title: SceneKit: move SCNNode by setting velocity property directly like in SpriteKit?
body: <p>In SpriteKit, it's possible to move nodes by directly setting their <code>velocity</code> property.</p>
  <p>This doesn't seem to work in SceneKit, however. Setting <code>velocity</code> -- both in game loop callbacks and outside of game loop functions -- seems to have no effect.</p>
  <p><a href="https://stackoverflow.com/questions/31214609/scenekit-scnphysicsbody-get-current-velocity/31217353#31217353">This answer</a> from one of the Apple SceneKit engineers suggests accessing the velocity property is only possible during a game loop callback like <code>updateAtTime</code>.</p>
  <p>So clearly there are limitations around the <code>velocity</code> property.</p>
  <p>Is controlling the property directly not possible with SCNNodes?</p>