Adobe After Effects: Keep "Expression-Relations" when duplicating multiple layers

Question

just wanted to ask, whether there is a way to keep the relations of expressions going when duplicating layers. E.g. I have two layers, "LayerA" and "LayerB". Now I have an expression going on in "LayerB" saying, that its position always equals the position of "LayerA". Now when I duplicate those two and get "LayerA 2" and "LayerB 2" I want the expression in "LayerB 2" to reference to "LayerA 2"'s position rather than "LayerA"'s position!

While it is no problem to simply change the expression when there is only one of them, it gets quite hard when you have multiple expressions going on ...

Answer 1

You might end up wanting to organize your comp differently, but, given your example (and exactly those name lengths), this position expression will work to find the appropriate 'target layer':

//base name to work from:
baseName = "Layer";
//length of that:
nameLen = baseName.length;
//this layer's name:
myName = thisLayer.name;
if (myName.length == nameLen) {
 //if they are the same, then it is the original
 // (non-duplicated) version
  thisComp.layer("LayerA").transform.position;
} else {
  //get tail string, the space and number:
  tailStr = myName.substring(nameLen+1, myName.length);
  //build new target layer name with "A":
  targetName = myName.substring(0, (nameLen)) + "A" + tailStr
  //new line pointing to target layer:
  thisComp.layer(targetName).transform.position;
}