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Deformation and detail projection on a dinosaur fossil scan, help with Gizmo

ZBrush Usage Questions
#1

Hello.
I’m not exactly new with Zbrush but I don’t use all it’s functionality extensively, and would need some help problem solving this in the name of paleontology.

tldr: I need to deform this skull but I don’t think my method is optimized enough, could need some help

I have a 3D scan of a Herrerasaurus skull print that is pretty deformed, and was messing around trying to fix it, but encountered some issues with the process, here’s how I did it:

Here’s how the scan looks
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I began by using dynamesh to make sure any possible errors from the file were fixed, and to get an easier file for zremesh to handle

After making a copy I zremeshed the model expecting to edit using Gizmo

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The point was to use the gizmo Deformer to fix the overall shape using a low poly mesh and project the detail later, but since it was the first time I did this I was surprised to know it wasn’t so simple

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I then froze the subd levels and carried on the gizmo Deformer normally, got my general shapes fixed and clicked to unfreeze my subd levels, the rest could be done with brushes

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Then I discovered that Zbrush projects the detail based on the pre-deformation mesh, not like a close array of polys as I expected

Since it didn’t worked, what I did instead was to use the high res skull, deleted the lowest division levels and used Gizmo’s deformer to fix the general shape. Then, I used reconstruct subdiv to get a low poly version and worked on the general shapes in the lowest subdvision

com-image%20(1)

Am I missing something or it’s pretty much how it would generally go to deform a mesh and keep the details using the Gizmo deformers (I know you can do with many different ways)? Is there any other way that’s faster and less troublesome?

Q: But why don’t you use move brushes/transpose on the low poly?
A: I would rather have a uniform deformation over the mesh than going through all the hassle of fine tunning each area individually

Also, since I’m here, is this behavior with the backfacemask activated and move topological brush normal? I never noticed before
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#2

Hello Douglas.

We shall attempt to solve this problem in the name of paleontology.

As you are probably aware, what you would like to do is somewhat outside the optimal order in which you would traditionally do things. Generally you would establish your major form before sculpting high level detail. Detail projection requires a mesh that is mostly the same shape/size in the worldspace. But we can probably make this work.

  1. If your hardware is up to it, simply perform the deformations on (a duplicate of) the high poly mesh before creating any subdivision levels for it, THEN re-mesh into a multi-subD tool.

or

  1. If that doesn’t work for you, in your situation you could use Transpose Master on a tool with multiple levels of subdivision, with a manageable low poly base, and the high frequency detail at the highest level of SubD. So you first have to establish the tool in that form if it isn’t already. Detail projection can be useful here, if you need to project the detail from your high detail mesh onto a new mesh with a low poly base and multiple subdivision levels.

  • Transpose Master is generally used to pose tools with multiple subtools and subdivision levels, but it can be used for this as well. It will create a new merged version of any visible subtools at the lowest level of subdivision, which can be posed or deformed more easily than working on a high poly mesh. Since it’s a single level of subdivision, the Gizmo Deformation tools can be used on it. You can’t do anything to change the actual topology though. When satisfied, send the T-Pose mesh back to your main tool, where the changes will update all the subdivision levels.

  • Note that if you make drastic changes to the form of the low poly geometry, you may have poly stretching issues. You may need to Re-mesh and project again after making the changes to redistribute the topology.

#3

Hello Spyndel,

Yes, I’m aware of the sculpting order. The problem is, this is a 3D scanned object, so the tool has only one subdivision lvl with around 1 million points.

I did project the detail into the new optimized subtool before doing any deformation, expecting this would make things easier with gizmo, but as demonstrate I was wrong.

I ended up doing pretty much what you suggested, performed the deformation tasks on the high density mesh, but I feel it would be easier if I could work with a low density mesh with multiple subdivions and then project the detail back in the end.

About the transpose tool, I really wouldn’t want to use something unreliable when we have cage deformations inside Zbrush, which permits more controlled and uniform changes to the tool, something it is noticeable hard to achieve with transpose and masking.

Cheers, Douglas.

#4

Douglas, if you click on the link I provided, you’ll see that it’s to Transpose Master, which is a plugin that will let you work with the deformation cage on a low poly version of the tool, and transfer those changes to the high poly version.

I explained this in some detail above.

1 Like
#5

My apologies, I didn’t know this Transpose Master functionality (I just used for pose rigs, haha) and ended up reading the rest as a Transpose Line process.

I followed the method and ended up with the results I need.

Thanks for your patience, and have a nice day :slightly_smiling_face: