• Adobe After Effects

  Random Lines expression help.

  Posted by Jeff Herring on August 7, 2006 at 9:59 pm

  I’m working with Dan’s expresison that will move a vertical bar back and forth across the screen randomly.

  tMin = .5; //minimum segment duration
  tMax = 2; //maximum segment duration

  end = 0;
  j = 0;
  while (time >= end){
  j++;
  seedRandom(j,true);
  start = end;
  end += random(tMin,tMax);
  }
  endVal = random(thisComp.width);
  seedRandom(j – 1,true);
  x = random(); //this is a throw-away value
  startVal = random()*this_comp.width;
  x = ease(time,start,end,startVal,endVal);
  [x,value[1]]

  I can’t for the life of me figure out how to modify it to make a horizontal bar move randomaly up and down.
  I’m a tinkerer not a coder.. I’ve modified every setting and line that I thought might pertain to horizontal/vertical or X/Y coords and yet the thing will still keep sliding vertically.

  What am I doing wrong.

  Thanks.
  Jeff

  Jeff Herring replied 19 years, 9 months ago 2 Members · 2 Replies
• 2 Replies

• 

  Mike Clasby

  August 7, 2006 at 10:48 pm

  Tinkerers Unite!

  Change the x’s to y’s and the last line as below and the last 4 lines become this:

  y = random(); //this is a throw-away value
  startVal = random()*this_comp.width;
  y = ease(time,start,end,startVal,endVal);
  [value[0],y]

  And you get Randomly moving Horz lines.
  I think your main problem was that last line,

  [value[0],value[1]]

  value [0] is the x, value [1] is the y, and if it was 3D value [2] is Z.
• 

  Jeff Herring

  August 8, 2006 at 4:49 pm

  Tinkerers Unite!!!

  Thanks yikesmies that did just what I needed it to.. YOU ROCK!!!!!!

  now to tinker with the speed

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