I’m trying to make a dynamo workflow that will create a cogo point at the center of selected arcs in civil 3d. By using Arc.ByObject I can get a list of the arc’s info. Is it possible to extract the centerpoint coordinate and radius from this list?
What have you tried? Searching for “arc” returns nodes that do exactly what you’re asking. If you’re having issues with something specific then you need to communicate that.
The error tells you that Arc.ByObject returns an AutoCAD arc object and not a normal geometry object, which is why you’re having issues. Try using one of the standard geometry nodes (or find a custom one) to either get the underlying arc/curve geometry from the object instead or convert the AutoCAD arc to a geometry object.
There are plenty of custom packages that deal with AutoCAD formats. I don’t use C3D, so I don’t know if there would be any specific restrictions there, but that seems like your best bet. GeniusLoci and Bimorph are both good options to start with.
Your other option is to use the API.