I was just practicing the multiple collection nesting. When he said you can unlink. I went ahead and unlinked ALL my cubes. Just to see what happened they all disappeared from the 3D view and the outliner. I did not leave them linked to Any collections. And they're simply gone.
Also, I just added a new Cube (SHIFT+A > Mesh> Cube), then I just unlinked it from the outliner. GONE!
They are orphan data now. Which means they will be clean out of the blend file unless you have them assigned to a fake user(Shield icon) in the outliner the second icon from the left is the display mode dropdown. click it and select orphan data. you will will see brushes which is always there. and meshes. expand and you will see the cubes. If you directly unlinked them I don't think you can get them back. If you unlinked the collection you can switch display mode to blend file. Then under collections right click on the collection and click link to scene.
First of all thank you very much for your response. It was very complete.
So I did find everything you mentioned and no, since I was just adding random cubes I did not have any fake users. however from the orphan data I am able to assign the object data to fake users. Also you are correct you cannot recover the objects as it's not the object that it's found in that list but the object data. The good thing is that I was able to grasp some understanding from the previous lessons about the difference between the object and the object data.
So, I created a plane (to test a little theory). And then went into the object data tab and assigned one of the cube's data to that plane. And the plane instantly transformed into a cube. As the object is pretty much just a place holder for all the data (in the object data) that makes up the mesh.
I really appreciate you taking the time to go over this. I learned so much from breaking things today and from your insight.
The Unlink function you are referring to is for when you have an object linked in to multiple collections, not the unlink the object data one. In the video JL uses a cube to illustrate that, he links the cube to multiple collections and then unlinks the cube from the collection. You probably used Unlink to get rid of the object data and that's where the confusion came in.
Hey Omar thank you for your response. I was working on the Outliner, there's no "unlink object data" in the right-click menu as far as I can tell.
However it turns out that if you have the object linked to a single collection and you unlink it from that collection. It'll just disappear as the object is not connected to no collection at all. So the object data exists but the object itself doesn't. As Dwayne explained that "unlinked" information is now "Orphan" just like an unused material pretty much.
He did explain where to get the orphan data which is really helpful.
You can try to replicate this issue yourself by adding an object and then unlinking it from its collection. (since it's only linked to that single collection it will just disappear)
You can also retrieve the mesh data by clicking and holding down left mouse button and dragging it to the 3D viewport. This is quicker than switching the mesh data of a mesh object. Like you did with the plane.