It is possible to unite many neighboring triangles into
quadrangles by deletion of the common edge.
-**To union several triangles:**
+*To union several triangles:*
-#. Select a mesh (and display it in the 3D Viewer if you are going to pick elements by mouse).
-#. In the **Modification** menu select the **Union of triangles** item or click **"Union of triangles"** button in the tool-bar.
-
- .. image:: ../images/image80.png
- :align: center
+.. |img| image:: ../images/image80.png
- .. centered::
- **"Union of triangles" button**
+#. Select a mesh (and display it in the 3D Viewer if you are going to pick elements by mouse).
+#. In the **Modification** menu select the **Union of triangles** item or click *"Union of triangles"* button |img| in the tool-bar.
-The following dialog box will appear:
+ The following dialog box will appear:
.. image:: ../images/a-unionoftriangles.png
:align: center
- * **The main list** shall contain the triangles which will be united. You can click on a triangle in the 3D viewer and it will be highlighted. After that click the **Add** button and the ID of this triangle will be added to the list. To remove a selected element or elements from the list click the **Remove** button. The **Sort** button allows to sort the list of IDs. The **Filter** button allows to apply a definite :ref:`filtering_elements` to selection of triangles.
+ * **The main list** shall contain the triangles which will be united. You can click on a triangle in the 3D viewer and it will be highlighted. After that click the **Add** button and the ID of this triangle will be added to the list. To remove a selected element or elements from the list click the **Remove** button. The **Sort** button allows to sort the list of IDs. The **Filter** button allows to apply a definite :ref:`filter <filtering_elements>` to selection of triangles.
* **Apply to all** radio button allows to apply the operation to all triangles of the selected mesh.
* **Preview** provides a preview in the viewer.
* **Criterion** menu allows to choose a quality criterion, which will be optimized to select triangles to unite.
:align: center
.. centered::
- "The chosen triangles"
+ The chosen triangles
.. image:: ../images/uniting_a_set_of_triangles2.png
:align: center
.. centered::
- "The union of several triangles - several quadrangular cells are created"
+ The union of several triangles - several quadrangular cells are created
**See Also** a sample TUI Script of a
:ref:`tui_uniting_set_of_triangles` operation.