<h2>Quadrangle Preference</h2>
-This additional hypothesis can be used together with Quadrangle (Mapping) and Netgen 2D
-algorithms.
+This additional hypothesis can be used together with 2D triangulation algorithms.
+It allows 2D triangulation algorithms to build quadrangular meshes.
-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. <i>This use
-case is obsolete now. Use <b>Quadrangle Parameters</b> hypothesis with
-type <b>Quadrangle Preference</b> set instead.</i>
<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).
-<h2>Triangle Preference <i>(obsolete)</i></h2>
-
-This additional hypothesis 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.
-<i>This hypothesis is obsolete now. Use <b>Quadrangle Parameters</b>
-hypothesis with type <b>Triangle Preference</b> set instead.</i>
-
\anchor viscous_layers_anchor
<h2>Viscous Layers</h2>
-<b>Viscous Layers</b> additional hypotheses can be used together with
-several 3D algorithms: NETGEN 3D, GHS3D and Hexahedron(i,j,k). This
+<b>Viscous Layers</b> additional hypothesis can be used together with
+3D algorithms, Hexahedron(i,j,k) for example. This
hypothesis allows creation of layers of highly stretched prisms near
mesh boundary, which is beneficial for high quality viscous
computations. The prisms constructed on the quadrangular mesh faces are
<ul>
<li><b>Name</b> - allows to define the name of the hypothesis.</li>
-<li><b>Total thicknes</b> - gives total thickness of layers of prisms.</li>
-<li><b>Number of layers</b> - defines number of layers of prisms.</li>
-<li><b>Stretch factor</b> - defines factor of growth of height of
-prisms from the mesh boundary towards inside of mesh.</li>
+<li><b>Total thicknes</b> - gives the total thickness of prism layers.</li>
+<li><b>Number of layers</b> - defines the number of prism layers.</li>
+<li><b>Stretch factor</b> - defines the growth factor of prism height
+from the mesh boundary inwards.</li>
<li><b>Faces without layers</b> - defines geometrical faces on which
-layers of prisms should not be constructed. By default the layers of
-prisms are not constructed on geometrical faces shared by solids.</li>
+prism layers should not be constructed. By default the prism layers
+are not constructed on geometrical faces shared by solids.</li>
</ul>
\image html viscous_layers_mesh.png A group containing viscous layer prisms.
