Field names follow headers under Gems/WorldStreaming/Code/Include/WorldStreaming/ and serialize reflection. Only author-facing fields are listed. Deep APIs: IWorldStreamingSystem.h.
WorldStreamingConfigComponent (bake-time)
Lives on the WorldConfig entity of the level root Prefab. Bake reads it and strips it—it never reaches the runtime Root Spawnable and has no component-panel editing. Written by WorldStreaming_Level, Migration Tool, or AuthorWorld* events.
| Field | Description |
|---|
WorldGuid / m_worldGuid | World identity (MP handshake, bake aggregation) |
CellIdSalt / m_cellIdSalt | CellId hash salt; regenerate on grid layout change |
Grids / m_grids | Grid level list |
Layers / m_layers | Content Layer descriptors |
HlodLayers / m_hlodLayers | HLOD layer descriptors |
WorldStreamingGridDesc
| Field | Default | Description |
|---|
m_gridLevel | 0 | Lower = finer when multiple grids |
m_cellSize | 128 m | Cell edge length |
m_defaultLoadRadius / m_defaultActivateRadius | 256 / 128 m | Fallback radii |
m_verticalPartitioning + m_cellSizeZ | off | Vertical (Z) grid |
m_singleTierActivation | off | Skip Loaded warmup |
m_use2DDistance | off | XY-plane distance on vertical grids |
m_streamingPriority | 0 | Budget ordering bias |
m_gridOriginD | (0,0,0) | Origin offset; changing re-partitions |
Narrative:
Authoring.
WorldStreamingMemberComponent (optional)
Ordinary entities do not need this component.
| Field | Default | Description |
|---|
IsSpatiallyLoaded / m_isSpatiallyLoaded | true | false = AlwaysLoaded |
RuntimeGridLevel / m_runtimeGridLevel | 0xFF (inherit) | Explicit target grid |
LayerId / m_layerId | 0 | Content Layer |
BundleGroupId / m_bundleGroupId | 0 | Strong co-load group |
DependentLoadTargets | empty | Targets must be ≥ Loaded before activate |
ExcludeFromHlod / m_excludeFromHlod | false | Exclude static meshes from HLOD |
SoftReferenceTargets | empty | Soft cross-cell refs |
WorldStreamingStreamingSourceComponent
| Field | Default | Description |
|---|
m_loadRadius / m_activateRadius | 256 / 128 m | Loaded / Activated rings |
m_targetGridLevel | 0xFF | All grids |
m_targetGridLevelMask | 0 | Non-zero overrides single level |
m_targetHlodLayerId / m_targetHlodLayerMask | 0xFFFF / 0 | HLOD-only targeting |
m_priority | Default | Low / Default / High / Critical |
m_enabled | true | |
m_shapes | empty | Non-empty ignores radii |
m_orientShapesToSource | false | Shapes follow entity orientation |
m_targetBehavior | Include | Exclude = carve |
m_loadingRangeScale | 1.0 | × global StreamingRangeScale |
m_predictVelocity | false | Prefetch; prediction never Activates |
m_debugName / m_debugColor | empty / 0 | Debug label / tint |
Narrative:
Runtime streaming.
WorldStreamingLayerDesc / HlodLayerDesc
Summaries live in
Content Layers and
HLOD. Key defaults:
| Descriptor | Notable defaults |
|---|
| Layer | Flags Runtime + EnabledByDefault; m_parentLayerId = 0xFFFF |
| HLOD | Source 0 → target 1; policy Merge (0); m_loadingRange 2048 m; m_requiresRegionMask true |
Bake-injected components
Authors normally do not add these by hand:
| Component | Role |
|---|
WorldStreamingCellComponent | Owning cellId (Entity → Cell lookup) |
WorldStreamingEntityKeyComponent | Stable entity key for cross-cell references |
Multiplayer and bridge components
| Component | Purpose |
|---|
WorldStreamingSyncNetworkComponent | On networked player Prefab; cell / layer state sync |
WorldStreamingAtomBridgeComponent | HLOD fragment show/hide → Atom (AtomMode = Bridge) |
WorldStreamingTerrainVegBridgeComponent | Cell enter/leave → Terrain / Vegetation |
WorldStreamingNavMeshBridgeComponent | Cell enter/leave → Recast |
Bridges mount from Bridge/*Mode Registry keys—no manual placement. See
Bridges and
Multiplayer.
Bus and interface index
| API | Header / module | Role |
|---|
WorldStreamingRequestBus | WorldStreamingBus.h | Script runtime requests |
WorldStreamingScriptNotificationBus | same | Script notifications |
WorldStreamingNotificationBus | same | C++ notifications |
WorldStreamingStreamingSourceProviderRequestBus | same | Pull streaming sources |
EditorWorldStreamingRequestBus | Editor | Bake, focus, AuthorWorld*, shards |
WorldStreamingMigrationRequestBus | Builders | Level migration |
WorldStreamingInterface / IWorldStreamingSystem | IWorldStreamingSystem.h | Full C++ capability surface |
IWorldStreamingPolyPartitionBridge | optional | PolyTerrain diagnostics |
Event catalogs:
Scripting.
Behavior constants (script)
| Family | Values |
|---|
CellRuntimeState_* | Unloaded 0 / Loaded 2 / Activated 4 |
LayerRuntimeState_* | Unloaded 0 / Loaded 1 / Activated 2 |
SourcePriority_* | Low 0 / Default 1 / High 2 / Critical 3 |
TargetBehavior_* | Include 0 / Exclude 1 |
StreamingPerformance_* | Ok 0 / Slow 1 / Critical 2 |
Asset types
| Extension | Role |
|---|
.wsworld | Authoring descriptor |
.wsmanifest | Runtime Manifest |
.wschunk | Optional Manifest chunk |
| Cell / HLOD Spawnables | Per-cell runtime products |
- Registry defaults:
Gems/WorldStreaming/Registry/WorldStreaming.setreg
