Creative Communities of the World Forums

The peer to peer support community for media production professionals.

Activity Forums Adobe After Effects Expressions is it possible to us expression for exponential scale?

  • is it possible to us expression for exponential scale?

    Posted by Ryan Chan on April 27, 2005 at 3:21 pm

    hello Dan and everybody, i just wondered if it is possible to use expression to achieve the same result as using exponential scale, so, i can modify the from/to value more easily? say, from 25% scale up to 2500% in 5sec, how to write the expression for this interpolation? thanks

    ryan

    Mike Clasby replied 19 years, 3 months ago 4 Members · 4 Replies
  • 4 Replies
  • Dan Ebberts

    April 27, 2005 at 3:46 pm

    Try this:

    
    v1 = 25;
    v2 = 2500;
    t1 = 0; //start time
    t2 = 5; //end time
    
    if (time <= t1){
      s = v1;
    }else if (time > t1 && time < t2){
      t = time - t1;
      T = t2 - t1;
      k = Math.log(v2/v1)/T;
      s = v1*Math.exp(k*t)
    }else{
      s = v2;
    }
    [s,s]
    
    
    

    Dan

  • Andrew Kramer

    April 27, 2005 at 3:58 pm

    Dan this is very creative how you solved this. Do you think you can explain it a little bit. Also could this be done with a linked slider.

    so if you keyframed the expression slider value at say 10 and then to 100 equal to scale would be 100-10000.

    this way you could alter it visually with keyframes.

    thanks
    Andrew

  • Ryan Chan

    April 28, 2005 at 1:53 am

    thanks Dan, you,re incredible! although it is far more complicated than i expected, but i will try to “Digest” this expression, thanks again.
    ryan

  • Mike Clasby

    April 28, 2005 at 8:01 pm

    Very cool little expression. It looks great on a 3D solid in Custom view 1, so you can actually see what’s going n. Thanks.

We use anonymous cookies to give you the best experience we can.
Our Privacy policy | GDPR Policy