ZBrush to Matrix


I have a big issue with Zbrush.
I have a dental scan of someones teeth in STL. I upload the scanned file in Zbrush to create a set of grillz.
After completion I export it to do further work on it in Matrix. The file appears resized in Matrix (either 30x bigger or smaller)

I’m not so familiar with Zbrush, not sure what is the issue.
Can anyone help?

Hi -

The STL file format doesn’t carry any units information and the receiving application will make something up. 30x seems like an unusual rate - most often it’s something like inches vs. millimeters. But then, it’d be 25.4x…

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super common issue with zbrush and it’s god forsaken UI. It was never intended to be an industrial design tool and as such units are an after thought they cobbled together and tossed over the wall.

there is a tool called scale master in ZB that you can use to help make actual units that are useable.

or do what most people do, make a 1" cube in rhino and import it into your model for reference then export back to rhino or matrix and use the cube to scale the entire scene correctly since you know the cube is a known size.


Hehe, yeah I’m sure Pixologic heard that suggestion many times … who knows, maybe Maxon will fix that, (or not?).

this is me dropping dead from holding my breath… <<

As mentioned, you can use Scale Master to set the scale, and then use the scale unify so in the ZB UI your model is at a good size for some of their tools to work properly [this does not change the real size of the object.
then you can also use the 3D print hub to export the STL, it will check the real size…
and then just to be sure, it’s good practice to open in Rhino and verify the size, [and correct if needed]
[I did once sent a 'very large ring for printing and casting… lucky it was cast in silver not gold :slight_smile:

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:rofl: my thoughts exactly.