Thank you all for your input. The video is good @MarioPeper
Because most all the input regarded functionality, I decided to do a test for System Resource Usage (memory and speed).
I made a source file with a huge object, consisting of a meshes with more than 10Million faces, then placed this object in a collection. I linked from the source to other files and duplicated:
- In the file MemoryTestCollection.blend I linked the collection and duplicated. Took that instance and duplicated it in the file using Copy&Paste, Αlt+D and Shift+D. Made no difference (since the copies are all place holders, no detail data)
- In the file MemoryTestLinkObjectAltD.blend I linked the object from the source and duplicated it, using Alt+D, Duplicate linked. Performance during editing, and resulting file size were the same as the first case
- In the file MemoryTestLinkObjectShiftD.blend I linked the object from the source but then duplicated it using Shift+D instead. The interesting note in this case is that the file spiked, despite the fact that you cannot edit the instance prototype and all instances are identical (and if you edit the source file all will modified).
File sizes, each file contains the original from the external source and 3 duplicates of that :
Conclusions regarding System Resources only:
- For a single instance in the file referencing, it is practically the same to Append, Link an Object or a Collection with that same object, from the source
- To duplicate identical instances, regardless for appended or linked objects use Alt+D, duplicate linked.
- Duplicating a linked collection instance can be done in every way without bloating the file size, but seems to be no more efficient than Alt+D duplicates of any original from an external source file.
- It was surprising to me, that Shift+D (or Copy&Paste) duplicates of linked originals from a source file (be it object or collection instancing) bloated file size.
I did not anticipate this since I thought I would be like copying a placeholder only, since the data is only a reference to an external bulky source, not the details of the source… nevertheless
Of course the cases above each have different functionality and hence applicability.
Among Linked Collections and Linked objects, Linked Collection Instances do seem more “clean” and fault-proof from careless duplication usage within a project file, even though it seems a slight overkill in the case of a collections consisting of a single object.