How to make trilateral (3-fold) symmetry? I know how to use the Mirror Modifier to make an object mirror over an axis, but I don't know how to do trilateral symmetry, like this:



Is there a way to configure the Mirror Modifier to do this, or will I just have to model one part, duplicate it twice and rotate the copies 120 degrees?
You can use an array modifier to duplicate your object three times, and an empty rotated 120° for the offset.





The empty needs to be in the same place as the object origin for the rotation to be correct.

Now, when you edit one object, the other two will also change.