Fem: Add support for 2D geometries to SectionPrint

src/Mod/Fem/femmesh/meshsetsgetter.py

@@ -423,51 +423,11 @@ class MeshSetsGetter:
             femobj["TieMasterFaces"] = result[-1:]
 
     def get_constraints_sectionprint_faces(self):
-        if not self.member.cons_sectionprint:
-            return
-        # TODO: use meshtools to get the surfaces
-        # see constraint contact or constraint tie
         for femobj in self.member.cons_sectionprint:
-            # femobj --> dict, FreeCAD document object is femobj["Object"]
-            sectionprint_obj = femobj["Object"]
-            if len(sectionprint_obj.References) > 1:
-                FreeCAD.Console.PrintError(
-                    "Only one reference shape allowed for a section print "
-                    "but {} found: {}\n".format(
-                        len(sectionprint_obj.References), sectionprint_obj.References
-                    )
-                )
-            for o, elem_tup in sectionprint_obj.References:
-                for elem in elem_tup:
-                    # there should only be one reference for each section print object
-                    # in the gui this is checked
-                    ref_shape = o.Shape.getElement(elem)
-                    if ref_shape.ShapeType == "Face":
-                        v = self.mesh_object.FemMesh.getccxVolumesByFace(ref_shape)
-                        if len(v) > 0:
-                            femobj["SectionPrintFaces"] = v
-                            # volume elements found
-                            FreeCAD.Console.PrintLog(
-                                "{}, surface {}, {} touching volume elements found\n".format(
-                                    sectionprint_obj.Label, sectionprint_obj.Name, len(v)
-                                )
-                            )
-                        else:
-                            # no volume elements found, shell elements not allowed
-                            FreeCAD.Console.PrintError(
-                                "{}, surface {}, Error: "
-                                "No volume elements found!\n".format(
-                                    sectionprint_obj.Label, sectionprint_obj.Name
-                                )
-                            )
-                    else:
-                        # in Gui only Faces can be added
-                        FreeCAD.Console.PrintError(
-                            "Wrong reference shape type for {} "
-                            "Only Faces are allowed, but a {} was found.\n".format(
-                                sectionprint_obj.Name, ref_shape.ShapeType
-                            )
-                        )
+            obj = femobj["Object"]
+            result = self._get_ccx_elements(obj)
+
+            femobj["SectionPrintFaces"] = result
 
     def get_constraints_heatflux_faces(self):
         for femobj in self.member.cons_heatflux:

src/Mod/Fem/femobjects/constraint_sectionprint.py

@@ -57,7 +57,7 @@ class ConstraintSectionPrint(base_fempythonobject.BaseFemPythonObject):
                 name="Variable",
                 group="Constraint Section Print",
                 doc="Set facial variable",
-                value=["Section Force", "Heat Flux", "Drag Stress"],
+                value=["Section Force", "Heat Flux", "Drag Stress", "Electric Flux"],
             )
         )
 

src/Mod/Fem/femsolver/calculix/write_constraint_sectionprint.py

@@ -56,8 +56,14 @@ def get_after_write_constraint():
 
 def write_meshdata_constraint(f, femobj, sectionprint_obj, ccxwriter):
     f.write(f"*SURFACE, NAME=SECTIONFACE{sectionprint_obj.Name}\n")
-    for i in femobj["SectionPrintFaces"]:
-        f.write(f"{i[0]},S{i[1]}\n")
+
+    for refs, surf, is_sub_el in femobj["SectionPrintFaces"]:
+        if is_sub_el:
+            for elem, fno in surf:
+                f.write(f"{elem},S{fno}\n")
+        else:
+            for elem in surf:
+                f.write(f"{elem},S2\n")
 
 
 def write_constraint(f, femobj, sectionprint_obj, ccxwriter):
@@ -71,6 +77,8 @@ def write_constraint(f, femobj, sectionprint_obj, ccxwriter):
         key = "FLUX"
     elif variable == "Drag Stress":
         key = "DRAG"
+    elif variable == "Electric Flux":
+        key = "FLUX"
 
     f.write(
         "*SECTION PRINT, SURFACE=SECTIONFACE{}, NAME=SECTIONPRINT{}\n".format(

src/Mod/Fem/femtaskpanels/task_constraint_sectionprint.py

@@ -63,7 +63,7 @@ class _TaskPanel(base_femtaskpanel._BaseTaskPanel):
 
         # geometry selection widget
         self.selectionWidget = selection_widgets.GeometryElementsSelection(
-            obj.References, ["Face"], False, False
+            obj.References, ["Edge", "Face"], False, False
         )
 
         # form made from param and selection widget