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Link to a certain active layer (like ActiveCamera)

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Tilman Commes
Link to a certain active layer (like ActiveCamera)
on Sep 14, 2018 at 2:03:39 pm

Hello everybody!

I have a long composition with lots of different tracking nulls. None of them are overlapping (time-wise). Can I tell a text for instance to always use the ACTIVE LAYERS position? I know there is the ActiveCamera expression.
Is it possible to say: Use Layer "tracking_X" when it's active?
Of course I would have to also tell: These are the layers you should check (if active) and please ignore these other layers.

...too bad expressions don't have voice commands yet...

Thanks a lot for your help!


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Kalleheikki Kannisto
Re: Link to a certain active layer (like ActiveCamera)
on Sep 14, 2018 at 3:42:34 pm

Using tracking data from several tracking results is easily achieved by applying the tracking data to nulls and parenting the nulls in sequence. The main thing you have to keep in mind is that you want to parent the layers at that point in time where the child layer's motion starts, so that you don't offset the child's position (which you will do if you parent everything at, say, the beginning of the comp).

Kalleheikki Kannisto
Senior Graphic Designer


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Tilman Commes
Re: Link to a certain active layer (like ActiveCamera)
on Sep 14, 2018 at 4:13:32 pm

Thanks for the reply!
Yes, parenting trackingnNulls in sequence does answer this particular question and works just fine.
But still I wonder, is there an expression like "activeLayer" ?
Or would I have to try this in a "if layer X is active, take it, else move on to the next layer" sort of fashion? And how would that be done, can expressions access that sort of data?

Tilman
Freelance Motion Designer


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Dan Ebberts
Re: Link to a certain active layer (like ActiveCamera)
on Sep 14, 2018 at 4:32:02 pm

A layer's .active attribute tells you if the current time is between the layer's in and out points. So you can loop through the layers until you find one that's currently active. Here's a usage example:

http://www.motionscript.com/design-guide/source-name.html

Dan



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Tilman Commes
Re: Link to a certain active layer (like ActiveCamera)
on Sep 16, 2018 at 9:42:09 am

That's just it! Thank you very much!


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