Starfield Backdrop Only

To make the world react to the player, I built a lightweight overlap-driven weather system. When the character enters a zone, the climate shifts in real time; when they leave, everything returns to normal. The system is fully data-driven, so each zone can feel different (snow, dust, heatwave, rainstorm, etc.) without new code.
Architecture
BP_WeatherOverlapActor
a trigger volume that holds the settings for a specific weather zone.
FWeatherData
a struct that defines those settings of the weather:
Key, ParticleSystem, SoundEffect, Amount, FollowingSpeed, Temp, Exposure Compensation
BP_WeatherSpawner
a single world controller that owns the Niagara, Audio, and Post-Process components and applies the incoming FWeatherData.
BP_SisyphusChar
the player pawn; its capsule generates the overlaps.
How it works

    Click to See Implementation details →   Begin Overlap:


    End Overlap: ClearWeatherData

    Authoring new weather zones
    1. Place a BP_WeatherOverlapActor in the level to mark the area.
    2. In its details, fill out an FWeatherData asset (pick Niagara, Sound Cue, and values for Amount/Temp/Exposure/FollowingSpeed).
    3. Make sure one BP_WeatherSpawner exists in the scene. Walking into the volume will apply your setup, and leaving will cleanly revert.