.. _taper_page:

*****
Taper
*****

**Taper** mesh quality criterion represents the ratio of the areas
of two triangles separated by a diagonal within a quadrilateral face.

::

	**JA = 0.25 * (A1 + A2 + A3 + A4)**
	**TAPER = MAX(|A1/JA - 1|, |A2/JA - 1|, |A3/JA - 1|, |A4/JA - 1|)**

**To apply the Taper quality criterion to your mesh:**


#. Display your mesh in the viewer.

#. Choose **Controls > Face Controls > Taper** or click **"Taper"** button in the toolbar.

	.. image:: ../images/image36.png
		:align: center

	.. centered:: 
		**"Taper" button**

	Your mesh will be displayed in the viewer with its elements colored according to the applied mesh quality control criterion:

	.. image:: ../images/image90.jpg
		:align: center

**See Also** a sample TUI Script of a 
:ref:`tui_taper` operation.