Here is how you can do it:
- I suggest you convert your model to meters and let rhino scale it for you, in case your’re working in mm. The model in Blender is much easier to handle in meters
- in the export obj settings, make sure you check the export rhino objects names either as obj objects or don’t export names
- one of the settings keeps each object separate
- the other setting would combine all objects in each layer, which I have found works nicely in Blender, sub-object editing is so much easier in Blender than it is in Rhino
- and then export rhino layer/group names: layers as obj groups
- in blender, make sure your axes align to what you use in rhino
- once your import is done, make sure you remove doubles
I haven’t test this in 2.8 yet, but this is the workflow I use for 2.79
It’s worth mentioning that @jesterKing, a rhino and cycles developer is writing a custom importer addon for blender that can directly open Rhino files. It works only for Rhino 6, but you should be able to download Rhino 6 beta for Mac. Here is the thread: Import Rhinoceros 3D files into Blender
I’ve also made a video on the process, in case you are interested:
