Need an expression to automatically position a Light between two tracked Lights.

[Jason Mckee]

This might help you out.

https://aescripts.com/malcolm-in-the-center/

If that one doesn’t work for you then you might be able to get something close with this one. I hope this helps.

https://aescripts.com/align-3d/

[Walter Soyka]

Here’s a project that demonstrates the scenario you describe:

[image]

14144_stringoflights.aep.zip
[project file]

In this setup, I’ve added three Effects Controls to each follower layer:
1) A Layer Control (renamed to “Beginning”), where I select the line’s beginning point
2) A second Layer Control (renamed to “End”), where I select the line’s ending point
3) A slider control (renamed to “Completion”), where I can animate along the line from the beginning to the end

Each follower layer also has this expression on its Position property. I’ve commented it here to explain what it’s doing. If you have questions, I’d be happy to try to answer them.
// get our effect controls into some variables we can easily use
var lA = effect("Beginning")("Layer");
var lB = effect("End")("Layer");
// make sure that the completion value scales from 0 to 1
var completion = linear(effect("Completion")("Slider"), 0, 100, 0, 1);

// get the positions of the Beginning and End points in world space
var pA = lA.toWorld(lA.anchorPoint);
var pB = lB.toWorld(lB.anchorPoint);

// start the beginning, then add a percentage of the vector from the beginning to the end
pA + (pB - pA) * completion;

Walter Soyka
Designer & Mad Scientist at Keen Live [link]
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
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