<li> \ref preview_anchor "Previewing the mesh" (optional)</li>
<li> \ref submesh_order_anchor "Changing sub-mesh priority" (optional)</li>
<li> \ref compute_anchor "Computing the mesh"</li>
+ <li> \ref edit_anchor "Editing the mesh" (optional)</li>
</ul>
-Mesh can be \ref use_existing_anchor "computed using your own meshing algorithms"
-written in Python.
-
\anchor create_mesh_anchor
<h2>Creation of a mesh object</h2>
<li>In the \b Mesh menu select <b>Create Mesh</b> or click <em>"Create
Mesh"</em> button in the toolbar.
+ <center>
\image html image32.png
<em>"Create Mesh" button</em>
+ </center>
The following dialog box will appear:
\image html createmesh-inv.png
<br>
</li>
+ <li> To filter off irrelevant meshing algorithms, you can
+ select <b>Mesh Type</b> in the corresponding list from <b>Any,
+ Hexahedral, Tetrahedral, Triangular </b> and \b Quadrilateral (there
+ can be less items for the geometry of lower dimensions).
+
+ Selection of a mesh type hides all meshing algorithms that cannot
+ generate elements of this type.</li>
+
<li>Apply \subpage basic_meshing_algos_page "meshing algorithms" and
- \subpage about_hypo_page "hypotheses" which will be used at computation of
+ \subpage about_hypo_page "hypotheses" which will be used to compute
this mesh.
"Create mesh" dialog box contains several tab pages titled \b 3D,
\b 2D, \b 1D and \b 0D. The title of each page reflects the
dimension of the CAD model (geometry) the algorithms listed on
- this page affect. For example, \b 3D page lists the algorithms
- that affect 3D geometrical objects (solids).
+ this page affect and the maximal dimension of elements the algorithms
+ generate. For example, \b 3D page lists the algorithms that affect
+ 3D geometrical objects (solids) and generate 3D mesh elements
+ (tetrahedra, hexahedra etc.)
\note
- Some page(s) can be disabled if the source geometrical
it is "Mesh_1". Then select the geometrical object you wish to
mesh in the Object Browser and click "Select" button near \b Geometry
field (if the name of the object has not yet appeared in \b Geometry field).
-
+ <center>
\image html image120.png
<em>"Select" button</em>
+ </center>
Now you can define 3D Algorithm and 3D Hypotheses, which will be
applied to the solids of your geometrical object. Click the <em>"Add
Hypothesis"</em> button to add a hypothesis.
-
+ <center>
\image html image121.png
<em>"Add Hypothesis" button</em>
+ </center>
+ Click the <em>"Plus"</em> button to enable adding more additional hypotheses.
Click the <em>"Edit Hypothesis"</em> button to change the values for the
current hypothesis.
-
+ <center>
\image html image122.png
<em>"Edit Hypothesis" button</em>
+ </center>
- Most standard 2D and 3D algorithms can work without hypotheses
- using some default parameters. The use of additional hypotheses
- is optional (i.e. you may leave "None" in this box).
+ Most 2D and 3D algorithms can work without hypotheses using
+ default meshing parameters. Some algorithms do not require any
+ hypotheses. After selection of an algorithm "Hypothesis" field of
+ the dialog can contain:
+ <ul>
+ <li> <em>\<Default\></em> if the algorithm can work using default
+ parameters.</li>
+ <li> <em>\<None\></em> if the algorithm requires a hypothesis defining
+ its parameters.</li>
+ <li> If the algorithm does not use hypotheses, this field is grayed.</li>
+ </ul>
+ After selection of an algorithm <b>Add. Hypothesis</b> field can contain:
+ <ul>
+ <li> <em>\<None\></em> if the algorithm can be tuned
+ using an additional hypothesis.</li>
+ <li> If the algorithm does not use additional hypotheses, this field is grayed.</li>
+ </ul>
Proceed in the same way with 2D and 1D Algorithms and Hypotheses that
will be used to mesh faces and edges of your geometry. (Note
that any object has edges, even if their existence is not
apparent, for example, a sphere has 4 edges). Note that the
choice of hypotheses and lower dimension algorithms depends on
- the higher dimension algorithm.
+ the higher dimension algorithm.
+
+ If you wish you can select different algorithms and/or hypotheses
+ for meshing some parts of your CAD model by \ref constructing_submeshes_page.
Some algorithms generate mesh of several dimensions, while others
- produce mesh of only one dimension. In the latter case there must be one Algorithm and zero or several
+ produce mesh of only one dimension. In the latter case there must
+ be one Algorithm and zero or several
Hypotheses for each dimension of your object, otherwise you will
not get any mesh at all. Of course, if you wish to mesh a face,
which is a 2D object, you do not need to define a 3D Algorithm and
In the <b>Object Browser</b> the structure of the new mesh will be
displayed as follows:
- \image html image88.jpg
+ <center>
+ \image html image88.jpg
+ </center>
- It contains:
+ It contains:
<ul>
+ <li>a mesh name (<em>Mesh_mechanic</em>);
<li>a reference to the geometrical object on the basis of
- which the mesh has been constructed;</li>
+ which the mesh has been constructed (\a mechanic);</li>
<li><b>Applied hypotheses</b> folder containing the references
to the hypotheses applied at the construction of the mesh;</li>
<li><b>Applied algorithms</b> folder containing the references
\image html hypo_sets.png
List of sets of hypotheses. Tag <em>[custom]</em> is
- automatically added to the sets defined by the user
+ automatically added to the sets defined by the user.
+
+ \note \a "Automatic" in the names of predefined sets of
+ hypotheses came from previous versions of SALOME where
+ \ref automatic_length_anchor "Automatic Length" hypothesis
+ was included in these sets, and not that these sets are suitable for
+ meshing any geometry.
</li>
</ol>
select \b Preview or click "Preview" button in the toolbar or activate
"Preview" item from the pop-up menu.
+<center>
\image html mesh_precompute.png
<em>"Preview" button</em>
+</center>
Select <b>1D mesh</b> or <b>2D mesh</b> preview mode in the Preview dialog.
<em>"Result mesh with order SubMesh_3, SubMesh_2, SubMesh_1 "</em></center>
As we can see, each mesh computation has a different number of result
-elements and a different mesh discretisation on the shared edges (the edges
+elements and a different mesh discretization on the shared edges (the edges
that are shared between <b>Face_1</b>, <b>Face_2</b> and <b>Face_3</b>)
Additionally, submesh priority (the order of applied algorithms) can
the <b>Object Browser</b>. From the \b Mesh menu select \b Compute or
click "Compute" button of the toolbar.
+<center>
\image html image28.png
<em>"Compute" button</em>
+</center>
-The Mesh Computation information box appears.
+After the mesh computation finishes, the Mesh Computation information
+box appears. In case of a success, the box shows
+information on number of entities of different types in the mesh.
\image html meshcomputationsucceed.png
If the mesh computation failed, the information about the cause of the
-failure is provided.
+failure is provided in \b Errors table.
\image html meshcomputationfail.png
After you select the error, <b>Show Sub-shape</b> button allows
-visualizing in magenta the geometrical entity that causes it.
+visualizing in magenta the geometrical entity that causes the error.
\image html failed_computation.png
<em>3D algorithm failed to compute mesh on a box shown using <b>Show
Sub-shape</b> button</em>
-
-\note Mesh Computation Information box does not appear if you set
-"Mesh computation/Show a computation result notification" preference
-to the "Never" value. This option gives the possibility to control mesh
-computation reporting. There are the following possibilities: always
-show the information box, show only if an error occurs or never.
-By default, the information box is always shown after mesh computation operation.
-
<b>Publish Sub-shape</b> button publishes the sub-shape, whose meshing
has failed, in GEOM component as a child of the mesh geometry, which
allows analyzing the problem geometry and creating a submesh on it in
switching the mesh to Wireframe visualization mode or switching off
the visualization of faces and volumes (if any).
+<b>Bad Mesh to Group</b> button creates groups of bad mesh entities
+to facilitate their analysis.
+
\image html show_bad_mesh.png
-<em>Too close nodes causing meshing failure are shown in magenta using <b>Show
+<em>Edges bounding a hole in the surface are shown in magenta using <b>Show
bad Mesh</b> button</em>
-<br><br>
-
-\anchor use_existing_anchor
-<h2>"Use existing edges" and "Use existing faces" algorithms</h2>
-
-It is possible to create a 1D or a 2D mesh in a python script
-(using <em>AddNode, AddEdge</em> and <em>AddFace</em> commands) and
-then use such sub-meshes in the construction of a 2D or a 3D mesh. For
-this, there exist two algorithms: <b>Use existing edges</b> and <b>Use
- existing faces</b>.
-For example, you want to use standard algorithms to generate 1D and 3D
-meshes and to create 2D mesh by your python code. Then you
-<ul>
- <li> create a mesh object, assign a 1D algorithm,</li>
- <li> invoke \b Compute command, which computes a 1D mesh,</li>
- <li> assign <b>Use existing faces</b> and a 3D algorithm,</li>
- <li> run your python code, which creates a 2D mesh,</li>
- <li> invoke \b Compute command, which computes a 3D mesh.</li>
-</ul>
-Consider trying a sample script demonstrating the usage of
-\ref tui_use_existing_faces "Use existing faces" algorithm for
-construction of a 2D mesh using Python commands.
+\note Mesh Computation Information box does not appear if you set
+"Mesh computation/Show a computation result notification" preference
+to the "Never" value. This option gives the possibility to control mesh
+computation reporting. There are the following possibilities: always
+show the information box, show only if an error occurs or never.
+By default, the information box is always shown after mesh computation operation.
-\image html use_existing_face_sample_mesh.png
-<em> Mesh computed by \ref tui_use_existing_faces "the sample script"
- shown in a Shrink mode.</em>
+<p><p>
+\anchor edit_anchor
+<h2>Editing the mesh</h2>
+
+It is possible to \ref modifying_meshes_page "edit the mesh" of
+lower dimension before generation of mesh of higher dimension.
+
+For example you can generate 2D mesh, modify it using e.g.
+\ref pattern_mapping_page, and then generate 3D mesh basing on the
+modified 2D mesh. The workflow is following:
+- Define 1D and 2D meshing algorithms.
+- Compute the mesh. 2D mesh is generated.
+- Apply \ref pattern_mapping_page.
+- Define 3D meshing algorithms without modifying 1D and 2D algorithms
+and hypotheses.
+- Compute the mesh. 3D mesh is generated.
+
+\note Nodes and elements added \ref adding_nodes_and_elements_page
+"manually" can't be used in this workflow because the manually created
+entities are not attached to any geometry and thus (usually) can't be
+found by a mesher paving some geometry.
+
+<b>See Also</b> a sample TUI Script demonstrates the possibility of
+\ref tui_editing_while_meshing "Intermediate edition while meshing"
*/