• Adobe After Effects Expressions

  Controlling AE light with layer luminance

  Posted by Pedro Torres on April 19, 2022 at 1:39 pm

  Hi, just wondering if some one could help me. I only know basic expressions so hopefully this is not too complicated.

  I have footage of a LED wall with graphics moving and flickering on and off mostly black and white.
  I ‘m placing a person in front of the LED plate shot on a green screen already keyed out, and want to match the lighting conditions.

  Can I use expressions to animated an after effect light intensity with the luminance of the LED layer.

  Dan Ebberts

  

  replied 4 years, 5 months ago 2 Members · 1 Reply
• 1 Reply

• 

  Dan Ebberts

  April 19, 2022 at 5:15 pm

  You could use sampleImage() to get the luminance of a section of the LED wall with something like this:

  L = thisComp.layer("LED Wall");
  s = L.sampleImage([L.width,L.height]/2,[100,100]);
  rgbToHsl(s)[2]*100

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