Cost of Level Streaming Volumes
UWorld::ProcessLevelStreamingVolumes iterates over each streaming Level and for each Level, that Level will begin loading if any local player is within any of the
volumes associated with that Level. Likewise, the Level will be begin unloading if all local players are outside all volumes.
UWorld::ProcessLevelStreamingVolumes exploits coherency in the following manner: for each Level, the volume that most recently contained a player is cached. This cached volume is checked first, so
that Levels a player is in or returns to are quickly accepted.
Volumes of any shape are fine, although obviously the fewer the better. An upper bound on the cost of Level Streaming Volumes can be approximated by the sum of the number of Level Streaming Volumes
associated with unloaded Levels.
Two stats exist under the "Streaming" stats group for monitoring level streaming performance. The "Streaming Volumes" stat tracks the number of Level Streaming Volumes tested against player viewpoints
per frame, while the "Volume Streaming Tick" stat tracks the amount of time spent in
UWorld::ProcessLevelStreamingVolumes per frame.