\page projection_algos_page Projection Algorithms
-\n Projection algorithms allow to define the mesh of a geometrical
+\tableofcontents
+
+Projection algorithms allow to define the mesh of a geometrical
object by the projection of another already meshed geometrical object.
+\note Source and target geometrical objects mush be topologically
+equal, i.e. they must have same number of sub-shapes, connected to
+corresponding counterparts.
+
+\image html topo_equality.png Topologically equal faces suitable for 2D projection.
+
+
+\section projection_1D Projection 1D
+
<b>Projection 1D</b> algorithm allows to define the mesh of an edge
(or group of edges)
by the projection of another already meshed edge (or group of edges).
The source and target groups must contain equal number of edges
and they must form topologically equal structures.
+\section projection_2D Projection 2D
+
\n <b>Projection 2D</b> algorithm allows to define the mesh of a face
(or group of faces) by the projection of another already meshed face
(or group of faces). This algorithm works only if all edges of the
contain an equal number of faces and form topologically equal
structures.
-\n <b>Projection 1D-2D</b> algorithm differs from <b>Projection 2D</b>
-algorithm in one aspect: it generates mesh segments on edges of
-the face according to the projected 2D elements; thus it does not
-require the edges to be meshed by any other 1D algorithm; moreover it
-does not allow to mesh edges of the face using another algorithm via
-definition of sub-meshes.
+\section projection_1D2D Projection 1D-2D
+
+\n <b>Projection 1D-2D</b> algorithm differs from
+\ref projection_2D algorithm in one aspect: it generates mesh segments
+on edges of the face according to the projected 2D elements; thus it
+does not require the edges to be meshed by any other 1D algorithm;
+moreover it does not allow to mesh edges of the face using another
+algorithm via definition of sub-meshes.
+
+\section projection_3D Projection 3D
\n <b>Projection 3D</b> algorithm allows to define the mesh of a shape by
the projection of another already meshed shape. This algorithm works
