[Dan Ebberts]

This Source Text expression appears to work:

numFrames = 5; // change colors every 5 frames
c1 = effect("Color Control 1")("Color");
c2 = effect("Color Control 2")("Color");
c3 = effect("Color Control 3")("Color");
c4 = effect("Color Control 4")("Color");
c5 = effect("Color Control 5")("Color");
colors = [c1,c2,c3,c4,c5];
f = timeToFrames(time);
seed = Math.floor(f/numFrames);
seedRandom(seed,true);
myExpr = "style";
for (i = 0; i < value.length; i++){
  myExpr += ".setFillColor(colors[Math.floor(random(colors.length))]," + i + ",1)";
}
eval(myExpr)

[Dan Ebberts]

You could add a Position Animator and set its Position value to 0,30. Add an Expression Selector, delete the Range Selector, and use this expression for the Expression Selector’s Amount property:

s = effect("Slider Control")("Slider").value;
ease(s,textIndex,textIndex+1,100,0)

It uses the same slider as your Source Text expression.

[Dan Ebberts]

Sorry, I’m completely lost. I wish I could help, but I still don’t understand what it is you’re trying to do. Maybe someone else will chime in with the solution.

[Dan Ebberts]

I don’t understand your formula. Why does having the checkbox on flip the effect of null1 and null2? It seems like it should just remove the effect of null2.

[Dan Ebberts]

Ah, OK. I don’t think you’ll ever be able to set it up so that the position doesn’t change instantly when you toggle the checkbox to bring the influence of Null 2 in or out. There’s no way for the expression to know the history of the checkbox (unless it’s keyframed or controlled by an expression).

[Dan Ebberts]

>as if it were a regular null.

I have to confess, that I have no idea what that means. Are you talking about parenting?

[Dan Ebberts]

If you want Null 1 to move based on the relative movement of the other nulls, the other nulls need reference points. One way to do it is to keyframe their movement and Null 1 can take on movement of the other nulls that has occurred since time = 0. That would look something like this:

n2 = thisComp.layer("Null 2");
n3 = thisComp.layer("Null 3");
n4 = thisComp.layer("Null 4");
includeN2 = effect("Checkbox Control")("Checkbox") == 1;
d2 = n2.position - n2.position.valueAtTime(0);
d3 = n3.position - n3.position.valueAtTime(0);
d4 = n4.position - n4.position.valueAtTime(0);
val = value + d3 + d4;
if (includeN2) val += d2;
val

Null 2’s movement only gets included if the checkbox is on. If you want to animate the checkbox, that’s a much more complicated proposition…

[Dan Ebberts]

In what way to the other nulls “influence” Null 1’s position? What does that mean, exactly?

[Dan Ebberts]

You could use an expression for Audio Levels where the amplitude falls off as the inverse square of the distance from the camera increases. You’d need to define a nominal distance where at that distance or closer the falloff is 0 db. Something like this:

nominalDist = 2800;
C = thisComp.layer("Camera 1");
T = thisComp.layer("Target");
d = length(C.position - T.position);
if (d > nominalDist){
  n = Math.log2(d/nominalDist);
  value - ((value instanceof Array) ? [n,n]*6 : n*6);
}else{
  value;
}

[Dan Ebberts]

Assuming you’re controlling the slider with keyframes, you probably need something like the linear keyframe integrator described here:

https://motionscript.com/articles/speed-control.html

motionscript.com

Expression Speed and Frequency Control

Dan Ebberts's resource for After Effects scripting and expressions