SceneMainLoop -> SceneTree

-=-=-=-=-=-=-=-=-=-=-=-=-=-

*YOUR SOURCE MIGHT NOT WORK*
For mor information on fix:
https://github.com/okamstudio/godot/wiki/devel_scene_tree

Other stuff:
-Shower of bullets demo
-Fixes all around

scene/3d/room_instance.cpp

@@ -147,7 +147,7 @@ void Room::set_room( const Ref<RoomBounds>& p_room ) {
 		set_base(RID());
 	}
 
-	if (!is_inside_scene())
+	if (!is_inside_tree())
 		return;