--- /dev/null
+/*!
+
+\page pattern_mapping_page Pattern mapping
+
+<br><h2>About patterns</h2>
+
+The pattern describes a mesh to generate: positions of nodes within a
+geometrical domain and nodal connectivity of elements. As well, a
+pattern specifies the so-called key-points, i.e. nodes that will be
+located at geometrical vertices. Pattern description is stored in
+\<pattern_name\>.smp file.
+
+The smp file contains 4 sections:
+<ol>
+<li>The first line holds the number of nodes (N).</li>
+
+<li>The next N lines describe nodes coordinates. Each line holds 2
+coordinates of a node.</li>
+
+<li>A key-points line: indices of nodes to be mapped on geometrical
+vertices. An index n refers to a node described on an n-th line of
+section 2. The first node index is zero.</li>
+
+<li>The rest lines describe nodal connectivity of elements, one line
+for an element. A line holds indices of nodes forming an element. An
+index n refers to a node described on an n-th line of the section
+2. The first node index is zero. There must be 3 or 4 indices on a
+line: only 2d elements are allowed.</li>
+</ol>
+
+The 2D pattern must contain at least one element and at least one
+key-point. All key-points must lay on boundaries.
+
+An example of a simple smp file and a preview of a pattern described
+in this file:
+
+\image html image94.gif
+
+<br><h2>Application of pattern mapping</h2>
+
+<em>To apply pattern mapping to a geometrical object:</em>
+
+From the \b Modification menu choose the <b>Pattern Mapping</b> item or click
+<em>"Pattern mapping"</em> button in the toolbar.
+
+\image html image98.gif
+<center><em>"Pattern mapping" button</em></center>
+
+The following dialog box shall appear:
+
+\image html patternmapping1.png
+
+\image html patternmapping2.png
+
+To apply a pattern to a geometrical object, you should specify:
+<ul>
+<li>a face having the number of vertices equal to the number of
+key-points in the pattern; the number of key-points on internal
+boundaries of a pattern must also be equal to the number of vertices
+on internal boundaries of a face;</li>
+<li>a vertex to which the first key-point should be mapped;</li>
+<li>reverse or not the order of key-points. (The order of vertices of
+a face is counterclockwise looking from outside).</li>
+</ul>
+
+Then you either load a .smp pattern file previously created manually
+by clicking on the <em>"Load pattern"</em> button, or click on the \b
+New button for automatic generation.
+\n For an automatic generation you just specify a geometrical face
+having a mesh built on it. Mesh nodes lying on face vertices become
+key-points. Additionally, you may choose the way of getting nodes
+coordinates by <b>projecting nodes on the face</b> instead of using
+"positions on face" generated by mesher (if there is any). Faces
+having a seam edge can?t be used for automatic pattern creation.
+
+When creating a pattern from an existing mesh, there are two possible
+cases:
+<ol>
+<li>A sub-mesh on face is selected. A pattern is created from the 2d
+elements bound to a face by mesher. Node coordinates are either
+"positions on face" computed by mesher, or coordinates got by node
+projection on a geometrical surface, according to your choice.</li>
+<li>A mesh where the main shape is a face, is selected. A pattern is
+created from all the 2d elements in a mesh. If all mesh elements are
+build by mesher, the user can select the way of getting nodes
+coordinates, else all nodes are projected on a face surface.</li>
+</ol>
+
+\image html a-patterntype.png
+
+\image html a-patterntype1.png
+
+<br><h2>Mapping algorithm</h2>
+
+The mapping algorithm is as follows:
+<ol>
+<li>Key-points are set in the order that they are encountered when
+walking along a pattern boundary so that elements are on the left. The
+first key-point is preserved.
+</li>
+
+<li>Find geometrical vertices corresponding to key-points by vertices
+order in a face boundary; here, "Reverse order of key-points" flag is
+taken into account.
+
+\image html image95.gif
+</li>
+
+<li>Boundary nodes of a pattern are mapped onto edges of a face: a
+node located between certain key-points on a pattern boundary is
+mapped on a geometrical edge limited by corresponding geometrical
+vertices. Node position on an edge reflects its distance from two
+key-points.
+
+\image html image96.gif
+</li>
+
+<li>Coordinates of a non-boundary node in a parametric space of a face
+are defined as following. In a parametric space of a pattern, a node
+lays at the intersection of two iso-lines, each of which intersects a
+pattern boundary at least at two points. Knowing mapped positions of
+boundary nodes, we find where isoline-boundary intersection points are
+mapped to, and hence we can find mapped isolines direction and then,
+two node positions on two mapped isolines. The eventual mapped
+position of a node is found as an average of positions on mapped
+isolines.
+
+\image html image97.gif
+</li>
+</ol>
+
+<br><b>See Also</b> a sample TUI Script of a
+\ref tui_pattern_mapping "Pattern Mapping" operation.
+
+*/
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