-
Move layer by random amount over time interval
Hi all,
Looking to write an expression that:
– moves a layer by a small amount every 15 frames.
– movement lasts 5 frames
– it shouldn’t jump around–just a single move from point a to point b
– the movement should be different each time.
I started by building an array of random numbers, with the goal of basically saying:
Start at point A. Point B will equal point A times the random number, determined by how many iterations we have gone through.
But I’m struggling to put this all together.
Would love your thoughts!
Thanks!
-
8 Replies
-
Do you want the movement constrained to a particular area, or each movement constrained to a maximum amount from the previous location?
-
OK, here’s an example that will wander around in the vicinity of the layer’s original position:
moveFrames = 15;
range = 200;
moveDur = framesToTime(moveFrames);
seed = Math.floor(time/moveDur);
t = time%moveDur;
seedRandom(seed,true);
offset1 = seed > 0 ? random([-range,-range],[range,range]) : [0,0];
p1 = value + offset1;
seedRandom(seed+1,true);
offset2 = random([-range,-range],[range,range]);
p2 = value + offset2;
linear(t,0,moveDur,p1,p2) // could use ease() instead -
Thanks so much Dan! And yes, definitely want the motion to all occur around the same position.
The only issue here is that I need the object to move for 5 frames, pause for 15, and repeat.
-
Ah, that would be like this:
moveFrames = 5;
holdFrames = 15;
range = 200;
moveDur = framesToTime(moveFrames);
totalDur = framesToTime(moveFrames+holdFrames);
seed = Math.floor(time/totalDur);
t = time%totalDur;
seedRandom(seed,true);
offset1 = seed > 0 ? random([-range,-range],[range,range]) : [0,0];
p1 = value + offset1;
seedRandom(seed+1,true);
offset2 = random([-range,-range],[range,range]);
p2 = value + offset2;
linear(t,0,moveDur,p1,p2) -
This is amazing! Thank you so much, Dan!
-
Hey Dan,
The expression works great–but it looks like it has sort of a hitch at around 4 seconds (video attached). IF it helps, I’m working in 23.98.
Thanks again for the help!
-
That’s interesting and strange. See if this makes it any better:
moveFrames = 5;
holdFrames = 15;
range = 200;
moveDur = framesToTime(moveFrames);
totalDur = framesToTime(moveFrames+holdFrames);
seed = Math.floor(time/totalDur);
t = time - seed*totalDur;
seedRandom(seed,true);
offset1 = seed > 0 ? random([-range,-range],[range,range]) : [0,0];
p1 = value + offset1;
seedRandom(seed+1,true);
offset2 = random([-range,-range],[range,range]);
p2 = value + offset2;
linear(t,0,moveDur,p1,p2) -
Thanks again, Dan! We actually adjusted the gap to 14 frames for now and that seemed to fix it, but I will check this one out as well. Appreciate your time.
Reply to this Discussion! Login or Sign Up