<ul>
<li>\ref max_element_area_anchor "Max Element Area"</li>
<li>\ref length_from_edges_anchor "Length from Edges"</li>
-<li>\ref quadrangle_preference_anchor "Quadrangle Preference"</li>
-<li>\ref triangle_preference_anchor "Triangle Preference"</li>
+<li>\ref hypo_quad_params_anchor "Quadrangle parameters"</li>
</ul>
<br>
\image html a-maxelarea.png
+\n
+
\image html max_el_area.png "In this example, Max. element area is very small compared to the 1D hypothesis"
<b>See Also</b> a sample TUI Script of a
\ref tui_length_from_edges "Length from Edges" hypothesis operation.
<br>
-\anchor quadrangle_preference_anchor
-<h2>Quadrangle Preference</h2>
+\anchor hypo_quad_params_anchor
+<h2>Quadrangle parameters</h2>
-This algorithm can be used only together with Quadrangle (Mapping)
-algorithm. It allows to build quadrangular meshes even if the number
-of nodes at the opposite edges of a meshed face is not equal,
-otherwise this mesh will contain some triangular elements.
-<br>
-This hypothesis has one restriction on its work: the total quantity of
-segments on all four sides of the face must be even (divisible by 2).
+\image html hypo_quad_params_dialog.png "Quadrangle parameters creation/edition dialog"
-<br>
-\anchor triangle_preference_anchor
-<h2>Triangle Preference</h2>
+<b>Quadrangle parameters</b> is a hypothesis for Quadrangle (Mapping).
+
+<b>Base vertex</b> parameter allows using Quadrangle (Mapping)
+algorithm for meshing of triangular faces. In this case it is
+necessary to select the vertex, which will be used as the fourth edge
+(degenerated).
+
+\image html hypo_quad_params_1.png "A face built from 3 edges"
+
+\image html hypo_quad_params_res.png "The resulting mesh"
+
+This parameter can be also used to mesh a segment of a circular face.
+Please, consider that there is a limitation on the selection of the
+vertex for the faces built with the angle > 180 degrees (see the picture).
+
+\image html hypo_quad_params_2.png "3/4 of a circular face"
+
+In this case, selection of a wrong vertex for the <b>Base vertex</b>
+parameter will generate a wrong mesh. The picture below
+shows the good (left) and the bad (right) results of meshing.
+
+\image html hypo_quad_params_res_2.png "The resulting meshes"
+
+<b>Type</b> parameter is used on faces with a different number of
+segments on opposite sides to define the algorithm of transition
+between them. The following types are available:
+
+<ul>
+<li><b>Standard</b> is the default case, when both triangles and quadrangles
+ are possible in the transition area along the finer meshed sides.</li>
+<li><b>Triangle preference</b> forces building only triangles in the
+ transition area along the finer meshed sides.
+ <i>This type corresponds to <b>Triangle Preference</b> additional
+ hypothesis, which is obsolete now.</i></li>
+<li><b>Quadrangle preference</b> forces building only quadrangles in the
+ transition area along the finer meshed sides. This hypothesis has a
+ restriction: the total quantity of segments on all
+ four sides of the face must be even (divisible by 2).</li>
+ <i>This type corresponds to <b>Quadrangle Preference</b>
+ additional hypothesis, which is obsolete now.</i></li>
+<li><b>Quadrangle preference (reversed)</b> works in the same way and
+with the same restriction as <b>Quadrangle preference</b>, but
+ the transition area is located along the coarser meshed sides.</li>
+<li><b>Reduced</b> type forces building only quadrangles and the transition
+ between the sides is made gradually, layer by layer. This type has
+ a limitation on the number of segments: one pair of opposite sides must have
+ the same number of segments, the other pair must have an even difference
+ between the numbers of segments on the sides.</li>
+</ul>
+
+<b>See Also</b> a sample TUI Script of a
+\ref tui_quadrangle_parameters "Quadrangle Parameters" hypothesis.
-This algorithm can be used only together with Quadrangle (Mapping)
-algorithm. It allows to build triangular mesh faces in the refinement
-area if the number of nodes at the opposite edges of a meshed face is not equal,
-otherwise refinement area will contain some quadrangular elements.
<br>
*/
