Extend Mesh

[pmueller2]

If you import a mesh from Gmsh you get a MeshGmsh object that saves beside a mesh also some Groups of ElementCollections (corresponding to Gmsh physical groups). I really like that feature and I think this is not related to Gmsh but should belong to our or an extended mesh class.

What do you think?

[TTitscher]

I like the idea of the extended mesh. But I am not sure, if that should be another class or not. I always like the separation. On the one hand, the user can choose his includes. E.g. UnitMesh? #include <.../UnitMeshFem.h> Gmsh? #include <.../MeshGmsh.h> And maybe now: #include <.../MeshFemCompanion.h>? :smile: On the user hand, the user has to know that something like that exists beside the mesh.

Features could include:

• keep track of groups
• efficient node selection (based on spatial data structures)
• additional infos (that are commonly requested) like
  • meshCompanion.DofValueAt(Eigen::Vector(42, 12), displacement);
  • meshCompanion.DofValueAt(node, displacement);
• (Maybe even perform NodeMerge/Extract?)

[vhirtham]

Maybe even perform NodeMerge/Extract

Yes please. A function that spits out a Eigen::MatrixXd containing the correctly ordered dof values would be really nice and saves the "user" 2 additional conversion steps:

• Merger.Extract -> ToEigen
• FromEigen -> Merger.Merge