\page selection_filter_library_page Selection filter library
-\n Selection filter library is a powerful tool enabling to create
-filters to be used on meshes. You can access to it from the Main Menu
-via <b>Tools / Selection filter library</b>.
+\n Selection filter library allows creating and storing in files
+the filters that can be later reused for operations on meshes. You can
+access it from the Main Menu via <b>Tools / Selection filter library</b>.
+It is also possible to save/load a filter by invoking the filter library
+from \ref filtering_elements "Filter dialog" launched from any mesh operation.
\image html selectionfilterlibrary.png
filter. By default it is prefixed with the corresponding entity type.
\anchor filtering_elements
+<h2>Filter Dialog</h2>
-When we use filters during a group creation or another operation (by
-clicking <b>Set Filters</b> button in the corresponding dialog), the
-menu for setting filters looks a bit differently (see the image below).
+When we use filters during group creation or another operation (by
+clicking <b>Set Filter</b> button in the corresponding dialog), the
+dialog for setting filters looks as shown below.
-Each filter can be applicable to \b Nodes, \b Edges, \b Faces or \b
-Volumes. You can combine many criteria in one filter, but they all
-must be of the same <b>Entity type</b>.
-\n The \b Add button creates a new criterion at the end of the list of
+\image html a-filteronfaces.png
+
+The \b Add button creates a new criterion at the end of the list of
criteria. The \b Insert button creates a new criterion before the
selected criterion. The \b Remove button deletes the selected
-criterion. The \b Clear button deletes all criteria.
+criterion. The \b Clear button deletes all criteria.\n
+If there is a choice of <b>Entity type</b> in the dialog, only
+criteria of currently selected type are used to create or change a
+filter, and criteria of hidden types (if were specified) are ignored.
\n Each <b>Entity type</b> has its specific list of criteria, however all
-filters have common syntax. For each criterion you should specify the
-<b>Threshold Value</b> and whether we search for the elements that should be
-\b More, \b Less or \b Equal to this \b Value. You can also reverse the
-sense of a criterion using \b Unary operator Not and you should
-specify logical relations between criteria using \b Binary operators
-Or and And.
-\n Some criteria should have the additional parameter of \b Tolerance.
-<br>
-Switching on <b>Insert filter in viewer</b> checkbox limits
+filters have common syntax. The <b>Threshold Value</b> should be specified
+for most criteria. For numerical criteria it is necessary to indicate if
+the found elements should be \b More, \b Less or \b Equal to this
+\b Value. You can also reverse the sense of a criterion using \b Unary
+operator \a Not and you should specify logical relations between
+criteria using \b Binary operators \a Or and \a And.
+\n Some criteria have the additional parameter of \b Tolerance.<br>
+Switching on <b>Insert filter in viewer</b> check-box limits
selection of elements in the Viewer to the current filter.
<br>
In the \b Source field you choose if the filter will be applied to
the whole \b Mesh, the <b>Initial Selection</b> or the <b>Current
-Group</b>. If \b Mesh is chosen, the elements satisfying the filter
+Dialog</b>. If \b Mesh is chosen, the elements satisfying the filter
will be selected in the 3D Viewer. If <b> Initial Selection</b> is
chosen, the filter will be applied to the selected elements and the
elements rejected by the filter will be deselected. If <b>Current
-Group</b> is chosen, the filter will be applied to the list of
+Dialog</b> is chosen, the filter will be applied to the list of
elements in the current dialog and the elements rejected
by the filter will be removed from the list.
<br>
is no selected mesh in the Object Browser and the filter can not be
created. You have to select the mesh and the button will be enabled.
-\image html a-filteronfaces.png
-
Some criteria are applicable to all <b>Entity types</b>:
<ul><li>
-<b>Belong to Geom</b> selects entities whose all nodes
-lie on the shape defined by <b>Threshold Value</b>.
-If the threshold shape is a sub-shape of the main shape of the mesh
-the algorithm works faster, if this is any other
-shape the algorithm works slower.
+<b>Belong to Geom</b> selects entities whose all nodes lie on the
+shape defined by <b>Threshold Value</b>.
+If the threshold shape is a sub-shape of the main shape of the mesh,
+the filtering algorithm works faster because node-to-shape association
+is used instead of measuring distance between nodes and the shape, and
+\b Tolerance is not used. If the threshold shape is any other shape,
+the algorithm works slower because distance between nodes and the
+shape is measured and is compared with \b Tolerance. The latter
+approach (distance measurement) is also used if an element is not
+associated to any shape.
</li><li>
<b>Lying on Geom</b> selects entities whose at least one node
lies on the shape defined by the <b>Threshold Value</b>.
-If the threshold shape is a sub-shape of the main shape of the mesh the
-algorithm works faster, if this is any other
-shape, the algorithm works slower.
+If the threshold shape is a sub-shape of the main shape of the mesh,
+the filtering algorithm works faster because node-to-shape association
+is used instead of measuring distance between nodes and the shape, and
+\b Tolerance is not used. If the threshold shape is any other shape,
+the algorithm works slower because distance between nodes and the
+shape is measured and is compared with \b Tolerance. The latter
+approach (distance measurement) is also used if an element is not
+associated to any shape.
+</li><li>
+<b>Belong to Mesh Group</b> selects entities included into the mesh group
+defined by the <b>Threshold Value</b>.
</li><li>
<b>Range of IDs</b> allows selection of entities with the specified
IDs.
</li>
</ul>
-Some criteria are applicable to all <b>Entity types</b>, except for
-<b>Nodes</b>
+Some criteria are applicable to entities of dimension
+more than zero, i.e. to \b Edges, \b Faces and \b Volumes:
<ul><li>
<b>Linear</b> allows selection of Linear or Quadratic elements (if Unary is set to "Not")
</li><li>
<b>Geometry type</b> allows selection of elements by their geometric type
defined by the <b>Threshold Value</b>. The list of available geometric
-types depends on the element entity type defined by the <b>Threshold Value</b>.
+types depends on the current entity type.
+</li><li>
+<b>Entity type</b> allows selection of elements by their type defined
+as a combination of geometry type and the number of nodes.
</li>
</ul>
-The following criteria are applicable to all <b>Entity types</b>
-except for <b>Volumes</b>:
+The following criteria are applicable to Entities of \b all types
+except for \a Volumes:
<ul><li>
<b>Belong to Plane</b> selects entities whose all nodes belong to a
specified plane within a given <b>Tolerance</b>.
The following criteria allow selecting mesh <b>Edges</b>:
<ul><li>
<b>Free Borders</b> selects free 1D mesh elements, i.e. edges belonging to
-one face only. See also a
+one element (face or volume) only. See also a
\ref free_borders_page "Free Borders quality control".
</li><li>
<b>Double edges</b> selects 1D mesh elements basing on the same set of nodes.
\ref area_page "Area quality control"), which is more, less or equal (within a given
<b>Tolerance</b>) to the predefined <b>Threshold Value</b>.
</li><li>
-<b>Free edges</b> selects 2D mesh elements consisting of edges belonging to
-one element of mesh only. See also a
+<b>Free edges</b> selects 2D mesh elements having at least one
+edge, which is not shared with other faces. See also a
\ref free_edges_page "Free Edges quality control".
</li><li>
<b>Free faces</b> selects 2D mesh elements, which belong to less than two volumes.
</li>
</ul>
-The following criteria allow selecting mesh <b>Volumes</b>:
+The following criteria allow selecting mesh <b>Volumes</b>:
<ul><li>
<b>Aspect ratio 3D</b> selects 3D mesh elements with an aspect ratio (see also an
\ref aspect_ratio_3d_page "Aspect Ratio 3D quality control"), which is more, less or equal
<b>Bad oriented volume</b> selects mesh volumes, which are incorrectly oriented from
the point of view of MED convention.
</li><li>
-<b>Over-constrained volumes</b> selects mesh volumes having only one border shared
+<b>Over-constrained volumes</b> selects mesh volumes having only one facet shared
with other volumes.
See also \ref over_constrained_volumes_page "Over-constrained volumes quality control".
</li><li>