--- /dev/null
+.. _convert_to_from_quadratic_mesh_page:
+
+****************************************
+Convert to/from Quadratic Mesh
+****************************************
+
+This functionality allows transforming linear meshes (or sub-meshes) to quadratic and vice versa.
+
+.. Note::
+ that conversion of a sub-mesh most probably will produce a non-conformal mesh. Elements on the boundary between quadratic and linear sub-meshes become (or remain) quadratic.
+
+See :ref:`adding_quadratic_elements_page` for more information about quadratic meshes.
+
+*To produce a conversion:*
+
+.. |img| image:: ../images/image154.png
+
+#. Select a mesh or a sub-mesh in the Object Browser or in the Viewer.
+#. From the Modification menu or from the contextual menu in the Object Browser choose **Convert to/from Quadratic Mesh** item, or click *"Convert to/from quadratic"* button |img| in the toolbar.
+
+ The following dialog box will appear:
+
+ .. image:: ../images/convert.png
+ :align: center
+
+#. In this dialog box specify:
+
+ * If it is necessary to convert a linear mesh to quadratic or a quadratic mesh to linear. **Convert to bi-quadratic** creates some types of quadratic elements with additional central nodes: TRIA7, QUAD9 and HEXA27 elements instead of TRIA6, QUAD8, and HEXA20 elements respectively.
+ * If it is necessary to place **medium nodes** of the quadratic mesh **on the geometry** (meshed shape). This option is relevant for conversion to quadratic provided that the mesh is based on a geometry (not imported from file).
+
+ .. image:: ../images/image156.gif
+ :align: center
+
+ .. centered::
+ Linear mesh (coarse mesh on a torus)
+
+
+ .. image:: ../images/image155.gif
+ :align: center
+
+ .. centered::
+ Quadratic mesh
+
+
+#. Click the **Apply** or **Apply and Close** button.
+
+
+**See Also** a sample TUI Script of a :ref:`tui_quadratic` operation.
+
+
