• Adobe After Effects Expressions

  random move in a grid

  Posted by Max Arch on October 4, 2015 at 4:12 am

  i have a square shape 40 by 40.
  i want it randomly appear inside my grid, my composition is 1080px by 200px.
  the grid is a by multiple of 40.

  the random function will generate multiple of 40.

  at the moment it appearing with no order.

  holdTime = .3; //time to hold each position (seconds)
minVal = [0 , 0];
maxVal = [1080, 200];
seed = Math.floor(time/holdTime);
seedRandom(seed,true);
random(minVal,maxVal);

  Dan Ebberts replied 10 years, 10 months ago 2 Members · 3 Replies
• 3 Replies

• 

  Dan Ebberts

  October 4, 2015 at 6:06 am

  This should work:

  holdTime = .3; //time to hold each position (seconds)
  numCols = 27;
  numRows = 5;
  seed = Math.floor(time/holdTime);
  seedRandom(seed,true);
  col = Math.floor(random(numCols));
  row = Math.floor(random(numRows));
  [col*40+20,row*40+20]

  Dan
• 

  Max Arch

  October 4, 2015 at 7:36 pm

  i want to be able to customize it for other size
  1-
  example change the code for comp size of 40×40
  and a grid of 10 pixel
  2-
  be able to control the section of the random exaple bettween the col 10 and 15
  it not working
  what did i do wrong

  v = 40; //grid size
a = 2; //mincol 0
b = 3; //maxcol 27
c = 2; //minrow 0
d = 3; //maxrow 5
num = random ( 0.1, 0.5); //speed

  holdTime = num; //time to hold each position (seconds)
seed = Math.floor(time/holdTime);
seedRandom(seed,true);
col = Math.floor(random(a,b));
row = Math.floor(random(c,d));
[col*v+(v/2),row*v+(v/2)]
• 

  Dan Ebberts

  October 4, 2015 at 8:28 pm

  Like this, I think:

  v = 40; //grid size
  a = 2; //mincol 0
  b = 3; //maxcol 27
  c = 2; //minrow 0
  d = 3; //maxrow 5
  seedRandom(index,true);
  holdTime = random ( 0.1, 0.5); //speed
  seed = Math.floor(time/holdTime);
  seedRandom(seed,true);
  col = Math.floor(random(a,b+1));
  row = Math.floor(random(c,d+1));
  [col*v+(v/2),row*v+(v/2)]

  Dan

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