3D curved mesh questions

Dear all,

I want to mesh a unit sphere as you will find in the attached file and have the following two questions:

The parameter N is supposed to control the mesh size.
However, it does only have an effect if N>4.
For N<=4, the mesh is always the same.
How can I obtain a coarser mesh for the sphere?

When curving the mesh as in the script, I can attach a parameter, in this case 3.
Does this simply mean that I'm going to obtain a third-order accurate approximation of the sphere surface?

Thanks, Philipp

Hi Philip,

you can use the following arguments to obtain a coarser mesh:

geo.GenerateMesh(maxh=1000, curvaturesafety=0.7)

maxh is the global maximal mesh size. Depending on the curvature of the geometry, the mesh-size is locally reduced. curvaturesafetry=x sets a mesh-size to x*curvature-radius.

Not all parameters of the Netgen-gui are ported to python. You can check the available arguments and default values via

>>> from netgen.meshing import MeshingParameters
>>> help (MeshingParameters)


Yes, you are right. mesh.Curve(3) computes a third order geometry approximation. For this we use Demkowizc-style "projection-based interpolation".

Best,
Joachim

Thank you very much, Joachim!
Best, Philipp