GGU-3D-SSFLOW: "Unrefine" menu item

You can "unrefine" the FEM mesh in a defined section, i.e. you can remove an element layer. If you click in a layer with the left mouse button, the node plane below it is deleted, together with the corresponding elements, i.e. the clicked layer is amalgamated with the layer below. The previous step can be undone using [Backspace].