Problems visualizing mesh after importing and meshing a step file with netgengui


I have a problem with the Netgen.gui() when importing and meshing a step file. I can import the geometry with OCCGeometry() and generate the mesh with GenerateMesh(), but when I use netgen.gui to look at the mesh and geometry, I can’t see the mesh, only the geometry. If I use “Generate Mesh” from netgen.gui(), then the mesh is shown to me normally.

I also tested this with the webgui in a jupyternotebook and there are no problems. I am able to draw the mesh without any issues.

The question is if it is a bug of the netgen.gui, because it works fine with the webgui, or do I do something wrong when creating geometry, mesh and Draw(mesh)?

Here is a minimal example where I use the netgen.gui which is called from a tkinter app:

import tkinter as tk
from tkinter import ttk

root = tk.Tk()

main_frame = tk.Frame(master=root)
main_frame.pack(fill=“both”, expand=True)

button = ttk.Button(master=main_frame, command=lambda: mesh_and_draw(), text=“netgen.gui”)

def mesh_and_draw():

import netgen.occ

geo = netgen.occ.OCCGeometry('path_to_file/file.stp')
mesh = geo.GenerateMesh(maxh=2.0)

from ngsolve import Draw, Mesh
mesh_ = Mesh(mesh)

import netgen.gui


Here is a minimal example where I use the webgui:

import netgen.occ
from ngsolve import Mesh
from ngsolve.webgui import Draw

geo = netgen.occ.OCCGeometry(‘path_to_file/file.stp’)
mesh = geo.GenerateMesh(maxh=2.0)


I hope someone can say something about this and thanks in advance.