\page selection_filter_library_page Selection filter library
\n Selection filter library allows creating and storing in files
-filters that can be later loaded and used for operations on meshes. You can
-access to it from the Main Menu via <b>Tools / Selection filter library</b>.
-It is also possible to save any filter by invoking the filter library
-from \a Filter dialog launched from any mesh operation.
+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
+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.
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. The <b>Threshold Value</b> should be specified
for most criteria. For numerical criteria it is necessary to indicate if
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.
+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>
</ul>
-Some criteria are applicable to all <b>Entity types</b> of dimension
+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>
</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>.
\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 having at least one of its
-edges not shared with other faces. 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
