A Voxel Re-mesh (to merge) in only a given area with selection tool or mask tool.
Reason: If you have a something you want to merge that is the same object. Like hands touching or holding your own heel, but you don’t want to lose any details in the face or hands etc. Doing a re-mesh all over. Will either result in a very high poly count or a loss of details where you need them.
Note: Made an edit. To describe the feature in a more clear way.
Hallo! This is a great idea, but then each quad should smoothly turn into two. It seems to me that this is already Autoretopology. Have you tried using the Boolean function to connect objects into one? It’s not as elegant, but it works for my purposes.
Hi. Really kind of you to show this 
. But it is not possible to do because it is the same object that I would like to merge. Maybe I explained the feature request badly. I made a small edit.
An example.
The first screenshot was the same but with her arm/ hand not in contact with her lap. (I can only attach one image as new user…)
Let’s say that the object was very large and the face was very detailed.
Then to merge the arm and hand with her lap. I would have to re-mesh and in doing so I would either end up with a very high poly count or I would have to lose the details in her face or other parts of the figure. This can be a very labor intensive task. I normally sculpt everything as one object including surroundings. Both because I prefer this look and because I used to sculpt with clay.
I hope this can explain my feature request in a better way. Being able to voxel re-mesh in only a selected area. Would in my case save me a lot of time and work.
If the arm and hand are separate objects then Boolean is the way to go. If they are the same object already (if I follow your explanation) then they don’t need merging.
Boolean merge allows you to join the objects without changing their detail 
Hi Bezzo.
I talk about the same object. Bear with me. 
I hope I can explain why I want to merge within the same object. The object could also be something else than an arm. Maybe a handle on a cup. That later had to be attached on both ends. Or just changing the figure/object. If one sculpt for video games. Each item would be is it’s own object. But when you sculpt artistic without perfection. Usally everything is in one piece like a block of Marble. Take the Eyes. With clay I would use an illusion by hollowing out the Iris and leave the pupil. Or I would carve out a very thin ring to make the Iris. Or simply leave it out.
I still do this in Nomad. 
But sculpting figures for games one would maybe make a sphear for both eyes and use color. The first might seem a little counter intuitive. But the feature would mean the world to me. Have you tried the app Putty3D on iPad ?. It is very basic I know. But it can do a few things that are different and that that most sculpting apps/ and software can’t do. Imagine sculpting the inside of a cut in half Swiss cheese. Adding and removing holes. That can maybe support my explanation. It is something that would be very hard to do with Nomad Sculpt but fairly easy with Putty3D. 
This impossible swiss cheese is made in Nomad……in 2 minutes……since your post. Note the different mesh densities, all in the same object simply booleaned together. I also have putty….waste of a purchase.
In your example above……I now realise what you’re chasing - simply split the arm off from the object and boolean the 2 objects back together
Not quite. 
But very impressive and fast. 
. Thank you.
I just took a Swiss cheese as an example. It could also be a cave. There need to be kind of small pillars that connect from above and bellow like a spider web. Or connected holes that move in and out of the cheese in a line that is not straight. It is those pillars that are hard to connect as they are the same object. That is why a feature to merge the same object in sellected area is useful.
With Putty3D the mesh/ clay attach itself when it is in contact with itself. Like real Clay. So I do not agree entirely with you. It has it’s own merit. But yes you can’t make finished and detailed work with Putty3D. But it is not entirely useless.
Here is an attachment it is not a very good looking cheese. 
So let’s say it is a cave with lots of ins and outs. 
Is this for 3D printing maybe? Why would you want those areas hidden inside the mesh? For a cave system in a game perhaps?? Boolean can do that - subtract / union / intersect.
All I am saying is that I think the tools are already there, you just have to use them correctly to achieve the end result.
Hi Bezzo.
It is great that we can have a discussion. I learn something.
I come from a more traditional background in sculpting and drawing. So that is why I prefer surfaces to stick together. If I was to sculpt a four legget animal that stood straight up. I would do it by making a cross in both directions with the trim tool and then shape the legs. I know that sounds silly. Why not attach and merge the ground to the legs after scupting the animal. ?. Maybe I would but not often. It is kind of like carving instead of adding. That is how I sculpt. Always with Dynamic typology on. I also never use symetry. Unless it is hard surface objects. But I have no doubt that you know Nomad better than I do. I could never make a cheese this fast. And I would love to see some of your work. I am still learning Nomad. But I do know how to sculpt. If you wish you can see what I do as I have a website. Maybe it will make a little better sense. It is just a feature I really need for the way that I use Nomad.
- subtract / union / intersect. I would guess you mean. subtracting a shape inside another shape
I think I got it:
You have one object. Two parts of that one object overlap. You want to merge the overlapping parts without having to remesh the whole thing, correct?
I think there is a way to do this which involves layers of masking areas, separating them, remeshing what’s needed, then merging the layers back together. The forget who did it but I’ll try to find the post.
Correct. It can be a huge problem. If I already made details on the face or on other parts of the object. The polygon count will be huge. As I often sculpt everything including the surroundings as one object.
Trying to keep a high polygon count in some places for details and low polygon count in other places is very tricky when you want to merge within the same object.
My M1 iPad Pro is already suffering. 
What you suggest seems like a workaround but a viable solution. Thank you so much for letting me know. I will cross my fingers and search for it as well.
Roger, over and out.