Im currently trying to do the exact same thing. I have a 8km square map with a 4km square playable area that is covered entirely by dense forest. I want the trees to always remain loaded but have the undergrowth only be loaded when its close to the player. I can’t seem to do this with world partition because it only loads the entire foliage actor in or out, not the individual foliage types, so I can’t just put my trees on a different runtime grid to my undergrowth. My load times are insane due to the millions of foliage instances on the map. My foliage is extremely performant after 3 years of constant development and there’s nothing much more I can do to get better performance out of it. My only real issue is the unacceptable load time that comes with having all the foliage loaded at once, even when everything but the trees are culled when they’re not close to the player. I have tested using landscape grass types to do my undergrowth and left my trees as procedurally generated foliage and it works perfectly with amazing performance and super quick load times even inside the editor, however I cannot use grass types as they don’t have collision or ways of interacting with them like a foliage instance static mesh does. All of my foliage needs to be interacted with in various different ways so grass types are out of the question. I am currently working on using HLODS for the trees so they remain visible in the distance while my foliage actors are loaded with world partition and it seems to be working but as chopping trees down is a major part of my game, I know I’m going to run into the issue of having my HLODS no longer accurately representing my trees as they get cut down. Does anyone know of a way to update a specific HLOD at runtime? Ideally when I chop a tree down I would want to remove its instance from the HLOD. Would be so much simpler if unreal would let you assign different runtime grids to different foliage components or treat the painted/generated foliage loading and unloading the same as they do grass types.