Warning: Although I call it a toilet bowl it is in reality just a freeform shape based on a quick glance at a toilet bowl. Please don't regard the drawing as anything other than a learning exercise.
Summary And Conclusions
I did a complex surface ("organic shape") in Rhino 3D was relatively easy for me to do in Rhino 3D but was too hard for me to do in AutoCad.
I brought it back into AutoCad by Export Selected as .dwg, .dxf and .3ds (there were more options) but the 3ds (3D Studio Max) seemed the optimum of these three.
What I got in AutoCad were polyface mesh objects which I could render or carry on using in an AutoCad drawing.
Ok. No longer have a NURB surface and probably lost accuracy in polyface conversion. Not an issue.
Rhino has the feel of Autocad and an AutoCad user should be very comfortable with Rhino fairly quickly if you don't fight the differences but accept them and get on with it.
Don't get locked into "which is the better package conflict". Regard Rhino 3D as invaluable drawing aid and file format utility. All other things being equal an Autocad user with access to both has a decided (even powerful) advantage over an operator restricted to AutoCad alone.
1. The Rhino 3D Model Saved As 3dm
toilet3dm.zip Version 2 (75kB unzipping to 124kB)
2. The Rhino 3D Export Selected In Various Formats
Note1: Only exported the objects. Could have Saved As (the 24 format options were identical in both File>Export Selected or File>SaveAs).
Note2: Use Zoom Extents to find the drawing after you get it into AutoCad
toiletdwg.zip (48kB unzipping to 114kB)
Created a layer in A2000 called DEFAULT (layer name used in Rhino) and put both objects on it.
toiletdxf.zip (38kB unzipping to 413kB)
Created a layer in A2000 called DEFAULT (layer name used in Rhino) and put both objects on it.
Responded the same in A2000 as the dwg format.
toilet3ds.zip (19kB unzipping to 34kB) **My choice**
Created an individual layer for each object when opened in A2000.
To Be Done:-
IGES (Including Inventor 5 format)
ASIS