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GoZ, noGoZ, other method?

ZBrush Usage Questions
#1

Hi All Zbrushers!

Ok. At the bottom are the two files, my Maya file and the Zbrush ztl with all the “blend shape layers”
The naming is the same for both items.

In Maya I have a copy of my original mesh and offset to the side but it isn’t attached as a blendshape to the main skin.

.
So far so good. I couldn’t get GoZ to work because of nGons, no biggy. So, I exported the selection(the green mesh there), as an .obj with the same name mesh_copy.

In Zbrush, I imported the mesh_copy, and added the layers to sculpt the various “blendshapes”. Since GoZ didn’t work, I used the export Blendshapes plugin. It opened Maya but it moved the mesh over the original model without the offset, as you can see.

The blendshapes window exists, which is great, the only problem is, the blends only affect the mesh_copy and not the original mesh.

My question is, before using the blendshapes plug-in, do I need to first attach the base(pre imported from zbrush blendshapes)mesh_copy to the existing mesh or should the plug-in automatically attach it. I mean it is attaching to the copy_mesh, but the copy_mesh isn’t attached to the main skin which obviously needs to be to affect it properly.

So do I need to attach the mesh_copy to the main mesh first, then use the blendshape plugin in Zbrush?

Any ideas?

Thanks!

Sean

files:

https://www.dropbox.com/s/0w3jtkgre2isxgt/frogMain.0220.ma

https://www.dropbox.com/s/el1riakcrqwdiz4/mesh_copy.ZPR

https://www.dropbox.com/s/gejp0sxrbl0oue2/mesh_copy.ZTL

#2

I thought I should mention that I have tried by deleting the extra mesh, and also changing the name of the mesh to the HIRES_body_mesh, as is in the file(on dropbox link), in Zbrush, so that when it exports the blendshapes via the plug-in, that it would be attached…
Nope, it deletes the skin’s cluster with all the painted weights…not good.

Still trying to figure this one out.

I’d love how to get the blendshape plugin to work seamlessly.

If anyone can help out, I’d appreciate it.

Thanks.

Sean

#3

You say you couldn’t get GoZ to work because of nGons. That’s where part of the problem lies. ZBrush does not support nGons, so when you import an OBJ with them they are converted, either to symmetrical tris or to quads + tris, depending on what you select in the dialog. That means that your mesh will then have a different number of points/polys from your original in Maya, so any blendshapes created in ZBrush will be different and can’t be applied to the original mesh.

#4

Ok,

So the fact that the mesh was altered, that does make sense. Now if the mesh wasn’t altered, then the Goz should work and I wouldn’t have to go around the wall to get through it?

Thanks. I’ll have to figure a different way of doing the blendshapes…Thanks!

Sean

#5

Not having MAYA here, so a guess, fix model there before sending to ZBrush. As in all tris or guads, No n-gons.

#6

So the fact that the mesh was altered, that does make sense. Now if the mesh wasn’t altered, then the Goz should work and I wouldn’t have to go around the wall to get through it?

Yes, that’s right. I’m not an expert in Maya but I believe it is possible to have blendshapes with different topology but the ZBrush plugin doesn’t handle that. You may be able to set your existing blendshapes to work, you’ll have to experiment. See here:
Maya - Blending objects with different topologies

If you are going to use ZBrush to create blendshapes then don’t create a duplicate mesh in Maya - the plugin will do this for you. Here’s a basic workflow:

  1. In Maya, select the mesh that you wish to create the blendshapes for. This must be a separate single mesh. (You may be able to combine meshes later in Maya, provided the blendshapes are set to ignore the topology.)
  2. Use GoZ to send the selected mesh to ZBrush, or export as a Maya ascii file (*.ma) and import into ZBrush, but note that your model shouldn’t have any nGons as ZBrush can’t use those and will need to change your mesh on import.
  3. In ZBrush create the layers you wish.
  4. Press the Maya Blend Shapes>Export Blend Shapes button to send the mesh and layers to Maya.
  5. Provided the name of the tool/subtools matches those in the Maya scene the blendshapes will be added correctly.
#7

Thanks for the response.

Yeah, I had that copy in there because I wasn’t sure how it was going to work. There is an ngon issue and unfortunately, I already have a skin cluster with weights painted and such and was told the mesh was ok to move forward with. If I had known the ngon was going to cause issues, I would have fixed those…this mesh was a bit difficult to work with LOL. I’m still learning, obviously.

So I did have zbrush convert(the first choice) and created the layers and named them by what their blendshape name would be, but the tool was named exactly what the original mesh is/was, HIRES_bod_mesh. I did get it to apply the blendshapes properly, after having deleted the duplcated mesh as you saw in the file, however it erased the skin cluster with all my weights.

So I guess there is no way of connecting it via the blendshapes plugin without erasing the skin cluster?

Thanks again for giving me direction!

#8

I don’t think you’ll be able to get the plugin output to work for this current project. But you may be able to export OBJs from ZBrush for the different layers and then connect them as blendshapes in Maya, making sure “Check Topology” is off (as in the link I posted above). As I said, I’m not a Maya expert, so I don’t know if this is possible but it would be worth looking into.

#9

Thanks Marcus,

Yeah, I wound up having to just do the sculpts in Maya to get them done for my assignment. I still wound up with some crazy errors, but they worked out ok. Someone actually pointed out a tutorial that I’ll have to try next time.

http://forums.cgsociety.org/showthread.php?t=407468

I appreciate your help.

Sean