Random position from index AND looping wiggle

[Bryan Woods]

Oh, wait! I think I got it. Re-reading Dan’s write-up on looping wiggle expressions, looks like I was forgetting the default values for the third and fourth spots in the wiggle() expression (1, 0.5). Adding these in make my code work! I’ve included the code below for anyone else who may want to use a randomly positioning layer in 3D space with random looping wiggle position

seedRandom(index,true);
s = thisComp.layer("Seed").effect("Seed")("Slider");

xMod = thisComp.layer("Seed").effect("X_Mod")("Slider");
yMod = thisComp.layer("Seed").effect("Y_Mod")("Slider");
zMod = thisComp.layer("Seed").effect("Z_Mod")("Slider");

a = [-s*xMod, -s*yMod, -s*zMod];
b = [s, s, s];

wigFreq = thisComp.layer("Seed").effect("WigFreq")("Slider");
wigAmp = thisComp.layer("Seed").effect("WigAmp")("Slider");
loopTime = 2;
t = time % loopTime;

wiggleX1 = wiggle(wigFreq, wigAmp, 1, 0.5, t);
wiggleX2 = wiggle(wigFreq, wigAmp, 1, 0.5, t - loopTime);
wiggleY1 = wiggle(wigFreq, wigAmp, 1, 0.5, t);
wiggleY2 = wiggle(wigFreq, wigAmp, 1, 0.5, t - loopTime);
wiggleZ1 = wiggle(wigFreq, wigAmp, 1, 0.5, t);
wiggleZ2 = wiggle(wigFreq, wigAmp, 1, 0.5, t - loopTime);
X=linear(t, 0, loopTime, wiggleX1, wiggleX2)[0];
Y=linear(t, 0, loopTime, wiggleY1, wiggleY2)[1];
Z=linear(t, 0, loopTime, wiggleZ1, wiggleZ2)[2];

position.value + random(a,b)+[X,Y,Z];

[Bryan Woods]

Ok, actually, I need a little more help. I need to be able to apply this expression to each layer thats already in a good position. The wiggle just needs to pick up from where the layer is, and I’m not getting that to work. I think this comes down to how I’m adding everything up on the last line.

Essentially, I like the value generated from position.value+random(a,b). Now I want to initiate the wiggle from that value.

[Kevin Camp]

this will generate a unique random position for each layer and then ‘wiggle’ it around that random value, but still allow you to manually adjust the random position (i.e., use the position property value). it generates the random position from a volume defined by the x, y, z variables for the back-lower-right corner and then it’s inverse for the front-upper-left corner of a cube. you can link those variable to your sliders. if needed, you could set up separate sliders to define the front-upper-left corner rathe than simply using the inverse. the rest of the code is from dan’s looping wiggle expression — which I think you are familiar with 😉
seedRandom(index,true);
x = 300;
y = 300;
z = 300;
p = random(-[x,y,z],[x,y,z])
freq = 1;
amp = 110;
loopTime = 3;
t = time % loopTime;
wiggle1 = wiggle(freq, amp, 1, 0.5, t);
wiggle2 = wiggle(freq, amp, 1, 0.5, t - loopTime);
w = linear(t, 0, loopTime, wiggle1, wiggle2);
normalize(value) + p + w

—– edit —-

scratch the ‘normalize()’ from the last line… completely unnecessary. should be just: p + w

Kevin Camp
Art Director
KCPQ, KZJO & KRCW