I remembered that I saw a wheatfield when talking to the two cows on Reapers coast.
Looking in the editor it looks like this:
https://imgur.com/a/mfOS2Two box trigger I can't figure out what does and no wheatfield.
So how did Larian do this? By using the triggers? Or did they deactivate Instances (as lots of things are missing). There is nothing in the Instance tool and I remove things from the instance tool they dissapear.