Does anyone know how to mask on one side of an object only? i.e on a plane if you hold down CTRL and spray on a mask, both sides are masked and boths sides are then extracted with extract mesh. I only one one side masked.
I guess thats a basic one 
No worries - just go to transform and there you need to turn off symetry [you can see letters X Y Z M R - those are used to turn on and off symetry. Turn off all of them and you can draw whatever you want. When You turn one one of them and try to draw you will surely see whats this option doing. M is a “mirror symetry” and is working in connection with others. R is “radial”. Just play with those options and You can surely see what they do.
Hope I can be of any help
I have a very thin object that I’m trying to mask. It has nothing to do with symetry. I’m talking about the front of the object and the back of the object. This only happens on really thin parts too. I can’t get it to mask just the front side without it affecting the other side. It must be because it is too thin and it goes right through to the other side.
Any help would be appreciated. Thanks.
Same problem here.
I have some really thin dragon wings… masking the front also masks the back.
And sculpting the front also sculpts the back, (but it’s inverted - zadd on the front is essentially a slightly weaker zsub on the back). Same thing happens when sculpting with alphas.
And in some cases, the object doesn’t have to be that thin to be affected. When sculpting scales on the front of my dragon arm (such as the bicep area, not that thin), the back of the arm would also be affected (again, inverted).
The sculpting brush is drawn as a circle, but is actually a sphere. Anything within the sphere will be effected, unless masked off.
If your thin geometry was derived from a mesh extraction, turning on the polyframe will show that the extracted mesh actually has three groups. (More, if the source model had multiple groups.) There’s an outside, sides, and an inside. Combined with the partial mesh visibility tools, it’s very easy to hide one side and then mask everything else. You can then unhide the mesh and sculpt without affecting the opposite side.
Aaaaaaaah (as in “oooooooh”, not as in screaming) that makes sense.
So, when applying alphas with the dragrect stroke, it is also creating a “sphere of influence” based on the size of the rectangle you drag (?)… hmmm.
Is that also why the flatten brush can cause some unpredictable results on the “other side” of meshes… or why the Zproject brush can adversely affect the other side of a mesh… it’s all beginning to click in my head.
I guess the solution for my dragon wings, would be to import a one sided mesh, extract, and then use the polygroups to hide/isolate sections.
Thank you. That helps me undestand it a lot more. I had a question about what you mentioned.
“Combined with the partial mesh visibility tools”
I’m new to this so where are the partial mesh visibility tools?
Thanks.
They allow you to hide parts of the mesh.
- Ctrl+Shift+Drag creates a green bounding box. Anything within that box when you release the mouse button will be visible, and anything not within it will be hidden.
- Doing the above, but releasing Ctrl or Shift during the drag will turn the box red instead. Anything inside the box will be hidden when you release the mouse.
- Ctrl+Shift+Click on a vertex in your model will hide everything except the polygons belonging to that vertex’s group.
- If a mesh is already partially hidden, then Ctrl+Shift+Click will hide the polygons belonging to that group.
- Ctrl+Shift+Click on a blank part of the canvas restores full visibility.
- Ctrl+Shift+Drag on a blank part of the canvas without selecting any points within the box will invert visibility.
- Transform>Lasso works like 1 and 2 above, but drags a selection lasso instead of a box.
When dragging selections, ZBrush by default uses a dynamic routine to determine what will be selected. It first looks to see if any complete polygons are within the selection area. If yes, then it will only affect complete polygons. Polygons that are only partially within the selection area will be ignored. If no complete polys are found, then it will affect all polygons that have at least one point in the selection area. You can override the first part of this behavior by turning on Transform>Pt Sel. This tells ZBrush to simply look for points, and affect any polygon that has one or more points in the selection area.
I am looking to create a mask of couple of circles on a cylinder. These will form the top of the points of a crown.
I have radial symmetry turned on, and am using mask circle, with the circle stroke turned on.
even if I start near the middle of the cylinder for my circle it still seems to be projecting this through to the other side of the cylinder.
I want to draw only the same number of masked circles as my radial amount, not double (the radial + the reverse projected mirrored!)
The circle is way smaller then the diameter of the cylidar, so my globe cant be hitting the other side.
Any help would be appreciated!
Note: Edited to correct my explanation of the process for beginners who might try this. Below I stated after making polygroups to delete the top, bottom and BACK, leaving you with a cylinder. There would only be a “back” to delete if you start with an open tube/cylinder form. With a primitive cylinder there is no backing to delete. I hope that this is a clarification and not more confusing.
Cynwolf, I think you would do better by using “mask by alpha” in the mask subpalette of the tools palette. Play around with the Horizontal tiling in the alpha menu to get the number of radial repeats you need and then apply the mask as I described. You may need to play around a bit with the vertical tiling or the mask itself to get the position exactly as you need it, as well as later 
applying a rectangle drag mask to the bottom to mask.
I’d start by taking a cylinder and (ctl shift) hiding the top and bottom edge, then using the autogroup feature in the polygroup subpalette.
Then I’d click to hide the edges and back polygroups and “delete hidden” in the geometery subpalette.
I’d mask what remains with the mask by alpha feature described above and use additional drawn or rectangle select masking to perfect my crown. then I’d select “make polygroups from masking”.
I’d once again hide/delete the parts I don’t want.
Finally I’d mask it all and in the subtools palette set my desired thickness and “extract” the final form via the subtools palette.
Disclaimer: I’m famous for “complicating a ham sammich”, so there may be a quicker, better way, but this works for me!
Thanks Nancyan,
It worked perfectly for me, great tip - I really appreciate you taking the time to respond to my query.
Thanks!