Fem: Add preference entry to set Netgen number of threads

src/Mod/Fem/Gui/Resources/ui/DlgSettingsNetgen.ui

@@ -79,6 +79,32 @@
           </property>
          </widget>
         </item>
+        <item row="1" column="0">
+         <widget class="QLabel" name="lbl_threads">
+          <property name="text">
+           <string>Number of threads</string>
+          </property>
+         </widget>
+        </item>
+        <item row="1" column="1">
+         <widget class="Gui::PrefSpinBox" name="sb_threads">
+          <property name="alignment">
+           <set>Qt::AlignLeft|Qt::AlignTrailing|Qt::AlignVCenter</set>
+          </property>
+          <property name="toolTip">
+           <string>Number of threads used for meshing</string>
+          </property>
+          <property name="minimum">
+           <number>1</number>
+          </property>
+          <property name="prefEntry" stdset="0">
+           <cstring>NumOfThreads</cstring>
+          </property>
+          <property name="prefPath" stdset="0">
+           <cstring>Mod/Fem/Netgen</cstring>
+          </property>
+         </widget>
+        </item>
        </layout>
       </item>
      </layout>
@@ -99,6 +125,11 @@
    <extends>QCheckBox</extends>
    <header>Gui/PrefWidgets.h</header>
   </customwidget>
+  <customwidget>
+   <class>Gui::PrefSpinBox</class>
+   <extends>QSpinBox</extends>
+   <header>Gui/PrefWidgets.h</header>
+  </customwidget>
  </customwidgets>
  <resources/>
  <connections/>

src/Mod/Fem/femmesh/netgentools.py

@@ -29,7 +29,7 @@ import numpy as np
 import shutil
 import sys
 import tempfile
-from PySide.QtCore import QProcess
+from PySide.QtCore import QProcess, QThread
 
 import FreeCAD
 import Fem
@@ -84,6 +84,7 @@ class NetgenTools:
         self.tmpdir = ""
         self.process = QProcess()
         self.mesh_params = {}
+        self.param_grp = FreeCAD.ParamGet("User parameter:BaseApp/Preferences/Mod/Fem/Netgen")
 
     def write_geom(self):
         if not self.tmpdir:
@@ -101,17 +102,16 @@ class NetgenTools:
 
     def prepare(self):
         self.write_geom()
-        grp = FreeCAD.ParamGet("User parameter:BaseApp/Preferences/Mod/Fem/Netgen")
         self.mesh_params = {
             "brep_file": self.brep_file,
-            "threads": self.obj.Threads,
+            "threads": self.param_grp.GetInt("NumOfThreads", QThread.idealThreadCount()),
             "heal": self.obj.HealShape,
             "params": self.get_meshing_parameters(),
             "second_order": self.obj.SecondOrder,
             "second_order_linear": self.obj.SecondOrderLinear,
             "result_file": self.result_file,
             "mesh_region": self.get_mesh_region(),
-            "verbosity": grp.GetInt("LogVerbosity", 2),
+            "verbosity": self.param_grp.GetInt("LogVerbosity", 2),
         }
 
         with open(self.script_file, "w") as file:
@@ -319,7 +319,7 @@ run_netgen(**{kwds})
             "inverttrigs": self.obj.InvertTrigs,
             "autozrefine": self.obj.AutoZRefine,
             "parallel_meshing": self.obj.ParallelMeshing,
-            "nthreads": self.obj.Threads,
+            "nthreads": self.param_grp.GetInt("NumOfThreads", QThread.idealThreadCount()),
             "closeedgefac": self.obj.CloseEdgeFactor,
         }
 

src/Mod/Fem/femobjects/mesh_netgen.py

@@ -485,15 +485,6 @@ class MeshNetgen(base_fempythonobject.BaseFemPythonObject):
                 value=True,
             )
         )
-        prop.append(
-            _PropHelper(
-                type="App::PropertyInteger",
-                name="Threads",
-                group="Mesh Parameters",
-                doc="Number of threads for parallel meshing",
-                value=4,
-            )
-        )
         prop.append(
             _PropHelper(
                 type="App::PropertyBool",

src/Mod/Fem/fempreferencepages/dlg_settings_netgen.py

@@ -25,6 +25,8 @@ __title__ = "Netgen preference page class"
 __author__ = "Mario Passaglia"
 __url__ = "https://www.freecad.org"
 
+from PySide.QtCore import QThread
+
 import FreeCAD
 import FreeCADGui
 
@@ -37,11 +39,13 @@ class DlgSettingsNetgen:
 
     def loadSettings(self):
         self.form.ckb_legacy.setChecked(self.grp.GetBool("UseLegacyNetgen", True))
+        self.form.sb_threads.setValue(self.grp.GetInt("NumOfThreads", QThread.idealThreadCount()))
         self.populate_log_verbosity()
 
     def saveSettings(self):
         self.grp.SetBool("UseLegacyNetgen", self.form.ckb_legacy.isChecked())
         self.grp.SetInt("LogVerbosity", self.form.cb_log_verbosity.currentData())
+        self.grp.SetInt("NumOfThreads", self.form.sb_threads.value())
 
     def populate_log_verbosity(self):
         values = {