Hello,

I am working on a graph where the user can select two different sets of polylines and have dynamo extract the overlapping geometry. The graph will then insert a hatch/polyline into C3D for the overlapping geometry. The typical workflow for us where this graph would be applied is determining the impervious areas within a drainage area boundary for stormwater design calculations.

I have attached a sample DWG that includes one set of polylines representing impervious area and another representing drainage area boundaries. The graph I have set up works great if the user wants to individually add the overlapping geometry to C3D (i.e. select one drainage area polyline, select one overlapping impervious area polyline, run the graph, overlapping geometry is added to C3D).

This alone can speed up the workflow of manually working with hatches in C3D. However, this graph has the potential to save huge amounts of time if it can be adjusted to extract all of the overlapping geometries for each drainage area at once.

Image A shows the sample polylines in C3D

Image B shows the selection of one drainage area boundary and one overlapping impervious polyline

Image C shows the result from Image B. A hatch and polyline are added for the overlapping geometry.

Image D shows the selection of one drainage area boundary and multiple overlapping geometries.

Image E shows the result from Image D. The same geometry from Image C is added. Additional overlapping areas are not incorporated.

This gets to where I need assistance. The Geometry.Intersect node is only set up to compare two geometries. I need to set up a loop structure that compares each drainage area polyline to all of the impervious area polylines. The overall end goal would be to have the user select all the impervious area polylines, select all the drainage area boundary polylines, run the graph, and have all overlapping geometries added to C3D. My assumption is that this can be done. I am just stuck on how to proceed. Any help is greatly appreciated. I am very excited about this graph.

JJH_Polyline_Intersections_rev0.dyn (31.4 KB)

TEST.dwg (901.7 KB)