Entity selection: Selection by criterion

Relation between entities

All the entities are connected one to another by relations .

  • a volume is connected to the bordering faces
  • a face is connected to the bordering lines
  • a line is connected to the ending points, …

Thus, it is possible to select all the lines bordering a face by selecting this face, or all faces bordering a volume by selecting this volume.

The user can also plan to select entities via common characteristics :

  • lines with the same visibility, or with the same color, ...
  • points carrying the same mesh point

Definition / use

One speaks about selection by criterion when the selection is carried out by:

  • the intermediary of the existing relations between the various entities (points belonging to a line...)
  • or the intermediary of characteristics common to several entities (faces with the same color, faces on the same surface...)
  • ...

Operation mode

The selection by criterion is available to the level of selection boxes and is carried out in three phases as that is presented in the table below (and on the example presented in the following block).

Stage Description
0 From a selection box …

The user :

  • open the criteria list (with the button )
  • and select a criterion to carry out his selection
  The specific selection box (with logical operators) is open

Then, he selects the entities which interested him

(He chooses one of the proposed selection modes:

graphic selection, by identifier or criterion)

3 And applies the selection operator to the group of entities


To select all the lines belonging to the face 23 :

The stages of selection and management of the entities can be imbricated and reiterated.

Selection criteria

An outline of the selection criteria is presented in the tables below.

General criteria
The option … allows …
Select all selection of all entities
Clean selection deselection of all the entities previously selected
Select last instance selection of the last selected entity
Selection by coordinates

selection of

the nearest entity to the entered coordinates

Specific criteria (implying the use of the operators)
The selection by … allows the selection of all the entities …
line / face / volume belonging to a line / face / volume
surface belonging to a surface (defined by a face)
linear / face / volume region belonging to a line / face / volume region
mechanical set belonging to a mechanical set
The selection by … allows the selection of all the entities …
color defined by a color (…)
visibility defined by a visibility (visible or invisible)
nature defined by a nature (standard, in air, no exist)
discretization characterized by a discretization (point or line)

Selection operators

To manage the logical operations on the groups of the selected entities, the user disposes the selection operators introduced in the table below.

Operator Function
Exclude to remove entities from the list
Union to add entities in the list
Intersect to carry out the intersection of two groups of selection