June 20, 2012, 05:08:18 pm
Ah, you mean the automatic terrain culling in Build mode. This is automatically turned off when you render still images and movies, so that you can see the whole terrain.
Incidentally, we're beta testing a new version of Lumion at the moment, and in that version you will be able to turn terrain culling on/off in Build mode by pressing the F7 key.