Structured faces

Automatic faces / structured faces

The faces created by Flux using the algorithms of automatic construction are faces belonging to planar, cylindrical or conical surfaces. These faces are named automatic faces.

It is possible to create faces belonging to other types of surfaces: spherical, toroidal or helical, by using the construction by extrusion. (See Construction by extrusion.) These faces are named structured faces.


The algorithm of automatic face construction is:

  • able to identify and to create a planar, cylindrical or conical face starting from its bordering lines
  • unable to identify and to create a spherical, toroidal or helical face starting from its bordering lines


To properly propagate an object (face / volume) containing structured faces, it is necessary to use a building option that includes the creation of faces / volumes (Add Faces, Lines and Points / Add Volumes, Faces, Lines and Points, etc.)

In fact, if the default option (Add only Lines and Points) is selected:

  • only points and lines are created
  • the face (volume) cannot be created using the Build Faces (Build Volumes) command

This is shown in the example below.


The example that follows shows that it is necessary to respect the building rule previously established in order to propagate a volume bordered by a toroidal face.

Step Description
1 Construction of the base volume bordered by the toroidal face


Propagation of the volume using a transformation (affine transformation with the respect to a plane using a scaling factor = –1 (planar symmetry))

… with the following building options:

Add only Lines and Points

Add Volumes, Faces, Lines and Points

3 Construction of faces

Warning: Neither the toroidal face, nor the volume are built
Note: The toroidal face and the volume bordered by this face are built