• Adobe After Effects Expressions

  Blink slider to control the Y position of another layer.

  Posted by Roberto Mata on January 22, 2015 at 1:17 pm

  Hello,

  I’m new to after effects an have some trouble solving this expression I need.
  I’m rigging the head of a 2D character. I have set a slider to control the blinks of its eyes.
  The slider has three pairs of blink associated with if/else.

  From 0 to 10: eyes closed.
  From 11 to 20: sibylline eyes.
  From 21 to 30: neutral eyes.
  Frpm 31 to 40: wide open eyes.

  I’ve used this kind of expression:

  a=thisComp.layer(“HEAD_CTRL”).effect(“BLINK”)(“Slider”);
  if((a>30)&&(a<=40)) 100 else 0

  NOW, I want the eyebrows to change their Y position with just one blink mode, the wide open eyes. So I wrote down the Y value for both positions and made an expression for Y position like this:

  a=thisComp.layer(“HEAD_CTRL”).effect(“BLINK”)(“Slider”);
  if((a>30)&&(a<=40)) 524 else 528

  And it worked, but then I needed to parent the eyebrows to the HEAD_CTRL, and when I did OBVIOUSLY the eye brows comp went crazy. I figured out it was because I set some fixed values for Y that wouldn’t work if I changed the HEAD_CTRL position.

  So I need some variation of that expression for any position of the HEAD_CTRL.
  I want the eyebrows, to be in some Y position when the blink slide is set to “SURPRISE EYES” and Y position +4 with any other.

  Something like this, but in proper java language:

  a=thisComp.layer(“HEAD_CTRL”).effect(“BLINK”)(“Slider”);
  if((a>30)&&(a<=40)) Y position else Y position+4

  Thanks.

  Roberto Mata replied 11 years, 7 months ago 2 Members · 2 Replies
• 2 Replies

• 

  Dan Ebberts

  January 22, 2015 at 2:57 pm

  Try this:

  if((a>30)&&(a<=40)) value else value+4

  Dan
• 

  Roberto Mata

  January 22, 2015 at 3:18 pm

  Worked great!

  Thanks, Dan. And sorry for my novice question.

Reply to this Discussion! Login or Sign Up