ZBrushCentral

Closing holes without filling other holes

ZBrush Usage Questions
#1

This is probably a real beginner question but I can’t find the answer anywhere and it’s halting my learning progress big time, so any advice or a link to a video etc is very much appreciated! Let’s say that I make something like in fig 1 below, by masking an alpha onto a cube and pulling it out (not extracting as I did here, I want to keep the exact shape of the mask), and then I chop it off from the cube and what I’m left with is this object which has holes in it but no back (fig 1). I want to put a back on it like in fig 3! How do I do this?! If I “Close Holes” I end up with fig 2 which covers the back but also some of the holes. Any suggestions? Hope this makes sense. Many thanks!
problem1.jpg

Attachments

problem1.jpg

#2

If that shape is the result of a subtool > extract, you can simply enable the “double sided” option when creating the extract, saving you this step.

From this point, in this particualr situation I would simply Tool > Geometry > Modify Topology > Mirror and Weld along the relevant axis. Depending on which side of the mirror plane the geo is on, you may need to flip it first with Tool > Deformation > relevant axis.

If the object is off center, activate local symmetry ( Transform > L.Sym) first.

#3

Many thanks for replying Scott, Mirror and Weld across the relevant axis seems like the best solution to my problem. This of course means that the object would be hollow right? Would that be a problem when 3d printing? Something I’ve yet to get into.

#4

No. As long as the volume is enclosed (no open geoemtry or holes), it reads as “solid” as far as 3d printing goes.

By the way, did you notice the first sentence I wrote? The easiest way to fix this is just to perform a Tool > subtool > extract from your masking again, with the “double sided” feature active. This will create an entirely separate subtool that is already mirrored and closed on both sides.

#5

Oh I see thank you, it may seem really obvious but as a traditional sculptor for many years I assumed what we’re working on is solid like a piece of clay, I was having trouble getting my brain around some things, makes more sense now I know it’s hollow.

I did see your first comment about the extract function, but I’d made an alpha and wanted exactly that shape, unless I’m using it wrong extraxting doesn’t just pull it forward- it expands my mask/alpha in all 3 directions distorting the original shape. Mirror and weld certainly did the job, as does shadowbox, basically I wanted to know how to put an enclosed hole through a solid shape, I think I have it figured out now, I also just read about holding alt when using insert brushes which is very useful.

Thank you very much for taking the time to reply, it’s much appreciated!