3 \page split_to_tetra_page Splitting volumes
5 \n This operation allows to split either any volumic elements into
6 tetrahedra or hexahedra into prisms. 2D mesh is modified accordingly.
8 <em>To split volumes:</em>
10 <li>Display a mesh, a sub-mesh or a group in the 3D viewer.</li>
11 <li>In the \b Modification menu select the <b>Split Volumes</b> item or
12 click <em>"Split Volumes"</em> button in the toolbar.
14 \image html split_into_tetra_icon.png
15 <center><em>"Split Volumes" button</em></center>
17 The following dialog box will appear:
19 \image html split_into_tetra.png
22 <b>Target element type</b> group of radio-buttons allows to select
23 a type of operation. If \b Tetrahedron button is checked, then the
24 operation will split volumes of any type into tetrahedra.
25 If \b Prism button is checked, then the operation will split hexahedra
26 into prisms, and the dialog will look as follows:
28 \image html split_into_prisms.png
31 <li>The main list contains list of volumes to split. You can click on
32 a volume in the 3D viewer and it will be highlighted (lock Shift
33 keyboard button to select several volumes). Click \b Add button and
34 the ID of this volume will be added to the list. To remove the
35 selected element or elements from the list click \b Remove button. <b>Sort
36 list</b> button allows to sort the list of IDs. \b Filter button allows to
37 apply a definite filter to the selection of volumes.
38 <br><b>Note:</b> If you split not all adjacent non-tetrahedral
39 volumes, your mesh becomes non-conform.</li>
40 <li><b>Apply to all</b> radio button allows to split all
41 volumes of the currently selected mesh.</li>
45 <li><b> Split hexahedron </b> group allows to specify a method of
49 <li><b>Into N tetrahedra/prisms</b> allows to specify the number of
50 tetrahedra or prisms a hexahedron will be split into. If the
51 specified method does not allow to get a conform mesh, a generic
52 solution is applied: an additional node is created at the gravity
53 center of a hexahedron, serving an apex of tetrahedra, all
54 quadrangle sides of the hexahedron are split into two triangles each
55 serving a base of a new tetrahedron.</li>
56 <li> <b> Facet to split </b> group allows to specify a side (facet) of a
57 hexahedron to split into triangles when splitting into prisms.
58 The facet to split is defined by specifying a point and a direction
59 close to normal of the facet. The operation finds a hexahedron most
60 close to the specified point and splits a facet whose normal is most
61 close to the specified direction. Then the splitting is propagated
62 from that hexahedron to all adjacent hexahedra.
64 <li> <b> Hexa location </b> allows to specify a <em> start
65 point </em> by which a first split hexahedron is found. <em>
66 Selection button</em> switches to selection of the element whose
67 barycenter will be used the start point and whose direction will be
68 used as a normal to facet to split into triangles. To return to
69 selection of volumes to split it is necessary to switch this button
71 <li> <b> Facet normal </b> allows to specify a direction of the
72 normal to hexahedron facet to split into triangles.</li>
74 <li><b> All domains </b> - if it is off the operation stops as all
75 hehexedra adjacent to the start hexahedron are split into
76 prisms. Else the operation tries to continue splitting starting from
77 another hexahedron closest to the <b> Hexa location</b>. </li>
81 <li><b>Select from</b> a set of fields allows to choose a sub-mesh or an
82 existing group whose elements will be added to the list as you ckick
86 <li>Click the \b Apply or <b>Apply and Close</b> button to confirm the operation.</li>