Change Expression based on Composition Name

[cameraman_nick]

What I'm trying to accomplish is to have a specific number in an expression change based off a number in the composition name.

I have a character rig composition which needs to be used in several seperate compositions (Scenes). I have attached the rig controls to expression controls in a seperate Scene. However, in order to animate the character in each seperate Scene, I need to dedicate a character rig composition for each scene. For Example, Character Rig_Scene 1 is used in Scene 1, Character Rig_Scene 2 is used in Scene 2, etc.

Each time I duplicate my Character Rig_Scene #, I'd like the number to automatically change in the comp("Scene #") part of the expression. So comp("Scene 4") will pull the number from "Character Rig_Scene 4" composition.

Can this be accomplished? If so, what's a good approach?

Thanks for your help.

Please see photo for more context.

[Dan Ebberts · Accepted solution]

I think something like this should work:

comp("Scene " + thisComp.name.split(" ").pop()).layer("Taylor Animation Control").effect("L Arm")("Angle")

[cameraman_nick]

Golly! That worked, thank you very much.

So how is this expression working now? Like how does it know to read the Scene #?

[Dan Ebberts]

It takes the name of the comp with the expression, splits that into an array of chunks wherever there's a space in the name, and then takes the last chunk (which is "4" in your example) and appends that to "Scene ".

[cameraman_nick]

Okay, I think I'm understanding. So the .pop() is how you are telling it to only see the last part – so the "4"?

[Dan Ebberts]

Yes. 

thisComp.name.split(" ")

Gives you this array:

["Taylor", "2.0_Scene", "4"]

and the .pop() gives you the last element of the array.

[cameraman_nick]

Incredible. Expressions rule!

Thank you much for your help and explanation on this.