Fixed. The extracted object is not masked anymore.
@Iceking I noticed you changed the forum topic. The ‘master’ is not necessary - its just something github appended because its a zip of the master branch. The addon is just named Sculpt Tools 
Woah, that was fast! Thanks!
Here’s a short demo of the addon:
Very cool demo video, thanks for making it!
Did you know you can use F6 to call up the redo menu and adjust your mask extraction parameters after the fact? The same menu normally appears in operator settings at the bottom of the toolbar but I see you have that hidden. (Unfortunately I can’t trigger the redo by adjusting the values in the sculpt tools panel itself, there are no callbacks available for python addons.)
By the way, since there’s the redo panel, the values in the ui are pretty redundant, and it’s not really the blender way of doing things. Do you think I should remove them?
Also worth noting is that it will work with multires and use the ‘preview’ resolution for the extraction (otherwise it would probably be too slow on heavy meshes). Though of course, the extracted mesh won’t be a multires mesh itself.
I cant seem to find the loop select mask tool? Can someone help me find it.
Loop-select-mask? I haven’t heard of anything like it. The name doesn’t make any sense to me either. What is it you want to do?
Edit: Oh. You mean the lasso select tool. It’s Ctrl-Shift-LMB, but you’ll need a build r61002 or newer.
Sorry I meant lasso select mask
Hi Piotr!
It didn’t occur to me to try that, I keep forgetting about f6 in general.
But it’s great! And you can just adjust the settings after doing the extraction, way better than guessing and trying. I’ll have to do another video. 
Yes, this makes the values on the panel a bit redundant. Seems ok to remove them, and we make the panel a bit smaller that way too.
Oh, and it’s great you got it to work with multires! Ian’s extract was dyntopo only and I didn’t think of trying.
Ok then, I’ve removed the redundant sliders
Yep, I used to forget about f6 too, but it’s pretty important functionality for Blender actually, so I bound it to the spacebar instead (I very rarely use search). Best keymap change I ever did.
Lasso mask?
Look 5 posts up.
Brilliant i missed the edit, Thanks
hi piotr, it seems it is a problem with the new mac versions of blender, maybe this info helps?
Not really, since i have no mac to test on. Tomorrow I’ll try to go through the commit logs and maybe find something mac related between now and 2.68 that would explain it. I wouldnt get my hopes up though. If it works on windows but not on mac then its a bug in blender and could be anywhere.
Hello, guys!
Can you make this great addon up to date? I’ve tested it with Blender 2.69.2 r61195 and it works. It wasn’t smooth
for the 1st time but after “Load Factory Settings” it started to work. I think it’s due to some issues with key bindings.
Generally it works… But when I’ve made a cut on a 1st mesh and then created 2nd mesh - it stops here. Applying scale, position and boolean union doesn’t help.
1st test is SculptUI_GreaseCut_Test1.blend (84.5 KB)
Then I’ve tried r60379. It seems to work a bit better… But still after some stage I’ve got some similar problem.
It can be tried from the 2nd test:
SculptUI_GreaseCut_Test2.blend (93.6 KB)
The tool is VERY great and I see it’s large potential even in it’s Python form and even without curves support.
IMHO it just ought to be updated to the last API changes and bug fixed (more stable is cooler than with a lot of
new features).
Thank you!
I’ve found why it’s not cutting in my cases! If you’ll be too close to the object (if a mesh is not fully in 3d view) then it will not cut.
So more precise strokes can be created closely but any cut operation must be performed when the whole mesh is inside 3d view borders.
Is it a limitation?
I found a way to make the border smooth and clean for hard surface
- first design the shape you want with the mask tool
1- extract the mesh with the flat option for better result
2- select the extracted mesh and enter edit mode
3- in face mode select all the face and add an inset operation like in the image #3
4- select all face and add an smooth operation 5 interaction image#5
6- with the mesh still selected add a LapRelax addons from paleajed apply various time after you are satisfying with the result this addons relax and distribute the geometry and keep the volume and border intact…
7- with the mesh still select add a solidify operation as you like image #8
8- in face mode select all face loop border and add a new material image#9
10- select by material all border this will act like polygroups in zbrush
11- add an inset operation to the selected border like image #11 [ optional ]
12- another inset [ optional ]
13- final result
Again, this is iceking’s code, not mine, but it’s certainly a useful clue, thanks.
Edit: just tested it, and it doesn’t seem to matter for me. Cuts fine either way.
I’m thinking you guys might be having problems because you’re forgetting to place the cursor anywhere near the cut. By default the cursor position determines the depth at which the grease pencil stroke will appear and should be somewhere near the cut area.
Cool beans. I’m considering various options to make the edges smoother, but so far haven’t found one that also works well with very irregular topology like with dyntopo - tiny triangles in one place, huge ones in another.
you can try adding and edge loop around the generate mesh like in zbrush loop and polish feature
Yeah, I get it’s Iceking’s code 
I was testing with different Cursor’s positions and I always place it in the closest point from the view before start GP drawing. So a cutting surface (probably) isn’t starting in a body. I practically understand how it works with Booleans. Don’t know… maybe it’s some option in Prefs that limits it with 3d view.
Hi, Iceking!
Is it possible to do the Grease cut here?
AlienBike_Concept1.blend (372 KB)
Exactly in this projection like I’ve set it.
I’ve made some cuts from the side then I’ve remeshed it then sculpted some details then remeshed again.
Now from side view it’s cutting but from this (front view, but it’s Back for Blender) view - can not. It tried but in Delete Outer it just leaves the intersecting surface. The right choice doesn’t work at all. What can be a reason? Cursor is in the place, seems that everything is fine.
Oh, I see! The generated surface wasn’t long enough!
Please, can you add some code lines that will get a size of a working mesh + a distance to Cursor and will send this measure to the algorithm so it will be always enough to cut through. Am I getting right the idea?