ZBrushCentral

World Space Confusion

ZBrush Usage Questions
#1

Hi

I’m a little confused with the world position when exporting something from ZBrush to Maya or 3ds Max. Give or take, every SubTool is roughly in ZBrush’s world centre.

A side question: apart from merging all the SubTools down so it’s one complete tool, is there no alternative way of zeroing everything using the Position X, Y, Z sliders, whilst still keeping everything where it should be for the character, such as arms and legs etc.? Like when you group everything in Max/Maya and zero the group to the centre of the world? I did try putting everything into a folder and then using Transpose Set, but that still only zeros out the SubTool selected in there. Seems a bit of a pain having to merge everything, zero it all out, and then manually split/separate everything again. Hell, I’ll take a custom made plugin if one exists. :slight_smile:

But the original point of this post… Everything looks to be zeroed out in ZBrush’s world:

ZBrush_dRqYKMObIY
ZBrush_dRqYKMObIY1416×638 19.4 KB

However, once I import each piece I’ve exported, everything is always to the far left of the centre grid.

3dsmax_GEfHkZCR3C
3dsmax_GEfHkZCR3C1176×719 23.9 KB

Is there any way of avoiding this? What could be causing it? Thanks.

#2

Hello @DustyShinigami ,

Assuming that you’re importing your meshes with the Import button and not with GoZ, then most causes of scale or position shifts are due to import procedure.

ZBrush’s effective worldspace is finite. Meshes that are significantly over / undersized, or extremely offset from center, will not perform well in the program and may be difficult or impossible to work with.

For this reason when you import a mesh into ZBrush when there are zero values in the Tool> Export menu, it auto-scales and centers the mesh to work well in ZBrush and then records the values required to restore the mesh to its original size and position in that same menu. The mesh will be exported at exactly the same size and offset as it came into the program.

Where problems arise is when another tool is active at the time of import that may have its own unique settings in that menu. Those settings are meant for that mesh and no other. If a mesh is imported while that tool is active it will inherit those settings and be exported based on them. In that scenario a mesh will always look like it’s centered and properly sized in ZBrush, but may shift drastically in size and offset upon export when viewed in another program.

The Tool> Export menu defaults to zero when no active 3d mesh is selected and the program is in 2.5 d mode. In most other cases it is recommended to switch to the default polymesh3d star before importing a mesh. This is only because that tool, unlike the other primitives, has Tool> Export settings of zero and you can be assured of a clean slate. The only time you want to import a mesh with another mesh active is when those meshes are the same size and you are trying to replace one with the other, for instance when updating UVs with an import.

So if attempting to import one mesh that is meant to fit to another mesh at the same size, the process would be:

  1. Select the polymesh3d Star. Import the main mesh, for instance a character body.

  2. Select the polymesh3D star. Import the secondary mesh and append it to the first tool. That tool will inherit the first tool’s specific scaling factors, and will size and position itself accordingly.

If that does not resolve your issue, then I would check the import preferences of your external program closely for any auto-scaling features that may be active in it.

Good luck!

1 Like
#3

I tend to import/export with the FBX plugin, or the Tool > Import, yeah. I have been exporting multiple meshes out together, which I believe I’ve done in the past without issues, but they’re not merged. I just export out whatever’s visible. For instance, I’ve exported out the head, eyes, teeth etc. as one export.

Would the Scale Master plugin be a responsible cause for this issue, too? I did try an earlier save before playing around with it, but the same issue happens, too. I’ve only tried setting the measurement from mm to cm though.

I’ve tried just exporting out a single SubTool - the head of my character - using both the Tool > Export menu, and trying as both OBJ and FBX. OBJ doesn’t appear to give me any options to pick on export, but FBX does. I just have Selected enabled, bin, and SNormal. The same problem happens.

Whenever I import an OBJ, I do usually insert/append a star primitive first. :slight_smile: I just didn’t know the imported mesh that overwrites it inherits its scaling etc. Either way, I tried exporting out the individual pieces from Maya, appending/inserting a star, and then importing a part of the character. But even if I export the new mesh together, with everything visible, or just export one part. such as the head, they’re still coming into Maya incorrectly. :frowning:

EDIT: I’ve even tried importing all the high poly meshes into a new scene in ZBrush (FBX). Same issue happens when I export/import them into Maya. Really weird. Not had this problem with any other project.

EDIT 2: I’ve even tried exporting out all of my pieces as OBJ, closed ZBrush, and then loaded it up with a new scene. I did the exact steps you outlined above with importing each one. The Scale Master wasn’t touched… The overall scale of the character appears bigger and is standing bang on the floor plane. But again, exporting just one SubTool (the head), and then importing it in Maya - same issue. It’s miles away from the centre grid. I even tried exporting out another project with all parts visible, and that appears in the centre of the world. Completely lost as to what’s wrong with this. o_O

#4

For now, I’ve just had to settle with bringing in all the parts into Maya, grouping them together, zeroing out the group, and then selecting all the meshes and freezing their transformations. Importing/exporting back and forth between ZBrush and Maya now seems fine and they’re all appearing where they should be. :slight_smile:

#5

Hi @DustyShinigami ,

I looked into your issue, and we are seeing some unexpected behavior with certain formats when the Export option is set to “All” in the scenario I described above where you import both meshes individually and append one to the other.

While we investigate this I recommend either exporting your individual subtools one by one with the “Selected” option, or to merge the geometry into a single subtool prior to exporting. In my testing the subtools retain the proper offset when exported individually.

Procedural errors here are still possible. If you imported a mesh with non-zero values in the Export menu active at any time, every subsequent export you make with that geometry may be off.

The Scale Master plugin can change the scale or offset of the selected objects in the worldspace. If you then export that geometry, it will have a different scale or offset than when it came into the program.

#6

When you say ‘when the Export option is set to “All”’, are you referring to the FBX plugin…? For that, I don’t have All selected. I use either Selected or Visible. The only other ‘All’ option I’m seeing is for GoZ, but I don’t use that.

As I mentioned previously, I’ve tried exporting out the SubTools individually, but still get the same problem. I’ve just tried merging them altogether too. Same problem. I’ve even gone right back to one of my early block-out stages, so no tampering with the Scale Master, and way before I prepped the mesh for Marvelous Designer, and the problem happens with that too. A single SubTool.

#7

I did have another thought that crossed my mind. Right at the very beginning of the project, I think I did take my mesh into 3ds Max and set up some measurement planes as the character is based on an existing one. It could be, because I didn’t add an X-Form before taking it back into ZBrush, that it could have messed things up…?

#8

Use only “Selected” and export one by one. Do not use “Visible”. Do not use “All”.

This results in export and offset as expected in the current versions of Maya and ZBrush when using the process I have described with two simple pieces of geometry:

exportests
exportests1920×3240 174 KB

If it does not for you, then there is either a problem with your procedure or another variable involved. You will need to contact ZBrush Support for further assistance.

Thank you!

#9

Yep, it’s as you say - the method you’ve outlined and shown works correctly and as intended. However, for my character, it does not. So yeah, there is a variable screwed somewhere. Which is why I think it’s related to when I took my blockout into 3ds Max when setting up measurement planes and failed to apply an X-Form before exporting out to take back into ZBrush. It’s the only logical thing I can think of as all of my previous saves and blockouts have the same issue. :slight_smile: