--- /dev/null
+/*!
+
+\page prism_3d_algo_page 3D extrusion meshing algorithm
+
+3D extrusion algorithm can be used for meshing prisms, i.e. <b>3D Shapes</b>
+defined by two opposing faces having the same number of vertices and
+edges and meshed using the \ref projection_algos_page "2D Projection"
+algorithm. These two faces should be connected by quadrangle "side"
+faces.
+
+The opposing faces can be meshed with either quadrangles or triangles,
+while the side faces should be meshed with quadrangles only.
+
+\image html image157.gif
+
+As you can see, the <b>3D extrusion</b> algorithm permits to build and to
+have in the same 3D mesh such elements as hexahedrons, prisms and
+polyhedrons.
+
+*/
\ No newline at end of file
