@tig said:

The 'Utility' tools that ship with SUp include 'Create Face' - you need to activate these from the Preferences > Extensions dialog; you then get an item under menu Tools > Utilities.
Alternatively there are other tools...
Try
Plugins Index > 'AddFaces' [TIG]
or
http://www.smustard.com/script/MakeFaces
[note you also need to get 'progressbar.rb' for this tool]

thx. 👍