Creating a swarm of individual compositions

[Kevin Camp]

i would try the wiggle() expression and key frame the amount of wiggle…

first add a slider expression control (from the effects menu choose expression controls>slider).

then select the position property of the pre comp that you just added the slider to and choose animation>add expression and copy/past this expression:
amount = effect("Slider Control")("Slider");
freq = 10; // value in number of times per second
wiggle(freq, amount)
now you can key frame the slider amount to go from 0 to some larger value and back to 0. the value measured in pixels, so a value of 500 should allow the layer to ‘wiggle’ as much as 500 pixels in any direction.

you can modify the freq value as needed, it’s measured in wiggle-per-second, the higher that value, the more often it will change directions.

Kevin Camp
Art Director
KCPQ, KZJO & KRCW

[Corrie Parks]

Tried it out on a few of my comps and this seems like it has potential. Looks like I could copy and paste the slider and expression as well, so setting it up on 300 different comps shouldn’t be too much trouble.

Is there are way to set a range limit for individual variables?

i.e. I would like the wiggle on the Z-axis to stay between 0-500, while the x value could be between -500, 500 and the y value between -300, 300.

Thanks!

[Kevin Camp]

apply the preset “separate xyz position”, this will give you x, y, z controls in the effect controls.

then select the slider that you have and duplicate it 2 more times. (this will be for controlling the amount of wiggle for x, y and z).

copy/paste the original expression into the X Position property of Separate XYZ Position. this will use the first slider for the amount.

paste the same expression into the y position, but change the first line of the slider to this (note the ‘2’ after the Slider Control name):
amount = effect("Slider Control 2")("Slider");
that property’s wiggle amount is now controlled by Slider Control 2, just change the.

for the z position, copy/paste this expression:
amount = effect("Slider Control 3")("Slider");
freq = 10; // value in number of times per second
Math.abs( wiggle(freq, amount) )
z should now be controlled by the 3rd slider, and will be limited to only positive values.

Kevin Camp
Art Director
KCPQ, KZJO & KRCW