Mirroring Problem

I’ve mirrored meshes in multiple projects, but always seem to have trouble getting the modifier to work. I think it’s mostly because I cannot force my brain to retain the unusual axis labels. I am currently stuck, yet again, attempting to mirror an object over what is generally the Y - axis (as in, mirrored beside the original), but Blender doesn’t call the Y - axis the Y - axis.

I digress; I’ve spent countless hours trying mirroring over each axis, applying the modifier, and still, no mirroring! How on earth do I get the object to mirror at its side? I’m at a loss.

Does your object have any rotation ? It mirrors across the object’s local axis not the world axis. You can clear any object rotation with Ctrl+A
It also mirrors across the object origin unless you set another object as the mirror object. If the origin is in the center of the obejct you may have the mirror sitting right on top of the original so you won’t see it.
Show us what you see and supply your .blend file

Yes, the mirror modifier is very hard to use. I’m struggling a bit too. It doesn’t help that blender uses z for what is usually y. I find it handy to refer to the bottom left of the viewport where it shows the axes in three colours.

when you apply the mirror modifier you can tweak the axis options in the modifier dialog until it looks how you want. You can also select any other object in the scene to use as a mirror image plane. If you don’t select another object, it will mirror the object along its own axis (so the mirrored version will be sitting on top of the original)

Final tip, you don’t need to use shift D to duplicate the object. The mirror modifier already does that.

Don’t focus on mirroring across an axis. Mirror “on” an axis. An X mirror makes negative X coordinates positive, and positive coordinates negative. In an X mirror Y and Z values are unchanged.

The mirror modifier is NOT hard to use. You have the ability to choose whichever axis you want to mirror, so just make sure you pick the right one.

There’s two things in the Mirror options that you want to turn on… Clipping and Adjust Edit Cage to Modifier Result. They are marked out here:


The second option allows you to see what’s going on on the mirrored side as you work.