GGU-3D-SSFLOW: "Linear sources" menu item

After going to this menu item you define a polygon by clicking 4 points anti-clockwise. The element nodes with their centroid within the thus marked quadrilateral are assigned a linear source with the user-defined value. If an element lies not entirely within the quadrilateral, the corresponding nodes are not assigned a linear source.

If you need to delete existing linear sources, define the polygon again and enter the value 0.