ZBrushCentral

Zbrus Blendshapes and Maya workkflow compatibility [Answered]

ZBrush Usage Questions
#1

Hi,

I had this problem for long time and I resolved it by staying inside Maya, now I would like to ask you if someone has a good alternative solution so that I can use Zbrush to model the blendshapes of my characters.

I have a character inside Maya and it has clean topology and ready to be rigged. It isn’t smooth and it uses the tool given from Maya to smooth the character only at render time by cliccling the “3” button on the keyboard before rendering.

This also means that all the blendshapes need to be modeled at subdivision level 0 (keyborad button “1”).

I can send the model from Maya (at subdivision 0) to Zbrush and start modeling the blendsshapes. …NOw the problem:

I might want to set the model to an higher subdivision level inside Zbrush , so that I can model and see the result in the smoothed version of the model ( lets say subdivision 3 in Zbrush) … this is great cause I can use all the great tools of Zbrush and I can get faster and better to the desired shape of the blendshape. Now I need to go back to subdivision level 1 of Zbrush (from where I started , which was the subdivision level 0 of Maya) and send the model to Maya to use as the first blendshape.

I think lot of you have noticed that once the model is back to Maya , the overall vertices position are changed. Not only the vertices that I moved inside Zbrush but also the one I had not moved. The whole mesh is a kind of a shrink version of the original. This prevents the use of the imported model as a blendshape of the original model.

There are way to resolve this issue in Maya , like the paint blendshapes tool… but it becomes too much work soon and it is not precise.

So I wonder if there is a way to tell Zbrush to not move the vertices of the mesh at level 1 which are not sculpted at the higher subdivision level.

PS. this is not related to map , displacement map , or the "re-importing the base mesh at level 1 "'s workflow …

Regards
Guido

#2

This is only a suggestion, you’ll have to test to see if it will work for what you want:

  1. Get the SmartDiv macro here : http://www.zbrushcentral.com/showthread.php?172391-Useful-small-ZScripts-and-Macros-for-ZBrush-4R4&p=1027128&viewfull=1#post1027128 What this does is keep the proportions of your model when you divide it.

  2. Before dividing your model in ZBrush, store a Morph Target.

  3. Use the macro to divide the number of times you want.

  4. Create 3D Layers for your blendshapes. Don’t do any sculpting other than while recording a layer.

  5. When you’ve finished, turn off all the layers and delete the higher subdivision levels.

  6. Switch the Morph Target.

  7. Use the BlendShapes plugin to export to Maya.

This method should mean that your low res mesh remains as close to the original as possible while allowing you to sculpt on a smoothed mesh.

#3

Hi Marcus ,

wow you did resolve my issue 100% . Thank you very much.

The macro is amazing and very intelligent , I am not totally sure which smoothing algorithm is closer to the one of Maya , if it is the default smt of Zbrush or if this macro. In both cases I think they are very close.

What I did miss was the correct workflow of using layers and the specific workflow explained from you. Particullary I have never tought of turn off the layer before going back to the subdivision 1.

Thank you very much , now Zbrush is totally my number 1 tool.

Great software.

Regards
Guido

#4

That’s great, Guido, I’m glad it worked.

Cheers,