Level streaming, interiors and huge world

I’m trying to explore the options of UE which could lead to a project I’ve had in my mind for over 10 years.

Yesterday, I’ve discovered the level streaming and world composition, which is exactly what I was hoping to find. I’d like to ask several questions.

  • Level streaming seems to be great - un/load a part of the world, according to the player’s location. Are there any cons or anything to keep in a mind? Something like “keep the levels small”, don’t have more than 9 levels loaded at once…
  • How to make un/loading parts of the terrain properly? My idea is: every terrain has 2 levels - big and small objects. Big objects like terrain and main buildings/landmarks have a bigger radius of visibility than small stuff like street lamps etc. Small objects unload when player is 1 km away, the big objects, when the player is…10 km away? Only when they are behind the fog? UE can handle them if they are LODs? Do I have a good approach?
  • How about interiors? Let’s say I have an apartment building with 9 floors and 5 accessible apartments. My idea is: the exterior is in the map tile’s level, the public part (stairs, elevator,…) in one level and the apartments, each in its own level. Is it a good approach? Somewhere I read something about a reccomendation to execute interiors like in GTA San Andreas (interiors in a separated map). The streaming option sounds better to me since it would be seamless and the windows could be actually transparent but I understand that it could potentially bring problems, so I’m asking for an opinion.
  • I heard that the max size for world in world composition is 20x20 km. Is it possible to put some unaccesible background terrain behind that area? In ArmA, there’s a vast undetailed terrain behind the border of the detailed map. I’d be happy if there were, let’s say, two kilometers of a low-poly terrain. Is it possible or everything must be within the limit?

Thank you in advance for your answers. :slight_smile:

PS: just to be clear, I’m only scouting the options, I know I won’t be able to finish or even actually start the real development anytime soon. I’m just prototyping and trying the tools and how to work with them.

One more question.
I’m trying to assign the level to the Streaming level volume. According to the tutorials, I should be supposed to see an option to assign the volumes but as you see, there’s nothing.
There’s one volume in the persistent level.

Solved, The world composition has to be off.

Well I have no experience using world composition but from what I understand is helpful in the construction of very large maps. Level streaming on the other hand has the misfortune of being named level streaming as to function when in fact functions more along the line of 3ds Max’s x-refercing system A level can be set to stream based on a blueprint or set to be loaded at all times A level can contain master lighting components or even set up as a lighting scenario to switch between day and night lighting. Verminous elements based on game types can bee added so that a singe map can be used for any game type configuration.

Streaming levels can also be used in team based environment development as with the x-referencing 100’s of levels can be worked on by 100’s of individuals.

Personally I’ve been using level streaming much the same way as I do in 3ds Max using x-reference as it is faster, more control over the environment and allows for a much better workflow pipeline between the two apps.