user4426: I want to put a 2D hat on a video clip of a person, whose head is tilting as he speaks.
I can face-track the face using After Effects CC 2017.
I end up with detailed tracking data, which includes face orientation information.
I can link the orientation information to a 3D null, but how do I link the positional information of the head?
The head appears to only be expressed as a percentage (of what?).  
Is there an easy way to connect this percentage data to 3D positional data on a null?
Equally, if I do a simple face track, I get an animated mask.  What's the right way to translate one of the points from that mask into a null that could be parented to another object?

user1950: You can access the position of a point in a mask with expressions (in AE CC 2017+) with expressions. To access the first point of a mask called "Mask 1" on layer called "my Layer" you'd use
pts = thisComp.layer("my Layer").mask("Mask 1").maskPath.points();
pts[0]

note that the points are numbered from 0, so the second point is pts[1], etc.
I'm not 100% sure I understand what you';re trying to do, have you tried doing a standard motion track using the inbuilt motion tracker or Mocha?

4426: <p>I want to put a 2D hat on a video clip of a person, whose head is tilting as he speaks.</p>

<p>I can face-track the face using After Effects CC 2017.
I end up with detailed tracking data, which includes face orientation information.
I can link the orientation information to a 3D null, but how do I link the positional information of the head?
The head appears to only be expressed as a percentage (of what?).  </p>

<p>Is there an easy way to connect this percentage data to 3D positional data on a null?</p>

<p>Equally, if I do a simple face track, I get an animated mask.  What's the right way to translate one of the points from that mask into a null that could be parented to another object?</p>
 1950: <p>You can access the position of a point in a mask with expressions (in AE CC 2017+) with expressions. To access the first point of a mask called "Mask 1" on layer called "my Layer" you'd use</p>

<pre><code>pts = thisComp.layer("my Layer").mask("Mask 1").maskPath.points();
pts[0]
</code></pre>

<p>note that the points are numbered from 0, so the second point is pts[1], etc.</p>

<p>I'm not 100% sure I understand what you';re trying to do, have you tried doing a standard motion track using the inbuilt motion tracker or Mocha?</p>
