\page extrusion_along_path_page Extrusion along Path
\n In principle, <b>Extrusion along Path</b> works in the same way
-as \b Extrusion, the main difference is that we define not a vector,
+as \ref extrusion_page "Extrusion", the main difference is that we define not a vector,
but a path of extrusion which must be a 1D mesh or 1D sub-mesh.
To get an idea of how this algorithm works, examine several examples,
starting from the most simple case of extrusion along a straight edge.
\image html image101.png
<center><em>"Extrusion along a path" button</em></center>
-The following dialog common for line and planar elements will appear:
+The following dialog will appear:
\image html extrusion_along_path_dlg.png
</li>
<li>In this dialog:
<ul>
-<li>select the type of elements which will be extruded (1D or 2D),</li>
-<li>specify the <b>IDs of the elements</b> which will be extruded
-
-<ul>
-<li><b>Select the whole mesh, sub-mesh or group</b> activating the corresponding check-box; or</li>
-<li>Choose mesh elements with the mouse in the 3D Viewer. It is
-possible to select a whole area with a mouse frame; or</li>
-<li>Input the element IDs directly in <b>ID Elements</b> field. The selected elements will be highlighted in the
-viewer; or</li>
-<li>apply Filters. <b>Set filter</b> button allows to apply a filter to the selection of elements. See more
-about filters in the \ref selection_filter_library_page "Selection filter library" page.</li>
-</ul>
-
-</li>
-<li>Define the \b Path along which the elements will be extruded.<br>
- Path definition consists of several elements:
- <ul>
- <li><b>Mesh or submesh</b> - 1D mesh or sub-mesh, along which proceeds the extrusion</li>
- <li><b>Start node</b> - the start node. It is used to define the direction of extrusion </li>
- </ul>
-</li>
-<li>Activate <b>Generate Groups</b> check-box if it is necessary to copy the groups of
- elements of the source mesh to the newly created one. </li>
+ <li>Use \a Selection button to specify what you are going to
+ select at a given moment, \b Nodes, \b Edges or \b Faces.
+\image html image120.png
+<center><em>"Selection" button</em></center>
+ </li>
+ <li>Specify \b Nodes, \b Edges and \b Faces, which will be extruded, by one
+ of following means:
+ <ul>
+ <li><b>Select the whole mesh, sub-mesh or group</b> activating this
+ checkbox.</li>
+ <li>Choose mesh elements with the mouse in the 3D Viewer. It is
+ possible to select a whole area with a mouse frame.</li>
+ <li>Input the element IDs directly in <b>Node IDs</b>, <b>Edge
+ IDs</b> and <b>Face IDs</b> fields. The selected elements will
+ be highlighted in the viewer, if the mesh is shown there.</li>
+ <li>Apply Filters. <b>Set filter</b> button allows to apply a
+ filter to the selection of elements. See more about filters in
+ the \ref filtering_elements "Selection filters" page.</li>
+ </ul>
+ </li>
+ <li>Define the \b Path along which the elements will be extruded.<br>
+ Path definition consists of several elements:
+ <ul>
+ <li><b>Mesh or submesh</b> - 1D mesh or sub-mesh, along which
+ proceeds the extrusion.</li>
+ <li><b>Start node</b> - the start node. It is used to define
+ the direction of extrusion. </li>
+ </ul>
+ </li>
+ <li>If you activate <b>Generate Groups</b> check-box, the <em>result elements</em>
+ created from <em>selected elements</em> contained in groups will be
+ included into new groups named by pattern "<old group
+ name>_extruded" and "<old group name>_top". For example if a
+ selected quadrangle is included in \a g_Faces group (see figures
+ below) then result hexahedra will be included in \a
+ g_Faces_extruded group and a quadrangle created at the "top" of
+ extruded mesh will be included in \a g_Faces_top group. <br>
+\image html extrusion_groups.png
+\image html extrusion_groups_res.png
+ <p> This check-box is active only if there are some groups in the mesh.
+ </li>
</ul>
</li>
<li>There are two optional parameters, which can be very useful:
<ul>
<li>If the path of extrusion is curvilinear, at each iteration the
-extruded elements are rotated to keep its initial angularity to the
-curve. By default, the <b>Base Point</b> around which the elements are rotated is
-the mass center of the elements, however, you can specify any point as
-the <b>Base Point</b> and the elements will be rotated with respect to this
-point.<br>
- Note that only the displacement of the <b>Base Point</b> exactly equals to the
- path, and all other extruded elements simply keep their position relatively to the <b>Base Point</b> at each iteration.
-</li>
-<li>The elements can also be rotated around the path to get the resulting
-mesh in a helical fashion. You can set the values of angles at the
-right, add them to the list of angles at the left by pressing the <em>"Add"</em>
-button and remove them from the list by pressing the <em>"Remove"</em> button.
-
+ extruded elements are rotated to keep its initial angularity to the
+ curve. By default, the <b>Base Point</b> around which the elements
+ are rotated is the mass center of the elements, however, you can
+ specify any point as the <b>Base Point</b> and the elements will be
+ rotated with respect to this point.<br>
+ Note that only the displacement of the <b>Base Point</b> exactly
+ equals to the path, and all other extruded elements simply keep
+ their position relatively to the <b>Base Point</b> at each
+ iteration.</li>
+<li>The elements can also be rotated around the path to get the
+ resulting mesh in a helical fashion. You can set the values of
+ angles at the right, add them to the list of angles at the left by
+ pressing the <em>"Add"</em> button and remove them from the list by
+ pressing the <em>"Remove"</em> button.
\image html add.png
<center><em>"Add" button</em></center>
-
\image html remove.png
<center><em>"Remove" button</em></center>
-<b>Linear variation of the angles</b> option allows defining the angle of gradual rotation for the whole path.
-At each step the elements will be rotated by <code>angle / nb. of steps</code>.
-
+<b>Linear variation of the angles</b> option allows defining the angle
+of gradual rotation for the whole path. At each step the elements will
+be rotated by <code>angle / nb. of steps</code>.
</li>
</ul>
</li>
-<li>Click \b Apply or <b> Apply and Close</b> button to confirm the operation.
-Mesh edges will be extruded into
-faces, faces into volumes. The external surface of the resulting 3d
-mesh (if faces have been extruded) is covered with faces, and corners
-with edges. If the path is closed, the resulting mesh can contain
-duplicated nodes and faces, because no sewing is done.
+<li>Click \b Apply or <b> Apply and Close</b> button to confirm the
+ operation. Mesh edges will be extruded into faces, faces into
+ volumes. The external surface of the resulting 3d mesh (if faces
+ have been extruded) is covered with faces, and corners with
+ edges. If the path is closed, the resulting mesh can contain
+ duplicated nodes and faces, because no sewing is done.
</li>
</ol>
