Re: [Libmesh-users] [RE]Re: [RB] How to obtain subdomain information from nodes

[Roy S. <roy...@ic...>]

On Tue, 20 Mar 2018, David Knezevic wrote:

> No, you should not have to redefine anything. If you're using Trelis, then
> define the subdomains by defining "blocks" in an ExodusII mesh, and they
> will be read into libMesh and stored as subdomain_ids. You should not have
> to change node numbers. In general your code should not care what the node
> numbering is.

Although I usually strongly agree with that last statement, I should
point out that there are people who disagree, and that at least 1% of
the time they're correct, so we do have some facility in libMesh for
accommodating such codes.  If you set mesh.allow_renumbering(false),
*before* calling mesh.read(whatever), then we'll respect the numbering
in the mesh file, even after adaptive refinement, at what I believe is
only a slight performance hit.
---
Roy