53061: "Clear mesh data" removes too many (if !HasShapeToMesh())

[modules/smesh.git] / doc / salome / gui / SMESH / input / about_meshes.doc

diff --git a/doc/salome/gui/SMESH/input/about_meshes.doc b/doc/salome/gui/SMESH/input/about_meshes.doc
index 470cb854da57d380967edefe89f8c359763639fb..621a47e990cd5cb5febd22133da91b94cdafbd3d 100644 (file)
--- a/doc/salome/gui/SMESH/input/about_meshes.doc
+++ b/doc/salome/gui/SMESH/input/about_meshes.doc
@@ -3,14 +3,19 @@
 \page about_meshes_page About meshes
 
 \n \b MESH represents a discrete approximation of a subset of the
 \page about_meshes_page About meshes
 
 \n \b MESH represents a discrete approximation of a subset of the

-three-dimensional space by \ref mesh_entities "elementary geometrical elements".
+three-dimensional space by \ref mesh_entities "elementary geometrical
+elements".
+
+A SALOME study can contain multiple meshes, but they do not
+implicitly compose one super-mesh, and finally each of them
+can be used (e.g. exported) only individually.

 
 Mesh module provides several ways to create the mesh:
 <ul>
   <li>The main way is to \subpage constructing_meshes_page "construct the mesh" 
     on the basis of the geometrical shape produced in the Geometry
     module. This way implies selection of 
 
 Mesh module provides several ways to create the mesh:
 <ul>
   <li>The main way is to \subpage constructing_meshes_page "construct the mesh" 
     on the basis of the geometrical shape produced in the Geometry
     module. This way implies selection of 

-    - a geometrical object (<em> main shape</em>) and
+    - a geometrical object (<em>main shape</em>) and

     - <em>meshing parameters</em> (\ref
       basic_meshing_algos_page "meshing algorithms" and
     characteristics (e.g. element size) of a
     - <em>meshing parameters</em> (\ref
       basic_meshing_algos_page "meshing algorithms" and
     characteristics (e.g. element size) of a


@@ -19,31 +24,31 @@ Mesh module provides several ways to create the mesh:
 
     Construction of \subpage constructing_submeshes_page "sub-meshes"
     allows to discretize some sub-shapes of the main shape, for example a face,
 
     Construction of \subpage constructing_submeshes_page "sub-meshes"
     allows to discretize some sub-shapes of the main shape, for example a face,

-    using different meshing parameters than other sub-shapes.<br>
+    using the meshing parameters that differ from those used for other sub-shapes.<br>

     Meshing parameters of meshes and sub-meshes can be 
     \subpage editing_meshes_page "edited". (Upon edition only mesh entities
     generated using changed meshing parameters are removed and will be
     re-computed).<br>
     Meshing parameters of meshes and sub-meshes can be 
     \subpage editing_meshes_page "edited". (Upon edition only mesh entities
     generated using changed meshing parameters are removed and will be
     re-computed).<br>

-    \note Algorithms and hypotheses used at mesh level are referred as
-    \a global ones and those used at sub-mesh level are referred as \a
+    \note Algorithms and hypotheses used at mesh level are referred to as
+    \a global ones and those used at sub-mesh level are referred to as \a

     local ones.
   </li>
   <li>Bottom-up way, using \ref modifying_meshes_page "mesh modification"
     operations, especially \ref extrusion_page "extrusion" and \ref
     local ones.
   </li>
   <li>Bottom-up way, using \ref modifying_meshes_page "mesh modification"
     operations, especially \ref extrusion_page "extrusion" and \ref

-    revolution_page "revolution". To create an empty mesh not based on
+    revolution_page "revolution". To create an empty mesh not based on a

     geometry, use the same dialog as to \ref constructing_meshes_page
     geometry, use the same dialog as to \ref constructing_meshes_page

-    "construct the mesh on geometry" but do not specify any geometry
-    nor meshing algorithm.
+    "construct the mesh on geometry" but do not specify a geometry
+    or a meshing algorithm.

   </li>
   </li>

-  <li>The mesh can be \ref importing_exporting_meshes_page "imported" from
+  <li>The mesh can be \subpage importing_exporting_meshes_page "imported" from

     (and exported to) the file in MED, UNV, STL, CGNS, DAT, GMF and
     SAUVE formats.
   </li>
     (and exported to) the file in MED, UNV, STL, CGNS, DAT, GMF and
     SAUVE formats.
   </li>

-  <li>The 3D mesh can be generated from the 2D mesh, \ref
+  <li>The 3D mesh can be generated from the 2D mesh, which was \ref

     importing_exporting_meshes_page "imported" or manually created. To
     importing_exporting_meshes_page "imported" or manually created. To

-    setup the meshing parameters of a mesh not based on geometry, just
+    setup the meshing parameters of a mesh not based on a geometry, just

     invoke \ref editing_meshes_page "Edit mesh / sub-mesh" command on
     invoke \ref editing_meshes_page "Edit mesh / sub-mesh" command on

-    your 3D mesh.
+    your 2D mesh.

   </li>
   <li>Several meshes can be \subpage building_compounds_page "combined"
     into a new mesh.
   </li>
   <li>Several meshes can be \subpage building_compounds_page "combined"
     into a new mesh.


@@ -66,29 +71,29 @@ Attractive meshing capabilities include:
   sub-meshes.
 
 The \b structure of a SALOME mesh is described by nodes and elements based on
   sub-meshes.
 
 The \b structure of a SALOME mesh is described by nodes and elements based on

-these nodes. Geometry of the element is defined by the sequence of
+these nodes. The geometry of an element is defined by the sequence of

 nodes constituting it and
 the <a href="http://www.code-aster.org/outils/med/html/connectivites.html">
   connectivity convention </a> (adopted from MED library). Definition of
 nodes constituting it and
 the <a href="http://www.code-aster.org/outils/med/html/connectivites.html">
   connectivity convention </a> (adopted from MED library). Definition of

-the element basing on elements of lower dimension is NOT supported.
+the element basing on the elements of a lower dimension is NOT supported.

 
 \anchor mesh_entities
 The mesh can include the following entities:
 <ul>
 
 \anchor mesh_entities
 The mesh can include the following entities:
 <ul>

-<li>\b Node &mdash; an entity of a mesh defining a position in 3D
+<li>\b Node &mdash; a mesh entity defining a position in 3D

   space with coordinates (x, y, z).</li>
   space with coordinates (x, y, z).</li>

-<li>\b Edge (or segment) &mdash; 1D element of a mesh linking two nodes.</li>
-<li>\b Face &mdash; 2D element of a mesh representing a part of
+<li>\b Edge (or segment) &mdash; 1D mesh element linking two nodes.</li>
+<li>\b Face &mdash; 2D mesh element representing a part of

   surface bound by links between face nodes. A face can be a
   triangle, quadrangle or polygon.</li>
   surface bound by links between face nodes. A face can be a
   triangle, quadrangle or polygon.</li>

-<li>\b Volume &mdash; 3D element of a mesh representing a part of 3D
+<li>\b Volume &mdash; 3D mesh element representing a part of 3D

   space bound by volume facets. Nodes of a volume describing each
   facet are defined by
   the <a href="http://www.code-aster.org/outils/med/html/connectivites.html">
   MED connectivity convention.</a> A volume can be a tetrahedron, hexahedron,
   pentahedron, pyramid, hexagonal prism or polyhedron.</li>
   space bound by volume facets. Nodes of a volume describing each
   facet are defined by
   the <a href="http://www.code-aster.org/outils/med/html/connectivites.html">
   MED connectivity convention.</a> A volume can be a tetrahedron, hexahedron,
   pentahedron, pyramid, hexagonal prism or polyhedron.</li>

-<li>\b 0D element &mdash; element of a mesh defined by one node.</li>
-<li>\b Ball element &mdash; discrete element of a mesh defined by a
+<li>\b 0D element &mdash; mesh element defined by one node.</li>
+<li>\b Ball element &mdash; discrete mesh element defined by a

   node and a diameter.</li>
 </ul>
 
   node and a diameter.</li>
 </ul>
 


@@ -97,13 +102,18 @@ generated on (if any). The node generated on the geometrical edge or
 surface in addition stores its position in parametric space of the
 associated geometrical entity.
 
 surface in addition stores its position in parametric space of the
 associated geometrical entity.
 

-SALOME supports elements of second order, without central node
-(quadratic triangle, quadrangle, tetrahedron, hexahedron, pentahedron
-and pyramid) and with central nodes (bi-quadratic triangle and
-quadrangle and tri-quadratic hexahedron).<br>
-Quadratic mesh can be obtained in two ways:
+Mesh entities are identified by integer IDs starting from 1.
+Nodes and elements are counted separately, i.e. there can be a node
+and element with the same ID.
+
+SALOME supports elements of second order, without a central node
+(quadratic triangle, quadrangle, polygon, tetrahedron, hexahedron,
+pentahedron and pyramid) and with central nodes (bi-quadratic triangle
+and quadrangle and tri-quadratic hexahedron).<br>
+Quadratic mesh can be obtained in three ways:

 - Using a global \ref quadratic_mesh_anchor "Quadratic Mesh"
 hypothesis. (Elements with the central node are not generated in this way).
 - Using \ref convert_to_from_quadratic_mesh_page operation.
 - Using a global \ref quadratic_mesh_anchor "Quadratic Mesh"
 hypothesis. (Elements with the central node are not generated in this way).
 - Using \ref convert_to_from_quadratic_mesh_page operation.

-
+- Using an appropriate option of some meshing algorithms, which
+generate elements of several dimensions starting from mesh segments.

 */
 */