# Selection filter library

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 Tools / Selection filter library.

Library file name shows the path and the file name where your filters will be stored. By clicking the browse button you can load an existing filter library.

Names of filters lists the filters created or uploaded for the current study. You can Add or Delete filters.

In Filter name box you can specify the name for your filter. By default it is prefixed with the corresponding entity type.

Each filter can be applicable to Nodes, Edges, Faces or Volumes. You can combine many criteria in one filter, but they all must be of the same Entity type.

The Add button creates a new criterion at the end of the list of criteria. The Insert button creates a new criterion before the selected criterion. The Remove button deletes the selected criterion. The Clear button deletes all criteria.

Each Entity type has its specific list of criteria, however all filters have common syntax. For each criterion you should specify the Threshold Value and whether we search for the elements that should be More, Less or Equal to this Value. You should also specify if the criterion is Unary or Binary.

Some criteria should have the additional parameter of Tolerance.

When we create a Standalone Group using filters (for this click Set Filters button in the Create Group menu), the menu for setting filters looks a bit differently. Toggling Insert filter in viewer checkbox enables to preview the group selected with your current filter in the viewer.

In the Source field you choose if the filter will be applied to the whole Mesh, the Initial Selection or the Current Group.

Copy from... button gives you a possibility to load an existing filter from Selection filter library and Add to... button gives you a possibility to save your current filter in the Library.