[Greensock]

I think I figured it out! I had to add some math to the position expression, but check it out in the After Effects file at https://www.greensock.com/Parented_3D_Stroke.zip. No super complex trigonometry required! You can move the parent around OR the controller null object and they work together beautifully (as far as I can tell thus far at least). Here’s the expression I had to put on the position:

controller = thisComp.layer(“Streak_Controller”);
controllerPos = controller.toWorld(controller.position);
parPos = controller.parent.position;
x = controllerPos[0] – ((controllerPos[0] – parPos[0]) / 2);
y = controllerPos[1] – ((controllerPos[1] – parPos[1]) / 2);
z = controllerPos[2] – ((controllerPos[2] – parPos[2]) / 2);
[x,y,z];

Hope this helps someone. I just about threw my computer out the window trying to get this to work.

Jack

[Greensock]

I think I figured it out! I had to add some math to the position expression, but check it out in the After Effects file at https://www.greensock.com/Parented_3D_Stroke.zip. No super complex trigonometry required! You can move the parent around OR the controller null object and they work together beautifully (as far as I can tell thus far at least). Here’s the expression I had to put on the position:

controller = thisComp.layer(“Streak_Controller”);
controllerPos = controller.toWorld(controller.position);
parPos = controller.parent.position;
x = controllerPos[0] – ((controllerPos[0] – parPos[0]) / 2);
y = controllerPos[1] – ((controllerPos[1] – parPos[1]) / 2);
z = controllerPos[2] – ((controllerPos[2] – parPos[2]) / 2);
[x,y,z];

Hope this helps someone. I just about threw my computer out the window trying to get this to work.

Jack

[Greensock]

Yep, I did use expressions to tie it to a null object that’s parented to the other spinning/scaling object. But I need to move the entire thing up during the animation (away from the parent’s anchor point) and that gets things all funky. Here’s a response I just got from Trapcode [sigh]:

——————–

Making the null object parented breaks the syncing because the coordinates are relative to the parented object after parenting. You can see this – the numbers change when you parent the layer. I tried writing a new type of expression that would take into account both nulls but so far I have not been able to nail it, the position is trivial, but the when it comes to rotation it becomes very complex.
I’m sure there is a way, but it will take some kind of expression guru to figure it out. I’ll think some more and let you know if I find a solution.

For now the only “workaround” I can think of is to not use parenting… not much help I know.

[Greensock]

Yep, I did use expressions to tie it to a null object that’s parented to the other spinning/scaling object. But I need to move the entire thing up during the animation (away from the parent’s anchor point) and that gets things all funky. Here’s a response I just got from Trapcode [sigh]:

——————–

Making the null object parented breaks the syncing because the coordinates are relative to the parented object after parenting. You can see this – the numbers change when you parent the layer. I tried writing a new type of expression that would take into account both nulls but so far I have not been able to nail it, the position is trivial, but the when it comes to rotation it becomes very complex.
I’m sure there is a way, but it will take some kind of expression guru to figure it out. I’ll think some more and let you know if I find a solution.

For now the only “workaround” I can think of is to not use parenting… not much help I know.

[Greensock]

I’m trying to get 3D stroke to work in 3D while parented to an object that’s spinning and scaling. I understand how to use expressions to link the 3D stroke effect to a null (no problems getting that to work). However, when I parent that null object to the stuff that’s spinning around and scaling in 3D, things shift and fall apart (they don’t stay synced up especially if I move the null object). Is this a known issue with 3D Stroke? I really wish the effect would orient itself with the layer that it’s applied to so that when I spin/rotate that layer in 3D, the effect is synced with it, but it appears as though the effect is independent of the layer in 3D space. Any way to get around this irritation?

And of course I

[Greensock]

I’m trying to get 3D stroke to work in 3D while parented to an object that’s spinning and scaling. I understand how to use expressions to link the 3D stroke effect to a null (no problems getting that to work). However, when I parent that null object to the stuff that’s spinning around and scaling in 3D, things shift and fall apart (they don’t stay synced up especially if I move the null object). Is this a known issue with 3D Stroke? I really wish the effect would orient itself with the layer that it’s applied to so that when I spin/rotate that layer in 3D, the effect is synced with it, but it appears as though the effect is independent of the layer in 3D space. Any way to get around this irritation?

And of course I