I'm using Sound Keys. I understand how to picwhip the scale parameter of another layer to the output of the SoundKeys layer but I want it to effect only the Z parameter in the scale, not the whole scale adjustment. Please any help would be greatly appreciated! Thanks
Define the value for z like this:
z = drag the pickwhip to the Sound Keys parameter you want to use;
Then set up your array to read the current value for x and y:
[value, value, z]
This is pretty basic expression language. You should spend some time with the expression reference guide if you plan on using expressions.
I hope that you understand that in order for Z scale to have any effect on the layer you must move the Anchor Point in Z. This will make the layer move in Z space.
The scale (and position and orientation) parameters of 3d layers are arrays of 3 values.
So, think of it as [scale0, scale1, scale2]
You just have to point the z value to it and not the x and y.
Something like [0,0,pickwhippedproperty] +value should do it for you.
Edit: I see Rick and I were typing at the same time. His would work too.