title: After Effects: centering Layer by Expression
body: <p>Iam trying zo position a Layer by expression. I need exacly the center of the Layer.</p>
  
  <pre><code>w=thisComp.width; //x
  h=thisComp.height;//y
  w2=w/2;
  h2=h/2;
  ??
  </code></pre>