Is it possible to create a mesh that contains a named subdomain consisting of one vertex? I would like to set a “dirichlet” condition at a single vertex.
I already know how to take the BitArray of Freedofs and clear one bit to do this. That works fine. However, it would be nice to create a (surface) mesh that has a specific point as a vertex in it. And to “name” that vertex so that I could impose it as a dirichlet condition, possibly using bbnd_dirichlet=“name”, or maybe it should be bbbnd_dirichlet=“name”, within the definition of the finite element space. Is this possible?
p.s. This is not for a 2nd order elliptic problem. I know that setting point conditions can be problematic there.
You name vertices in the OCC - geometry, and then you can ask for mesh.GetBBBoundaries(), and mesh.BBBoundaries(“V1”), and the bbbnd_dirichlet works as well.
Ok, but suppose I want a sphere surface mesh (radius=1, centered at origin), and I want (0,0,1) to be a vertex in the mesh that gets generated. Can I still do that? The example above seems to imply that the only available vertices are the corners of the box.
and it does create a vertex labeled “P0”. But when I look at the coordinates of that point, it is NOT (0.3, 0.5, z0). Not even close. Is it possible to force that point to be a vertex in the mesh?
Just to recap, I have tried creating a 3-D box mesh with a diagonal line segment “glued” to it. When I draw the shape, I can see that line segment. But the generated mesh does not conform to it.
So this feature is not implemented, right? You can’t force netgen to create a mesh that conforms to a given vertex or line segment (in 3-D for instance). I just want to be sure I’m not missing something.
p.s. I know you can have embedded subdomains (of the same dimension) with a conforming mesh. I have seen that example.