/*! \page uniting_set_of_triangles_page Uniting a set of triangles \n It is possible to unite many neighboring triangles into quadrangles by deletion of the common edge. To union several triangles:
  1. Select a mesh (and display it in the 3D Viewer if you are going to pick elements by mouse).
  2. In the \b Modification menu select the Union of triangles item or click "Union of triangles" button in the tool-bar. \image html image80.png
    "Union of triangles" button
    The following dialog box will appear: \image html a-unionoftriangles.png
  3. Click the \b Apply or Apply and Close button to confirm the operation.
If some selected triangle elements have no adjacent edges with one of the others, the operation on these elements shall take no effect. \image html uniting_a_set_of_triangles1.png "The chosen triangles" \image html uniting_a_set_of_triangles2.png "The union of several triangles - several quadrangular cells are created"
See Also a sample TUI Script of a \ref tui_uniting_set_of_triangles "Uniting a Set of Triangles" operation. */