2. How the GDK for Unreal fits into your game stack
When you set up your game using the SpatialOS GDK for Unreal, you add GDK functionality to your game’s servers and game clients. These interact with the SpatialOS Runtime which co-ordinates the game world.
Image: Architecture of a game developed with the SpatialOS GDK for Unreal.
There is a SpatialOS Runtime instance for every game world, holding SpatialOS representations of Unreal Actor data in its entity database. The Runtime determines which Unreal Engine server simulates each Actor, and coordinates updates to Actor data between multiple game servers and between game servers and game clients.(Learn more about the Runtime.)
For a game developed using the GDK for Unreal:
Servers: SpatialOS replicates Unreal Actors, Components and Subobjects and executes RPCs to send updates to the SpatialOS Runtime. SpatialOS also sends updates from the Runtime to servers and between servers.
Game clients: SpatialOS executes RPCs to send updates from game clients to the SpatialOS Runtime. SpatialOS also sends updates from the Runtime to game clients.
The game clients, servers, and SpatialOS Runtime all use SpatialOS networking protocols to send updates.
You can monitor the state of game clients, servers and the game world with SpatialOS tools, as well as view logs and metrics.