• Adobe After Effects Expressions

  Controlling Blink Expression

  Posted by Dawood Al-kiyumi on December 9, 2012 at 9:48 pm

  Hello,

  I know this simple blink expression that applies to opacity:

  Speed =10;
  n = Math.sin(time*Speed);
  if (n<=0) 0 else 100;

  But this gives me the same period of time for 0 opacity and 100 opacity.

  What I’m trying to do, is to have control over the period of time the opacity is 0, and the period of time the opacity is 100.

  Let’s say, I want the layer to appear just for half a second every 2 seconds.

  How can I do this?

  Thank you.

  Dawood Al-kiyumi replied 13 years, 9 months ago 2 Members · 2 Replies
• 2 Replies

• 

  Dan Ebberts

  December 9, 2012 at 10:42 pm

  I think I’d do it like this:

  onTime = .5;
  period = 2;
  ((time-inPoint)%period < onTime) ? 100 : 0;

  Dan
• 

  Dawood Al-kiyumi

  December 9, 2012 at 10:48 pm

  Thank you very much Dan.
  I don’t think I’d figure that out. =)

Reply to this Discussion! Login or Sign Up