i duplicate/copy an object with a material several times, the material is being copied as an instance which is ok for some work but not for others.
selecting then all the copied objects to give each a unique material by clicking on the “create a unique editable copy” flag in the properties material does not work for all, i still have to click through every single one individually.
when you want to create a lot of colour variations that is incredibly tedious, i am not sure if that is a bug but if not then i strongly believe that would make a lot of sense.
though it indicates in the properties when one of the materials is already unlinked the flag disappears and reappears when i deactivate that.
Thing is that a new unique material is created, but for all those objects that are selected. I believe this is how it has been designed to work.
create a box
assign a material
make five copies of the box
select all six boxes
note there is no “Create a unique editable copy”
select two boxes
note there is now the “Create a unique editable copy”
click the “Create a unique editable copy”
note there is a new material now, and the “Create a unique editable copy” has disappeared (Why? Because all objects with the same material have been selected)
unselect everything
select one of the two boxes previously selected
note the “Create a unique editable copy”
add the other of the previously selected boxes to the selection
note the “Create a unique editable copy” disappears. (Why? Because all objects with the same material have been selected)
unselect everything
select three different boxes from the previous selection
note the “Create a unique editable copy” is visible
add the fourth box that was not in the previous selections to the selection
note the “Create a unique editable copy” disappears
remove the fourth box from the selection
click the reappearing “Create a unique editable copy”
note a new material is created and “Create a unique editable copy” has disappeared (Why? All objects with that new material have been selected)
The “Create a unique and editable copy” action appears only when a subselection of objects assigned a particular material has been made.
If you want to randomize materials in bulk you are probably better of scripting it?