I need to import a shape file with lots of polygons with shared boundaries and also islands etc.
Using mapimport I tried both import polygons as closed polylines ticked and unticked and I do get all the shape to display correctly in CAD.
My problem is that GIS has two overlapping lines for polygons with shared boundaries, while in CAD we only have a single line representing the border between adjacent polygons. I need to create Topology with the imported polygons and this you cannot do if there are lines on top of each other. I tried to remove them with Drawing cleanup but no lines are removed.
Any suggestions on how to get rid of the duplicate lines or to prevent them during import?
Patrice BRAUD
I have attached the DWG.
If you look at the linework almost everywhere there are 2 lines on top of each other.
I have also done an "explode" command and then "Drawing clean up" to remove the duplicate lines, but no objects were removed.
I want to create topologies, it will not work with the duplicate lines. see jpg or dwg attached.
I generally work in ArcGIS, (so I am not a CAD expert) and only use 3D map for digitizing polygons from geotiff images for seafloor classification. I then create topologies and export to shapefile. In this case I had to go back to CAD to do additional digitizing, but this does not seem so easy.
Hi
I just solved my own problem:
I converted the polygon shapefiles to line shapefiles in ArcGIS before importing into Map 3D.
I can also create a centroid for each polygon in ArcGIS which will already have the correct attribut to assign the layer.
Patrice BRAUD
Try Drawing Cleanup for the original dwg with my settings - polygons.dpf. . (Could only attach with the extension zip).
There is only one error in the topology after it.
Hi,
To use MAPCLEAN to do the job, you have to add 3 actions
(Sorry for french interface, hope english order of action is the same as french) :
1st : cut object at intersection (3rd position in list)
2nd : remove duplicate objects (1st position in list)
3rd : connect free node (7th position in list)
You have to execute MAPCLEAN twice with same options before you can create topology without errors.
Olivier
Olivier Eckmann
@O_Eckmann wrote:Hi,
To use MAPCLEAN to do the job, you have to add 3 actions
(Sorry for french interface, hope english order of action is the same as french) :
1st : cut object at intersection (3rd position in list)
2nd : remove duplicate objects (1st position in list)
3rd : connect free node (7th position in list)
You have to execute MAPCLEAN twice with same options before you can create topology without errors.
Olivier
Probably, "7th position in list", Décomposer les nœuds... - Snap Clustered Nodes? I have this 6th position.
If I do only these three actions, then after twice their launch, the topology creation shows me many errors. Mainly because of Dangling objects or gaps.
Hi Alexander,
Here is my screencast to proceed from OP drawing with my settings in Mapclean and success of creation of polygonal's topology
Olivier Eckmann
Hi, Olivier,
Yes, you are absolutely right!
These three actions of yours are really enough!
My mistake was that I decided to use the tolerances not 0.
And this led to unnecessary actions.
As always, when I want to be "too smart"! 🙂
Can't find what you're looking for? Ask the community or share your knowledge.