--- /dev/null
+.. _revolution_page:
+
+**********
+Revolution
+**********
+
+Revolution is used to build mesh elements of plus one
+dimension than the input ones. Boundary elements around generated
+mesh of plus one dimension are additionally created. All created
+elements can be automatically grouped. Revolution can be used to create
+a :ref:`structured mesh from scratch <extrusion_struct>`.
+See :ref:`extrusion_page` page for general information on Revolution,
+which can be viewed as extrusion along a circular path.
+
+*To apply revolution:*
+
+.. |img| image:: ../images/image92.png
+.. |sel| image:: ../images/image120.png
+
+#. From the **Modification** menu choose the **Revolution** item or click **"Revolution"** button in the toolbar.
+
+ The following dialog will appear:
+
+ .. image:: ../images/revolution1.png
+ :align: center
+
+
+#. In this dialog:
+
+ * Use *Selection* button |sel| to specify what you are going to select at a given moment, **Nodes**, **Edges** or **Faces**.
+
+ * Specify **Nodes**, **Edges** and **Faces**, which will be revolved, by one of following means:
+ * **Select the whole mesh, sub-mesh or group** activating this 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 **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` page.
+ * Specify the **Axis** of revolution:
+ * Specify the coordinates of the start **Point** of the axis of revolution; either directly or by picking a node in the Viewer (selection of nodes is activated as you click the *Selection* button).
+ * Specify the **Vector** of the axis in either of three ways:
+ * directly adjust vector components;
+ * click *Selection* button, choose **From Origin to selected Point** in the opened menu and pick a node in the Viewer;
+ * click *Selection* button, chose **Normal to selected Face** in the opened menu and pick a mesh face in the Viewer.
+ * Specify the **Angle** of revolution and the **Number of steps** of revolution,
+ * **Angle by Step** - the elements are revolved by the specified angle at each step (i.e. for Angle=30 and Number of Steps=3, the elements will be extruded by 30 degrees twice for a total of 30*3=90)
+
+ .. image:: ../images/revolutionsn2.png
+ :align: center
+
+ .. centered::
+ Example of Revolution with Angle by Step. Angle=30 and Number of Steps=3
+
+ * **Total Angle** - the elements are revolved by the specified angle only once and the number of steps defines the number of iterations (i.e. for Angle=30 and Number of Steps=3, the elements will be revolved by 30/3=10 degrees twice for a total of 30).
+
+ .. image:: ../images/revolutionsn1.png
+ :align: center
+
+ .. centered::
+ Example of Revolution with Total Angle. Angle=30 and Number of Steps=3
+
+
+
+ * Specify the **Tolerance**, which is used to detect nodes lying on the axis of revolution.
+ * Activate **Preview** check-box to see the result mesh in the viewer.
+ * 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 "<old group name>_rotated" and "<old group name>_top". For example if a selected quadrangle is included in *g_Faces* group (see figures below) then result hexahedra will be included in *g_Faces_rotated* group and a quadrangle created at the "top" of revolved mesh will be included in *g_Faces_top* group.
+
+ .. image:: ../images/extrusion_groups.png
+ :align: center
+
+ .. image:: ../images/extrusion_groups_res.png
+ :align: center
+
+
+ This check-box is active only if there are some groups in the mesh.
+
+#. Click **Apply** or **Apply and Close** button to confirm the operation.
+
+**See Also** a sample TUI Script of a :ref:`tui_revolution` operation.
