Large-Scene Support

forge3d large-scene work is scoped to offline map-production diagnostics for MapScene.validate, not live globe streaming or hosted tile delivery.

Capability	Support level	Scope	Diagnostics
Memory budget estimates	supported	Validation estimates known output, terrain/raster dimensions, point counts, building geometry counts, and tile metadata where available.	estimated_gpu_memory when the configured budget is exceeded.
Cache/LOD stat availability	underdeveloped	Terrain, point cloud, building, and tile layers can preserve cache/LOD metadata when supplied; unavailable stats are reported instead of invented.	unavailable_cache_lod_stats.
Instancing status	unsupported	MapScene records requested instancing workflows and blocks unsupported product paths before render.	unsupported_instancing_path.
Bottleneck layer types	underdeveloped	Validation can summarize bottleneck layer types from known memory, count, cache, LOD, or timing metadata with deterministic ordering.	Summary data in validation reports.
Live globe streaming	non-goal	forge3d does not host or stream a browser globe.	Documentation boundary.
Hosted tile-provider parity	non-goal	Hosted Mapbox/Cesium-style provider ecosystems are outside this offline workflow.	Documentation boundary.
Blender parity	non-goal	General DCC scene authoring is outside the map-production contract.	Documentation boundary.
Unreal parity	non-goal	Game/editor runtime behavior is outside the map-production contract.	Documentation boundary.
General DCC	non-goal	Non-map rendering and cinematic/general content tooling are not the P2 goal.	Documentation boundary.

Large-scene P2 gaps are non-MVP-blocking when they are diagnosed before render. Validation must preserve known memory budget estimates, cache/LOD stat availability, instancing status, and bottleneck layer types without claiming hosted streaming capability or parity with Blender, Unreal, Cesium, Mapbox GL, or browser-hosted engines. The phrase cache/LOD stat availability is the product boundary: known stats are reported, unknown stats are diagnosed, and precision is not invented.

The PRD classification missing remains available for capabilities with no product feature at all; the Milestone 5 items in this guide prefer diagnosed unsupported, underdeveloped, or experimental status where substrate exists.