Civil 3D Get Poly Curve from corridor shape or Idea to generate solid from corridor

[kovacsv]

Well, you can’t extract solids directly using API in C3D 2022.
If you are able to upgrade I suggest at least 2023 as this is possible from version 2023.2:

Extract Solids for Multiple Corridors

Good news everyone! This is now covered in the 2023.2 Update API. Here’s a test script: # Load the Python Standard and DesignScript Libraries import sys import clr # Add Assemblies for AutoCAD and Civil3D clr.AddReference('AcMgd') clr.AddReference('AcCoreMgd') clr.AddReference('AcDbMgd') clr.AddReference('AecBaseMgd') clr.AddReference('AecPropDataMgd') clr.AddReference('AeccDbMgd') # Import references from AutoCAD from Autodesk.AutoCAD.Runtime import * from Autodesk.AutoCAD.ApplicationServi…

As an alternative option, theoretically, if you create corridor sections you can use the SectionPoints Property to access section points and recreate shapes for Dynamo to loft solids.
https://help.autodesk.com/view/CIV3D/2025/ENU/?guid=ae047b27-4c49-e496-9486-6649e2228764
https://help.autodesk.com/view/CIV3D/2025/ENU/?guid=c19d4bb4-c946-9c3e-34f3-5c1a78903702
I have no idea how complicated this method would be, so if you really need this and you have access to newer versions I advise you to upgrade to 2023 or above.