Creating groups

In MESH you can create groups of elements of different types. To create a group of elements in the Mesh menu select Create Group.
To create any group you should define the following:

• Mesh - the name of the mesh whose elements will form your group. You can select your mesh in the Objet Browser or in the 3D viewer.
• Elements Type - set of radio buttons allows to select the type of elements which will form your group:
  • Nodes
  • Edges
  • Faces
  • Volumes
• Name field allows to enter the name of your new group.

SALOME Platform distinguishes between the two Group types: Standalone Group and Group on Geometry.

"Standalone Group"

Standalone Group consists of mesh elements, which you can define in the following ways:

• Choosing them manually with the mouse in the 3D Viewer. You can click on an element in the 3D viewer and it will be highlighted. After that click the Add button and the ID of this element will be added to the list.
• Applying Filters. The Set filter button allows to apply a definite filter to selection of the elements of your group. See more about filters on the Selection filter library page.
• By adding all existing entities of the chosen type to the group. For this turn on the Select All check box. In this mode all controls, which allow selecting the entities manually or by filters, are disabled.

To remove a selected element or elements from the list click the Remove button. The Sort List button allows to sort the list of IDs of mesh elements.
Select from set of fields allows to choose a submesh or an existing group whose elements of the previously defined type will be added to the list of elements which will form the new group.
Color - allows to assign to the group a certain color, for example, defining boundary conditions. This feature introduces a useful element of preprocessing in Mesh module. Note that Color attribute defines the colors used for the display of the elements of the group.
Warning The Med Color group interface may change in future versions of Salome.

For example, to create a new group containing all entities of the existing group and some other faces selected in the viewer:

• select the "Face" type of entities and input the name of the new group.
• checks "Group" checkbox in "Select From" group.
• select the existing group in the object browser or in the viewer.
• click "Add" in "Content" group. "Id Elements" list will be filled with IDs of faces belonging to the exising group.
• select other faces in the viewer.
• click "Apply" button to create the new group.

Please note that the new group does not have references to the source group. It contains only the list of face IDs. So if the old group will be changed, the new one will not be modified.

In this picture the brown cells belong to a group defined manually.

In this picture the brown cells belong to the group defined by the criterion Taper > 0.

See Also a sample TUI Script of a Create a Standalone Group operation.

"Group on Geometry"

To create a group on geometry check Group on geometry in the Group type field. Group on geometry contains the elements of a certain type belonging to the selected geometrical object. To define a group select in the Objet Browser or in the 3D viewer a geometrical object from which the elements will be taken. After confirmation of the operation a new group of mesh elements will be created.

In this picture the cells which belong to a certain face are selected in green.

See Also a sample TUI Script of a Create a Group on Geometry operation.