How the he#@ do you mirror a subtool with subdivisions?

If you’ve ever tried to mirror a SubTool with subdivision levels in ZBrush, you’ve probably hit a wall and thought, “Why is this so annoying?”… I’ve been there too.

For context, someone asked me this on socials the other day and to be honest, since I’ve been using ZBrush for years, this kind of thing feels trivial now. It’s just part of my workflow, so I don’t even think twice about it anymore.

But here’s the thing… If you’re new to ZBrush or just haven’t dealt with this type of workflow before, mirroring something with subdivisions isn’t exactly intuitive. So I figured I’d break it down and show you the simple way I do it. No fluff, just what works.

1. So I have this boot I created for one of my TEM characters and it has a clean base and 5 subdivision levels (also it is made out of multiple separate pieces).

The instinctive thing would be to select the SubTool, duplicate it, go to the Deformation palette, and hit ‘Mirror’… right? Well, you can’t. You’ll get that annoying pop-up saying “this function cannot be applied to a mesh with multiple subdivision levels.” So yeah… classic ZBrush.

Ok fair enough… so then you might thing, well we can Freeze the subdivision levels and then just mirror that… Yep that works great, until you ‘unfreeze’ the subdivision levels and you get this completely crooked damaged mesh that I like to sarcastically called ‘the bundle of joy’:

So the solution is actually pretty simple, and when you stop to think about it, it's kind of basic. But I get it. If you don’t know, it’s really annoying trying to get this to work.

So here’s what you do:

1. First, duplicate your SubTool. This is handy if you want to end up with two (left and right boot)
2. On the duplicate, make sure you’re on the highest subdivision level and delete the lower subdivision levels.
3. Now that you’ve got no subdivision levels, you can use the Mirror button from the Deformation palette. Easy.

Done! All you need to do now is click on the ‘Reconstruct Subdiv’ button from the Geometry palette a few times to recover your subdivision levels. That’s it!

And if you want, since you now have two identical SubTools with the same amount of subdivision levels, you can just merge them together and keep them as a single SubTool with all your subdivision levels intact:

If you already know how to do this, I get that it might seem like a basic thing. That was my initial reaction too when someone asked me. But after giving it a bit more thought, I realised it’s not as obvious as it looks.

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