NPC in open world

Hi,
I’m working on a small open world RPG (“The Elder Scrolls” like) and I have some problem with NPC setup.

Like in most (all?) open world RPG, I want my NPCs to be visible and active while in player radius, then be invisible and “paused” while out of radius but I really don"t know what’s the best way to achieve this. Plus I’m using world composition. Any help/ideas are welcome.

in theory they should be getting culled when they arent in the zone that you are in, but i dont know the specifics on how world composition handles characters in particular. you could also look into occlusion culling, theres some good info from Tim Hobson at the following Link.

Edit: im not sure the culling portion is still on that site sorry about that.

They are loaded/unloaded with level streaming distance but that’s not what i’m looking for.
In almost every Open world RPG, NPCs fade in/out at a certain distance around the player.
When they walk out of this distance, they fade out. When you follow them and you’re close enough, they fade in and keep walking from the location they faded out.