Enable FreeCAD to generate mesh in different formats

src/Mod/Fem/App/FemMesh.cpp

@@ -142,6 +142,7 @@ FemMesh& FemMesh::operator=(const FemMesh& mesh)
 void FemMesh::copyMeshData(const FemMesh& mesh)
 {
     _Mtrx = mesh._Mtrx;
+    _FileExt = mesh._FileExt;
 
     // See file SMESH_I/SMESH_Gen_i.cxx in the git repo of smesh at
     // https://git.salome-platform.org
@@ -1879,6 +1880,44 @@ void FemMesh::readZ88(const std::string& FileName)
                         Base::TimeElapsed::diffTimeF(Start, Base::TimeElapsed()));
 }
 
+void FemMesh::readMsh(const std::string& FileName)
+{
+    Base::TimeElapsed Start;
+    Base::Console().Log("Start: FemMesh::readMsh() =================================\n");
+
+
+    Base::FileInfo File(FileName);
+    _FileExt = File.extension();
+
+    PyObject* module = PyImport_ImportModule("feminout.importMshMesh");
+    if (!module) {
+        return;
+    }
+    try {
+        Py::Module mshmod(module, true);
+        Py::Callable method(mshmod.getAttr("read"));
+        Py::Tuple args(1);
+        args.setItem(0, Py::String(FileName));
+        Py::Object mesh(method.apply(args));
+        if (PyObject_TypeCheck(mesh.ptr(), &FemMeshPy::Type)) {
+            FemMeshPy* fempy = static_cast<FemMeshPy*>(mesh.ptr());
+            FemMesh* fem = fempy->getFemMeshPtr();
+            *this = *fem;  // the deep copy should be avoided, a pointer swap method could be
+                           // implemented see
+                           // https://forum.freecad.org/viewtopic.php?f=10&t=31999&start=10#p274241
+        }
+        else {
+            throw Base::FileException("Problems reading file");
+        }
+    }
+    catch (Py::Exception& e) {
+        e.clear();
+    }
+    Base::Console().Log("    %f: Done \n",
+                        Base::TimeElapsed::diffTimeF(Start, Base::TimeElapsed()));
+}
+
+
 void FemMesh::read(const char* FileName)
 {
     Base::FileInfo File(FileName);
@@ -1924,9 +1963,15 @@ void FemMesh::read(const char* FileName)
         // read Z88 mesh file
         readZ88(File.filePath());
     }
+    else if (File.hasExtension("msh")) {
+        // read .msh mesh file
+        readMsh(File.filePath());
+    }
     else {
         throw Base::FileException("Unknown extension");
     }
+
+    _FileExt = File.extension();
 }
 
 void FemMesh::writeABAQUS(const std::string& Filename,
@@ -2562,10 +2607,20 @@ unsigned int FemMesh::getMemSize() const
 
 void FemMesh::Save(Base::Writer& writer) const
 {
+    std::string filename;
+
+    if (_FileExt.empty()) {
+        filename = "FemMesh.unv";
+    }
+    else {
+        filename = "FemMesh." + _FileExt;
+    }
+
+
     if (!writer.isForceXML()) {
         // See SaveDocFile(), RestoreDocFile()
         writer.Stream() << writer.ind() << "<FemMesh file=\"";
-        writer.Stream() << writer.addFile("FemMesh.unv", this) << "\"";
+        writer.Stream() << writer.addFile(filename.c_str(), this) << "\"";
         writer.Stream() << " a11=\"" << _Mtrx[0][0] << "\" a12=\"" << _Mtrx[0][1] << "\" a13=\""
                         << _Mtrx[0][2] << "\" a14=\"" << _Mtrx[0][3] << "\"";
         writer.Stream() << " a21=\"" << _Mtrx[1][0] << "\" a22=\"" << _Mtrx[1][1] << "\" a23=\""

src/Mod/Fem/App/FemMesh.h

@@ -215,11 +215,13 @@ class FemExport FemMesh: public Data::ComplexGeoData
     void readNastran95(const std::string& Filename);
     void readZ88(const std::string& Filename);
     void readAbaqus(const std::string& Filename);
+    void readMsh(const std::string& Filename);
 
 private:
     /// positioning matrix
     Base::Matrix4D _Mtrx;
     SMESH_Mesh* myMesh;
+    std::string _FileExt;
 
     std::list<SMESH_HypothesisPtr> hypoth;
     static SMESH_Gen* _mesh_gen;

src/Mod/Fem/CMakeLists.txt

@@ -147,6 +147,7 @@ SET(FemInOut_SRCS
     feminout/importCcxFrdResults.py
     feminout/importFenicsMesh.py
     feminout/importInpMesh.py
+    feminout/importMshMesh.py
     feminout/importPyMesh.py
     feminout/importToolsFem.py
     feminout/importVTKResults.py
@@ -399,6 +400,8 @@ SET(FemTestsMesh_SRCS
     femtest/data/mesh/tetra10_mesh.vtk
     femtest/data/mesh/tetra10_mesh.yml
     femtest/data/mesh/tetra10_mesh.z88
+    femtest/data/mesh/tetra10_mesh.msh
+    femtest/data/mesh/beam_mesh.msh
 )
 
 SET(FemTestsMystran_SRCS

src/Mod/Fem/Gui/DlgSettingsFemGmsh.ui

@@ -106,6 +106,52 @@
           </property>
          </widget>
         </item>
+        <item row="2" column="0">
+         <widget class="QLabel" name="l_mesh_file_format">
+          <property name="text">
+           <string>Mesh format</string>
+          </property>
+         </widget>
+        </item>
+        <item row="2" column="1">
+         <widget class="Gui::PrefComboBox" name="cb_mesh_file_format">
+          <property name="minimumSize">
+           <size>
+            <width>148</width>
+            <height>0</height>
+           </size>
+          </property>
+          <property name="toolTip">
+           <string>Enter the mesh file format</string>
+          </property>
+          <property name="prefEntry" stdset="0">
+           <cstring>MeshFileFormat</cstring>
+          </property>
+          <property name="prefPath" stdset="0">
+           <cstring>Mod/Fem/Gmsh</cstring>
+          </property>
+          <item>
+           <property name="text">
+            <string>.unv</string>
+           </property>
+          </item>
+          <item>
+           <property name="text">
+            <string>.vtk</string>
+           </property>
+           </item>
+          <item>
+           <property name="text">
+            <string>.inp</string>
+           </property>
+           </item>
+           <item>
+           <property name="text">
+            <string>.msh</string>
+           </property>
+           </item>
+         </widget>
+        </item>
        </layout>
       </item>
      </layout>
@@ -143,6 +189,11 @@
    <extends>QCheckBox</extends>
    <header>Gui/PrefWidgets.h</header>
   </customwidget>
+  <customwidget>
+   <class>Gui::PrefComboBox</class>
+   <extends>QComboBox</extends>
+   <header>Gui/PrefWidgets.h</header>
+  </customwidget>
  </customwidgets>
  <resources>
   <include location="Resources/Fem.qrc"/>

src/Mod/Fem/Gui/DlgSettingsFemGmshImp.cpp

@@ -26,10 +26,11 @@
 #ifndef _PreComp_
 #include <QMessageBox>
 #endif
-
+#include <App/Application.h>
 #include "DlgSettingsFemGmshImp.h"
 #include "ui_DlgSettingsFemGmsh.h"
-
+#include <App/Application.h>
+#include <Base/Console.h>
 
 using namespace FemGui;
 
@@ -49,14 +50,41 @@ DlgSettingsFemGmshImp::~DlgSettingsFemGmshImp() = default;
 
 void DlgSettingsFemGmshImp::saveSettings()
 {
+
     ui->cb_gmsh_binary_std->onSave();
     ui->fc_gmsh_binary_path->onSave();
+    ui->cb_mesh_file_format->onSave();
+
+    ParameterGrp::handle hGrp = App::GetApplication().GetParameterGroupByPath(
+        "User parameter:BaseApp/Preferences/Mod/Fem/Gmsh");
+    std::string meshFormats[] = {".unv", ".vtk", ".inp", ".msh"};
+    int ind = ui->cb_mesh_file_format->currentIndex();
+    hGrp->SetASCII("MeshFileFormat", meshFormats[ind]);
 }
 
 void DlgSettingsFemGmshImp::loadSettings()
 {
+    ParameterGrp::handle hGrp = App::GetApplication().GetParameterGroupByPath(
+        "User parameter:BaseApp/Preferences/Mod/Fem/Gmsh");
+    std::string str = hGrp->GetASCII("MeshFileFormat", ".unv");
+    int ind = 0;
+    if (str == ".unv") {
+        ind = 0;
+    }
+    else if (str == ".vtk") {
+        ind = 1;
+    }
+    else if (str == ".inp") {
+        ind = 2;
+    }
+    else if (str == ".msh") {
+        ind = 3;
+    }
+
+    ui->cb_mesh_file_format->setCurrentIndex(ind);
     ui->cb_gmsh_binary_std->onRestore();
     ui->fc_gmsh_binary_path->onRestore();
+    ui->cb_mesh_file_format->onRestore();
 }
 
 /**
@@ -65,7 +93,9 @@ void DlgSettingsFemGmshImp::loadSettings()
 void DlgSettingsFemGmshImp::changeEvent(QEvent* e)
 {
     if (e->type() == QEvent::LanguageChange) {
+        int c_index = ui->cb_mesh_file_format->currentIndex();
         ui->retranslateUi(this);
+        ui->cb_mesh_file_format->setCurrentIndex(c_index);
     }
     else {
         QWidget::changeEvent(e);