World Streaming subsystem bridges

Optional bridge targets connect World Streaming cell enter/leave (and HLOD visibility) to Terrain, Vegetation, Recast navigation, and Atom. Modes are Settings Registry strings under /WorldStreaming/Bridge/.

Mode matrix

Key	Default	Values
`TerrainMode`	`"Bridge"`	Off / Coexist / Bridge
`VegetationMode`	`"Coexist"`	Off / Coexist / Bridge / BridgeResidency
`NavMeshMode`	`"Coexist"`	Off / Coexist / Bridge
`AtomMode`	`"Off"`	Off / Bridge

Rule of thumb: Off / Coexist = no behavioral takeover; only Bridge (and Vegetation BridgeResidency) lets World Streaming drive the subsystem.

Example project override:

{
 "WorldStreaming": {
 "Bridge": {
 "TerrainMode": "Bridge",
 "VegetationMode": "Coexist",
 "NavMeshMode": "Coexist",
 "AtomMode": "Bridge"
 }
 }
}

Bridge components mount from Registry—no manual entity placement is required.

Terrain

Mode	Behavior
Off / Coexist	No WS-driven terrain region changes
Bridge	Cell Activated enter/leave refreshes terrain regions

Default is Bridge. Pair with heightfield or PolyTerrain as your project already does; World Streaming does not replace either system.

Vegetation

Mode	Behavior
Coexist (default)	Camera-driven vegetation only; WS records diagnostics
Bridge	On Activated enter/leave, `RefreshRegionD`; still constrained by the camera window
BridgeResidency	Bridge plus registering activated regions as vegetation residency regions

NavMesh

Mode	Behavior
Coexist (default)	No automatic nav updates from WS
Bridge	Cell Activated enter/leave triggers Recast region updates

Custom non-PhysX geometry without volume collection may fall back to full rebuilds.

Atom (HLOD visibility)

Mode	Behavior
Off (default)	HLOD show/hide decisions still resolve; meshes are not driven
Bridge	`OnHlodFragmentVisibilityChanged` → Atom mesh visibility

Rendering projects that use HLOD should set AtomMode = Bridge, or handle the notification themselves. See HLOD.

Diagnostics

Command	Scope
`WsDumpBridgeStats`	Terrain / Vegetation
`WsDumpNavBridgeStats`	NavMesh
`WsDumpAtomBridgeStats`	Atom

Optional WorldStreaming.Debug adds ImGui (ws_imguiPanel). See Configuration and debugging.

Next steps

HLOD: why Atom bridge matters for proxies.
Configuration and debugging: Bridge keys in the full Registry table.