• Adobe After Effects Expressions

  Turn on/off layer opacity with specific color value

  Posted by Itay Bartal on January 27, 2021 at 5:16 pm

  Hi,

  The layer opacity is linked to a Color Control.

  I want to turn on to 100 the opacity when I get the color value: [0.973,0.831,0.055,1]

  and if I get other color value I want to turn off the opacity to 0.

  This is what I tried but didn’t work:

  yellow_color = [0.973,0.831,0.055,1];

  if (comp(“_FF_Dark_01”).layer(“CHANGE_COLOR_HERE”).effect(“Color Control”)(“Color”) == yellow_color) {100} else {0}

  THANKS

  Itay Bartal replied 5 years, 7 months ago 3 Members · 3 Replies
• 3 Replies

• 

  Kevin Camp

  January 28, 2021 at 6:43 pm

  try just one = (equal sign). I think since it is a numerical value comparison, it should just be one equal.
• 

  Dan Ebberts

  January 28, 2021 at 8:37 pm

  Colors are arrays, so I think you need to check them element by element. Also, floating point values may not match exactly, so I think I’d include a “close enough” tolerance. Something like this:

  tolerance = .001;
  yellow_color = [0.973,0.831,0.055,1];
  function compareColors(color1,color2,theTolerance){
    for (i = 0; i < color1.length; i++){
      if (Math.abs(color1[i] - color2[i]) > theTolerance) return false;
    }
    return true;
  }
  color = comp("_FF_Dark_01").layer("CHANGE_COLOR_HERE").effect("Color Control")("Color").value;
  compareColors(yellow_color, color, tolerance) ? 100 : 0
• 

  Itay Bartal

  January 29, 2021 at 6:47 am

  Like magic!

  THANKS DAN!

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