This is the easiest process we’ll look at. Though one of the most commonly used tools, it doesn’t work the way a lot of people expect.
Joining objects does not geometrically connect them together. It simply “marks” them as one object. This means they move, rotate, scale, and animate like one object, but they are not attached. So if you 3D-print an object “joined” in Blender, it wouldn’t print as one object. Rather, the result would be multiple objects.
That said, joining is still incredibly useful for working with complex scenery or characters, or when working with a print that must be assembled. You can join the pieces in their assembled state, and then have them printed individually.
Before joining objects, there are a couple of things to understand:
- One object be the “parent” of all of the others that are getting joined. You must choose the one you think is the most prominent, and let that one be the parent.
- You must remember that even if the objects are touching when you join them, they do not connect together. They are still detached from each other, and they are only intersecting through each other. Joining simply makes them act as one object. For this reason, it’s not recommended to print when there are intersecting or contradicting objects in a model.
Here’s how to join two or more objects:
- Right-click to select the first object, one which you do not want to be the parent. Once it is selected, hold down shift and right-click the other objects you want to join. The last object you select is the parent.
- Once everything you want joined is selected, you can either left-click the “Join” button in the toolbox (as shown in the image), or you can simply press CTRL + J on your keyboard. Now, both objects look, move, and act as one.
- If you cannot see the toolbox in the 3D editor, hover your mouse over the editor, and press T on your keyboard. Alternatively, you can left-click the tiny “+” tab near the top left corner of the 3D editor. The toolbox will appear, and can be dragged further if desired. To hide the toolbox, you can press T while it’s visible, or drag the right edge of the toolbox all the way to the left until it disappears.
This is a very handy tool to have, but what if we really need to connect two objects together? Not to worry! Though it requires more steps, it’s still rather simple.