# *************************************************************************** # * * # * Copyright (c) 2016 - Bernd Hahnebach * # * * # * This program is free software; you can redistribute it and/or modify * # * it under the terms of the GNU Lesser General Public License (LGPL) * # * as published by the Free Software Foundation; either version 2 of * # * the License, or (at your option) any later version. * # * for detail see the LICENCE text file. * # * * # * This program is distributed in the hope that it will be useful, * # * but WITHOUT ANY WARRANTY; without even the implied warranty of * # * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * # * GNU Library General Public License for more details. * # * * # * You should have received a copy of the GNU Library General Public * # * License along with this program; if not, write to the Free Software * # * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 * # * USA * # * * # *************************************************************************** __title__ = "Tools for the work with GMSH mesher" __author__ = "Bernd Hahnebach" __url__ = "http://www.freecadweb.org" ## \addtogroup FEM # @{ import FreeCAD import Fem import Units import subprocess import tempfile from platform import system class FemGmshTools(): def __init__(self, gmsh_mesh_obj, analysis=None): self.mesh_obj = gmsh_mesh_obj if analysis: self.analysis = analysis # group meshing turned on else: self.analysis = None # group meshing turned off # part to mesh self.part_obj = self.mesh_obj.Part # clmax, ElementSizeMax: float, 0.0 = 1e+22 self.clmax = Units.Quantity(self.mesh_obj.ElementSizeMax).Value if self.clmax == 0.0: self.clmax = 1e+22 # clmin, ElementSizeMin: float self.clmin = Units.Quantity(self.mesh_obj.ElementSizeMin).Value # order, ElementOrder: ['Auto', '1st', '2nd'] self.order = self.mesh_obj.ElementOrder if self.order == '1st': self.order = '1' elif self.order == 'Auto' or self.order == '2nd': self.order = '2' else: print('Error in order') # dimension, ElementDimension: ['Auto', '1D', '2D', '3D'] self.dimension = self.mesh_obj.ElementDimension def create_mesh(self): print("\nWe gone start GMSH FEM mesh run!") print(' Part to mesh: Name --> ' + self.part_obj.Name + ', Label --> ' + self.part_obj.Label + ', ShapeType --> ' + self.part_obj.Shape.ShapeType) print(' ElementSizeMax: ' + str(self.clmax)) print(' ElementSizeMin: ' + str(self.clmin)) print(' ElementOrder: ' + self.order) self.get_dimension() self.get_tmp_file_paths() self.get_gmsh_command() self.get_group_data() self.write_part_file() self.write_geo() error = self.run_gmsh_with_geo() self.read_and_set_new_mesh() return error def get_dimension(self): # Dimension # GMSH uses the hightest availabe. # A use case for not auto would be a surface (2D) mesh of a solid or other 3d shape if self.dimension == 'Auto': shty = self.part_obj.Shape.ShapeType if shty == 'Solid' or shty == 'CompSolid': # print('Found: ' + shty) self.dimension = '3' elif shty == 'Face' or shty == 'Shell': # print('Found: ' + shty) self.dimension = '2' elif shty == 'Edge' or shty == 'Wire': # print('Found: ' + shty) self.dimension = '1' elif shty == 'Vertex': # print('Found: ' + shty) FreeCAD.Console.PrintError("You can not mesh a Vertex.\n") self.dimension = '0' elif shty == 'Compound': print('Found: ' + shty) print('I do not know what is inside your Compound. Dimension was set to 3 anyway.') # TODO check contents of Compound # use dimension 3 on any shape works for 2D and 1d meshes as well ! # but not in combination with sewfaces or connectfaces self.dimension = '3' else: self.dimension = '0' FreeCAD.Console.PrintError('Could not retrive Dimension from shape type. Please choose dimension.') elif self.dimension == '3D': self.dimension = '3' elif self.dimension == '2D': self.dimension = '2' elif self.dimension == '1D': self.dimension = '1' else: print('Error in dimension') print(' ElementDimension: ' + self.dimension) def get_tmp_file_paths(self): if system() == "Linux": path_sep = "/" elif system() == "Windows": path_sep = "\\" else: path_sep = "/" tmpdir = tempfile.gettempdir() # geometry file self.temp_file_geometry = tmpdir + path_sep + self.part_obj.Name + '_Geometry.brep' print(' ' + self.temp_file_geometry) # mesh file self.mesh_name = self.part_obj.Name + '_Mesh_TmpGmsh' self.temp_file_mesh = tmpdir + path_sep + self.mesh_name + '.unv' print(' ' + self.temp_file_mesh) # GMSH input file self.temp_file_geo = tmpdir + path_sep + 'shape2mesh.geo' print(' ' + self.temp_file_geo) def get_gmsh_command(self): self.gmsh_bin = None gmsh_std_location = FreeCAD.ParamGet("User parameter:BaseApp/Preferences/Mod/Fem/Gmsh").GetBool("UseStandardGmshLocation") if gmsh_std_location: if system() == "Windows": gmsh_path = FreeCAD.getHomePath() + "bin/gmsh.exe" FreeCAD.ParamGet("User parameter:BaseApp/Preferences/Mod/Fem/Gmsh").SetString("gmshBinaryPath", gmsh_path) self.gmsh_bin = gmsh_path elif system() == "Linux": p1 = subprocess.Popen(['which', 'gmsh'], stdout=subprocess.PIPE) if p1.wait() == 0: gmsh_path = p1.stdout.read().split('\n')[0] elif p1.wait() == 1: error_message = "GMSH binary gmsh not found in standard system binary path. Please install gmsh or set path to binary in FEM preferences tab GMSH.\n" # if FreeCAD.GuiUp: # QtGui.QMessageBox.critical(None, "No GMSH binary ccx", error_message) raise Exception(error_message) self.gmsh_bin = gmsh_path else: if not self.gmsh_bin: self.gmsh_bin = FreeCAD.ParamGet("User parameter:BaseApp/Preferences/Mod/Fem/Gmsh").GetString("gmshBinaryPath", "") if not self.gmsh_bin: # in prefs not set, we will try to use something reasonable if system() == "Linux": self.gmsh_bin = "gmsh" elif system() == "Windows": self.gmsh_bin = FreeCAD.getHomePath() + "bin/gmsh.exe" else: self.gmsh_bin = "gmsh" self.gmsh_bin = self.gmsh_bin print(' ' + self.gmsh_bin) def get_group_data(self): if self.analysis: print(' Group meshing.') import FemMeshTools self.group_elements = FemMeshTools.get_analysis_group_elements(self.analysis, self.part_obj) print(self.group_elements) else: print(' NO group meshing.') def write_part_file(self): self.part_obj.Shape.exportBrep(self.temp_file_geometry) def write_geo(self): geo = open(self.temp_file_geo, "w") 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!') 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: gdata = self.group_elements[group] # print(gdata) # geo.write("// " + group + "\n") ele_nr = '' if gdata[0].startswith('Solid'): physical_type = 'Volume' for ele in gdata: ele_nr += (ele.lstrip('Solid') + ', ') elif gdata[0].startswith('Face'): physical_type = 'Surface' for ele in gdata: ele_nr += (ele.lstrip('Face') + ', ') elif gdata[0].startswith('Edge') or gdata[0].startswith('Vertex'): geo.write("// " + group + " group data not written. Edges or Vertexes group data not supported.\n") print(' Groups for Edges or Vertexes reference shapes not handeled yet.') if ele_nr: ele_nr = ele_nr.rstrip(', ') # print(ele_nr) geo.write('Physical ' + physical_type + '("' + group + '") = {' + ele_nr + '};\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") geo.write("//Mesh.HighOrderOptimize = 1;\n") # but does not really work, in GUI it does geo.write("Mesh.Algorithm3D = 1;\n") geo.write("Mesh.Algorithm = 2;\n") geo.write("Mesh " + self.dimension + ";\n") geo.write("Mesh.Format = 2;\n") # unv if self.analysis and self.group_elements: geo.write("// For each group save not only the elements but the nodes too.;\n") geo.write("Mesh.SaveGroupsOfNodes = 1;\n") geo.write("// Needed for Group meshing too, because for one material there is no group defined;\n") # belongs to Mesh.SaveAll but anly needed if there are groups geo.write("// Ignore Physical definitions and save all elements;\n") geo.write("Mesh.SaveAll = 1;\n") geo.write("\n") geo.write('Save "' + self.temp_file_mesh + '";\n') geo.write("\n\n") geo.write("//////////////////////////////////////////////////////////////////////\n") geo.write("// GMSH documentation:\n") geo.write("// http://gmsh.info/doc/texinfo/gmsh.html#Mesh\n") geo.write("//\n") geo.write("// We do not check if something went wrong, like negative jacobians etc. You can run GMSH manually yourself: \n") geo.write("//\n") geo.write("// to see full GMSH log, run in bash:\n") geo.write("// " + self.gmsh_bin + " - " + self.temp_file_geo + "\n") geo.write("//\n") geo.write("// to run GMSH and keep file in GMSH GUI (with log), run in bash:\n") geo.write("// " + self.gmsh_bin + " " + self.temp_file_geo + "\n") geo.close def run_gmsh_with_geo(self): self.error = False comandlist = [self.gmsh_bin, '-', self.temp_file_geo] # print(comandlist) try: p = subprocess.Popen(comandlist, shell=False, stdout=subprocess.PIPE, stderr=subprocess.PIPE) output, error = p.communicate() # print(output) # stdout is still cut at some point but the warnings are in stderr and thus printed :-) # print(error) except: error = 'Error executing: {}\n'.format(self.gmsh_command) FreeCAD.Console.PrintError(error) self.error = True return error def read_and_set_new_mesh(self): if not self.error: fem_mesh = Fem.read(self.temp_file_mesh) self.mesh_obj.FemMesh = fem_mesh print(' The Part should have a pretty new FEM mesh!') else: print('No mesh was created.') del self.temp_file_geometry del self.temp_file_mesh # @}