Pan Behind tool on a 3D layer for Scale

Question

Appologies. Unable to find any info yet on whether there is a way to use the Pan Behind tool on the Z axis of a 3D layer for scale. I would like the said 3D layer to be pushed back in Z space, but to appear as if it hasn't changed size in the camera. My guess is that the scale would automatically adjust as the layer is pushed back in Z space. Have I missed something in the manuals and forums? Thanks for a reply.

Answer 1

I'd use a simple expression for the scale property. You could then adjust the position of the layer or the position of the camera and keep the layer the same size in the frame. Changing the anchor point in Z would then also change the relative size of the layer in the camera view. I've written out the expression in long form so that it's easier to understand. It uses the length (distance) between the 3D layer and the camera/divided by the zoom value (focal length) to create a scale multiplier. Here you go:
point1 = thisComp.layer("Camera 1").transform.position;
point2 = position;
d = length(point1, point2);
z = thisComp.layer("Camera 1").cameraOption.zoom;
     sa = 100 * d/z; //scale adjustment
[sa, sa, sa]