Once you install the Datasmith Exporter Plugin for Rhino, you have an Unreal Datasmith (.udatasmith) filetype available to you when you save or export a scene.
Follow the steps below in Rhino to export your scene using this new filetype.
From the Rhino File menu, select either one of the following options:
Save As: A
.udatasmithfile is created containing all visible elements.Export Selected : A
.udatasmithfile is created containing all the selected elements. Layers containing no selected elements are not exported.Export with Origin : A
.udatasmithfile is created containing all visible elements. The scene exports with the specified position offset.
In the Export window, select the Unreal Datasmith (.udatasmith) option from the Save As type dropdown.
Browse to the location where you want to save your exported file, set the File name, and click Save.
Alternatively, click the Export 3D View button on the Datasmith Toolbar. This creates a .udatasmith file containing all visible elements.
For more information about the Datasmith toolbar, see Using the Datasmith Toolbar.
End Result
Your .udatasmith file should now be ready to try importing into Unreal Engine 4. See Importing Datasmith Content into Unreal Engine. If your data needs additional cleaning, merging, or other modifications during the import process, see Dataprep Import Customization.