# Surfaces Replication

Surfaces Replication contains parameters that set the behaviour for the mesher when working with surfaces.

There is only one option called Parameters in this tab that is composed by some sub-options. By marking the Replicate Open Surfaces option, a parallel layer of open objects is generated in the mesh generation process. If replication is marked, the elements of all the open objects are replicated to an automatic frequency-dependent distance from the original ones. By clicking on the advanced button, the window shown in the next Figure will appear where additional features can be configured.

• Replication Area. The criterion to replicate open objects can be edited.
• Automatic Replication. It is the default option. Let div_plane and div_curve are the number of divisions per wavelength for planar and curved surfaces, any object with a total area greater than:
(1) $a\ge 10\cdot {\left(\frac{lambda}{maximum\left(di{v}_{plane},di{v}_{curve}\right)}\right)}^{2}$
• Replicate all open objects. Any object is replicated, by default.
• Replicate objects with area greater than. To specify manually the threshold of the minimum total area of the objects to be replicated, in square meters.
• Replication Distance. The distance between the original objects and their parallel replicas can also be edited.
• Automatically calculate. By default, the distance is given by the following expression:
(2) $d=0.03\cdot \left(\frac{lambda}{maximum\left(di{v}_{plane},di{v}_{curve}\right)}\right)$
• Specified distance. To specify manually the desired distance, in meters.