If you look at the Orography tab in the attached file there is a graph. The blue line represents a hill or ridge. The dots represent the position of a scaffold on the hill. On the left is the upwind side and there is an orange line. If the scaffold is above this line then it is affected by the terrain and a set of equations need to be checked. I want to shade above the line. On the right is the downwind side. I want to shade below the grey line down to blue. I can introduce dummy nodes to place a node on the blue line directly under the grey line node. I can do the same the other side at 0,900. I cannot find how to shade these areas?