FEM: gmsh mesh tool, add different mesh element size for Shape elements

src/Mod/Fem/FemGmshTools.py

@@ -223,6 +223,23 @@ def get_group_data(self):
             print(self.group_elements)
         else:
             print('  NO group meshing.')
+        self.ele_length_map = self.mesh_obj.CharacteristicLengthMap
+        self.ele_node_map = {}
+        if self.ele_length_map:
+            import FemMeshTools
+            print(self.ele_length_map)
+            self.ele_node_map = {}
+            for e in self.ele_length_map:
+                if not e.startswith('Solid'):
+                    # Face, Edge, Vertex
+                    ele_shape = self.part_obj.Shape.getElement(e)
+                else:
+                    # Solid
+                    ele_shape_index = int(e.lstrip('Solid')) - 1
+                    ele_shape = self.part_obj.Shape.Solids[ele_shape_index]
+                ele_vertexes = FemMeshTools.get_vertexes_by_element(self.part_obj.Shape, ele_shape)
+                self.ele_node_map[e] = ele_vertexes
+            print(self.ele_node_map)
 
     def write_part_file(self):
         self.part_obj.Shape.exportBrep(self.temp_file_geometry)
@@ -232,7 +249,7 @@ def write_geo(self):
         geo.write('Merge "' + self.temp_file_geometry + '";\n')
         geo.write("\n")
         if self.analysis and self.group_elements:
-            print('  We gone have found elements to make mesh groups for!')
+            print('  We gone have found elements to make mesh groups for.')
             geo.write("// group data\n")
             # we use the element name of FreeCAD which starts with 1 (example: 'Face1'), same as GMSH
             for group in self.group_elements:
@@ -256,6 +273,14 @@ def write_geo(self):
                     # print(ele_nr)
                     geo.write('Physical ' + physical_type + '("' + group + '") = {' + ele_nr + '};\n')
             geo.write("\n")
+        if self.ele_length_map:
+            # we use the index FreeCAD which starts with 0, we need to add 1 for the index in GMSH
+            geo.write("// Characteristic Length according CharacteristicLengthMap\n")
+            for e in self.ele_length_map:
+                ele_nodes = (''.join((str(n + 1) + ', ') for n in self.ele_node_map[e])).rstrip(', ')
+                geo.write("// " + e + "\n")
+                geo.write("Characteristic Length { " + ele_nodes + " } = " + self.ele_length_map[e] + ";\n")
+            geo.write("\n")
         geo.write("Mesh.CharacteristicLengthMax = " + str(self.clmax) + ";\n")
         geo.write("Mesh.CharacteristicLengthMin = " + str(self.clmin) + ";\n")
         geo.write("Mesh.ElementOrder = " + self.order + ";\n")

src/Mod/Fem/FemMeshTools.py

@@ -1162,6 +1162,49 @@ def find_element_in_shape(aShape, anElement):
         FreeCAD.Console.PrintError('Compound is not supported.\n')
 
 
+def get_vertexes_by_element(aShape, anElement):
+    # we gone extent the method find_element_in_shape and return the vertexes
+    # import Part
+    ele_vertexes = []
+    ele_st = anElement.ShapeType
+    if ele_st == 'Solid' or ele_st == 'CompSolid':
+        for index, solid in enumerate(aShape.Solids):
+            if is_same_geometry(solid, anElement):
+                for vele in aShape.Solids[index].Vertexes:
+                    for i, v in enumerate(aShape.Vertexes):
+                        if vele.isSame(v):  # use isSame, because orientation could be different
+                            ele_vertexes.append(i)
+                # print('  ' + str(sorted(ele_vertexes)))
+                return ele_vertexes
+        FreeCAD.Console.PrintError('Error, Solid ' + str(anElement) + ' not found in: ' + str(aShape) + '\n')
+    elif ele_st == 'Face' or ele_st == 'Shell':
+        for index, face in enumerate(aShape.Faces):
+            if is_same_geometry(face, anElement):
+                for vele in aShape.Faces[index].Vertexes:
+                    for i, v in enumerate(aShape.Vertexes):
+                        if vele.isSame(v):  # use isSame, because orientation could be different
+                            ele_vertexes.append(i)
+                # print('  ' + str(sorted(ele_vertexes)))
+                return ele_vertexes
+    elif ele_st == 'Edge' or ele_st == 'Wire':
+        for index, edge in enumerate(aShape.Edges):
+            if is_same_geometry(edge, anElement):
+                for vele in aShape.Edges[index].Vertexes:
+                    for i, v in enumerate(aShape.Vertexes):
+                        if vele.isSame(v):  # use isSame, because orientation could be different
+                            ele_vertexes.append(i)
+                # print('  ' + str(sorted(ele_vertexes)))
+                return ele_vertexes
+    elif ele_st == 'Vertex':
+        for index, vertex in enumerate(aShape.Vertexes):
+            if is_same_geometry(vertex, anElement):
+                ele_vertexes.append(index)
+                # print('  ' + str(sorted(ele_vertexes)))
+                return ele_vertexes
+    elif ele_st == 'Compound':
+        FreeCAD.Console.PrintError('Compound is not supported.\n')
+
+
 def is_same_geometry(shape1, shape2):
     # the vertexes and the CenterOfMass are compared
     # it is a hack, but I do not know any better !

src/Mod/Fem/_FemMeshGmsh.py

@@ -80,6 +80,8 @@ def __init__(self, obj):
         obj.Algorithm3D = _FemMeshGmsh.known_mesh_algorithm_3D
         obj.Algorithm3D = 'Automatic'  # ?
 
+        obj.addProperty("App::PropertyMap", "CharacteristicLengthMap", "FEM GMSH Mesh Params", "Map of CharacteristicLength of Shape elements")
+
     def execute(self, obj):
         return