• Adobe After Effects Expressions

  Linking opacity expression wiggle with brightness

  Posted by Olly Lawer on January 24, 2013 at 10:21 am

  Hi,

  I’ve got one layer with a wiggle(4,100) and I have pick whipped it to a brightness effect (brightness and contrast) on another layer. I am gathering it’s not working because the values are different, % vs no.

  How to I change it to get it to work AND change the subtly of the effect, meaning that when the wiggle goes to say 4% opacity, the brightness value is not so dark you cannot see the image?

  Thank you!

  thisComp.layer("Audience Retention").effect("Brightness & Contrast")("Brightness")

  Olly Lawer

  Vojtěch Palme replied 13 years, 6 months ago 2 Members · 1 Reply
• 1 Reply

• 

  Vojtěch Palme

  February 26, 2013 at 3:02 pm

  That depends on what you aplyed the wiggle to. If you’ve aplyed to position, that has 2 values, you cannot just pick whip brightness to entire position, but only to one of its values.
  If you want both X and Y pos. to affect the brightness you can do something like this:

  val = thisComp.layer("wiggling layer").transform.position[0]+thisComp.layer("wiggling layer").transform.position[1]/2; //evridge of the position x,y values
linear(val,1100,1300,-30,100) //this changes the resoult values (1100 and 1300 were my resoult values) to range between -30 and 100 (bright enaugh)

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