I want to create a Dynamo script that can export object geolocation and attribute data to either an SDF or SHP file. The objects could be polylines, blocks, points, etc. Basically, I want to have the same functionality as the MAPEXPORT command so that I can automate the process of selecting different objects on different layers and saving them out as separate SDF/SHP files.
I tried to create a Python node but didn’t get it to work (I’m not strong with Python). Does anyone have any ideas?
I’m not aware of any method for this in Dynamo (although could exist)
An alternative is to use the OGR2OGR utility, which is part of ‘GDAL’- basically a set of opensource GIS applications.
The following sample would export to a shapefile
ogr2ogr -where "OGR_GEOMETRY='LINESTRING' AND LAYER='LAYER1'" -f "ESRI Shapefile" c:\temp\out.shp c:\temp\in.dxf
That’s very interesting! I’ve never heard of GDAL before. I’m still hoping to find a way to accomplish this with Dynamo, but I haven’t made any progress yet. Thank you for your idea, I appreciate it.
If you want to invest time in GDAL, you better look at the APIs in Civil 3D. It is default available and you don’t need other libraries.
It’s not easy, when you don’t have experience with Python or other language, but GDAL isn’t either.
@mzjensen Have you found any solution for exporting lines from Civil as shp or sdf ? Im also looking for a solution but i think Im stuck for the moment 
Not really…my solution for now is a Python node that sends a string of inputs to the command line for the -MAPEXPORT command (i.e. without the dialog box). Not very elegant, but it works for now.
Do you maybe have a screencast from your workflow today?
We would alos like to export the SHP files via Dynamo. But maybe it is more convenient to provide this via FME.
@mzjensen, @jacob.small, @Anton_Huizinga, @Andrew_Hannell @cristi.balaban
I spoke last week with Mohsen Assaqqaf about exporting SHP out of Civil 3D via Dynamo.
We currently see 2 possibilities:
Export shp files with DynaMaps (@Mostafa_El_Ayoubi) if it is possible?
https://dynamobim.org/dynamaps/
To do it in just Dynamo with Zero-Touch nodes and work with the API that Civil 3D provides.
https://github.com/DotSpatial/DotSpatial
Do you have another idea or agreement with the above?
Thanks in advance.
Python
MAPEXPORT is the easiest- but it depends if you have specific requirements that this command does not address.
Shapefiles are widespread and reliable- but fairly old technology with some limitations- such as only storing a single geometry type.
Generally speaking, spatial databases such as Spatialite or SDF (a flavour of spatialite), or full-blown databases such as Postgres/PostGIS are more flexible- but it depends what you want to achieve.
What we currently want to achieve is the following:
C3D (polygones) -> Dynamo (SHP) -> Infraworks (SHP)
Maybe DynaMaps can help us to get the polygones in Dynamo, in Dynamo we need to provide a Python node that can export the data to SHP format (as indicated by @Paolo_Emilio_Serra1) .
Hello, why not to export to sqlite? https://knowledge.autodesk.com/support/autocad-map-3d/learn-explore/caas/CloudHelp/cloudhelp/2021/ENU/MAP3D-Use/files/GUID-B4CD55ED-560D-42C7-8348-66AE770B2342-htm.html
https://ironpython-test.readthedocs.io/en/latest/library/sqlite3.html
I’d start here: pyshp · PyPI
C3D is irrelevant as you learn how to use that. Just write a few polygons or whatever out to SHP. Then transition to D4C3D and a real data set. Then work on the import step.
You might be over-complicating it. If all you want to do is export stuff to a shapefile- MAPEXPORT will do just that.
I would do the following:
Hope this helps
Do you have experience with this Drbohlav?
No, Sorry.
This is my method as well. I’ve found that MAPEXPORT is the easiest, but the problem is that I typically want many separate SDF files to import into InfraWorks as coverage areas because then they will show up separately in the surface layers window. That way you can toggle the visibility on/off for individual layers. With MAPEXPORT you can export multiple features along with their CAD layer attribute to a single file, but then in InfraWorks you only have one data source and therefore lose the visibility control.
Hence the need to automate. Here’s a screen recording of my current solution, which I don’t really like, but it works. It basically just builds up a big string to send to the command line and execute the MAPEXPORT command multiple times. Eventually I want a more direct export method via the Map API, but for now this works.
MapExportTest.dwg (386.5 KB)
MapExportByLayer.dyn (61.3 KB)
@j.boonen I’m not sure why it’s like that, it doesn’t do that on my end. Anyway, here is the code, it’s just a few lines to send a string to the command line.
import System
from System import *
output = "Error"
inputList = IN[0]
app = System.Runtime.InteropServices.Marshal.GetActiveObject("Autocad.Application")
adoc = app.ActiveDocument
for i in inputList:
adoc.SendCommand(i)
OUT = "Success"