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Object Container Streaming (OCS) is the umbrella term for all the technology in Star Engine that makes a vast seamless universe possible, by which Star Citizen (and to an extent Squadron 42) can provide an extremely large virtual world through which the players can move without seeing a loading screen.[1]
Related technology
Server-Side Object Container Streaming
Server-Side Object Container Streaming (SOCS) is a streaming technology needed to expand the scale of the universe on Star Citizen servers.[2] The basic concept is that if no player is near an object, the game can "freeze" that object's state. And instead of keeping the frozen entity in memory (incurring a cost), the game can serialize (using Serialized Variables) its state and store the serialized state in a database. While a client is moving through the virtual world, the server updates its view into the database to restore entities now in proximity as well as free and store away no-longer-needed entities.[1]
Entity Streaming Manager and StarHash
StarHash is used to store in-game entities in a way allowing efficient searches for all entities in an area of space by utilizing a data structure called a RadixTree. The Entity-StreamingManager is then the logic-driving the StarHash-RadixTree queries to trigger loading and unloading of entities on the server, based on the positions of all connected clients.[1]
Cross Session Persistence
Cross Session Persistence allows the game to store the entity in a frozen state in an in-process database that can be used by different server or machine. It is an efficient network access layer to allow the storing of the entity in a database on a different machine. Before Cross Session Persistence, the state of an entity is lost when the server crashes or is restarted (besides the state the game already persist). With Cross Session Persistence, object state will persist over server restarts and crashes (until the persistence database is wiped).[1]
I-cache
I-cache is a back-end system and service that provides and manages reliable persistence of all player and entity data.[2] First major part of I-cache was completed and tested internally in March 2019. It was introduced as a replacement of the existing pCache. It is a highly distributed and fault-tolerant storage/query engine that greatly out-performs pCache. It provides an indexing and query system that can be utilized by other services for specific and complex item queries.[3]
Server Meshing
Server Meshing is a technology that allows the game instance to utilize multiple servers. Instead of having a single server manage all the views, the game will distribute the individual views over multiple servers. Doing this will reduce the load on each participating server. When those servers are placed on different machines on Amazon Web Services (AWS), the game can easily scale with the player count.[1]
Network Bind Culling
Network Bind Culling is the process of deciding what entities to load and unload on any client. Specifically, it works on units of Entity Aggregates, using the information of the Entity Component Update Scheduler to decide what Entity Aggregates to load or unload on each client.[1]
Network Bind Culling was first mentioned in November 2016 as entity bind culling.[4]
Entity Component Update Scheduler
Entity Component Update Scheduler is a system designed to control the update of entity components, based on how they are spatially placed relative to the player. It allows the game to skip updates of individual components which are too far away. The same information is utilized by Network Bind Culling.[1]
It was first mentioned in April 2018 as being refactored and nearly finished.[5]
Entity Ownership Hierarchy and Entity Aggregates
Entity Ownership Hierarchy keeps track of entities that are related to each other. If they are related, the game treats them as one group, or Entity Aggregate. Compared to Object Containers that split the static level geometry and objects into building blocks at level design time, Entity Aggregates are consisted of dynamic entities (e.g. players, ships, etc.) that can move around in the universe.[1]
Entity Ownership Hierarchy was first mentioned in March 2017 with the development of Entity Owner Manager.[6]
Entity Spawn Batches and Entity Snapshots
Entity Spawn Batches represent a set of entities that should be spawned together and only made active when all spawned. Entity Snapshots are the values of the Serialized Variables belonging to the entity. They are also used for serializing entity state to persistence, or for Squadron 42 save games.[1]
Serialized Variable Culling
Serialized Variable Culling is a system that would only send network updates to clients if that client is in proximity of the updated Entity-Aggregate. It provides a noticeable performance improvement on the clients. Additionally, it was the first real-life test of running our client game-simulation with only partial information of the whole universe.[1]
It was originally planned for Alpha 3.0, but was delayed to Alpha 3.1.[1]
