Make Symmetry

There are three differents ways to make the symmetry of an element:

  • Symmetry by point

  • Symmetry by line

  • Symmetry by plane

Symmetry by point

To make the symmetry of an element by point, you need to define:

  • the element

  • the symmetry center

elts = doc.makeSymmetryPoint (grid, orig)

Operations on elts: Elements

Here is an example where we make the symmetry of a grid:

Example

 1# -*- coding: latin-1 -*-
 2# Copyright (C) 2009-2026  CEA, EDF
 3#
 4# This library is free software; you can redistribute it and/or
 5# modify it under the terms of the GNU Lesser General Public
 6# License as published by the Free Software Foundation; either
 7# version 2.1 of the License, or (at your option) any later version.
 8#
 9# This library is distributed in the hope that it will be useful,
10# but WITHOUT ANY WARRANTY; without even the implied warranty of
11# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12# Lesser General Public License for more details.
13#
14# You should have received a copy of the GNU Lesser General Public
15# License along with this library; if not, write to the Free Software
16# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
17#
18# See http://www.salome-platform.org/ or email : webmaster.salome@opencascade.com
19#
20
21######## Make Symmetry Point ########
22
23import hexablock
24
25
26# ======================================================= make_grid
27def make_grid (doc) :
28
29    ori  = doc.addVertex ( 0, 0, 0)
30    vz   = doc.addVector ( 0, 0, 1)
31    vx   = doc.addVector ( 1 ,0, 0)
32
33    dr = 1
34    da = 360
35    dl = 1
36
37    nr = 1
38    na = 6
39    nl = 1
40    grid = doc.makeCylindrical (ori, vx,vz, dr,da,dl, nr,na,nl, False)
41    #####  doc .saveVtk ("cyl_grid.vtk")
42    return grid
43
44
45# ======================================================= test_sym_point
46def test_sym_point () :
47
48    doc  = hexablock.addDocument ("default")
49    grid = make_grid (doc)
50
51    orig = grid.getVertex(3)
52    grid2 = doc.makeSymmetryPoint (grid, orig)
53
54    #####  doc .saveVtk ("sym_point.vtk")
55    return doc
56    
57
58# ================================================================= Begin
59doc = test_sym_point  ()
60

Result

_images/grid.png

Initial

_images/make_sym_point.png

Symmetry of a grid by point

Symmetry by line

To make the symmetry of an element by line, you need to define:

  • the element

  • a point and a direction to define the line of symmetry

elts = doc.makeSymmetryLine (grid, orig, dir)

Operations on elts: Elements

Example

Code

 1# -*- coding: latin-1 -*-
 2# Copyright (C) 2009-2026  CEA, EDF
 3#
 4# This library is free software; you can redistribute it and/or
 5# modify it under the terms of the GNU Lesser General Public
 6# License as published by the Free Software Foundation; either
 7# version 2.1 of the License, or (at your option) any later version.
 8#
 9# This library is distributed in the hope that it will be useful,
10# but WITHOUT ANY WARRANTY; without even the implied warranty of
11# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12# Lesser General Public License for more details.
13#
14# You should have received a copy of the GNU Lesser General Public
15# License along with this library; if not, write to the Free Software
16# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
17#
18# See http://www.salome-platform.org/ or email : webmaster.salome@opencascade.com
19#
20
21######## Make Symmetry Line ########
22
23import hexablock
24
25
26# ======================================================= make_grid
27def make_grid (doc) :
28
29    ori  = doc.addVertex ( 0, 0, 0)
30    vz   = doc.addVector ( 0, 0, 1)
31    vx   = doc.addVector ( 1 ,0, 0)
32
33    dr = 1
34    da = 360
35    dl = 1
36
37    nr = 1
38    na = 6
39    nl = 1
40    grid = doc.makeCylindrical (ori, vx,vz, dr,da,dl, nr,na,nl, False)
41    #####  doc .saveVtk ("cyl_grid.vtk")
42    return grid
43
44
45# ======================================================= test_sym_line
46def test_sym_line () :
47
48    doc  = hexablock.addDocument ("default")
49    grid = make_grid (doc)
50
51    orig = grid.getVertex(3)
52    dir   = doc.addVector (0, 0, 1);
53    grid2 = doc.makeSymmetryLine (grid, orig, dir)
54
55    #####  doc .saveVtk ("sym_line.vtk")
56    return doc
57
58
59# ================================================================= Begin
60doc = test_sym_line  ()

Result

_images/make_sym_line.png

Symmetry of a grid by line

Symmetry by plane

To make the symmetry of an element by plane, you need to define:

  • the element

  • a point and a direction to define the plane of symmetry

elts = doc.makeSymmetryPlane (grid, orig, dir)

Operations on elts: Elements

Example

Code

 1# -*- coding: latin-1 -*-
 2# Copyright (C) 2009-2026  CEA, EDF
 3#
 4# This library is free software; you can redistribute it and/or
 5# modify it under the terms of the GNU Lesser General Public
 6# License as published by the Free Software Foundation; either
 7# version 2.1 of the License, or (at your option) any later version.
 8#
 9# This library is distributed in the hope that it will be useful,
10# but WITHOUT ANY WARRANTY; without even the implied warranty of
11# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12# Lesser General Public License for more details.
13#
14# You should have received a copy of the GNU Lesser General Public
15# License along with this library; if not, write to the Free Software
16# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
17#
18# See http://www.salome-platform.org/ or email : webmaster.salome@opencascade.com
19#
20
21######## Make Symmetry Plane ########
22
23import hexablock
24
25
26# ======================================================= make_grid
27def make_grid (doc) :
28
29    ori  = doc.addVertex ( 0, 0, 0)
30    vz   = doc.addVector ( 0, 0, 1)
31    vx   = doc.addVector ( 1 ,0, 0)
32
33    dr = 1
34    da = 360
35    dl = 1
36
37    nr = 1
38    na = 6
39    nl = 1
40    grid = doc.makeCylindrical (ori, vx,vz, dr,da,dl, nr,na,nl, False)
41    #####  doc .saveVtk ("cyl_grid.vtk")
42    return grid
43
44
45# ======================================================= test_sym_plane
46def test_sym_plane () :
47
48    doc  = hexablock.addDocument ("default")
49    grid = make_grid (doc)
50
51    orig = grid.getVertex(3)
52    dir   = doc.addVector (0, 1, 0);
53    grid2 = doc.makeSymmetryPlane (grid, orig, dir)
54
55    #####  doc .saveVtk ("sym_plane.vtk")
56    return doc
57
58# ================================================================= Begin
59doc = test_sym_plane  ()

Result

_images/make_sym_plane.png

Symmetry of a grid by plane

GUI command: Make elements by symmetry