X-Git-Url: http://git.salome-platform.org/gitweb/?p=modules%2Fsmesh.git;a=blobdiff_plain;f=doc%2Fsalome%2Fgui%2FSMESH%2Finput%2Fextrusion.doc;h=6b07af9e1aa89d836a8adb0cb9140eb05388f725;hp=cb061b314fabd3de22c4f883875429f563aea733;hb=ada19000459ece97c85c84af0711d3401b9a3dae;hpb=1067ffa6e7e5c394e3a1b17219d8b355a57607cd
diff --git a/doc/salome/gui/SMESH/input/extrusion.doc b/doc/salome/gui/SMESH/input/extrusion.doc
index cb061b314..6b07af9e1 100644
--- a/doc/salome/gui/SMESH/input/extrusion.doc
+++ b/doc/salome/gui/SMESH/input/extrusion.doc
@@ -3,18 +3,33 @@
\page extrusion_page Extrusion
\n Extrusion is used to build mesh elements of plus one
-dimension than the input ones. Any node, segment or 2D element can be
-extruded. Each type of elements has a corresponding type of extruded elements:
+dimension than the input ones. Boundary elements around generated
+mesh of plus one dimension are additionally created. All created
+elements can be automatically grouped. Extrusion can be used to create
+a \ref extrusion_struct "structured mesh from scratch".
+
+\image html extrusion_box.png "If you extrude several quadrangles, you get exactly the same mesh as if you meshed a geometrical box (except for that the initial quadrangles can be incorrectly oriented): quadrangles and segments are created on the boundary of the generated mesh"
+
+
Any node, segment or 2D element can be extruded. Each type of
+elements is extruded into a corresponding type of result elements:
-Extruded element | Result elements |
-Node | Segments |
-Segment | Quadrilaterals |
-Triangle | Pentahedrons |
-Quadrilateral | Hexahedrons |
-Polygon | Polyhedrons |
+Extruded element | Result element |
+Node | Segment |
+Segment | Quadrilateral |
+Triangle | Pentahedron |
+Quadrilateral | Hexahedron |
+Polygon | Polyhedron |
Hexagonal polygon | Hexagonal prism |
+When 2D elements are extruded, in addition to 3D elements segments are
+created on the ribs of the resulting 3D mesh. Free edges of input 2D elements
+generate logically horizontal rib segments. Logically vertical rib
+segments are generated from the nodes belonging to a sole input 2D element
+(the figure below illustrates this rule).
+
+\image html extru_rib_segs.png "Two triangles extruded: no vertical rib segments generated from nodes #2 and #3 as they are shared by both triangles"
+
To use extrusion:
- From the \b Modification menu choose the \b Extrusion item or click
@@ -25,54 +40,121 @@ extruded. Each type of elements has a corresponding type of extruded elements:
"Extrusion" button
-The following dialog common for line and planar elements will appear:
+The following dialog will appear:
\image html extrusionalongaline1.png
-\image html extrusionalongaline2.png
-
- In this dialog:
- - Select the type of elements which will be extruded (0D, 1D or 2D).
- - Specify the IDs of the elements which will be extruded by one
- following means:
+
- 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
+ "Selection" button
+
+ - Specify \b Nodes, \b Edges and \b Faces, which will be extruded, by one
+ of following means:
- - Select the whole mesh, submesh or group activating this
- checkbox.
+ - Select the whole mesh, sub-mesh or group activating the
+ corresponding check-box.
- Choose mesh elements with the mouse in the 3D Viewer. It is
possible to select a whole area with a mouse frame.
- - Input the element IDs directly in ID Elements
- field. The selected elements will be highlighted in the viewer.
+ - Input the element IDs directly in Node IDs, Edge
+ IDs and Face IDs fields. The selected elements will
+ be highlighted in the viewer, if the mesh is shown there.
- Apply Filters. Set filter button allows to apply a
filter to the selection of elements. See more about filters in
the \ref filtering_elements "Selection filters" page.
- - If the Extrude to Distance radio button is selected
-
- - specify the distance at which the elements will be extruded.
-
- - If the Extrude Along Vector radio button is selected
-
- - specify the coordinates of the vector along which the elements
- will be extruded, or select the face (the normal to the face will
- define the vector),
- - specify the distance of extrusion along the vector.
+
+ - If the Extrusion to Distance radio button is selected
+
+ - specify the translation vector by which the elements will
+ be extruded.
+
+
+
+ - If the Extrusion Along Vector radio button is selected
+\image html extrusionalongaline2.png
+
+ - specify the components of the \b Vector along which the elements
+ will be extruded, either directly or by selecting the mesh face (the
+ normal to the face will define the vector),
+ - specify the \b Distance of extrusion along the vector (it can
+ be negative).
+
+
+
+ - If the Extrusion By Normal radio button is selected,
+ every node of the selected faces is extruded along the \a average
+ of the \a normal vectors to the faces sharing the node. (Nodes and
+ edges cannot be extruded in this mode.)
+\image html extrusionalongaline3.png
+
+ - Specify the \b Distance of extrusion (it can be negative),
+ - Use Along average normal check-box to specify along
+ which vector the distance is measured.
+
+ - If it is \a activated the distance is measured along the
+ average normal mentioned above.
+ - If it is \a deactivated every node is extruded along the
+ average normal till its intersection with a virtual plane obtained
+ by translation of the face sharing the node along its own normal
+ by the \b Distance.
+
+ The picture below shows a cross-section of a 2D mesh extruded
+ with Along average normal activated (to the left) and
+ deactivated (to the right).
+
+ \image html extrusionbynormal_alongavgnorm.png "'Along average normal' activated (to the left) and deactivated (to the right)"
+
+
+ - Use only input elements check-box specifies what
+ elements will be used to compute the average normal.
+ - If it is \a activated only selected faces, among faces
+ sharing the node, are used to compute the average normal at
+ the node.
+ - Else all faces sharing the node are used.
+
+ The picture below shows a cross-section of a 2D mesh the upper
+ plane of which is extruded with Use only input elements
+ activated (to the left) and deactivated (to the right).
+
+ \image html extrusionbynormal_useonly.png "'Use only input elements' activated (to the left) and deactivated (to the right)"
+
+
- - Specify the number of steps.
- - If you activate Generate Groups check-box, the created
- elements contained in groups will be included into new groups named
- by pattern "_extruded".
+
+ - Specify the Number of steps.
+ - If you activate Generate Groups check-box, the result elements
+ created from selected elements contained in groups will be
+ included into new groups named by pattern "_extruded" and "_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.
+\image html extrusion_groups.png
+\image html extrusion_groups_res.png
+ This check-box is active only if there are some groups in the mesh.
+
- Click \b Apply or Apply and Close button to confirm the operation.
+
+
+\anchor extrusion_struct
+
Example: creation of a structured mesh from scratch
-\image html image77.jpg "The mesh with an edge selected for extrusion"
+\image html image75.jpg "A node is extruded into a line of segments"
+
+\image html image76.jpg "The line of segments is extruded into a quadrangle mesh"
+
+\image html image77.jpg "The quadrangle mesh is revolved into a hexahedral mesh"
-\image html image76.jpg "The mesh with extruded edge"
See Also a sample TUI Script of an
\ref tui_extrusion "Extrusion" operation.