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Good Workflow for transferring CAD Models into a clean Mesh?

ZBrush Usage Questions
#1

Hello there,

I am a Newbie to ZBrush. Although I have seen related posts to this topic, I couldn’t really find a satisfying solution that worked out for me.
At the Moment I am trying to figure out the best workflow for transferring a messed up hard surface CAD Mesh (wich comes as a STP-File and has a strange triangulation) into a nice and clean topology.
So at the moment my Workflow is like this:

  1. Load STP-File into Okinos Polytrans64 and convert it into a readable Obj.-File
  2. Import the Obj. into ZBrush
    3.Create ZRemesher Guides via the Polygroup Tools(I guess I tried every tool to achieve clean Polygroups but they are still a bit “wobbly” or don’t really work)
    4.Then I create my Guides via Stroke>Curve Functions>Frame Mesh
    5.Click ZRemesher with Curves Strenghts set to 100

Result: The Mesh is getting cleaner but although I have created guidelines around the sharp edges, they are still getting rounded.

I have checked out the usual ZBrush Documentation, Tutorials and related threads. But I can’t figure out how to get a clean Quad Mesh with sharp edges and without total destruction of the old mesh form. If you have any suggestions to my recent workflow or any ideas I would be very thankful.:confused:small_orange_diamond:cry:

#2

How complex is the original mesh? You could possibly clean it up with the Zmodeler brush, deleting unwanted edges and loops to get it back to quads. If your mesh is too dense this method is probably out of the question and too labor intensive.

There’s also manual retopology with zspheres or topology brush. Again, could be labor intensive depending on your mesh. But it’s very controlled and you can get clean results.

If you’re bringing your model in to sculpt on, your method of zremeshing could work fine. If you have your original model loaded, and a zremeshed version, you can project your zremeshed model onto your original model as you go up in subdivisions to keep your sharp edges. That may not be the answer your looking for though, cause the mesh still wont be entirely “clean”

Or just dynamesh the thing.

#3

Hey, thanks for you answer.

a manual clean up seems to be senseless, for the density of the model is too high and the model itself is too complex(at least in my case).

Your Point with Dynamesh was a big help. So I dynameshed the whole thing. Now that I had my quad mesh I was able to create much cleaner masks via mask peaks and valleys and transform those into Polygroups. After that, I returned to ZRemesher and switched on Polypaint and set the “Edge Polygroups” to 4 and the rest to 0.25. Then hit ZRemesher. So the model still needs some corrections but it is going in the right direction. Though the mesh is still high res to achieve a more or less good result.

Is it possible to export the projected mesh, you mentioned, as an Obj.? Or is it just projecting the details in ZBrush?

#4

You can export the projected mesh as an obj, since it would be actual geometry. But it’ll most likely be high res, depending on how many times you divide it. And once it’s exported as an obj, you lose your subdivision levels (though that may not matter to you)

#5

Hi,
we regularly convert CAD models into poly models at work but we failed so far to find an automated process. We tried the same like you described but also failed to receive clean beveled edges. In the end all you can do is export a mid res poly model from the CAD app and do the retopo manually.

But it would of course be great to have a more precise hard surface retopo tool