ZBrushCentral

Scale issues when importing

ZBrush Usage Questions
#1

Hi

I sculpted a head in Zbrush. For retopologize I use TopoGun, because I am a betatester, and it has few features that Zbrush lacks currently (most important that it moves the point over the surface during transform). So I’ve exported the sculpted mesh as an OBJ, did my job in Topogun, and exported back to ZBrush as a new topology mesh. Voila! The newly imported mesh differs in size to the original sculpture. As far as I see, ZBrush uses bounding boxes for defining scale. It looks like that the new mesh bounding box differs to the original…Alas I can’t post sample images, as I don’t have the permission.

Any suggestion?

#2

When you import a model into ZBrush it is scaled to 1 ZBrush unit. The exception is if you already have a model selected that has no subdivision levels. In that case, ZBrush will use whatever scaling exists for the current model.

So what may work for you is to clone your multi-res model and delete the subdivision levels from it. Then import the new version of the model while the cloned model is still selected.

If that doesn’t do the trick, then you’ll need to start investigating things like the Tool>Export menu and whatever scaling options are available in your other app.

#3

Hey Aurick, I may be totally wrong but I had similar problems of meshes importing super huge into maya and then importing super small (by comparison) back into zbrush. I actually found that doing Deformation > Unify (just once) in zbrush before exporting anything fixed both the giant export and the tiny imports. As well as a host of other little oversize related issues while working in ZB.

Please let me know if Unify has nothing to do with that kinda import/export size problem and it was just a giant placebo effect :stuck_out_tongue: I’ts entirely possible i accidentally did your solution around the same time and just thought Unify was the answer… Might be worth a look though!

#4

Thanks Aurick, it works, when I start Zbrush, and select load a model file. But when I load a tool, and I have to put it on the canvas, Unify helps a bit. The problem is, that a retopologized mesh may differ in size (du to the unsubdivided or cage-like nature) to the original high poly (subdivided) mesh, and therefore it takes time to fix it.

So the next question is that how can I draw a tool onto the canvas with a fix scale of 1 unit?

The second question is that will be there an update to Zbrush retopology feature, that allows to move points over the surface? Currently that is my main problem with the retopology in Zbrush. And I could avoid similar issues, if it were fixed.

Thanks,

Jester

#5

Another fix to this problem: store a morph target before exporting and after importing, switch to the morph target.

#6

That is not a solution since the model to import has different topology than the model in Zbrush

#7

My bad! I was thinking of UVs, not retopology…sorry!

#8

If you use Unify before exporting and after importing, both versions of the model will be identically scaled. Unify sets the model to 1 ZBrush unit in size.

As for your second question, I can’t discuss the future.