Set Meshing Options with Python?

Hello,

I am new to Netget/NGSolve.

I hope you guys can help me, here the manual way I do:

I load a new Geometry into NGSolve.
After that I navigate into "Meshing options..." select "Mash granularity=very coarse" after that under "Mesh Size/Elements per curv...radius" I switch it to the value 5.

After that "Export Mesh" to a *.STL file.

that works fine, but I need to do this automaticly.

I allready wrote a little phyton file:

from netgen.NgOCC import *
from ngsolve import *

geo = LoadOCCGeometry('Part.stp')
mesh = geo.GenerateMesh()
Draw(Mesh(mesh))
# mesh.Export('Part2.stl','STL Format')


But I do not have any idea how I can set the "meshing options" first?

Anyone can help?

thanks much,
regards, mario

no one any idea?

Hi Mario,

There are arguments you can pass to the GenerateMesh() function to control the meshing algorithms. For your case, try the following code
Best,
Matthias

thx much for your answer, but it does not generate a mesh:

from netgen.NgOCC import *
geo = LoadOCCGeometry('Part.stp')

from netgen.meshing import MeshingParameters, meshsize
mesh = geo.GenerateMesh(meshsize.very_coarse, curvaturesafety=5)
Draw(Mesh(mesh))

it just shows me the Part.stp in the GUI, but not the generated mesh.

what wrong with this?

regards, mario

This comes from the console:

NETGEN-6.2-dev
Developed by Joachim Schoeberl at
2010-xxxx Vienna University of Technology
2006-2010 RWTH Aachen University
1996-2006 Johannes Kepler University Linz
Including OpenCascade geometry kernel
optfile ./ng.opt does not exist - using default values
togl-version : 2
OCC module loaded
loading ngsolve library
NGSolve-6.2.1905
Using Lapack
Including sparse direct solver Pardiso
Including sparse direct solver UMFPACK
Running parallel using 6 thread(s)
importing NGSolve-6.2.1905
(should) load python file 'Skript.py'
load OCC geometry Number of colours in STEP File: 1
Colour [1] = STEELBLUE3 : (0.380392,0.576471,0.752941)
Highest entry in topology hierarchy:
1 solid(s)
Traceback (most recent call last):
File "<string>", line 4, in <module>
ImportError: cannot import name 'meshsize' from 'netgen.meshing' (C:\Program Files\ngsolve-v6.2.1905\lib\site-packages\netgen\meshing.py)
Finished executing Skript.py
Preparing visualization (deflection = 0.01) ... done

Seems your version of NGSolve is outdated (19.05), I suggest you download a recent version. Note that you might also need to update Python to 3.7.

Best,
Matthias