--- /dev/null
+.. _quad_from_ma_algo_page:
+
+***************************************************
+Medial Axis Projection Quadrangle meshing algorithm
+***************************************************
+
+Medial Axis Projection algorithm can be used for meshing faces with
+sinuous borders and a channel-like shape, for which it can be
+difficult to define 1D hypotheses such that to obtain a good shape of
+resulting quadrangles. The algorithm can be also applied to faces with ring
+topology, which can be viewed as a closed 'channel'. In the latter
+case radial discretization of a ring can be specified by
+using *Number of Layers* or *Distribution of Layers*
+hypothesis.
+
+.. image:: ../images/quad_from_ma_mesh.png
+ :align: center
+
+.. centered::
+ A mesh of a river model (to the left) and of a ring-face (to the right)
+
+The algorithm provides proper shape of quadrangles by constructing Medial
+Axis between sinuous borders of the face and using it to
+discretize the borders. (Shape of quadrangles can be not perfect at
+locations where opposite sides of a 'channel' are far from being parallel.)
+
+.. image:: ../images/quad_from_ma_medial_axis.png
+ :align: center
+
+.. centered::
+ Medial Axis between two blue sinuous borders
+
+The Medial Axis is used in two ways:
+
+#. If there is a sub-mesh on a sinuous border, then the nodes of this border are mapped to the opposite border via the Medial Axis.
+#. If there are no sub-meshes on sinuous borders, then the part of the Medial Axis that can be mapped to both borders is discretized using a 1D hypothesis assigned to the face or its ancestor shapes, and the division points are mapped from the Medial Axis to both borders to find positions of nodes.
+
+.. image:: ../images/quad_from_ma_ring_mesh.png
+ :align: center
+
+.. centered::
+ Mesh depends on defined sub-meshes: to the left - sub-meshes on both wires, to the right - a sub-mesh on internal wire only
+
+
+**See Also** a sample TUI Script of a :ref:`tui_quad_ma_proj_algo`.
+