added documentation for new method

MeshLib/MeshGenerators/LayeredMeshGenerator.h

@@ -62,6 +62,16 @@ protected:
     /// Adds another layer to the subsurface mesh
     virtual void addLayerToMesh(MeshLib::Mesh const& mesh_layer, unsigned layer_id, GeoLib::Raster const& raster) = 0;
 
+	/**
+	 * Calculates the node Position of a subsurface node based on the given raster but also constrained the DEM layer
+	 * the layer located below.
+	 * @param dem_node          The node at this xy-location on the DEM
+	 * @param last_layer_node   The node at this xy-location on the layer below
+	 * @param raster            The raster file for the current layer
+	 * @param new_node_id       Node ID to be used if there is a meaningful node position to be found
+	 * @param minimum_thickness The minimum thickness required for the layer (i.e. if the distance to the bottom is smaller, the node is collapsed)
+	 * @result A new node at the given xy position.
+	 */
     MeshLib::Node* getNewLayerNode(MeshLib::Node const& dem_node, 
                                    MeshLib::Node const& last_layer_node, 
                                    GeoLib::Raster const& raster,