+++ /dev/null
-/*!
-
-\page extrusion_along_path_page Extrusion along Path
-
-\n In principle, <b>Extrusion along Path</b> works in the same way
-as \ref extrusion_page "Extrusion", the main difference is that we
-define not a vector, but a path of extrusion which must be an 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.
-In the examples the sample mesh will be extruded along different
-paths and with different parameters.
-This 2D mesh has two quadrangle faces and seven edges. Look
-at the picture, where white digits are the node numbers and green
-are the element numbers:
-
-\image html mesh_for_extr_along_path.png
-
-<br><center><h2>Extrusion along a straight edge</h2>(not using base point
-or angles)</center>
-
-\image html straight_before.png
-<center>The image shows a 1D path mesh, built on a linear edge, and the initial 2D mesh.</center>
-
-\image html straight_after.png
-<center> The image shows the result of extrusion of two edges
-(#1 and #2) of the initial mesh along the path. \n Node #1 of path mesh
-has been selected as Start node.</center>
-
-<br><center><h2>Extrusion along a curvilinear edge</h2>(with and
-without angles)</center>
-
-\image html curvi_simple_before.png
-<center>The image shows a 1D path mesh, built on curvilinear edge, and
-the initial 2D mesh.</center>
-
-\image html curvi_simple_after.png
-<center>The central image shows the result of extrusion of one edge
-(#2) of the initial mesh along the path. \n Node #1 of path mesh has
-been selected as <b>Start node</b>.</center>
-
-\image html curvi_angles_after.png
-<center>The same, but using angles {45, 45, 45, 0, -45, -45, -45}</center>
-
-<br><center><h2>Extrusion of a 2D face along a mesh built on a wire</h2></center>
-
-In this example the path mesh has been built on a wire containing 3
-edges. Node 1 is a start node. Linear angle variation by 180 degrees
-has also been applied.
-
-\image html extr_along_wire_before.png
-<center><em>Meshed wire</em></center>
-
-\image html extr_along_wire_after.png
-<center><em>The resulting extrusion</em></center>
-
-<br><center><h2>Extrusion of 2d elements along a closed path</h2></center>
-
-\image html circle_simple_before.png
-<center>The image shows a path mesh built on a closed edge
-(circle).</center>
-
-\image html circle_simple_after.png
-<center>The central image shows the result of extrusion of both faces
-of the initial mesh. \n Note, that no sewing has been done, so, there are
-six coincident nodes and two coincident faces in the resulting
-mesh.</center>
-
-\image html circle_angles_after.png
-<center>The same, but using angles {45, -45, 45, -45, 45, -45, 45, -45}
-</center>
-
-<br><em>To use Extrusion along Path:</em>
-<ol>
-<li>From the \b Modification menu choose the <b>Extrusion along a
-path</b> item or click <em>"Extrusion along a path"</em> button in the toolbar.
-
-\image html image101.png
-<center><em>"Extrusion along a path" button</em></center>
-
-The following dialog will appear:
-
-\image html extrusion_along_path_dlg.png
-</li>
-
-<li>In this dialog:
-<ul>
- <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
- check-box.</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 sub-mesh</b> - 1D mesh or sub-mesh, along which
- proceeds the extrusion.</li>
- <li><b>Start node</b> - the start node of the Path. 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 (note that it can
- differ from the gravity center computed by \a Geometry module for the
- underlying shape), 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>.
-</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>
-</ol>
-
-<br><b>See Also</b> a sample TUI Script of an
-\ref tui_extrusion_along_path "Extrusion along a Path" operation.
-
-*/
