0020427: EDF 868 SMESH : Be able to define the submeshing order

doc/salome/gui/SMESH/input/constructing_meshes.doc

@@ -152,10 +152,88 @@ evaluation will be displayed in the following information box:
 
 \image html mesh_evaluation_succeed.png
 
+</li>
+
+</ol>
+
+It is allowed to change submesh priority in mesh computation when
+there are concurrent submeshes present. I.e. user can change priority of
+applying algorithms on shared subshapes of Mesh shape.
+<em>To change submesh priority:</em>
+<ol>
+<li>From the Mesh menu choose the "Change submesh priority" on
+selected Mesh item, or invoke from popup menu.
+
+There are example of submesh order modifications of Mesh created on a Box
+shape. The main Mesh object:
+<ul>
+<li><i>3D</i> <b>Tetrahedron (Netgen)</b> with Hypothesis<b>Max Element Volume</b></li>
+<li><i>2D</i> <b>Triangle (Mefisto)</b> with Hypothesis<b>Max Element Area</b>
+</li>
+<li><i>1D</i> <b>Wire discretisation</b> with <b>Number of Segments</b>=20</li>
+</ul>
+The first submesh object "<b>Submesh_1</b>" created on "<b>Face_1</b>"
+is:
+<ul>
+<li><i>2D</i> Netgen 1D-2D with Hypothesis <b>Netgen Simple parameters</b>
+(Number of Segments = 4)</li>
+</ul>
+The second submesh object "<b>Submesh_2</b>" created on "<b>Face_2</b>"
+is:
+<ul>
+<li><i>2D</i> Netgen 1D-2D with Hypothesis <b>Netgen Simple parameters</b>
+(Number of Segments = 8)</li>
+</ul>
+
+And the last third submesh object "<b>Submesh_3</b>" created on "<b>Face_3</b>"
+is:
+<ul>
+<li><i>2D</i> Netgen 1D-2D with Hypothesis <b>Netgen Simple parameters</b>
+(Number of Segments = 12)</li>
+</ul>
+The submeshes can become concurrent if thir algorithms leads to mesh shared subshape
+with different algorithms (or different algorithms parameters, i.e. hypothesises).
+In fact, we have three submeshes with concurrent algorithms, becase
+they has different hypothesises assigned to them. 
+
+The first mesh computation made with:
+\image html mesh_order_123.png
+<center><em>"Mesh order SubMesh_1, SubMesh_2, SubMesh_3"</em></center>
+\image html mesh_order_123_res.png
+<center><em>"Result mesh with order SubMesh_1, SubMesh_2, SubMesh_3 "</em></center>
+
+The next mesh computation with:
+\image html mesh_order_213.png
+<center><em>"Mesh order SubMesh_2, SubMesh_1, SubMesh_3"</em></center>
+\image html mesh_order_213_res.png
+<center><em>"Result mesh with order SubMesh_2, SubMesh_1, SubMesh_3 "</em></center>
+
+And the last mesh computation with:
+\image html mesh_order_321.png
+<center><em>"Mesh order SubMesh_3, SubMesh_2, SubMesh_1"</em></center>
+\image html mesh_order_321_res.png
+<center><em>"Result mesh with order SubMesh_3, SubMesh_2, SubMesh_1 "</em></center>
+
+As we can see each mesh computation has different number of result
+elements and different mesh descretisation on shared edges (edges,
+that shared between <b>Face_1</b>, <b>Face_2</b> and <b>Face_3</b>)
+
+Additionally, submesh priority (order of algorithms to be applied) can
+be modified not only in separate dialog box, but in <b>Preview</b>
+also. This helps to preview different mesh results, modifying submesh
+order.
+\image html mesh_order_preview.png
+<center><em>"Preview with submesh priority list box"</em></center>
+
+If no concurrent submeshes under Mesh object user will see the
+following information dialog box
+\image html mesh_order_no_concurrent.png
+<center><em>"No concurrent submeshes detected"</em></center>
+and no mesh order list box appear in Preview dialog box.
+
+</ol>
 
 Consider trying a sample script for construction of a mesh from our 
 \ref tui_creating_meshes_page "TUI Scripts" section.
-</li>
-</ol>
 
 */