title: How to use Unity editor script to drag asset object to Scene View like Unity editor > Project view
body: <p>For instance, I found out that the Unity plugin "Octave3d Level Design" has this feature
  <a href="https://i.stack.imgur.com/SppIB.gif" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/SppIB.gif" alt="enter image description here"></a></p>
  
  <p>I hope to make my own prefab manager, since Octave3d prefab manager is not fit for my need. So the question is: when mouse is overlapping Scene View, how to make mouse seize a object and put it in Scene View?</p>