• Adobe After Effects Expressions

  Mask opacity offset

  Posted by Jacques Levet on September 4, 2008 at 6:16 pm

  Hello everyone
  I am trying to offset the opacity of a large amount of masks. I would like each mask to look at the previous one for opacity value and turn on. this is how far i got

  mask(“Mask 217”).maskOpacity.valueAtTime(time-0.1)

  it does what i want it to, except i have to manually pick whip each mask opacity to the previous one for this to work properly (and i have 217 masks). My question is, is there a way to change the expression so that it automatically looks at the previous mask value, and that I can paste it to all the masks at once?

  Thank you in advance for your help.
  Jacques

  Lloyd Alvarez replied 17 years, 8 months ago 2 Members · 4 Replies
• 4 Replies

• 

  Lloyd Alvarez

  September 4, 2008 at 7:14 pm

  Here you go Jacques:

  mask(propertyGroup(1).propertyIndex -1).maskOpacity.valueAtTime(time-0.1) 

  -Lloyd

  https://aescripts.com
• 

  Lloyd Alvarez

  September 4, 2008 at 7:17 pm

  by the way, if you are doing (time-0.1) because you are wanting to look at the previous frame, this is a more accurate way to do it:

  mask(propertyGroup(1).propertyIndex -1).maskOpacity.valueAtTime(time-framesToTime(1, fps = 1.0 / thisComp.frameDuration)) 

  -Lloyd

  https://aescripts.com
• 

  Jacques Levet

  September 4, 2008 at 7:32 pm

  thank you Lloyd.
  very helpful
  Actually, I dont know if you remember but we did a job together a few years ago.
  Thanks again for your help
  j
• 

  Lloyd Alvarez

  September 8, 2008 at 1:42 pm

  Yeah! Was it at Y&R?

  https://aescripts.com

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