Hi Mary,
you can do the meshing from python:
Code:
from netgen.stl import STLGeometry
from ngsolve import *
geo = STLGeometry(filename)
mesh = Mesh(geo.GenerateMesh(maxh=, ..., perfstepsend=MeshingStep.MESHSURFACE) )
this also only meshes the surface and no volume. To do this in the gui you can select meshing options -> Last Step -> Optimize Surface.
you can also load generated meshes, but the stl geometry is not stored with the mesh, so for example curving or refinement (that respects the true geometry) would not work, to allow this as well set the geometry:
Code:
mesh = Mesh(meshfile)
geo = STLGeometry(geofile)
mesh.ngmesh.SetGeometry(geo)
Best
Christopher