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SDK 1.3
SDK 1.3
  • Welcome
  • Overview
    • Features
    • Roadmap
  • Getting started
    • Get the Unity SDK
    • Setup a project
      • Scene setup
      • Prefab setup
      • Sample connection UIs
      • Local development
        • Local testing using Builds
        • Local testing via Unity's Multiplayer Play Mode (MPPM)
        • Local testing via ParrelSync
      • Test in the cloud
        • Deploy a Replication Server
        • Share builds
    • Video tutorials
    • Samples and tutorials
      • Package samples
      • First Steps tutorial
        • 1. Basic syncing
          • 1.2. Animation parameters
          • 1.3. Sending commands
        • 2. Physics / Authority transfer
        • 3. Areas of interest
        • 4. Parenting entities
        • 5. Complex hierarchies
        • 6. Persistence
      • Campfire project
        • Game mechanics
        • Leveraging object pooling
        • Remote interactions: Chairs
        • Remote interactions: Trees
        • A unique object with complex state
        • Custom instantiation and destruction
        • Running a server-side NPC
        • Playing audio and particles
        • A simple text chat
      • Beginner's guide to networking
  • Manual
    • Unity Components
      • CoherenceSync
      • CoherenceBridge
      • CoherenceNode
      • CoherenceLiveQuery
      • CoherenceTagQuery
      • PrefabSyncGroup
      • CoherenceInput
      • Order of execution
    • Networking state changes
      • Supported types
      • Messaging with Commands
      • Syncing child GameObjects
      • Animation
      • CoherenceSync references
      • [Sync] and [Command] Attributes
      • [OnValueSynced] Attribute
      • Creating your own syncable member
      • Custom Component Actions
      • Rigid Bodies
      • Interpolation
    • Authority
      • Authority transfer
      • Server-authoritative setup
    • Lifetime
      • Persistence
      • Uniqueness
      • Example: A global counter
    • Parenting network entities
      • Direct children CoherenceSyncs
      • Deeply-nested CoherenceSyncs
      • Nesting Prefabs at Edit time
    • Asset management
      • Instantiate via
      • Load via
      • Instantiating from CoherenceSyncConfig
    • Scene management
    • Baking (code generation)
    • Replication Server
      • Rooms and Worlds
      • Replication Server API
    • Simulators (Servers)
      • Scripting: Client vs Simulator
      • Run local Simulators
      • World Simulators
      • Room Simulators
      • Simulator slugs
      • Multi-Room Simulators
      • Build and Deploy
      • Command-line arguments
    • Client Connections
    • Optimization
      • Areas of Interest
      • Level of Detail (LOD)
      • Profiling
      • Simulation Frequency
    • Project Settings
    • Advanced topics
      • Big worlds
        • World Origin Shifting
        • Load balancing
      • Competitive games
        • Simulation Frame
        • Determinism, Prediction and Rollback
      • Team workflows
        • Version Control integration
        • Continuous Integration
      • Schema explained
        • Specification
        • Field settings
        • Archetypes
      • Code Stripping
      • Command-line interface tools
      • Single-player gameplay
    • Scripting API
  • Hosting
    • Choosing where to host
    • coherence Cloud
      • Online Dashboard
      • Manage Worlds
      • Configure Rooms
      • Lobbies
      • Game Services
        • Account
        • Key-Value Store
      • coherence Cloud APIs
        • Worlds API
        • Rooms API
        • Lobbies API
        • Game Services
          • Authentication Service (Player Accounts)
          • Key-value store
    • Peer-to-peer
      • Implementing Client hosting
  • Support
    • Release notes
    • Glossary
    • Unreal Engine support
    • WebGL support
    • ECS / DOTS support
    • Known issues and troubleshooting
    • Upgrade guide
      • Upgrade 1.2 -> 1.3
      • Upgrade 1.1 -> 1.2
      • Upgrade 1.0 -> 1.1
      • Upgrade 0.10 -> 1.0
      • Upgrade 0.9 -> 0.10
    • Credit cost & pricing
    • Report a bug
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  1. Manual
  2. Networking state changes

CoherenceSync references

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Entity references let you set up references between Entities and have those be synchronized, just like other value types (like integers, vectors, etc.)

To use Entity references, simply select any fields of type GameObject, Transform, or CoherenceSync for syncing in the Configuration window:

The synchronization works both when using reflection and in baked sync scripts.

Limitations

It's important to know about the situations when an Entity reference might become null, even though it seems like it should have a value:

  • The owner of the Entity reference might sync the reference to the Replication Server before syncing the referenced Entity. This will lead to the Replication Server storing a null reference. If possible, try setting the Entity references during gameplay when the referenced Entities have already existed for a while.

  • Cyclic references are undefined behavior for now. Therefore multiple entities created on the same Client that reference each other might never get synced properly. This is also holds true for references that exist through intermediate entities (A has reference to B has reference to C has reference A - cyclic).

In any case, it's important to use a defensive coding style when working with Entity references. Make sure that your code can handle missing Entities and nulls in a graceful way.

Entity references can also be used as arguments in .

A client might not have the referenced entity in its LiveQuery. A local reference can only be valid if there's an actual Entity instance to reference. If this becomes a problem, consider switching to using the component or of prefabs, which ensures that that Entity stays part of the query.

Commands
CoherenceNode
Parent-Child relationships