[Pete Burges]

Hi John,

That’s perfect. The only adjustment I needed to make was to increase the division to 200. Perhaps that’s because I’m using 20 repeater instances- in which case I am guessing that number should always be number of instances x10, then…?
Initially it gave me some error about not subtracting from the position matrix, but the error vanished after I scrubbed through the timeline so I guess it wasn’t important. It works just fine.
So let me see if I understand correctly; we’re getting the comp position of both anchor points and then subtracting the shape layer’s position from the vanishing point’s position to get the direction, multiplying by the slider value divided by repeater instances x10, and then finally subtracting the local anchor point position of the shape layer…?
This is great, I often have to animate text with stylised perspective and this will help me to make a reliable, reusable setup for handling the fake extrusion. Thank you very much, John…!

[Pete Burges]

Aha, that explains a lot. Thanks Dan, much appreciated!

[Pete Burges]

Mr Ebberts, you are a legend. That seemed to do the trick- thanks!
I was thinking that after the first few lines the value was changed to the result of r, but your solution suggests that the pre-expression value persists until the end. A lot of my (very amateur) scripting attempts work under this incorrect assumption, so would you mind explaining a little about it…?
Thanks,
Pete

[Pete Burges]

Sorry to Necro this thread but I thought it was better than starting another one…

In most cases, pickwhipping will work but sometimes it just won’t- for instance trying to link the source point in Trapcode Shine to a null (they’ve now included a link to null function, I know).
Linking start and end points of advanced lightning, or some gradient plugins doesn’t work either, at least not as expected. I’ve tried several setups for this, including parenting the linked nulls to the effect layer, using 3d nulls and using expressions to track null anchor points in comp space, but some effects just won’t respond to any of these.
I am assuming they are using some way other than comp space or layer position to get their coordinates, so can anyone shed some light on what they could be and suggest workarounds…?

[Pete Burges]

Sorry to necro this thread, but I’ve noticed that with Shine (and other effects too) using an expression to have the source point follow another layer doesn’t give the expected result. The source point always seems to be offset from the layer it’s meant to track. Does anyone know why this is and how to correct it…?

[Pete Burges]

Hi Dan, thanks for your reply.
Yeah, whenever this has happened I assumed that it must be a typo on my part (almost all the time, human error is to blame), even though I couldn’t find one . It doesn’t happen often, but often enough that I felt compelled to test it: so, this time I was very careful about typing it in correctly and then I copied what I typed so I could compare it with the pickwhipped version later. I pasted them in the same text document (and you can see them both below) and I could not find a difference at all, not even in the spaces (which are often “invisible” culprits). I even tried pasting one over the other and toggled undo/redo to see if I could spot a jump anywhere, but I couldn’t see anything. Weirdly, pasting either of them back into the expression field worked fine! But, for whatever reason, After Effects sometimes just doesn’t seem to like me typing things in from scratch…it must just be some random glitch when I’ve left it running too long (I often leave my projects open all week, until eventually something crashes them- I have a lot of scripts and plugins and they don’t all get along).

What I should also have done, but forgot, was to take a screenshot of the error-flagged expression so you could see it…and of course now I can’t get it to happen again. But here are both versions anyway:

comp(“H1”).layer(“Eye CTRL”).transform.position
comp(“H1”).layer(“Eye CTRL”).transform.position

I wondered if any other users had had the same experience, but perhaps it’s just something with my particular installation of AE?

[Pete Burges]

I hate to resurrect a dead thread but this was the most relevant…

The expression used here works great as long as the layers you’re positioning between have keyframes on them. But what if they themselves are parented, or driven by expressions? In that case you need a way to track the anchor points….and that’s where I am stumped.
…Or, I was. As I was typing my attempted script here I realised what was wrong with it and came up with the following, which worked!

targetA = thisComp.layer(“targetA”);

targetB = thisComp.layer(“targetB”);

A = targetA.toComp(targetA.anchorPoint);
B = targetB.toComp(targetB.anchorPoint);

(A+B)/2

[Pete Burges]

Dennis, you might want to download DUIK Bassel, which is a free animation
toolkit for After Effects. It includes just the kind of expression you’re
describing where you can apply spring or elastic motion to your
keyframes (with the touch of a button) and adjust the settling and bouncing time.

[Pete Burges]

Hi Dan

So sorry… I should have tested it further before responding. When I set it up (footage layer with null target), moving the null produced no movement in the layer. However, if I link the first null to another and move that, I get the desired movement. So it does work!
Thank you so much Dan, I cannot overstate how much I appreciate this. It’s a super useful bit of script and I have been trying to crack it for over a year but, yeah, I am just not that good at scripting…! Cheers,

Pete

[Pete Burges]

Thank you so much for your response, Dan! That’s a much more elegant bit of code than mine.

However, it didn’t give the intended result; it only works if I key the position of the target object, which is basically the same effect as using the myParent* script (which is what I used as the basis for mine). What I am hoping to get is for the child object to follow the position of the target’s anchor in comp space while maintaining relative position, even if the target is parented to another object and has no keyed position. I am starting to wonder if that’s actually even possible, as I haven’t seen it covered anywhere else yet… but if anyone would know, it’s you.

*

myParent = thisComp.layer(“master”);

myProp = myParent.transform.position;

value + (myProp.value – myProp.valueAtTime(0))