/*!
-\page split_to_tetra_page Splitting volumes into tetrahedra
+\page split_to_tetra_page Splitting volumes
-\n This operation allows to split volumic elements into tetrahedra.
-2D mesh is modified accordingly.
+\n This operation allows to split either any volumic elements into
+tetrahedra or hexahedra into prisms. 2D mesh is modified accordingly.
<em>To split volumes:</em>
<ol>
-<li>Display a mesh or a submesh in the 3D viewer.</li>
-<li>In the \b Modification menu select the <b>Split into Tetrahedra</b> item or
-click <em>"Split into Tetrahedra"</em> button in the toolbar.
+<li>Display a mesh, a sub-mesh or a group in the 3D viewer.</li>
+<li>In the \b Modification menu select the <b>Split Volumes</b> item or
+click <em>"Split Volumes"</em> button in the toolbar.
\image html split_into_tetra_icon.png
-<center><em>"Split into Tetrahedra" button</em></center>
+<center><em>"Split Volumes" button</em></center>
The following dialog box will appear:
\image html split_into_tetra.png
-\par
-<ul>
-<li>The main list contains the list of volumes. You can click on
-a volume in the 3D viewer and it will be highlighted (lock Shift
-keyboard button to select several volumes). Click \b Add button and
-the ID of this volume will be added to the list. To remove the
-selected element or elements from the list click \b Remove button. <b>Sort
-list</b> button allows to sort the list of IDs. \b Filter button allows to
-apply a definite filter to the selection of volumes.
-<br><b>Note:</b> If you split not all adjacent non-tetrahedral volumes, your mesh becomes
-non-conform.</li>
-<li><b>Apply to all</b> radio button allows to split all
-volumes of the currently displayed mesh or submesh.</li>
-</ul>
+<br>
+First it is possible to select the type of operation:
+- If \b Tetrahedron button is checked, the operation will split volumes of any type into tetrahedra.
+- If \b Prism button is checked, the operation will split hexahedra into prisms.
<ul>
-<li>\b Split hexahedron
+<li>The main list contains the list of volumes to split. You can click on
+ a volume in the 3D viewer and it will be highlighted (lock Shift
+ keyboard button to select several volumes). Click \b Add button and
+ the ID of this volume will be added to the list. To remove the
+ selected element or elements from the list click \b Remove button. <b>Sort
+ list</b> button allows to sort the list of IDs. \b Filter button allows applying a filter to the selection of volumes.
+ <br><b>Note:</b> If you split not all adjacent non-tetrahedral
+ volumes, your mesh becomes non-conform.</li>
+
+<li><b>Apply to all</b> radio button allows splitting all
+ volumes of the currently selected mesh.</li>
+
+<li>If \b Tetrahedron element type is selected, <b> Split hexahedron </b> group allows specifying the number of tetrahedra a hexahedron will be split into. If the chosen method does not allow to get a conform mesh, a generic solution is applied: an additional node is created at the gravity center of a hexahedron, serving an apex of tetrahedra, all quadrangle sides of the hexahedron are split into two triangles each serving a base of a new tetrahedron.</li>
+
+<li>If \b Prism element type is selected, the <b>Split hexahedron</b> group looks as follows:
+
+\image html split_into_prisms.png
<ul>
-<li><b>Into 5 tetrahedra</b>, <b>Into 6 tetrahedra</b> and <b>Into 24 tetrahedra</b> allows to
-specify the number of tetrahedra a hexahedron will be split into. If the specified method does
-not allow to get a conform mesh, a generic solution is applied: an additional node
-is created at the gravity center of a hexahedron, serving an apex of tetrahedra, all quadrangle sides of the hexahedron are split into two triangles each serving a base of a new tetrahedron.</li>
+<li><b>Into 2 (or 4) prisms</b> allows to specify the number of prisms a hexahedron will be split into.</li>
+<li> <b> Facet to split </b> group allows to specify the side (facet) of the hexahedron, which is split into triangles. This facet is defined by a point and a direction. The algorithm finds a hexahedron closest to the specified point and splits a facet whose normal is closest to the specified direction. Then the splitting is propagated from that hexahedron to all adjacent hexahedra.
+The point and the direction by which the first split hexahedron is found can be specified:
+<ul>
+ <li> by input of coordinates in <b> Hexa location </b> and <b> Facet normal </b> fields, or </li>
+ <li> by clicking <b>Selection</b> button and selecting in the viewer the element whose barycenter will be used as the start point and whose direction will be used as a normal to facet to split into triangles. Switch this button
+off to return to selection of volumes to split.</li>
</ul>
-
+
+<li> If <b> All domains </b> option is off, the operation stops when all
+ hehexedra adjacent to the start hexahedron are split into
+ prisms. Else the operation tries to continue splitting starting from
+ another hexahedron closest to the <b> Hexa location</b>. </li>
</li>
+</ul>
-<li><b>Select from</b> a set of fields allows to choose a submesh or an
-existing group whose elements will be automatically added to the
-list.</li>
+<li><b>Select from</b> set of fields allows choosing a sub-mesh or an
+ existing group whose elements will be added to the list as you click \b Add button.</li>
</ul>
-<li>Click the \b Apply or <b>Apply and Close</b> button to confirm the operation.</li>
+<li>Click \b Apply or <b>Apply and Close</b> button to confirm the operation.</li>
</ol>
*/
