Create progressive 2D structured mesh with Z-set mesher

When simulating large domains with structured mesh (to avoid border effects for instance), it could be usefull to use the NG_extension mesher function of Z-Set (which - of course - is not even mentioned in Z-Set documentation).

This function allows to extend a 2D quadrilateral mesh, divinding the mesh size by two. The function takes the following parameters:

*bset _bset_ : the border set to extend

*length _float_ : total length of the extension

*nb\_extension _int_ : number of extension (2 will for instance consists of two extension floor divinding th initial size by 4)

*direction _x y z_ : direction of extension

The following example computes a simple 2D extension

What about 3D ?

For 3D meshes, a simple way to use the above function is to combine two extension planes as follows: