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Last Update: 2023-07-06

Network

Network is a common property that manages data synchronization between server and client in the multiplayer system. It is a crucial component for creating entities that properly function in Don't Starve Together's client-server architecture.

Overview​

Don't Starve Together uses a client-server networking model where:

  • The server (master simulation) maintains the authoritative game state
  • Clients receive updates from the server and send input to the server
  • Network components handle the synchronization of entity data

The Network property is essential for any entity that needs to be visible and interactive across all clients in a multiplayer game.

Adding Network to an Entity​

The Network component must be added during entity creation:

local function CreateNetworkedEntity()
    local inst = CreateEntity()
    
    inst.entity:AddTransform()
    inst.entity:AddAnimState()
    
    -- Add network component
    inst.entity:AddNetwork()
    
    -- Complete network initialization
    inst.entity:SetPristine()
    
    if not TheWorld.ismastersim then
        return inst
    end
    
    -- Server-only code here
    
    return inst
end

Network Architecture​

Server vs. Client Code​

In networked entities, code is organized into server (master simulation) and client sections:

local function MyPrefab()
    local inst = CreateEntity()
    
    -- Components required by both client and server
    inst.entity:AddTransform()
    inst.entity:AddAnimState()
    inst.entity:AddNetwork()
    
    -- Networked properties setup
    inst:AddTag("networked_tag")
    
    inst.entity:SetPristine()
    
    -- Early return for clients
    if not TheWorld.ismastersim then
        return inst
    end
    
    -- Server-only components and logic
    inst:AddComponent("inventoryitem")
    
    return inst
end

Networking Entity Data​

Basic Networking​

Only certain types of data are automatically synchronized:

  1. Transform position and rotation
  2. AnimState animations and visual states
  3. Entity tags added before SetPristine()
  4. Explicit network variables

Network Variables​

To synchronize custom data between server and clients:

-- Create a networked variable (server code)
inst.bird_type = net_string(inst.GUID, "bird.type", "bird_type_dirty")

-- Set the value (server only)
inst.bird_type:set("crow")

-- Listen for changes (client code)
inst:ListenForEvent("bird_type_dirty", OnBirdTypeDirty)

NetWorking Components​

Don't Starve Together provides specialized components for networking:

NetComponents​

Wrapper components that handle network synchronization for you:

-- Add a networked component
inst:AddComponent("container")
inst.components.container:WidgetSetup("backpack")

-- These components handle their own networking

Classified Entities​

For complex data structures, classified entities are used:

-- Create a classified entity for private data
local classified = SpawnPrefab("myentity_classified")
classified.entity:SetParent(inst.entity)
classified.Network:SetClassifiedTarget(inst)
classified:AddTag("CLASSIFIED")

inst.classified = classified

Network Optimization​

Network Priority​

Control how frequently an entity is updated:

-- Set network update priority
inst:AddComponent("networkproximityfader")

Dormant Entities​

Entities far from players can become dormant:

-- Make entity go dormant when far from players
inst:AddComponent("knownlocations")

Common Networking Patterns​

Master Simulation Check​

Always check if code is running on the server:

if TheWorld.ismastersim then
    -- Server-only code
end

Event Handling Across Network​

Events can be sent across the network:

-- Server pushing events to clients
TheWorld:PushEvent("my_global_event", {data = value})

-- Server-to-client targeted events
SendRPCToClient(CLIENT_RPC.DoSomething, player.userid, ...)

Debugging Network Issues​

Common Issues​

  1. Client-server desynchronization
  2. Missing network component
  3. Not initializing network with SetPristine()
  4. Modifying client-side data that should be server-authoritative

Debug Tools​

-- Print entity network status
print(inst, "has network:", inst.entity:HasNetwork())

-- View network statistics
c_printnetnumber() -- Console command

Example: Fully Networked Entity​

-- Server-client synchronized entity
local function MyNetworkedEntity()
    local inst = CreateEntity()
    
    -- Basic components
    inst.entity:AddTransform()
    inst.entity:AddAnimState()
    inst.entity:AddSoundEmitter()
    inst.entity:AddNetwork()
    
    -- Setup animation
    inst.AnimState:SetBank("myentity")
    inst.AnimState:SetBuild("myentity")
    inst.AnimState:PlayAnimation("idle")
    
    -- Networked tags
    inst:AddTag("myentity")
    
    -- Networked variables
    inst.entity_state = net_string(inst.GUID, "myentity.state", "state_dirty")
    
    -- Complete network initialization
    inst.entity:SetPristine()
    
    -- Client-side handlers
    if not TheWorld.ismastersim then
        inst:ListenForEvent("state_dirty", function(inst)
            local state = inst.entity_state:value()
            inst.AnimState:PlayAnimation(state)
        end)
        
        return inst
    end
    
    -- Server-only components
    inst:AddComponent("inspectable")
    
    -- Server-side state control
    inst.SetState = function(inst, state)
        inst.entity_state:set(state)
        inst.AnimState:PlayAnimation(state)
    end
    
    -- Initial state
    inst.entity_state:set("idle")
    
    return inst
end

return Prefab("mynetworkedentity", MyNetworkedEntity)