ZBrushCentral

Split Model by Polypaint areas

ZBrush Usage Questions
#1

Hi!

i am very new to Zbrush and it is a fantastic peace of software!
I am modeling my first character and want to bring it over to Cinema 4D to render
it in redshift.
I have a head where I painted on eyes, the inner ears have another color and the face has another color.
Is there a way to split the head into parts by the polypaint areas.
My goal is to have separated parts of the head (at the moment it is one peace) in Cinema 4D to put on different materials.
I found out, that I can display the powlypaint areas in Cinema, that’s nice, but I want to materialize the diffent parts of the face and that’s not possible with one piece of geometry
and I don’t want to select the polygons in Cinema to attach a material to it.

I tried the slice curve to split the head into several pieces but I am not so happy with that because when I start to boarder the peaces of the head it seems that I am not able to stop the slice curve- rotate the head- and going on slice curve the head.

Is there a simple way to get the poly painted areas split into single peaces, meshes or subtools?

Thanks in advance and best

Nikolai

#2

Hi @nhstudio

Yes there is a simple way, but it may not be the best way.

In ZBrush Polypaint = Masking = Polygroups. Any of these things can be converted into the other. You can convert Polypaint into Polygroups with the Polygroup > From Polypaint. Likewise you can convert your Polypaint into Masking with the Masking> Mask by Color , and then into Polygroups with Polygroups> Group Masked which will give you some more options for shaping the mask and the eventual polygroup.

Once you have polygroups, you can split them into seperate subtools with Subtool> Split> Groups split. Or you can simply unweld the geometry along polygroup borders with Geometry> Modify Topology> Unweld. This will separate the mesh into non-contiguous (separate) meshes within the same subtool. However both of these solutions will have implications for how that geometry is smoothed, and how easy it is to work with in ZBrush. I recommend exploring C4D resources for tips on how to apply multiple material effects to a single piece of geometry in that program.

However, the results you get with all of this are going to strongly depend on the quality of your topology. If your topology is haphazard, the resulting polygroups will likely be poorly shaped with jagged edges of polygons. This may or may not be suitable for your purpose here.

To get the cleanest results, in most cases it is necessary to retopologize your model with deliberately drawn, low poly clean quad topology, and then manually assign polygroups so they fall along clean borders.

You can retopologize a model, subdivide it, and then project the detail from the original high res mesh onto the new, using one of the various methods.

Good luck!

#3

Hi @Spyndel

thanks a lot for the reply!
I tried the way with masking and then split groups, it worked like a charm!
You are right, after splitting the geometry hat not that clean edges und should get a retopolgy.
Thanks and best

Nikolai