How do I get an object to react to changes to the beneath it?

I am trying to use blender for virtual surgical planning. What I am trying to ddo is to make this soft tissue mask react to changes to the bone. As you can see, it already does it to some extent, but I need to go even further (this rig is done automatically by an addon). I want for it to react to changes on specific places, like if I sculpt a 10 mm protuberance on the bone, then the soft tissue would also react by going 10 mm outwards.

Exemple: if I do a sculp like this on the bone, then the mask would deform only on the part.

I made a video so its easier to understand: https://streamable.com/7h7xcw

Hello and welcome here !

Well good news is that there are different ways to approach this and improve your setup, bad news is that none of these is straightforward to explain and it might be a bit tricky to drive you through it if a forum’s written form. It’s basically advanced stuff…

Anyway, you can in one hand learn about various deformation techniques :
Lattice, Surface Deform, Mesh Deform, Displace…
There are others but at least they should give you different type of deformations , from very broad ones like lattices and much fine narrow deformations like with displace.

Geometry nodes is also very helpful to create custom deformations but there is a learning curve…

Then you should also consider to have a baseline and a deformed object for the sculpt, so it’s possible to extract the deformation and apply it to the target mesh (skin)…

Anyway, it’s just a lot information thrown in the air… If you have time study these different points separately and then see how they can apply to your case.
In general what works best on forums is to provide a simple example scene (.blend) that describes well your issue and then see if someone is willing to solve your problem.

If you don’t have much time to look into that I suggest you to find a blender technical artist near you that can look closely at your problem and provide technical solutions / tools and so on… So you can focus more on practical aspect of the tool rather than solving tech stuff…

Anyway, happy to discuss that further, but ATM it’s hard to see were to start here :slight_smile: