/*!

\page a2d_meshing_hypo_page 2D Meshing Hypotheses

<br>
<ul>
<li>\ref max_element_area_anchor "Max Element Area"</li>
<li>\ref length_from_edges_anchor "Length from Edges"</li>
<li>\ref hypo_quad_params_anchor "Quadrangle parameters"</li>
<li>\ref quadrangle_preference_anchor "Quadrangle Preference"</li>
<li>\ref triangle_preference_anchor "Triangle Preference"</li>
</ul>

<br>
\anchor max_element_area_anchor
<h2>Max Element Area</h2>

<b>Max Element Area</b> hypothesis is applied for meshing of 2D faces
composing your geometrical object. Definition of this hypothesis
consists of setting the <b>maximum area</b> of meshing elements (depending on
the chosen meshing algorithm it can be <b>triangles</b> or <b>quadrangles</b>),
which will compose the mesh of these 2D faces.

\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_max_element_area "Maximum Element Area" hypothesis
operation. 

<br>
\anchor length_from_edges_anchor
<h2>Length from Edges</h2>

<b>Length from edges</b> hypothesis builds 2D mesh segments having a
length calculated as an average edge length for a given wire.

<b>See Also</b> a sample TUI Script of a 
\ref tui_length_from_edges "Length from Edges" hypothesis operation.

<br>
\anchor hypo_quad_params_anchor
<h2>Quadrangle parameters</h2>

<b>Quadrangle parameters</b> is a hypothesis for
Quadrangle (Mapping), which allows using this algorithm for meshing of
triangular faces.In this case it is necessary to select the <b>Base vertex</b> 
used as a degenerated edge.

\image html hypo_quad_params_1.png "A face built from 3 edges"

\image html hypo_quad_params_res.png "The resulting mesh"

This hypothesis can be also used to mesh a segment of a circular face.
Please, consider that there is a limitation on the selectiion of the degenerated
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>Quadrangle parameters</b>
hypothesis 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"

<br>
\anchor quadrangle_preference_anchor
<h2>Quadrangle Preference</h2>

This algorithm can be used together with Quadrangle (Mapping) and Netgen 2D
algorithms. 

It allows Netgen 2D to build quadrangular meshes at any conditions.

It allows Quadrangle (Mapping) 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).


<br>
\anchor triangle_preference_anchor
<h2>Triangle Preference</h2>

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>
*/