title: Ray-plane intersection to find the Z of the intersecting point
body: <p>I have a rectangle in 3d space <code>(p1, p2, p3, p4)</code> and when the mouse rolls over it I need to calculate the exact Z of the point on the rect, given the mouse coordinates <code>(x, y)</code>.</p>
  
  <p>Would a Ray-plane intersection find the Z of the intersecting point?</p>
  
  <p>Thanks</p>