title: Rotating around anchor point in SceneKit
body: <p><strong>Objective</strong>: There is a <code>SCNCylinder</code> object in my scene. I want to be able to drag one end of the cylinder and rotate the cylinder in any direction, while keeping the other end in the same position.</p>
  
  <p>Currently, I am calling <code>localRotate(by: SCNQuaternion)</code> to first rotate the node, then calculate the position offset needed to move the cylinder so that the other end can go back to its original position.</p>
  
  <p>How can I achieve the objective in one step instead of what I am doing now?</p>