Trigger Zones

Trigger Zones are intended to be used as rectangular spaces that do something when players enter and exit them.

You can easily add "Visibility zones" to your scene or prefabs with this component. It's essentially a "Trigger Box" with specific conditions for only player-agents being able to use it. You are expected to setup the events of what you want to happen when someone enters or exits.

The original use case was for Visibility Zones, so a player entering a building would disable the roof until they left the area. If you want shadows inside (like the red tower building) then you can check out the prefab to see the objects that are set to Shadows Only in the mesh renderer settings. The "shadowbox" group is just some meshes that are casting shadows when the roof is gone, but arent rendering their mesh.

The Blue Tower just toggles the building roof object off, which may be what works better for your project. The choice here is up to you.

There are many use cases for this component, so use it freely.