Add more options for assigning subdomains #32456
Description
Motivation
When 'flooding' elements (see the new SurfaceMeshGeneratorBase flood operation introduced in #32390), it's quite natural to use subdomains to limit the extent of the flooding operations.
But right now we essentially mostly have an "analytic" / parsed expression way of setting subdomain IDs.
It would be better to have more options such as:
- do a first round of 'flooding' to assign subdomain IDs
- use the partitioner to assign subdomain IDs
- ...
if any other technique comes to mind? Please let us know here
Design
Add a SubdomainsFromPartitionerGenerator
Add a flooding MG that can assign subdomains
Impact
More flexibility in mesh generation
Support ongoing research projects