Options of construction by extrusion

Building options

Some building options are proposed in order to simplify the user's work and to carry out semi-automatically a certain number of repetitive tasks.

These options, classified in two categories, are presented in the table below:

The options … allow …
for geometric building
  • to define the form of connection elements
  • to define the geometric entities (points, lines, faces, volumes) created during the extrusion
for mesh preparation
  • to create the extrusion mesh generator associated to the transformation
  • to assign the extrusion mesh generator to the entities created by transformation
Important: These options are proposed only for the extrusion of lines and faces.

Shape of the connection elements

In many cases, the user wishes to have connection elements whose shape depends on the transformation applied (segments for a translation, arcs of circle for a rotation). But in certain particular cases he can wish to apply other rules.

Two extrusion types are proposed and presented below:

  • standard type, where the shape of the connection elements depends on the type of transformation (see the table below)
The type of transformation is a … the connection elements are …
translation segments
rotation arcs of circle
affinity segments
helix arcs of circle
  • straight forced type, where the connection elements are obligatorily segments

Example of extrusion

The two extrusion types, standard and straight forced, are presented below, line extrusion with a transformation (rotation with 30° around a pivot point P).

Standard type

(connection elements = arcs of circle)

Straight Forced type

(connection elements = segments)

Options for geometric building

The options for geometric building allow to define the geometric entities (points, lines, faces, volumes) created during the extrusion.

These options are presented in the table below:

Action Available options
Add points, lines Add points, lines, faces
Extrude Lines
Add points, lines Add points, lines, faces, volumes
Extrude Faces

Option for mesh preparation

Simultaneously with the creation of faces and/or volumes the option for mesh preparation allows:

  • to automatically create the extrusion mesh generator associated with the transformation used for extrusion
  • and to assign this extrusion mesh generator to the faces / volumes created
Attention: This option for mesh preparation simplifies the meshing process (The operations of creation and assignment of mesh generators are automatically performed.) but it does not replace the operations of mesh adjustment and meshing itself.

This option is presented in the table below:

Action Available options Name of mesh generator (automatically assigned)
  Creation of … and assignment of …  
Extrude Lines extrusive mesh generator associated to transformation mesh generator to created faces

EXTRUSIVE_NAMETRANSF
Extrude Faces extrusive mesh generator associated to transformation mesh generator to created volumes

Where NAMETRANSF is the name of the transformation.

For more information on extrusive mesh generator refer to chapter Mesh: software aspects.