ZBrushCentral

Precisely scale tool by percentage

ZBrush Usage Questions
#1

I have a model that was created without consideration for what the final scale would need to be. All the Zbrush detailing has been done on it, and it now needs to be scaled up, by 10.33 times for example.

I know of one method: export the lowest and highest sub-d’s as obj’s, scale both the same way in maya, bring the lowest sub-d back into Zbrush, subdivide it to the same number of levels as before, and then import the scaled high sub-d back into the highest sub-d position of the newly subdivided and scaled base mesh - voila it’s scaled.

BUT - that method presumes that you can export the highest sub-d, and I have in the past had the case where I was not able to export it due to it being composed of too many points (I presume).

I’m wondering if anyone knows of a better method, preferably one directly within Zbrush.

#2

Presumably the change of scale is only necessary when you are exporting the model to another app? In which case you can use the Tool>Export>Scale slider to set the scale you want.

#3

Thanks Marcus, I hadn’t noticed that feature.

I would however prefer a method that will change the scale permanently within Zbrush as well. Do you know of one?

#4

The simplest method is probably to use the same slider:

  1. Set the Tool>Export>Scale slider to the value you want.
  2. Export an OBJ from the lowest subdivision level.
  3. Set the Tool>Export>Scale slider to 1.
  4. Import the OBJ exported at (2).

The higher levels will automatically update. However, note that the absolute values of additive 3D Layers are not adjusted so their effect will be reduced/increased depending on if the new scale is larger/smaller.

#5

Yeah, that doesn’t do what I need. That’s just one half of the process I described earlier which adds the step of scaling the highest subd level as well, then re-imports that in order to get back the finer details in proper proportion.

Any other ideas?

#6

Well, you could use the Tool>Deformation>Size slider but you’d need to work out the values. But using the export method there’s no need to import the high res detail as the higher subdivision levels are adjusted automatically. It’s only Layers which would be a problem.

#7

The same thing happens whether you have layers or not. Specifically - if I set the export scale to 10, export the lowest subD, and then set the export scale to 1 and re-import the previously exported mesh, the model increases in size as expected, but when I view the highest subdivision level all of the details are smoothed out. It appears to me that these higher subD details are occurring on the model at the same absolute depth levels that they had when the model was smaller over-all, and so are now disproportionately shallow.

#8

I’ve not seen that. It looks as though you’re limited to your original method.

#9

FYI - I’ve tested my claims with a Zbrush primitive sphere in addition to the model in question, and have the same results. For the results to be noticeable you need to have significant details on the highest SubD level that are not represented at all on the lowest SubD level.