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Random X,Y Array for Lightning Source Points
Ok Cow Gurus,
I have a concept that may make blood shoot out your nose.
I’m looking to create an array of pre-set X,Y coordinates (say 5-6 entries) that I would like a the built-in lightning effect to use as start and end points.
But I would like the start and end points to randomly change from one set to the next.
I wouldn’t care if each change would happen at a regular interval, I just want the start and end points to be different each time the expression is fired.
– If you were me, you’d be home by now!
Joe Jozwowski
The Video Alchemist -
4 Replies
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You’ll need separate expressions for start and end, but this is the basic idea:
points = [[100,100],[200,100],[300,100],[400,100],[500,100]];
idx = Math.floor(random(points.length));
points[idx]It gets slightly more complicated if you decide you don’t really want it to change every frame, or if you want a particular start point to always go with a particular end point.
Dan
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How much more complicated?
Right now I have 6 shape layers that are on a constant wiggle so their X-Y coordinates fluctuate throughout.
Where you have points = [[100,100],[200,100], etc]…
Could I just use the X-Y coordinates of those shape layers, e.g.
points = [[thisComp.layer(“Shape Layer 6”).transform.position[0],thisComp.layer(“Shape Layer 6”).transform.position[1]],[thisComp.layer(“Shape Layer 5”).transform.position[0],thisComp.layer(“Shape Layer 5”).transform.position[1]], etc.]
If perchance that the Start and End points are the same, that I’m not worried about…
– If you were me, you’d be home by now!
Joe Jozwowski
The Video Alchemist -
Dan,
I just saw another post you commented on a while back dealing with a similar issue, and you suggested to add a seedRandom(index,true) into the mix.
With that, I can just add a Slider control, with a Hold Keyframe every second and increment that “index” by whatever I want, and that would change the seedRandom value when I specify, correct?
– If you were me, you’d be home by now!
Joe Jozwowski
The Video Alchemist -
I would calculate the seed based on which time interval you’re in. Here’s an example that would calculate a new seed every half second (not tested, but should be close).
segDur = .5;
t = time – inPoint;
seed = Math.floor(t/segDur);
seedRandom(seed,true);Dan
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