Re: [Libmesh-users] Reading Mesh produced from Gmsh to use as as Unstructured Mesh--Higher Order Elements?

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

On Wed, 22 Nov 2017, Zack Vitoh wrote:

>  GmshIO gmsh_io(mesh);
>  gmsh_io.read("disk.vtu");
>
> but--and I am not sure if this is possible--imposing additional nodes on
> each element generated in the triangularization generated by gmsh with
> nodes such that I have, say, Tri6 elements.

You have Tri3 elements now?  After the read calling
mesh.all_second_order();
will turn them into Tri6 elements.

> Is this possible through libmesh, or something I would I have to do
> something in gmsh instead?

I'm afraid if you have a disk then this is something you *should* do
in gmsh instead if that's possible.  By the time libMesh reads a
first-order triangulation, curvature information has been discarded,
and we don't try to reconstruct it, so you'll still get straight-sided
elements rather than curved-sided elements.  The only way to get the
best second-order boundary geometry is to patch it up manually,
looping over boundary nodes and "snapping" them to the curve where you
know they should be.
---
Roy