ZBrushCentral

Problems with scale in Zbrush

ZBrush Usage Questions
#1

Hi!

I just wanted to know how to make Zbrush work well with other application when modeling to scale. I use 3DS Max as my main application, and I’ve set Max to work in cm rather than simple units. This is all well and good, but when I try to export simple objects from Max to Zbrush, they are too large for Zbrush to function well.

I’ve heard Zbrush is scale-independent, but I don’t believe that. Because when I import objects that Zbrush interpret as huge, some tools won’t work as they should, and this is a big problem, I don’t want to re-scale objects every time I export and import.

I can’t be the only guy who use Max with Zbrush, so I would assume someone else also has experienced problems with scales. Does anyone have any advice or solution to these problems?

Here is a image to illustrate the problem.

Thanks for the help. :slight_smile:

#2

Append polymesh 3d star. Select it. Click import under tool pallet. Selected file should replace the star and be the correct scale. Also check your preferences pallet for import export options.

#3

Yes, I’ve seen this. If I start Zbrush with a polymesh 3d star tool already in the canvas, the object from 3DS Max will replace the star. But through the GoZ-process, Zbrush will scale up the GoZ-object after replacing the star, so the scale is “correct” based on the source.

I could just hit undo once after GoZ is done, and it will scale down to a more Zbrush-friendly scale, but that would make it off-scale once I import it back to Max. I want to avoid the process of manually re-scaling the objects after import and export.

But thanks anyway. :slight_smile:

#4

I have the same issue with GoZ and Blender. I’m actually working on a reasonable workaround and doing a write up now. I don’t have 3ds Max but I think the same workaround will work. I’d like to experiment a bit more on it. If you could send me a couple of files from 3ds max that would help and I can post my results and the workaround.

Create and post or send me the following files:

Create a cylinder that is 10cm diameter and 1 cm high. Export to cylinder10cm.obj

Create a cylinder that is 100cm diameter and 10 cm high. Export to cylinder100cm.obj

Create a cylinder that is 10cm diameter and 1 cm high. GoZ to Zbrush and save the tool as cylinder10cmGOZ.ztl

Create a cylinder that is 100cm diameter and 10 cm high. GoZ to Zbrush and save the tool as cylinder100cmGOZ.ztl

Save your 10cm or 100cm diameter cylinder as Zbrush project, .zpr file.

I work in mm units but I’d like to compare some things with cm units as well. If you could send me these files I think I’ve got it all figured out.

#5

Thanks. :slight_smile: Here is the file.

I included some screenshots to show the scale compared to the grid. I used the default .obj export options from 3DS Max, so the export scale is set to 1. Let me know when you’ve downloaded the file, so I know when I can delete it from the dropbox. :slight_smile:

#6

Those should work. I’ll take a look at them and see if it’s doing the same thing as Blender, which I highly suspect it is.

I’ll post an extensive write up with the solution hopefully by the end of this weekend.

#7

That’s fantastic. :slight_smile: Thank you!

I’m surprised I couldn’t find anymore info about this problem, because I would think many people use GoZ between Max and Zbrush, and model with real-world units. Yet nothing to find anywhere I looked. Hopefully you’ll have the answers I’m looking for. :slight_smile:

#8

I’m close to finishing up the write up on the solution and the cause of the problem.

However I can see a potential problem with your model from 3ds max.

The 10cm x 1cm cylinder is actually at 2 x .2 units.
The 100cm x 10cm cylinder is at 20 x 2 units.

I checked the .obj in Blender, Zbrush, and Geomagic and the dimensions are the same in all three.

You might need to check your unit options in 3ds max, as of now it doesn’t look like it’s the correct dimensions on exporting. It might also be an issue with your export .obj settings in Max. I know in Blender there’s an option to apply modifiers on the export and if it isn’t checked then sometimes you don’t get the same model in the .obj as in the Blender model.

Note that is not the same issue as the GoZ scaling problem, or at least it shouldn’t be. But you may need to check your settings to make sure they’re correct. Since I deal with 3d printing my unit scale and settings have to be exact, where as most 3d users just need the correct proportions for renderings.

#9

Here’s the thread I posted on the problem:

http://www.zbrushcentral.com/showthread.php?168239-Scaling-Issues-(GoZ-Blender-Max-etc-)-Solution-and-explanation