GGU-3D-SSFLOW: "Modify depths" menu item

All depths in a given plane can be altered as a function of the existing depths in a different plane.

In the example shown in the dialog box above, all nodes of plane 4 (= top of layer 3) were moved 3 length units above the existing level of plane 3 (= top of layer 2). This menu item can be used to generate parallel layers, especially for complex layer surfaces.