Production patterns and test gates

Pattern: open-world traversal

• One default runtime grid until evidence requires another.
• Player source plus a velocity/look-ahead strategy for fast travel.
• Spatial environment actors; true global systems outside placed-world lifetime.
• HLOD for distant static silhouette.
• Runtime Data Layers only for cohesive world phases.
• Cooked traversal benchmark covering slow walk, sprint, fastest vehicle, abrupt turn, and return path.

Pattern: seamless teleport or fast travel

• Destination streaming source enabled before travel.
• Loading/transition presentation begins.
• Wait for streaming completion and project-specific gameplay readiness.
• Server performs authoritative move.
• Client camera/input resumes after possession and local presentation are ready.
• Temporary source retires after the normal source owns the area.
• Timeout returns to a known safe location or explicit failure UI.

Pattern: stateful location

• Durable quest/state data lives in save/gameplay state.
• Server maps that truth to Runtime Data Layer state.
• Loaded prewarms the destination; Activated reveals the chosen phase.
• Streamed interactables reconstruct local presentation from durable IDs/state.
• Late join and load-game tests confirm the same phase.

Pattern: repeated point of interest

• Level Instance for mixed gameplay/content assembly.
• Packed Level Blueprint only when the assembly is supported static visual content.
• OFPA for collaborative editing.
• Instance-level Data Layer supplies the broad phase; internal layers only for truly reusable variants.
• Validate every instance transform, HLOD, navigation, and references.

Pattern: persistent manager

Use a framework class or subsystem appropriate to its lifetime. A placed always-loaded actor is acceptable only when world placement is semantically required and its lifetime/cost are explicit.

Required test matrix

Axis	Minimum cases
Build	PIE, standalone, cooked Development, shipping-equivalent target
Cache	cold start and warm repeat
Motion	slow, fastest sustained, burst/teleport, sudden reversal
Network	listen/dedicated as applicable, late join, reconnect, packet impairment
State	each Runtime Data Layer transition and save/load reconstruction
Memory	baseline, worst vista, repeated round trip, long soak
HLOD	source/proxy comparison, transition in motion, rebuild after source edit
Failure	missing/late cell, timeout, cancelled travel, invalid reference

Acceptance gates

• No player reaches absent collision or interactive state.
• No unbounded memory rise after repeated traversal.
• Cell/HLOD transitions meet the project's visible-pop and hitch budgets.
• Server and clients agree on authoritative Data Layer/gameplay state.
• A clean builder run is reproducible from source control.
• Packaged behavior matches editor intent.
• Debug overrides are removed and experimental dependencies are documented.