Been on this for 2 days now without any success. Just want to know that it's absolutely not possible to use the DragAndDrop class for dragging something from and EditorWindow into the SceneView for custom instantiation? I think not, because every time the mouse leaves my window I get "DragExited" event. Which just kills any DragAndDrop events from that point on until the mouse comes back into the Window. I've tried looking at Unity source, but can't see any hidden magic going on. How have Unity managed to use DragAndDrop from the ProjectView to the SceneView without hitting a DragExit event? I'm completely baffled. Adding a SceneView.onSceneGUIDelegate callback is no help either, as that never receives any event other than "repaint" and "layout"