• Adobe After Effects Expressions

  AfterEffectsExpressions, PropertyIndex question

  Posted by Assaf Goldlust on February 23, 2018 at 2:34 pm

  So im learning how to use expressions with the book “AE Expression”.

  He reached when he applies the next expression on a 4 color gadient:
  effect("4-Color Gradient").param(propertyIndex - 2).valueAtTime(time – .5)

  After reciving an error when tried to apply the expression i googled for answered and i found this:

  
I think the problem is that when the book was written, thisProperty was implied when referring to attributes of the property housing the expression. Somewhere along the line it was changed so that now you have to explicitly include it. This should work:

  effect("4-Color Gradient").param(thisProperty.propertyIndex - 2).valueAtTime(time - .5)

  Dan


  That one left me confused, if “thisPoperty” was used back then for the property that holds the expression.
  what does that mean today?

  Assaf Goldlust replied 8 years, 2 months ago 2 Members · 2 Replies
• 2 Replies

• 

  Dan Ebberts

  February 23, 2018 at 4:55 pm

  Same thing. It used to be that you could just say

  propertyIndex

  and the expression engine would assume you meant

  thisProperty.propertyIndex

  and no error was generated. Now you have to include thisProperty to avoid the error.

  Dan
• 

  Assaf Goldlust

  March 2, 2018 at 8:56 pm

  Thanks,
  but is there a reson for why you still need to user propertyindex?

  why is it not possible to just write:

  effect("4-Color Gradient").param(thisProperty, - 2).valueAtTime(time - .5)

  thisComp.layer(thisLayer, + 1).transform.rotation . valueAtTime(time − .5)
  why there is a need for a comma between the “thisLayer” and the “+1”

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