How can I use mapped mesh on faces with more than 4 edges?

In order to use mapped mesh generator on faces with more than 4 edges, it is necessary to assimilate this face to a rectangle, i.e. structure the face by grouping the lines. To structure a face consists in choosing 4 vertex points to delimit 4 groups of lines (4 sides of the reference rectangle).

1	Activate the Structure mesh / Structure faces for mapped mesh command
2	Fill out the dialog box: designate in order the 4 vertex points of the face (whatever rotation sense) click on OK

Activate the Structure mesh / Structure faces for mapped mesh command

Fill out the dialog box:

designate in order the 4 vertex points of the face (whatever rotation sense)
click on OK