Multipart Features in AutoCAD

Happy New Year 2014.  I am apologetic for the fact I was sailing this weekend (Jan 5^th) shoe-less, in shorts and a white T-shirt until the sun went down… then it started to get a little chilly.   I was sailing around a collection of little islands, the islands when mapped are all part of the same city geometry, but have separate polygon borders because they are separated by water.  The water is not part of the city boundary.  This type of city boundary is modeled in ArcGIS and ArcGIS for AutoCAD with a GIS object called a multipart feature.

ArcGIS for AutoCAD supports ArcGIS multipart features in both feature services and in local feature classes.  Multipart features in ArcGIS for AutoCAD are group entities. When I connect to a feature service that contains multipart points, or polylines or polygons those features appear in my AutoCAD session as simple AutoCAD entities that are grouped.  Likewise using ArcGIS for Desktop's EXPORT TO CAD tool, multipart features are exported to AutoCAD drawings fully attributed, in their respective feature classes as GROUP entities. 

I create multipart features in ArcGIS for AutoCAD for feature services or local feature classes by employing the standard AutoCAD GROUP command. 

The attributes of the multipart feature technically live on the group entity.  Therefore when I create a grouped set of entities, I will always group the objects first then set their feature attributes.  If I toggle between different AutoCAD GROUP settings I know that to be dealing with the ArcGIS for AutoCAD multipart feature I need the GROUP functionality to be enabled on the collection of objects that make up the feature. 

Pretty simple... in ArcGIS for AutoCAD multipart GIS features are handled as GROUP entities in AutoCAD.