layer using Trapcode Sound Keys

  Posted by James Bazza on January 6, 2012 at 4:52 pm

  Hi there,

  Im trying to use the result of an output of sound keys to incrementally move the position of a layer..

  This is what I have tried, I cannot get the value to continually increment

  Thanks in advance for any help!

  SK = thisComp.layer("Soundkeys").effect("Sound Keys")("Output 1").valueAtTime(time+0.1)
xPos = value[0] ;
yPos = value[1] ;
if (SK > 80){
[xPos +20, yPos];
}else{ [xPos , yPos ] ; }

  James Bazza replied 14 years, 8 months ago 3 Members · 5 Replies
• 5 Replies

• 

  Kevin Camp

  January 6, 2012 at 5:25 pm

  i can’t experiment with this now, but i think you should be able to incorporate dan’s beat counter expression:

  https://www.motionscript.com/design-guide/audio-count.html

  the beat counter expression is the second one on that page.

  Kevin Camp
  Senior Designer
  KCPQ, KMYQ & KRCW
• 

  Dan Ebberts

  January 6, 2012 at 6:34 pm

  Another possibility is to set the Sound Keys Range Falloff control to “None (integrate)”. This causes the output value to continually increase in response to the audio.

  Dan
• 

  James Bazza

  January 8, 2012 at 10:20 am

  thanks for the replies…

  Ok I tried using a while loop but am still stumped… I cant get the position to keep on incrementing

  SK = thisComp.layer("Soundkeys").effect("Sound Keys")("Output 1").valueAtTime(time+0.1);
xPos = value[0] ;
yPos = value[1] ;
frame = Math.round(time / thisComp.frameDuration);

  while (frame >= 0){
  t = frame * thisComp.frameDuration;
  if (SK > 80){
  xPos = xPos+20;

  }else {
  xPos = xPos;
  }
  frame--
  }

  [xPos, yPos]
• 

  Dan Ebberts

  January 8, 2012 at 4:39 pm

  Try this:

  
SK = thisComp.layer("Soundkeys").effect("Sound Keys")("Output 1");
x = 0;

  for (f = timeToFrames(time); f >= 0; f--){
  t = framesToTime(f);
  if (SK.valueAtTime(t) > 80) x += 20;
  }

  value + [x,0]


  Dan
• 

  James Bazza

  January 8, 2012 at 5:08 pm

  ahh!! thanks so much, appreciate it. I see the mistakes I was making

  Cheers!

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