Clone Nonterrain Surface
Create copy of surface group faces, cut by mask.
Apply to control geometry, not terrain. Select a non-terrain surface, and select a mask, then run Clone Nonterrain Surface. This is useful to extract a smaller area out of a larger control group.
Type: CloneMenu: Extensions > Landshape > Clone > Clone Nonterrain Surface
Why Clone Surface
Let's say you have a large terrain, and also large single Zone control group that you have used to zone the terrain.
Now, later on in your workflow, you may want to impose a zone change to your terrain. However, you only want to change a small, local area.
This is where Clone Nonterrain Surface is handy.
An Example
For instance, you can first run Clone Zone to extract a 2D terrain material representation of the entire terrain. Then, later on, you can create a separate mask group. Then, select both the zone clone group and the mask group. Now, run Clone Surface. This will create a copy of the subset, limited by the mask.