I have a level which is an outdoor 4Km x 4Km level set in a desert valley surrounded by hills and I’m having problems trying to light it without getting a bazillion warnings from Lightmass. This brings up some questions:
Lightmass complains there is no Lighmass Importance Volume. Do you still use one on large open areas?
I have never been able to use grass without getting errors that the lightmap is too large. I’m using a Grass Node inside the landscape shader to place the grass. The grass isn’t nearly as dense as some levels I’ve seen, so I don’t get why this is causing issues.
The level uses dynamic lighting for the sun and there are currently no other lights in the level.