0020868: EDF 1251 SMESH: Pattern 3D mapping

Add documentation and sample scripts for 3D pattern mapping
This commit is contained in:
dmv 2010-05-12 05:49:38 +00:00
parent ed467c6060
commit 69e7a358b8
4 changed files with 215 additions and 77 deletions

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@ -11,30 +11,83 @@ located at geometrical vertices. Pattern description is stored in
\<pattern_name\>.smp file.
The smp file contains 4 sections:
<ol>
<li>The first line holds the number of nodes (N).</li>
<li>The next N lines describe nodes coordinates. Each line holds 2
coordinates of a node.</li>
<li>A key-points line: indices of nodes to be mapped on geometrical
vertices. An index n refers to a node described on an n-th line of
section 2. The first node index is zero.</li>
<li>The rest lines describe nodal connectivity of elements, one line
-# The first line holds the total number of the pattern nodes (N).
-# The next N lines describe nodes coordinates. Each line holds 2
coordinates of a node for 2D pattern or 3 cordinates for 3D pattern.
Note, that for 3D pattern only relateive values in range [0;1] are
valid for coordinates of the nodes.
-# A key-points line: indices of nodes to be mapped on geometrical
vertices (for 2D pattern only). An index n refers to a node described
on an n-th line of section 2. The first node index is zero. For 3D
pattern key points are not specified.
-# The rest lines describe nodal connectivity of elements, one line
for an element. A line holds indices of nodes forming an element. An
index n refers to a node described on an n-th line of the section
2. The first node index is zero. There must be 3 or 4 indices on a
line: only 2d elements are allowed.</li>
</ol>
line for 2D pattern (only 2d elements are allowed) and 4, 5, 6 or 8
indices for 3D pattern (only 3d elements are allowed).
The 2D pattern must contain at least one element and at least one
key-point. All key-points must lay on boundaries.
An example of a simple smp file and a preview of a pattern described
in this file:
The 3D pattern must contain at least one element.
\image html image94.gif
An example of a simple 2D pattern smp file:
\code
!!! SALOME 2D mesh pattern file
!!!
!!! Nb of points:
9
200 0 !- 0
100 0 !- 1
0 0 !- 2
0 -100 !- 3
0 -200 !- 4
100 -200 !- 5
200 -200 !- 6
200 -100 !- 7
100 -100 !- 8
!!! Indices of 4 key-points
2 0 4 6
!!! Indices of points of 6 elements
0 1 8
8 5 6 7
2 3 8
8 3 4 5
8 7 0
8 1 2
\endcode
The image below provides a preview of above described pattern:
\image html pattern2d.png
An example of a simple 3D pattern smp file:
\code
!!! SALOME 3D mesh pattern file
!!!
!!! Nb of points:
9
0 0 0 !- 0
1 0 0 !- 1
0 1 0 !- 2
1 1 0 !- 3
0 0 1 !- 4
1 0 1 !- 5
0 1 1 !- 6
1 1 1 !- 7
0.5 0.5 0.5 !- 8
!!! Indices of points of 6 elements:
0 1 5 4 8
7 5 1 3 8
3 2 6 7 8
2 0 4 6 8
0 2 3 1 8
4 5 7 6 8
\endcode
<br><h2>Application of pattern mapping</h2>
@ -50,86 +103,89 @@ The following dialog box shall appear:
\image html patternmapping1.png
<center><b> 2D Pattern Mapping dialog box</b></center>
\image html patternmapping2.png
<center><b> 3D Pattern Mapping dialog box</b></center>
To apply a pattern to a geometrical object, you should specify:
<ul>
<li>a face having the number of vertices equal to the number of
key-points in the pattern; the number of key-points on internal
boundaries of a pattern must also be equal to the number of vertices
on internal boundaries of a face;</li>
<li>a vertex to which the first key-point should be mapped;</li>
<li>reverse or not the order of key-points. (The order of vertices of
a face is counterclockwise looking from outside).</li>
</ul>
-# For 2D pattern
- A face having the number of vertices equal to the number of
key-points in the pattern; the number of key-points on internal
boundaries of a pattern must also be equal to the number of vertices
on internal boundaries of a face;
- A vertex to which the first key-point should be mapped;
- Reverse or not the order of key-points. (The order of vertices of
a face is counterclockwise looking from outside).
-# For 3D pattern
- 3D block (Solid) object;
- Two vertices that specify the order of nodes in the resulting
mesh.
Then you either load a .smp pattern file previously created manually
by clicking on the <em>"Load pattern"</em> button, or click on the \b
New button for automatic generation.
\n For an automatic generation you just specify a geometrical face
having a mesh built on it. Mesh nodes lying on face vertices become
key-points. Additionally, you may choose the way of getting nodes
coordinates by <b>projecting nodes on the face</b> instead of using
New button for automatic generation of the pattern.
For an automatic generation you just specify a geometrical face (for
2D) or solid (for 3d) having a mesh built on it. Mesh nodes lying on
face vertices become key-points of 2D pattern. Additionally, for 2D
pattern you may choose the way of getting nodes coordinates by
<b>projecting nodes on the face</b> instead of using
"positions on face" generated by mesher (if there is any). Faces
having a seam edge can't be used for automatic pattern creation.
When creating a pattern from an existing mesh, there are two possible
cases:
<ol>
<li>A sub-mesh on face is selected. A pattern is created from the 2d
elements bound to a face by mesher. Node coordinates are either
- A sub-mesh on face/solid is selected. A pattern is created from the 2d/3d
elements bound to a face/solid by mesher. For 2D pattern, node coordinates are either
"positions on face" computed by mesher, or coordinates got by node
projection on a geometrical surface, according to your choice.</li>
<li>A mesh where the main shape is a face, is selected. A pattern is
created from all the 2d elements in a mesh. If all mesh elements are
build by mesher, the user can select the way of getting nodes
coordinates, else all nodes are projected on a face surface.</li>
</ol>
projection on a geometrical surface, according to the user choice. For
3D pattern, nodes coordinates correspond to the nodes computed by mesher.
- A mesh where the main shape is a face/solid, is selected. A pattern is
created from all the 2d/3d elements in a mesh. In addition, for 2D
pattern, if all mesh elements are build by mesher, the user can select
the way of getting nodes coordinates, else all nodes are projected on
a face surface.
\image html a-patterntype.png
<center><b> 2D Pattern Creation dialog box</b></center>
\image html a-patterntype1.png
<center><b> 3D Pattern Creation dialog box</b></center>
<br><h2>Mapping algorithm</h2>
The mapping algorithm is as follows:
<ol>
<li>Key-points are set in the order that they are encountered when
walking along a pattern boundary so that elements are on the left. The
first key-point is preserved.
</li>
The mapping algorithm for 2D case is as follows:
<li>Find geometrical vertices corresponding to key-points by vertices
order in a face boundary; here, "Reverse order of key-points" flag is
taken into account.
- Key-points are set in the order that they are encountered when
walking along a pattern boundary so that elements are on the left. The
first key-point is preserved.
- Find geometrical vertices corresponding to key-points by vertices
order in a face boundary; here, "Reverse order of key-points" flag is
taken into account. \image html image95.gif
- Boundary nodes of a pattern are mapped onto edges of a face: a
node located between certain key-points on a pattern boundary is
mapped on a geometrical edge limited by corresponding geometrical
vertices. Node position on an edge reflects its distance from two
key-points. \image html image96.gif
- Coordinates of a non-boundary node in a parametric space of a face
are defined as following. In a parametric space of a pattern, a node
lays at the intersection of two iso-lines, each of which intersects a
pattern boundary at least at two points. Knowing mapped positions of
boundary nodes, we find where isoline-boundary intersection points are
mapped to, and hence we can find mapped isolines direction and then,
two node positions on two mapped isolines. The eventual mapped
position of a node is found as an average of positions on mapped
isolines. \image html image97.gif
\image html image95.gif
</li>
For 3D case the algorithm is similar.
<li>Boundary nodes of a pattern are mapped onto edges of a face: a
node located between certain key-points on a pattern boundary is
mapped on a geometrical edge limited by corresponding geometrical
vertices. Node position on an edge reflects its distance from two
key-points.
\image html image96.gif
</li>
<li>Coordinates of a non-boundary node in a parametric space of a face
are defined as following. In a parametric space of a pattern, a node
lays at the intersection of two iso-lines, each of which intersects a
pattern boundary at least at two points. Knowing mapped positions of
boundary nodes, we find where isoline-boundary intersection points are
mapped to, and hence we can find mapped isolines direction and then,
two node positions on two mapped isolines. The eventual mapped
position of a node is found as an average of positions on mapped
isolines.
\image html image97.gif
</li>
</ol>
<br><b>See Also</b> a sample TUI Script of a
<b>See Also</b> a sample TUI Script of a
\ref tui_pattern_mapping "Pattern Mapping" operation.
*/

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@ -768,7 +768,6 @@ mesh.RotationSweepObject(GroupRotate, axisXYZ, angle45, 4, 1e-5)
\code
import geompy
import smesh
# define the geometry
@ -802,17 +801,100 @@ algo2D.MaxElementArea(240)
isDone = Mesh_2.Compute()
if not isDone: print 'Mesh Mesh_2 : computation failed'
# create a pattern
# create a 2d pattern
pattern = smesh.GetPattern()
isDone = pattern.LoadFromFace(Mesh_2.GetMesh(), Face_2, 0)
if (isDone != 1): print 'LoadFromFace :', pattern.GetErrorCode()
# apply the pattern to a face of the first mesh
pattern.ApplyToMeshFaces(Mesh_1.GetMesh(), [17], 0, 0)
facesToSplit = Mesh_1.GetElementsByType(smesh.SMESH.FACE)
print "Splitting %d rectangular face(s) to %d triangles..."%(len(facesToSplit), 2*len(facesToSplit))
pattern.ApplyToMeshFaces(Mesh_1.GetMesh(), facesToSplit, 0, 0)
isDone = pattern.MakeMesh(Mesh_1.GetMesh(), 0, 0)
if (isDone != 1): print 'MakeMesh :', pattern.GetErrorCode()
# create quadrangle mesh
Mesh_3 = smesh.Mesh(Box_1)
Mesh_3.Segment().NumberOfSegments(1)
Mesh_3.Quadrangle()
Mesh_3.Hexahedron()
isDone = Mesh_3.Compute()
if not isDone: print 'Mesh Mesh_3 : computation failed'
# create a 3d pattern (hexahedrons)
pattern_hexa = smesh.GetPattern()
smp_hexa = """!!! Nb of points:
15
0 0 0 !- 0
1 0 0 !- 1
0 1 0 !- 2
1 1 0 !- 3
0 0 1 !- 4
1 0 1 !- 5
0 1 1 !- 6
1 1 1 !- 7
0.5 0 0.5 !- 8
0.5 0 1 !- 9
0.5 0.5 0.5 !- 10
0.5 0.5 1 !- 11
1 0 0.5 !- 12
1 0.5 0.5 !- 13
1 0.5 1 !- 14
!!! Indices of points of 4 elements:
8 12 5 9 10 13 14 11
0 8 9 4 2 10 11 6
2 10 11 6 3 13 14 7
0 1 12 8 2 3 13 10"""
pattern_hexa.LoadFromFile(smp_hexa)
# apply the pattern to a mesh
volsToSplit = Mesh_3.GetElementsByType(smesh.SMESH.VOLUME)
print "Splitting %d hexa volume(s) to %d hexas..."%(len(volsToSplit), 4*len(volsToSplit))
pattern_hexa.ApplyToHexahedrons(Mesh_3.GetMesh(), volsToSplit,0,3)
isDone = pattern_hexa.MakeMesh(Mesh_3.GetMesh(), True, True)
if (isDone != 1): print 'MakeMesh :', pattern_hexa.GetErrorCode()
# create one more quadrangle mesh
Mesh_4 = smesh.Mesh(Box_1)
Mesh_4.Segment().NumberOfSegments(1)
Mesh_4.Quadrangle()
Mesh_4.Hexahedron()
isDone = Mesh_4.Compute()
if not isDone: print 'Mesh Mesh_4 : computation failed'
# create another 3d pattern (pyramids)
pattern_pyra = smesh.GetPattern()
smp_pyra = """!!! Nb of points:
9
0 0 0 !- 0
1 0 0 !- 1
0 1 0 !- 2
1 1 0 !- 3
0 0 1 !- 4
1 0 1 !- 5
0 1 1 !- 6
1 1 1 !- 7
0.5 0.5 0.5 !- 8
!!! Indices of points of 6 elements:
0 1 5 4 8
7 5 1 3 8
3 2 6 7 8
2 0 4 6 8
0 2 3 1 8
4 5 7 6 8"""
pattern_pyra.LoadFromFile(smp_pyra)
# apply the pattern to a face mesh
volsToSplit = Mesh_4.GetElementsByType(smesh.SMESH.VOLUME)
print "Splitting %d hexa volume(s) to %d hexas..."%(len(volsToSplit), 6*len(volsToSplit))
pattern_pyra.ApplyToHexahedrons(Mesh_4.GetMesh(), volsToSplit,1,0)
isDone = pattern_pyra.MakeMesh(Mesh_4.GetMesh(), True, True)
if (isDone != 1): print 'MakeMesh :', pattern_pyra.GetErrorCode()
\endcode
<br>