This post will cover different methods of duplicating and copying objects and mesh elements in Blender. We will also cover linking data between objects so one object will update when changes are made to another.
I also have related posts about how to separate parts of objects and how to join multiple objects together.
Duplicate Objects in Object Mode
To duplicate an object in Blender, select the object in Object Mode and press “Shift + D.”
Then you can immediately move the mouse and the duplicated object will move with the cursor. Left click to lock the duplicated copy into place.
To limit this movement along an axis, we can press X, Y or Z and the movement will be restricted to the selected axis.
This method creates a non-linked duplicate. The new object will be entirely new and will not share any data with the original object. It will have the same materials assigned to it. The addition of a new data block requires more data storage and memory use.
Create a Linked Duplicate in Object Mode
When we create a linked duplicate of an object, the new copy will share data with the original object. This is more efficient and allows edits to one object to affect all linked duplicates.
To create a linked duplicate of an object in Blender, select the object in Object Mode and press “Alt + D.”
If you want to learn more about how data blocks work in Blender, I have a full post on how Blender uses data.
When to Use Linked vs Non-Linked Duplicates
Duplicate objects and linked duplicates both have their own uses, advantages and disadvantages. In some cases, one is a more appropriate use than another. We can always add a new primitive if we want to start modeling a new object.
When to Use Linked Duplicates (Alt + D)
If you need to create lots and lots of copies of the exact same object for a scene, using a linked duplicate is probably best. Creating a new set of data for an identical object is wasteful and will cause Blender to work harder to keep track of them all.
If the objects are supposed to be identical, linked duplicates are the way to go.
Also, if you may want to make future changes to all of the copied objects, you will want to use linked duplicates. With linked duplicates, we can select any of the objects and make changes in Edit Mode.
Those changes will be immediately reflected on all linked copies.
Without linked duplicates, we would have to make the same change to every single object.
When to Use Unlinked Duplicates (Shift +D)
We would use an unlinked duplicate if we intend to make changes to one object but don’t want the copied object(s) affected by the change.
For example, let’s say we made the base shape of a 3D house model. We may want to copy the base shape to make a second house but then modify the houses independently so they’re not exactly the same.
In this example, we would want to create a non-linked duplicate so both objects use their own separate data. Speaking of houses, take a look at my set of very affordable 3D house models available on Blender Market.
How to Un-Link Objects in Blender
If you used Alt + D to create a linked duplicate of an object but later want to unlink the object, follow these steps.
To unlink an object in Blender, select it (Object Mode) and press F3 to open a search menu. Search for and select “Make Single User.” Choose the option for “Object and Data.”
Alternatively, we can find this option by going to “Object” in the top menu and under “Relations” choose “Make Single User.”
Make “Single User” ?
The term “Make Single User” refers to how Blender manages data. With linked duplicates, each object is a “User” of a shared piece of data that defines the object’s geometry. When we make the object a single user, we are telling Blender to create its own data that is not shared with other “users.”
Single User Options
When we instruct Blender to make an object a “Single User” we are given several sub-options for how to do it. They are:
Each of these are combinations of what type of data associated to the object should be separated when creating a single user.
Generally, we will want to use “Object and Data” for making a single user.
Using the option for “Object” will not accomplish any goal of making the object’s geometry separate from the original.
“Object & Data” will make the selected object have its own data block (it’s own geometry) that can be separated. But, it will not affect the materials or animation data. The single user will still share the material of the original object and if that material is edited, the single user’s will also be.
Adding “Materials” to the selection will cause the materials assigned to the object to be duplicated. The new object will have an identical material assigned to it, but this material can be edited independently of the original.
Animation data is also shared by linked duplicates and if you intend to have each object animated differently, you will need to also choose an option which includes “Animation.”
How to Link Unlinked Objects
We may encounter a time when we have two or more objects that are not linked but want to link them. Perhaps we accidentally made a lot of unlinked duplicates and now need to edit them all at once.
Here’s how to create links between unlinked objects and their data in Blender:
- Select all objects you wish to have shared / linked data. Choose the object whose data you want to copy FROM last. All objects should be outlined in orange with the final object (the active object) being outlined in yellow.
- In the top menu, go to “Object” and find “Link/Transfer Data.”
- Choose “Link Object Data”
Now all of the objects will share the data (the geometry) of the object that was selected last and was outlined in yellow (the active object).
If all of the objects already had the exact same geometry, you won’t notice any changes. But now editing one object’s geometry will change all of the objects – exactly as if they had been created as linked duplicates.
If the objects had different geometry, all of the geometry from the non-active object will be lost. The objects will take on the geometry and shape of the active object.
The geometry of an object is controlled by its assigned “Data Block.” Data blocks can be shared or “linked” between objects within a Blender scene. The sharing of linked data reduces memory and storage use by Blender. If we want identical objects in Blender, it’s best to link their data or create them as linked duplicates using “Alt +D.”
Unlinked duplicates will be entirely separate objects that can be edited independently. We create unlinked duplicates using “Shift +D.”
We can link unlinked object data by selecting the objects and linking them.
We can unlink linked objects by making them “Single Users” which means they will have their own, un-shared data.
There are uses for both linked and unlinked duplicates depending on what we are trying to accomplish.
My name is Brandon and I’m a Blender Artist. Have a look around my site for more useful Blender tutorials and guides. I also have helpful straight-forward Blender tutorials on my YouTube channel – I’d love to see you there. Stay Creative!
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