Hi,
so as the topic states, I’m using the various Insert brushes on a Dynamesh Tool hoping to cut out some geometry. Unfortunately, my ZBrush install only adds to the Dynamesh. It does not subtract when I use the ‘Sub’ button.
It used to work initially for a bit, but it’s stopped working as of yesterday.
Any ideas on how to get this working again?
Interesting side note, I also can’t get the SliceCurve brush to work (nothing happens). Maybe the two problems are related?
Thanks for reading!
Yeah, I’m getting the same problem here, all it ever does is add, doesn’t work with the shortcut (ctrl-alt-drag) or when clicking manually on the sub button either.
Not sure if I’m missing something or what?
And yeah for SliceCurve, for me it just adds an edge loop along the slice, not sure if that’s all it’s supposed to do, thought it should separate the objects? Didn’t look into to it so much yet, maybe that’s another tool…
Oh actually I figured it out for the subtraction, you have to press Alt when drawing on the mesh, I thought it was only necessary to do it at the end once you have the inserted object placed correctly. Hope that works for you Lone Deranger.
The slice curve requires you to have Group button selected next to Dynamesh then use slice curev, then remesh (Ctrl Drag) before you get a seperate piece.
I have a bit of a problem subtracting an inserted mesh; ZBrush crashes when I try to remesh. I see where you say using Ctrl + Alt Drag subtracts the mesh; I have been using just Ctrl Drag. Do you have any problems subtracting if you just use Ctrl Drag? The documentation doesn’t seem to indicate needing to use Ctrl + Alt Drag. I’m using XP SP3; what are your system specs if you don’t mind sharing?
The crash aside, as someone else said, the process is exactly the same as with adding except you hold down Alt when you draw the insert obect. Once you’ve done that you can move it, size it etc. Then when you remesh (ctrl-click as normal) the mesh is subtracted.
Wow… you guys… that’s terrific help. Both Balbafu’s advice on the Subtract and DLangley’s on the SliceCurve were spot on and solved my problems. More Pixologic keyboard voodoo it seems. 
Unfortunately I cannot reciprocate with sound advice as I haven’t experienced any crashes when remeshing. The only semi-consistant crashes I’m getting are with Adaptive Skin previews on ZSpheres.
DLangley, I’m using Mac OSX 10.6.7 on a MacBook Pro with 8GB of ram. I left all the Mem and Performance preferences as default. Did you change them by any change? If so, maybe try returning them to defaults and see if that helps?
Thanks a lot for the help guys! 
The slice button works, but unless groups is pressed next to Dynamesh(as mentioned above), it wont update into separate “pieces”. It still divides the polygroups, though, which you can see if Polyframe is on.
Out of curiosity, has anyone gotten the “sub” button to do anything but add?
I’m aware you can hold down alt to make a negative mesh, and that works for subtracting, but from the description, it sounds like the Sub button is supposed to force subtractions with inserted meshes regardless of whether you alt-inserted them.
It doesn’t appear to be functional, if that is the case. If you alt-insert negative meshes it will subtract them, but then, so will regular old re-meshing. Despite the description, any positive meshes are just added like normal. The button appears to serve no purpose. Am I misunderstanding?
sub button double click when you want to add surface noise to dynamesh… it’s in the manual.
Does it work for you?
i found process for subtracting meshes to be like this.
hold down alt, when you are inserting mesh, so that ZB will take it as a mesh to be subtracted afterwards.
once you’ve drawn the inserted mesh, ZBrush will generate a mask so that you can move rotate modify the inserted mesh without interfering with main object.
once this done, just ctrl - drag once to clear any mask,
then ctrl - drag again to perform remesh, and ZB will cut into the main object using the inserted mesh.
you can also duplicate inserted meshes, using transpose and clicking ctrl when moving. once duplicated and remeshed, will cut them out of main object all at once.
hope this helps.
confusion comes from ctrl drag being the same process to clear the mesh and remesh for dynamesh.
Yes, I don’t think anyone has trouble remeshing with negative meshes, when alt-inserting them. I think the issue is with the “Sub” button, that doesn’t seem to do what is advertised. The description suggests it should subtract any inserted mesh regardless of whether it was designated negative.
Right now, it doesn’t seem to serve much purpose, other than being an alternate way to trigger a normal remesh.
Well … subtract does not seem to work with a custom made inserted mesh over here … ?
—> Create a custom insert brush —> ALT-drag it : the mesh to be sculpted is masked so you can edit the inserted mesh —> CTRL-click to clear mask —> CTRL- click to remesh —> then SUBTRACT works but on the INSERTED mesh : the inserted mesh becomes the remeshed mesh when it should be the non-inserted mesh that should be remeshed.
Anyone else noticed this?
SUBTRACT does work as I expected with the standard insert mesh brushes, but with a custom insert mesh brush SUBTRACT seems to inverse the order of the meshes?
(EDIT : Oh, and I just noticed that when inserting the NOSE with the InsertNose brush, the original mesh does not get masked. Maybe I should send Pixologic a bug report about that…)
(Edit 2 : Watch the videos of cannedmushrooms ( http://www.youtube.com/playlist?list=PL621AE72489A4A7C0 ) : when doing subtract operations it’s best to press the “ZSub” button in the menu instead of holding the ALT-key!)
Sub and And doesn’t seem to work here even with the standard insert brushes. It looks like add/subtract is set at the moment of the insert, so the only way to subtract I see is pressing ALT or having Zsub on when you insert the mesh.
I’m trying to subtract an inserted mesh and no matter what I try, it just adds. ALT, or sub don’t work. ALT does work on sculpting brushes so I know its not my keyboard 
El-d
as an addendum: the transpose / duplicate mesh with ALT does subtract the mesh.
1)In edit mode, Select Sphere primitive. Make Polymesh 3d
2)Turn on Dynamesh.
Insert sphere using insert sphere brush, while holding alt.
Hit Ctrl+Shift+A to clear mask, and then Ctrl -Drag in empty canvas (or simply Ctrl_drag twice…the first time will clear the mask, second will remesh)
done.
Doh! :o
I was just single dragging. … just got too excited with the new toys
Cheers.
El-d
My system (windows xp and 2 gig ram, single core amd 3700+ 2.7 GHz and service pack 3) crashes no matter what method I used for subtraction. It works just fine adding, but subtracting will cause it to crash every time. It says I’m out of memory. Does it really take that much more to subtract a simple object than adding it? Any ideas?
I can sub tracked any of the standard insert brushes (circle, cylinder etc), but when I use the brush with a custom brush, it seems to subtract the main mesh, from the inserted one. Do we have any ideas about this?
Gordon Robb : I can sub tracked any of the standard insert brushes (circle, cylinder etc), but when I use the brush with a custom brush, it seems to subtract the main mesh, from the inserted one. Do we have any ideas about this?
Exactly my experience …
Same problem 
Strange, but work if i save the brush and use it after restart zbrush
