Operating system: linux 64-bit
Graphics card: nvidia geforce gtx-650
It is not documented afaict, perhaps it should be, but suppose a user does the following, it becomes very difficult to tell in how to restore their deleted object/s.
The issue is that it is difficult to "restore" orphan data.
The feature Ctrl-G to add a new Collection (Blender 2.8) prevents it from appearing on the Scene as expected, the issue arises later as a consequence of using Ctrl-G.
Take a new blender workspace, with its default cube selected and apply Ctl-G, and name its additional collection called 'Collection 2'.
The cube is now a member of two collections, 'Collection' and 'Collection 2', and this can be verified in its Object property-panel(orange square) under 'Collections'.
The Outliner (View-Layer) presents just one collection for the cube.
The Outliner orphan-data view presents 'Collection 2'.
Despite confusion, (I'm a bit new to blender), supposedly this is transitioning-development and this may change in the future so that 'Collection 2' at this point would not appear in the orphan-data view.
The problem arises now when a user performs the following::
In the object property panel (orange quare) for the cube, the removing of 'Collection' from the list now causes the cube to disappear from the scene.
The cube now appears under 'Collection 2' in the Outliner's orphan data view.
So here is the problem:
How does one "restore" 'Collection 2'/cube so that that the cube object can be placed(undelete) back onto the Scene?
The only way I could figure out how to do this after a long time of searching online, and checking any documentation on this was to create two Outliner views.
Have one Outliner view in 'View Layer', and have another Outliner view in 'Orphan data view',
Now drag and drop the 'Collection 2'(containing the cube -- from Orphan Data view), into the Outliner 'View Layer' with the heading 'Collections', and the object is now restored back fully into the Scene.
Perhaps there should be a new feature with a 'warning' or choice-box before blender sends the cube missing from the scene offering to set 'Collection 2' to the scene.
I don't see a bug, but I do see a lack of documentation on this, and believe reporting this might help another user or give an idea to development for improving this difficult task.
It's not documented and most users would not be able to figure out on how to do this as one would have to use two Outliners in order to properly restore the missing object. It is possible to use a blender file link and still access the marked 'fake user' orphan data from a new workspace(and that's another way to restore missing orphan data) but that is not the case i'm referring to, nor should it be the case..
Please improve this area or at least have this documented somewhere so that this problem can be prevented as it is extremely difficult to restore things this way.