The Layer expression control is useful to have a layer use certain properties from another layer. In this example, we have two text layers that have different text.
If we want layer two to always have the same text as layer one, we will first go to Effects > Expression Controls > Layer Control. Then, we’ll add an expression for the Source Text property of the layer and pickwhip up to the layer control. Now, if we change the layer listed in the layer control to layer one, we’ll see the text update to be the same text that layer one has. No matter what we change the text in layer one to be, layer two will follow.
This also works for effects. Here, we have the Light Burst effect on layer one and also on layer two. We can set an expression for Ray Length on layer two. We want to keep what’s written by default, so we’ll deselect the expression text and then pickwhip up to the layer control. Then, we’ll add a period in-between the text segments (right before the second appearance of the word effect).
Immediately, we see the ray length of both layers match (although the ray angles are the default result of the anchor points). If we adjust the Ray Length in the effect on layer one, layer two updates to match.
Watch this short tutorial to see how it works:
