smesh/doc/salome/gui/SMESH/input/tui_creating_meshes.doc

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/*!
\page tui_creating_meshes_page Creating Meshes
\n First of all see \ref tui_creating_meshes_page "Example of 3d mesh generation",
which is an example of good python script style for Mesh module.
\n Other examples of python scripts will be also updated soon to use
smesh package instead of direct usage of idl interface.
<br>
<h2>Construction of a Mesh</h2>
\code
import geompy
import smesh
# create a box
box = geompy.MakeBox(0., 0., 0., 100., 200., 300.)
idbox = geompy.addToStudy(box, "box")
# create a mesh
tetra = smesh.Mesh(box, "MeshBox")
algo1D = tetra.Segment()
algo1D.NumberOfSegments(7)
algo2D = tetra.Triangle()
algo2D.MaxElementArea(800.)
algo3D = tetra.Tetrahedron(smesh.NETGEN)
algo3D.MaxElementVolume(900.)
# compute the mesh
ret = tetra.Compute()
if ret == 0:
print "problem when computing the mesh"
else:
print "mesh computed"
pass
\endcode
<br>
\anchor tui_construction_submesh
<h2>Construction of a Submesh</h2>
\code
from geompy import *
import smesh
# create a box
box = MakeBoxDXDYDZ(10., 10., 10.)
addToStudy(box, "Box")
# select one edge of the box for definition of a local hypothesis
p5 = MakeVertex(5., 0., 0.)
EdgeX = GetEdgeNearPoint(box, p5)
addToStudyInFather(box, EdgeX, "Edge [0,0,0 - 10,0,0]")
# create a hexahedral mesh on the box
quadra = smesh.Mesh(box, "Box : quadrangle 2D mesh")
# create a regular 1D algorithm for the faces
algo1D = quadra.Segment()
# define "NumberOfSegments" hypothesis to cut
# all the edges in a fixed number of segments
algo1D.NumberOfSegments(4)
# create a quadrangle 2D algorithm for the faces
quadra.Quadrangle()
# construct a submesh on the edge with a local hypothesis
algo_local = quadra.Segment(EdgeX)
# define "Arithmetic1D" hypothesis to cut the edge in several segments with increasing arithmetic length
algo_local.Arithmetic1D(1, 4)
# define "Propagation" hypothesis that propagates all other hypotheses
# on all edges of the opposite side in case of quadrangular faces
algo_local.Propagation()
# compute the mesh
quadra.Compute()
\endcode
<br>
\anchor tui_editing_mesh
<h2>Editing of a mesh</h2>
\code
import geompy
import smesh
def PrintMeshInfo(theMesh):
aMesh = theMesh.GetMesh()
print "Information about mesh:"
print "Number of nodes : ", aMesh.NbNodes()
print "Number of edges : ", aMesh.NbEdges()
print "Number of faces : ", aMesh.NbFaces()
print "Number of volumes : ", aMesh.NbVolumes()
pass
# create a box
box = geompy.MakeBox(0., 0., 0., 20., 20., 20.)
geompy.addToStudy(box, "box")
# select one edge of the box for definition of a local hypothesis
subShapeList = geompy.SubShapeAll(box, geompy.ShapeType["EDGE"])
edge = subShapeList[0]
name = geompy.SubShapeName(edge, box)
geompy.addToStudyInFather(box, edge, name)
# create a mesh
tria = smesh.Mesh(box, "Mesh 2D")
algo1D = tria.Segment()
hyp1 = algo1D.NumberOfSegments(3)
algo2D = tria.Triangle()
hyp2 = algo2D.MaxElementArea(10.)
# create a sub-mesh
algo_local = tria.Segment(edge)
hyp3 = algo_local.Arithmetic1D(1, 6)
hyp4 = algo_local.Propagation()
# compute the mesh
tria.Compute()
PrintMeshInfo(tria)
# remove a local hypothesis
mesh = tria.GetMesh()
mesh.RemoveHypothesis(edge, hyp4)
# compute the mesh
tria.Compute()
PrintMeshInfo(tria)
# change the value of the 2D hypothesis
hyp2.SetMaxElementArea(2.)
# compute the mesh
tria.Compute()
PrintMeshInfo(tria)
\endcode
<br>
\anchor tui_export_mesh
<h2>Export of a Mesh</h2>
\code
import geompy
import smesh
# create a box
box = geompy.MakeBox(0., 0., 0., 100., 200., 300.)
idbox = geompy.addToStudy(box, "box")
# create a mesh
tetra = smesh.Mesh(box, "MeshBox")
algo1D = tetra.Segment()
algo1D.NumberOfSegments(7)
algo2D = tetra.Triangle()
algo2D.MaxElementArea(800.)
algo3D = tetra.Tetrahedron(smesh.NETGEN)
algo3D.MaxElementVolume(900.)
# compute the mesh
tetra.Compute()
# export the mesh in a MED file
tetra.ExportMED("/tmp/meshMED.med", 0)
\endcode
*/