Need Help | Finalizing a character for 3D-Print

[ToBe]

Hello all,

this is my first post in this forum.

I have a question about the processes and steps involved in creating and finalizing a model in ZBrush.

As an example you can see in the screenshot an Orc with a Cyborg arm. This currently consists of about 50 subtools. Head, body and umpteen parts for the arm.

This one is still WIP but should be ready in a few days and then I would like to print it. So far my steps have always been the following:

• Bring all subtolls to the same, currently highest (5) subdivision level.
• Merge all subtools
• Put all subtools into the same polygroup
• Decimation Master Master + Remesh by Union

I often ZRemesh Parts and use Project all, to bring the details back. But in case with the arm, that doesn’t work and destroys a alot of details.

Head and body currently have the most polygons and 5 subdivisions. The cyborg arm is only created with dynamic subdivisions. If I bring all parts of the arm to sub 5 to merge everything, the model exceeds 14 million pixels.

So my question is: How do I get all the parts together without destroying the level of detail? And are there other ways than the one listed above?

[tobor8man]

If the purpose is 3D printing only then you can eliminate a ZRemeshing step. ZRemeshing can destroy detail which you may not easily recover, for example hard surface as you’ve described. It’s not required for 3D printing, rather for sculpting.

If you’ve merged all your subtools and then just Remesh by Union and then Decimate. Don’t need to decimate first.

If you have lots of subtools then it might be easier to use folders. With all subtools visible and the Gizmo multi-select icon active (3 bars on the upper right), make a New folder which will put all subtools there. Then Folder Action : Boolean Folder (with or without DSdiv as the case may be). Since you have multiple Start groups you’ll get multiple results immediately below the folder. Put those in a folder and Boolean then for a final combined result. There should be no problem preserving your original detail this way because topology only changes along the line of intersection of the parts when a Boolean is performed. Nothing else it touched. Finally Decimate.

Working with folders this way is neat because you always have the sources of your Booleans at hand and can easily tweak as needed.

[ToBe]

Thanks!

The “Start Group” in my Subtools were actually a mistake didn’t know, this function even existed. I probably clicked/activated this by accident at some point during work.

But I can’t avoid to create 5 subdivisions of the Cyborg Arm first to merge the whole model at the end right?

[tobor8man]

Put all subtools in a folder as described (get rid of unnecessary start groups). Raise all subtools using real subdivisions to their maximum subd level (See ZPlugin:Subtool Master). For the hard surface subtool which is using Dynamic Subdiv just leave it as it is. Then use the Folder action (folder gear icon) Boolean Folder with DSdiv. This will boolean all subtools and use the hard surface dynamic subdiv subtool at its maximum level. So there is no need to Apply the Dynamic Subdiv before the boolean operation.

(I hope I’ve understood your question correctly).

[ToBe]

Thanks for the tip, it worked. Strangely, 5 parts of the arm were not merged in this process?

Any idea?

[tobor8man]

That will happen if parts of the arm collection of subtools don’t intersect or if you have Start groups within the collection of arm subtools. Since you’re 3d printing this can be a useful indicator.

[ToBe]

I still don’t get it could you pls explain, what’s the problem and how i can solve it?

There are no Parts, that are Start Groups anymore…and that no part is suspended in the air but overlaps with others.

The left one is the original, the right one is the one from Boolean with DSDiv

[ToBe]

Ok, it worked with your advice. Had to do Boolean with DSDiv first and then Boolean Folder. Then he merged the missing parts to the body.

The Operation “Boolean with DSDiv” merges all subtools together and autmatically turns dynamic into real subdivisions right?

I still want to understand, why Zbrush doesn’t do it with the first Boolean Operation?

And one more question please: I tried these steps with another model i did and it worked perfectly. The only thing i mentioned is, the model gets from around 1 Mil polys to around 13 at the end. Why’s that?

[tobor8man]

OK, still not exactly sure what problem you are having. Might be specific to your model. See below about checking. I just tried Boolean with DSdiv on 4 subtools in a folder three having real subdivisions of 4,5,6 and set at their highest level (Union) and one having DSdiv with 5 levels (Subtract) and I got a single UMesh with the topology exactly matching that of each subtool at their maximum subdiv level.

Sometimes you will also get floating bits if there are problems with some of the subtools. Often it’s just junk that can be deleted, for example, where faces are almost coplanar. Its worth running Check Mesh Integrity/Fix Mesh on subtools before your final Boolean. Maybe even Close holes and repeat the Check/Fix until the polycount doesn’t change.

If there are subtools with DSdiv then the polycount goes up in the final Boolean result because during the Boolean operation these subtools are converted to real subdivisions. Dynamic subdivs are merely a visual preview. So yes, the final polycount goes up. However Decimation will reduce the polycount a lot, and you need to do that for 3D printing anyway.