rnd(M03): add rendered ground query facade

RENDER.md

@@ -929,11 +929,25 @@ $exe = Join-Path $env:TEMP 'godot-4.6.1-openwc\Godot_v4.6.1-stable_win64.exe'
   matches those ownership categories.
 - Scene composition may still reference the loader script and the facade's
   implementation path; those are composition details, not mutable queue access.
-- Renderer diagnostic probes are outside this gameplay/editor checklist.
+- Renderer diagnostic probes are added explicitly as their facade contracts land.
-  `probe_render_terrain_height.gd` remains a documented temporary exception until
-  readiness and ground-query facade contracts replace its internal inspection.
 - This is a source-only boundary check and changes no renderer behavior or fidelity.
 
+## 2026-07-16 Rendered Ground Query Facade
+
+- `WorldRenderFacade.sample_ground_height()` accepts `GodotWorldPosition` and
+  returns renderer-owned immutable `RenderedGroundSample` from already loaded
+  quality/tile-LOD render meshes, avoiding a render-to-gameplay dependency.
+- `renderer_ground_query_snapshot()` preserves the terrain probe's tile readiness,
+  queue position, mesh bounds and nearby seam-fallback diagnostics as a detached
+  Dictionary; callers receive no queue, tile-state, Mesh or Node reference.
+- `probe_render_terrain_height.gd` now uses this facade snapshot and no longer reads
+  `_tile_states`, `_tile_load_queue`, `_tile_loading_tasks` or `_available_tiles`.
+- Gameplay continues using the independently composed M02 `TerrainQuery`/
+  `AdtTerrainQuery`. Loaded render meshes are diagnostic and are not authoritative
+  movement collision.
+- The ray height, 3x3 tile search and `2/5/10/20/40`-unit nearby fallback are
+  preserved. No terrain geometry, cache, streaming or visual behavior changed.
+
 ## Practical Rule For Future Work
 
 If something improves quality but creates visible hitch, it is not done. Move it to bake/cache/background work, split finalization over frames, or prewarm it before the player can see it.

coordination/claims/M03-RND-FACADE-GROUND-QUERY-001.md

@@ -40,7 +40,7 @@ terrain-height probe away from direct streamer state/queue access.
 ## Contracts and data
 
 - Input: immutable `GodotWorldPosition` in Godot world units
-- Output: immutable `TerrainGroundSample` plus optional detached diagnostic Dictionary
+- Output: renderer-owned immutable `RenderedGroundSample` plus optional detached diagnostic Dictionary
 - Sampling source: loaded quality or tile-LOD Mesh and its live tile transform
 - M02 ADT query cache, renderer cache versions and coordinate contracts: unchanged
 

docs/modules/terrain-query.md

@@ -5,10 +5,10 @@
 | Field | Value |
 |---|---|
 | Status | Implemented |
-| Target/work package | M02 / M02-GMP-TERRAIN-QUERY-001 |
+| Target/work package | M02 / M02-GMP-TERRAIN-QUERY-001; M03 renderer consumer `M03-RND-FACADE-GROUND-QUERY-001` |
 | Owners | Gameplay terrain-query contract; ADT adapter owns parsed tile cache |
 | Last verified | `a45d521`, 2026-07-14 |
-| Profiles/capabilities | Current sandbox ADT ground height; renderer/physics backend planned |
+| Profiles/capabilities | Current sandbox ADT ground height; loaded-render-mesh diagnostic query; authoritative physics backend planned |
 
 ## Purpose
 
@@ -47,6 +47,8 @@ Allowed dependencies:
 - Existing native `ADTLoader` at the ADT adapter boundary.
 - Dynamic dictionaries only inside the native-format adapter.
 - Player scene composition may inject any `TerrainQuery` implementation.
+- Renderer diagnostics reuse `GodotWorldPosition` through `WorldRenderFacade`
+  but return renderer-owned `RenderedGroundSample`, preserving the render/gameplay boundary.
 
 Forbidden dependencies:
 
@@ -65,6 +67,7 @@ Forbidden dependencies:
 | `AdtTerrainQuery.new(extracted_directory, map_directory_name, loader_override)` | Adapter constructor | Configures one map and optional test/data-source loader | Query lifetime | Production validates native loader and file presence lazily |
 | `AdtTerrainQuery.sample_ground_height(position)` | Adapter method | Loads/caches tile and interpolates ADT outer heights | Main thread; cache lives with query | Returns stable failure code |
 | `ThirdPersonWowController.set_terrain_query(query)` | Composition method | Replaces terrain backend independently of movement/presentation | Call before scene ready or on main thread | Null is rejected and current query retained |
+| `WorldRenderFacade.sample_ground_height(position)` | Separate renderer diagnostic API | Samples already loaded terrain Mesh and returns `RenderedGroundSample` without exposing streamer state | Main thread; immutable sample | Stable `render_terrain_*` unavailable code; not injected into player by default |
 
 ## Inputs and outputs
 
@@ -206,6 +209,9 @@ Existing ADT/native/cache format versions remain unchanged.
 ## Extension points
 
 - Streaming renderer or physics backend may implement `TerrainQuery` without changing player/movement.
+- The current facade intentionally uses a separate renderer-owned result and is
+  not a `TerrainQuery` implementation. A future adapter must explicitly translate
+  readiness/results and define gameplay authority before composition.
 - Future result may grow separate slope, surface, liquid or collision contracts;
   incompatible additions require a versioned contract rather than Dictionary fields.
 - Test/authoring data sources may use constructor loader override.
@@ -218,7 +224,8 @@ Existing ADT/native/cache format versions remain unchanged.
 | Typed replaceable ground-height query | Implemented | Contract and injected player regression | Integrate target checklist after review |
 | Existing ADT height interpolation | Implemented | Synthetic fractional-grid fixture | Compare terrain contact with build 12340 |
 | Per-tile success/failure cache | Implemented | Loader call-count regression | Add explicit invalidation only with authoring/hot reload |
-| Renderer/streaming cache backend | Planned | Boundary permits replacement | M03 renderer facade/public terrain backend |
+| Renderer loaded-mesh diagnostic backend | Implemented | M03 facade typed sample and detached snapshot contract | Not composed into gameplay; triangle Mesh ray is diagnostic only |
+| Authoritative renderer/physics backend | Planned | Boundary permits replacement | Define holes/slopes/collision/readiness semantics before gameplay composition |
 | Holes/slopes/collision | Planned | Outside height-only contract | Later movement/physics package |
 | Liquid/swim query | Planned | Outside contract | M09/M12 world gameplay |
 
@@ -240,6 +247,7 @@ Existing ADT/native/cache format versions remain unchanged.
 | `src/gameplay/terrain/terrain_query.gd` | Replaceable typed query boundary |
 | `src/gameplay/terrain/adt_terrain_query.gd` | Native ADT adapter, cache, chunk selection and interpolation |
 | `src/scenes/player/third_person_wow_controller.gd` | Query composition and existing ground-snap consumer |
+| `src/render/world_render_facade.gd` | Read-only loaded-render-mesh diagnostic consumer of typed position/sample contracts |
 | `src/tools/verify_terrain_query.gd` | Synthetic contract/cache/failure/injection regression |
 | `src/tests/scenes/player_input_regression.tscn` | Asset-free player composition fixture |
 

docs/modules/world-renderer.md

@@ -5,7 +5,7 @@
 | Field | Value |
 |---|---|
 | Status | Partial |
-| Target/work package | M00 baseline; `M01-RND-STREAMING-FOCUS-001`; `M01-QAR-SERVER-SPAWN-RENDERER-001`; `M03-RND-FACADE-001`; `M03-RND-STREAMING-PLANNER-001`; `M03-RND-SCHEDULER-001` |
+| Target/work package | M00 baseline; `M01-RND-STREAMING-FOCUS-001`; `M01-QAR-SERVER-SPAWN-RENDERER-001`; `M03-RND-FACADE-001`; `M03-RND-STREAMING-PLANNER-001`; `M03-RND-SCHEDULER-001`; `M03-RND-INTERNAL-ACCESS-GATE-001`; `M03-RND-FACADE-GROUND-QUERY-001` |
 | Owners | Renderer workstream / milestone integrator |
 | Last verified | Worktree `work/sindo-main-codex/m03-render-budget-scheduler`, 2026-07-16 |
 | Profiles/capabilities | `Performance`, `Balanced`, `High`, `Custom`; Blizzlike fidelity incomplete |
@@ -65,9 +65,9 @@ Forbidden dependencies:
 
 ## Public API
 
-Runtime, capture and probe callers use `WorldRenderFacade` for focus and metrics.
+Runtime, capture and probe callers use `WorldRenderFacade` for focus, metrics and
-`StreamingWorldLoader` remains the internal scene implementation while later M03
+rendered-ground diagnostics. `StreamingWorldLoader` remains the internal scene
-packages add environment, entity-visual and ground-query contracts.
+implementation while later M03 packages add environment and entity-visual contracts.
 Gameplay modules and Godot `EditorPlugin` package sources are repository-gated
 from externally reading/writing loader-private queue, task, cache and tile-state fields.
 
@@ -80,6 +80,8 @@ from externally reading/writing loader-private queue, task, cache and tile-state
 | `WorldRenderFacade.set_streaming_focus` | Public method | Accepts focus from app/editor/tool composition | Main thread/session | Missing internal renderer is diagnosed; no state is duplicated |
 | `WorldRenderFacade.refresh_streaming_focus` | Public method | Samples configured source and delegates existing refresh thresholds | Main thread/session | Returns `false` when dependency/focus is unavailable |
 | `WorldRenderFacade.renderer_metrics_snapshot` | Public method | Returns a deep-detached queue/cache/activity snapshot | Main thread/caller-owned result | Missing/invalid implementation result returns empty snapshot with diagnostic |
+| `WorldRenderFacade.sample_ground_height` | Public read-only query | Samples already loaded render terrain at a typed Godot world position | Main thread; immutable caller-held result | Stable unavailable code for missing mesh/intersection/facade; not gameplay authority |
+| `WorldRenderFacade.renderer_ground_query_snapshot` | Public diagnostic query | Returns ground height plus detached tile/readiness context without exposing mutable state | Main thread; caller-owned deep copy | Missing/invalid renderer returns empty snapshot with diagnostic |
 | `WorldRenderFacade.streaming_world_loader_path` | Internal adapter property | Resolves the existing implementation without exposing it to consumers | Main thread, scene lifetime | Missing method/path produces one diagnostic until recovery |
 | `camera_path` | Exported property | Camera used only by optional automatic overview positioning | Main thread, scene lifetime | Missing camera skips automatic positioning |
 | `quality_preset` | Exported property | Applies renderer budgets/radii | Before/at runtime depending property | Invalid combination should be diagnosed |
@@ -96,6 +98,7 @@ loader configuration remains transitional composition data, not a caller API.
 |---|---|---|---|---|---|
 | Input | `StreamingFocus` | Player/spectator/editor/capture adapter | `WorldRenderFacade` | Immutable caller value | Main thread/session |
 | Input | Focus-source `NodePath` | Runtime/test scene composition | `WorldRenderFacade` source adapter | Scene-owned node, sampled position | Main thread/scene lifetime |
+| Input | Ground-query `GodotWorldPosition` | Renderer probe/future adapter | `WorldRenderFacade` | Immutable caller-held value | One main-thread query |
 | Input | Map/configuration | Scene/app/editor | `StreamingWorldLoader` | Caller config, copied/read | Main thread/session |
 | Input | WDT/ADT/M2/WMO/BLP bytes | Extracted asset repository | Native loaders/builders | Loader result owns parsed data | Worker or controlled load |
 | Input | Baked resources | Cache build tools | Streamer/builders | Shared immutable resource/cache entry | Session/cache lifetime |
@@ -105,6 +108,8 @@ loader configuration remains transitional composition data, not a caller API.
 | Output | Desired tile/detail operations | Streamer plan application | Finalize queues | Loader-owned | Cross-frame |
 | Output | Terrain/M2/WMO/liquid instances | Loader/builders | Godot world/renderer | Loader/world owner | Main-thread attach |
 | Output | Detached renderer metrics | `WorldRenderFacade` | Capture/baseline tools | Caller-owned deep copy | On demand |
+| Output | `RenderedGroundSample` | `WorldRenderFacade`/loaded terrain | Renderer diagnostics | Immutable caller-held value | One query |
+| Output | Detached rendered-ground snapshot | `WorldRenderFacade` | Terrain-height probe | Caller-owned deep copy | One query |
 | Output | Logs/diagnostics | Hitch/stat instrumentation | Logs/baseline tools | Immutable records | Periodic/frame |
 | Test output | Diagnostic spawn marker and cold/warm PNGs | Checkpoint capture tool | Human/integrator review | SceneTree marker; `user://` files | One capture process |
 
@@ -140,6 +145,8 @@ flowchart TD
     B --> M2[M2 group/MultiMesh attach]
     B --> WMO[WMO instance/group attach]
     B --> Liquid[Liquid attach]
+    Loaded[Loaded terrain Mesh and Transform] --> Ground[Facade ground query]
+    Ground --> GroundSample[RenderedGroundSample / detached diagnostics]
     Terrain --> World[Godot world]
     M2 --> World
     WMO --> World
@@ -192,6 +199,9 @@ sequenceDiagram
     Budget-->>Stream: true while lane remains bounded
     Stream->>Render: attach permitted terrain/M2/WMO/liquid work
     Stream->>Render: evict outside retention range
+    Source->>Facade: sample_ground_height(typed position)
+    Facade->>Stream: sample loaded render terrain
+    Stream-->>Facade: RenderedGroundSample / diagnostic snapshot
     Stream->>Budget: shutdown: cancel permit issuance
     Stream->>Worker: shutdown: wait for WorkerThreadPool tasks
     Stream->>Stream: shutdown: finish registered ResourceLoader requests
@@ -204,6 +214,10 @@ sequenceDiagram
 - `StreamingWorldLoader` владеет tile states, queues, task registries, active world instances и render caches session scope.
 - `WorldRenderFacade` owns only scene-relative adapter paths. It does not own the
   streamer, focus source, returned metrics, queues, caches, nodes or RIDs.
+- Rendered-ground query results and diagnostic snapshots are caller-owned values;
+  the facade never returns Mesh, Node, tile-state or queue references.
+- Loaded-mesh ground sampling is renderer diagnostics, not authoritative gameplay
+  collision. M02 `TerrainQuery` composition and ADT cache ownership remain unchanged.
 - `StreamingTargetPlanner` is stateless and owns only call-local calculations;
   its immutable plan is consumed synchronously by the streamer.
 - `RenderBudgetScheduler` owns only per-frame lane counters and a terminal
@@ -230,6 +244,7 @@ sequenceDiagram
 | Cache version mismatch | Required format constant | Reject stale cache/fallback | Version diagnostic | Rebuild matching cache |
 | Worker failure | Task result/empty data | Skip/degrade affected asset | Queue/task warning | Retry/rebuild source |
 | Main-thread hitch | Named section timing | Frame spike, work remains queued | `HITCH` log | Lower budget/fix finalize path |
+| Render terrain unavailable | Facade ground query | Immutable unavailable sample | Stable `render_terrain_*` failure code and optional snapshot | Wait for streaming or use gameplay-owned query backend |
 | D3D12 descriptor exhaustion | Rendering backend error | Render failure/fallback backend | Godot error + baseline report | Dedup resources/fix settings |
 | Teleport/map change | Focus/session transition | Old jobs become stale | Target/session generation | Cancel/drop stale results |
 | Shutdown leak | Godot leak/RID diagnostics | Resource retained | Verbose shutdown report + cache shutdown verifier | Drain requests, preserve tree ownership, then free detached prototypes and clear resource caches |
@@ -276,6 +291,8 @@ Exact exported settings and cache versions remain documented in [`../../RENDER.m
 - Internal-access contract: derives the current streamer's private queue/task/
   cache/state field inventory and rejects external member/reflection access from
   gameplay or EditorPlugin package code.
+- Ground-query facade contract: available/unavailable typed result delegation,
+  detached nested diagnostics and terrain-probe source migration without private access.
 - Integration/E2E: Eastern Kingdoms/Kalimdor streaming scenes, seven M00
   cold/warm checkpoints and one dedicated mapped server-spawn checkpoint.
 - Fidelity evidence: семь локальных build 12340 reference JPG покрывают terrain/ADT/M2/WMO/liquid/sky и реальный `GryphonRoost01`; automated cold/warm metrics имеют `compared=14`, `missing=0`. Sky использует приблизительно paired camera, а animated-M2 остаётся asset-paired/placement-unpaired из-за synthetic probe.
@@ -301,10 +318,11 @@ Exact exported settings and cache versions remain documented in [`../../RENDER.m
 | Character presentation | Prototype | Character creator/player experiment | Full customization/equipment states |
 | Camera-independent streaming focus | Implemented | Typed contract, two player-focused runtime scenes and three explicitly camera-focused diagnostic tools | Multi-focus/direction/velocity belong to planner extraction |
 | Golden server-spawn visualization | Implemented | Pinned AzerothCore fixture, validated renderer manifest and diagnostic origin-marker capture at ADT `(32,48)`/MCNK `(3,12)` | No TrinityCore row or original-client visual-parity claim |
-| Stable renderer facade | Partial | `M03-RND-FACADE-001` contract/runtime/tool regressions | Focus and metrics migrated; environment/entity visuals/ground query remain |
+| Stable renderer facade | Partial | Facade contracts cover focus, metrics and loaded-mesh ground query | Environment and entity visuals remain |
 | Pure streaming target planner | Implemented | `M03-RND-STREAMING-PLANNER-001` asset-free contract/performance regression | Queue scheduling and loaded-tile LOD application remain in streamer |
 | Bounded render budget scheduler | Implemented | `M03-RND-SCHEDULER-001` asset-free permit/cancellation/performance regression | Queue storage, worker concurrency and operation execution remain in streamer/services |
-| Gameplay/editor internal-access boundary | Implemented | `M03-RND-INTERNAL-ACCESS-GATE-001` scans actual private streamer declarations against gameplay and EditorPlugin sources | Renderer diagnostic probes remain a scoped exception pending ground-query/readiness facade contracts |
+| Gameplay/editor/tool internal-access boundary | Implemented | Access gate scans gameplay, EditorPlugin packages and terrain probe against actual private streamer declarations | Add future renderer diagnostic tools explicitly to the protected list |
+| Rendered terrain ground query | Implemented | `M03-RND-FACADE-GROUND-QUERY-001` typed result/snapshot isolation and probe migration | Diagnostic Mesh ray only; not movement/collision authority |
 
 ## Known gaps and risks
 
@@ -325,15 +343,16 @@ Exact exported settings and cache versions remain documented in [`../../RENDER.m
 - D3D12 descriptor issues remain. Explicit shutdown ownership removes the GUI capture's Node/resource/RID leaks in focused and seven-checkpoint runs; a timing-dependent ObjectDB warning for anonymous zero-reference `RefCounted` objects remains as a separate engine-teardown diagnostic.
 - M2/WMO/material/particle/ribbon/portal parity incomplete.
 - Public API is mostly exported configuration rather than stable contracts.
-- `probe_render_terrain_height.gd` remains a renderer-only diagnostic exception
+- Rendered-ground sampling generates a triangle mesh on demand and retains the
-  that reads tile readiness/terrain internals; it is excluded from the gameplay/
+  historical nearby seam fallback. It is appropriate for diagnostics, not a
-  EditorPlugin gate until equivalent ground-query and readiness facade contracts exist.
+  per-physics-frame gameplay query or a claim of exact terrain collision parity.
 
 ## Source map
 
 | Path | Responsibility |
 |---|---|
-| `src/render/world_render_facade.gd` | Stable caller boundary for typed focus and detached renderer metrics |
+| `src/render/world_render_facade.gd` | Stable caller boundary for typed focus, detached metrics and rendered-ground queries |
+| `src/render/terrain/rendered_ground_sample.gd` | Immutable renderer-owned available/unavailable ground query result |
 | `src/render/streaming/streaming_target_planner.gd` | Scene-free wanted/retained ADT target calculation |
 | `src/render/streaming/streaming_target_policy.gd` | Immutable renderer radius/prefetch policy |
 | `src/render/streaming/streaming_target_plan.gd` | Immutable planner result with read-only tile-key sets |
@@ -341,10 +360,10 @@ Exact exported settings and cache versions remain documented in [`../../RENDER.m
 | `src/scenes/streaming/streaming_world_loader.gd` | Current runtime orchestration, queues, caches and attachment |
 | `src/domain/streaming/streaming_focus.gd` | Immutable camera-independent streaming position contract |
 | `src/tools/verify_streaming_focus.gd` | Headless contract, dependency and runtime/tool wiring regression |
-| `src/tools/verify_world_render_facade.gd` | Facade delegation, snapshot isolation and consumer wiring regression |
+| `src/tools/verify_world_render_facade.gd` | Focus/metrics/ground delegation, snapshot isolation and consumer wiring regression |
 | `src/tools/verify_streaming_target_planner.gd` | Planner behavior, dependency and bounded timing regression |
 | `src/tools/verify_render_budget_scheduler.gd` | Scheduler bounds, shared-lane priority, cancellation and timing regression |
-| `src/tools/verify_renderer_internal_access.gd` | Gameplay/EditorPlugin boundary gate derived from private streamer fields |
+| `src/tools/verify_renderer_internal_access.gd` | Gameplay/EditorPlugin/registered renderer-tool boundary gate derived from private streamer fields |
 | `addons/mpq_extractor/loaders/adt_builder.gd` | Terrain/material/liquid construction |
 | `addons/mpq_extractor/loaders/m2_builder.gd` | Static M2 mesh/material construction |
 | `addons/mpq_extractor/loaders/m2_native_animated_builder.gd` | Native animated M2 experiment |
@@ -360,7 +379,7 @@ Exact exported settings and cache versions remain documented in [`../../RENDER.m
 | `src/tools/verify_server_spawn_renderer.gd` | Fixture-to-renderer checkpoint contract verification |
 | `tools/sweep_render_checkpoint_camera_pose.ps1` | Offline yaw/pitch capture grid and paired-error ranking |
 | `src/tools/verify_render_coordinate_calibration.gd` | Build 12340 camera-coordinate golden point round-trip diagnostic |
-| `src/tools/probe_render_terrain_height.gd` | Offline active-mesh terrain height and camera-clearance report |
+| `src/tools/probe_render_terrain_height.gd` | Offline facade-backed active-mesh terrain height and camera-clearance report |
 | `src/tools/probe_render_camera_occluders.gd` | Scene-tree placement containment and camera-to-target AABB intersection report |
 
 ## Related decisions and references

src/render/terrain/rendered_ground_sample.gd

@@ -0,0 +1,50 @@
+class_name RenderedGroundSample
+extends RefCounted
+
+## Immutable result of sampling currently loaded render terrain in Godot world units.
+## This diagnostic value is renderer-owned and is not authoritative gameplay collision.
+
+var is_available: bool:
+	get:
+		return _is_available
+
+var height_units: float:
+	get:
+		return _height_units
+
+var failure_code: StringName:
+	get:
+		return _failure_code
+
+var _is_available: bool
+var _height_units: float
+var _failure_code: StringName
+
+
+## Creates an available finite rendered-ground sample in Godot world units.
+static func available(height_units_value: float) -> RenderedGroundSample:
+	return RenderedGroundSample.new(true, height_units_value, &"")
+
+
+## Creates an unavailable rendered-ground sample with a stable failure code.
+static func unavailable(failure_code_value: StringName) -> RenderedGroundSample:
+	return RenderedGroundSample.new(false, 0.0, failure_code_value)
+
+
+func _init(
+		is_available_value: bool,
+		height_units_value: float,
+		failure_code_value: StringName
+) -> void:
+	_is_available = is_available_value and is_finite(height_units_value)
+	_height_units = height_units_value if _is_available else 0.0
+	if _is_available:
+		_failure_code = &""
+	elif not is_finite(height_units_value):
+		_failure_code = &"render_terrain_height_not_finite"
+	else:
+		_failure_code = (
+			failure_code_value
+			if not failure_code_value.is_empty()
+			else &"render_terrain_unavailable"
+		)

src/render/terrain/rendered_ground_sample.gd.uid

@@ -0,0 +1 @@
+uid://c744ldnnn87a8

src/render/world_render_facade.gd

@@ -7,6 +7,7 @@ extends Node
 
 const GODOT_WORLD_POSITION_SCRIPT := preload("res://src/domain/coordinates/godot_world_position.gd")
 const STREAMING_FOCUS_SCRIPT := preload("res://src/domain/streaming/streaming_focus.gd")
+const RENDERED_GROUND_SAMPLE_SCRIPT := preload("res://src/render/terrain/rendered_ground_sample.gd")
 
 ## Internal renderer implementation resolved relative to this node.
 ## The referenced node remains owned by its scene parent.
@@ -66,6 +67,33 @@ func renderer_metrics_snapshot() -> Dictionary:
 	return (metrics_variant as Dictionary).duplicate(true)
 
 
+## Samples the currently loaded render terrain at a typed Godot world position.
+## This read-only renderer view is diagnostic and does not replace authoritative
+## gameplay collision or the independently composed [TerrainQuery].
+func sample_ground_height(godot_world_position: GodotWorldPosition) -> RefCounted:
+	var loader := _resolve_streaming_world_loader()
+	if loader == null:
+		return RENDERED_GROUND_SAMPLE_SCRIPT.unavailable(&"render_facade_unavailable")
+	var sample_variant = loader.call("sample_rendered_ground_height", godot_world_position)
+	if sample_variant is RefCounted and sample_variant.get_script() == RENDERED_GROUND_SAMPLE_SCRIPT:
+		return sample_variant
+	push_error("WorldRenderFacade received an invalid rendered ground sample.")
+	return RENDERED_GROUND_SAMPLE_SCRIPT.unavailable(&"render_ground_sample_invalid")
+
+
+## Returns a detached diagnostic snapshot for one rendered-ground query.
+## Mutating the result cannot mutate streamer queues, tile state or resources.
+func renderer_ground_query_snapshot(godot_world_position: GodotWorldPosition) -> Dictionary:
+	var loader := _resolve_streaming_world_loader()
+	if loader == null:
+		return {}
+	var snapshot_variant = loader.call("render_ground_query_snapshot", godot_world_position)
+	if not (snapshot_variant is Dictionary):
+		push_error("WorldRenderFacade received a non-Dictionary ground query snapshot.")
+		return {}
+	return (snapshot_variant as Dictionary).duplicate(true)
+
+
 func _capture_streaming_focus_from_source() -> void:
 	if streaming_focus_source_path == NodePath():
 		return
@@ -99,6 +127,8 @@ func _resolve_streaming_world_loader() -> Node:
 		&"set_streaming_focus",
 		&"refresh_streaming_focus",
 		&"render_baseline_snapshot",
+		&"sample_rendered_ground_height",
+		&"render_ground_query_snapshot",
 	]:
 		if not candidate.has_method(required_method):
 			if not _missing_loader_reported:

src/scenes/streaming/streaming_world_loader.gd

@@ -17,6 +17,7 @@ const GODOT_WORLD_POSITION_SCRIPT := preload("res://src/domain/coordinates/godot
 const COORDINATE_MAPPER_SCRIPT := preload("res://src/domain/coordinates/coordinate_mapper.gd")
 const ADT_TILE_COORDINATE_SCRIPT := preload("res://src/domain/coordinates/adt_tile_coordinate.gd")
 const ADT_TILE_LOCAL_POSITION_SCRIPT := preload("res://src/domain/coordinates/adt_tile_local_position.gd")
+const RENDERED_GROUND_SAMPLE_SCRIPT := preload("res://src/render/terrain/rendered_ground_sample.gd")
 const STREAMING_TARGET_PLANNER_SCRIPT := preload("res://src/render/streaming/streaming_target_planner.gd")
 const STREAMING_TARGET_POLICY_SCRIPT := preload("res://src/render/streaming/streaming_target_policy.gd")
 const RENDER_BUDGET_SCHEDULER_SCRIPT := preload("res://src/render/streaming/render_budget_scheduler.gd")
@@ -25,6 +26,7 @@ const REQUIRED_SPLAT_TILE_FORMAT_VERSION := 1
 const REQUIRED_CONTROL_SPLAT_TILE_FORMAT_VERSION := 3
 const M2_MATERIAL_REFRESH_VERSION := 2
 const WMO_MATERIAL_REFRESH_VERSION := 10
+const RENDER_GROUND_QUERY_RAY_HEIGHT_UNITS := 5000.0
 
 const TILE_SIZE := COORDINATE_MAPPER_SCRIPT.ADT_TILE_SIZE_YARDS
 const CHUNK_SIZE := COORDINATE_MAPPER_SCRIPT.ADT_CHUNK_SIZE_YARDS
@@ -1038,6 +1040,173 @@ func render_baseline_snapshot() -> Dictionary:
 	}
 
 
+## Samples already loaded render terrain at one typed Godot world position.
+## This diagnostic rendering view is not authoritative gameplay collision.
+func sample_rendered_ground_height(godot_world_position: GodotWorldPosition) -> RefCounted:
+	var ground_query_snapshot := render_ground_query_snapshot(godot_world_position)
+	if ground_query_snapshot.has("terrain_height"):
+		return RENDERED_GROUND_SAMPLE_SCRIPT.available(float(ground_query_snapshot["terrain_height"]))
+	var query_status := StringName(ground_query_snapshot.get("status", "render_terrain_unavailable"))
+	match query_status:
+		&"mesh_not_ready":
+			return RENDERED_GROUND_SAMPLE_SCRIPT.unavailable(&"render_terrain_mesh_not_ready")
+		&"no_intersection":
+			return RENDERED_GROUND_SAMPLE_SCRIPT.unavailable(&"render_terrain_no_intersection")
+		_:
+			return RENDERED_GROUND_SAMPLE_SCRIPT.unavailable(&"render_terrain_unavailable")
+
+
+## Returns a detached diagnostic read model for the loaded terrain around one
+## typed position. Queue/cache ownership and mutable tile state stay internal.
+func render_ground_query_snapshot(godot_world_position: GodotWorldPosition) -> Dictionary:
+	var world_position := Vector3(
+		godot_world_position.x_units,
+		godot_world_position.y_units,
+		godot_world_position.z_units
+	)
+	var tile_coordinate = COORDINATE_MAPPER_SCRIPT.godot_to_adt_tile(godot_world_position)
+	var highest_terrain_height := -INF
+	var intersected_tile_key := ""
+	var ready_mesh_count := 0
+	for tile_y in range(tile_coordinate.tile_y - 1, tile_coordinate.tile_y + 2):
+		for tile_x in range(tile_coordinate.tile_x - 1, tile_coordinate.tile_x + 2):
+			var tile_key := _tile_key(tile_x, tile_y)
+			if not _tile_states.has(tile_key):
+				continue
+			var terrain_state: Dictionary = _tile_states[tile_key]
+			var terrain_height_variant = _intersect_rendered_terrain_state(terrain_state, world_position)
+			if terrain_height_variant == null:
+				continue
+			ready_mesh_count += 1
+			var terrain_height := float(terrain_height_variant)
+			if terrain_height > highest_terrain_height:
+				highest_terrain_height = terrain_height
+				intersected_tile_key = tile_key
+
+	if is_finite(highest_terrain_height):
+		return {
+			"status": "sampled",
+			"tile": intersected_tile_key,
+			"terrain_height": highest_terrain_height,
+		}
+
+	var focus_tile_key := _tile_key(tile_coordinate.tile_x, tile_coordinate.tile_y)
+	var missing_snapshot := {
+		"status": "no_intersection" if ready_mesh_count > 0 else "mesh_not_ready",
+		"tile": focus_tile_key,
+	}
+	missing_snapshot.merge(
+		_render_ground_tile_diagnostic(focus_tile_key, world_position),
+		true
+	)
+	if bool(missing_snapshot.get("quality_mesh_present", false)) or bool(
+			missing_snapshot.get("tile_lod_mesh_present", false)):
+		missing_snapshot["status"] = "no_intersection"
+		missing_snapshot.merge(_nearest_rendered_terrain_sample(world_position), true)
+		if missing_snapshot.get("nearest_sample_distance", null) != null:
+			missing_snapshot["status"] = "sampled_nearby"
+			missing_snapshot["terrain_height"] = float(missing_snapshot["nearest_sample_height"])
+	return missing_snapshot
+
+
+func _intersect_rendered_terrain_state(terrain_state: Dictionary, world_position: Vector3):
+	var terrain_mesh: Mesh = terrain_state.get("quality_terrain_mesh", null)
+	if terrain_mesh == null:
+		terrain_mesh = terrain_state.get("tile_lod_mesh", null)
+	if terrain_mesh == null:
+		return null
+	var triangle_mesh := terrain_mesh.generate_triangle_mesh()
+	if triangle_mesh == null:
+		return null
+	var tile_root := terrain_state.get("root", null) as Node3D
+	if tile_root == null or not is_instance_valid(tile_root):
+		return null
+	var inverse_transform := tile_root.global_transform.affine_inverse()
+	var local_ray_origin := inverse_transform * Vector3(
+		world_position.x,
+		RENDER_GROUND_QUERY_RAY_HEIGHT_UNITS,
+		world_position.z
+	)
+	var local_ray_direction := inverse_transform.basis * Vector3.DOWN
+	var intersection: Dictionary = triangle_mesh.intersect_ray(local_ray_origin, local_ray_direction)
+	if intersection.is_empty():
+		return null
+	var local_hit: Vector3 = intersection.get("position", Vector3.ZERO)
+	return (tile_root.global_transform * local_hit).y
+
+
+func _render_ground_tile_diagnostic(tile_key: String, world_position: Vector3) -> Dictionary:
+	var queued_index := -1
+	for request_index in _tile_load_queue.size():
+		var tile_request: Dictionary = _tile_load_queue[request_index]
+		if String(tile_request.get("key", "")) == tile_key:
+			queued_index = request_index
+			break
+	var diagnostic_snapshot := {
+		"available": _available_tiles.has(tile_key),
+		"queued_index": queued_index,
+		"loading": _tile_loading_tasks.has(tile_key),
+		"state_present": _tile_states.has(tile_key),
+		"load_queue_size": _tile_load_queue.size(),
+	}
+	if not _tile_states.has(tile_key):
+		return diagnostic_snapshot
+
+	var terrain_state: Dictionary = _tile_states[tile_key]
+	var quality_mesh: Mesh = terrain_state.get("quality_terrain_mesh", null)
+	var tile_lod_mesh: Mesh = terrain_state.get("tile_lod_mesh", null)
+	diagnostic_snapshot["quality_mesh_present"] = quality_mesh != null
+	diagnostic_snapshot["tile_lod_mesh_present"] = tile_lod_mesh != null
+	diagnostic_snapshot["quality_source"] = String(terrain_state.get("quality_terrain_source", ""))
+	diagnostic_snapshot["tile_lod"] = int(terrain_state.get("tile_lod", -1))
+	var tile_root := terrain_state.get("root", null) as Node3D
+	if tile_root != null and is_instance_valid(tile_root):
+		var local_position := tile_root.global_transform.affine_inverse() * world_position
+		diagnostic_snapshot["tile_root_position"] = _render_ground_vector3_array(tile_root.global_position)
+		diagnostic_snapshot["probe_local_position"] = _render_ground_vector3_array(local_position)
+	var diagnostic_mesh := quality_mesh if quality_mesh != null else tile_lod_mesh
+	if diagnostic_mesh != null:
+		var mesh_bounds := diagnostic_mesh.get_aabb()
+		diagnostic_snapshot["mesh_aabb_position"] = _render_ground_vector3_array(mesh_bounds.position)
+		diagnostic_snapshot["mesh_aabb_size"] = _render_ground_vector3_array(mesh_bounds.size)
+	return diagnostic_snapshot
+
+
+func _nearest_rendered_terrain_sample(world_position: Vector3) -> Dictionary:
+	for radius_units in [2.0, 5.0, 10.0, 20.0, 40.0]:
+		for offset in [
+			Vector2(radius_units, 0.0),
+			Vector2(-radius_units, 0.0),
+			Vector2(0.0, radius_units),
+			Vector2(0.0, -radius_units),
+		]:
+			var sample_position := world_position + Vector3(offset.x, 0.0, offset.y)
+			var typed_sample_position = GODOT_WORLD_POSITION_SCRIPT.new(
+				sample_position.x,
+				sample_position.y,
+				sample_position.z
+			)
+			var sample_tile = COORDINATE_MAPPER_SCRIPT.godot_to_adt_tile(typed_sample_position)
+			var sample_tile_key := _tile_key(sample_tile.tile_x, sample_tile.tile_y)
+			if not _tile_states.has(sample_tile_key):
+				continue
+			var terrain_height_variant = _intersect_rendered_terrain_state(
+				_tile_states[sample_tile_key],
+				sample_position
+			)
+			if terrain_height_variant != null:
+				return {
+					"nearest_sample_distance": radius_units,
+					"nearest_sample_height": float(terrain_height_variant),
+					"nearest_sample_tile": sample_tile_key,
+				}
+	return {"nearest_sample_distance": null}
+
+
+func _render_ground_vector3_array(vector: Vector3) -> Array[float]:
+	return [vector.x, vector.y, vector.z]
+
+
 func _tick_runtime_stats(delta: float) -> void:
 	if not runtime_stats_enabled or Engine.is_editor_hint():
 		return

src/tools/probe_render_terrain_height.gd

@@ -5,9 +5,7 @@ extends SceneTree
 ##   [--wait 3.0] [--output user://render_terrain_height/report.json]
 
 const MANIFEST_PATH := "res://src/tools/render_baseline_manifest.json"
-const COORDINATE_MAPPER_SCRIPT := preload("res://src/domain/coordinates/coordinate_mapper.gd")
 const GODOT_WORLD_POSITION_SCRIPT := preload("res://src/domain/coordinates/godot_world_position.gd")
-const RAY_HEIGHT := 5000.0
 
 
 func _initialize() -> void:
@@ -61,7 +59,15 @@ func _run_async() -> void:
 		camera.global_position = camera_position
 		render_facade.call("refresh_streaming_focus", true)
 		await create_timer(maxf(0.1, wait_seconds)).timeout
-		var terrain_sample := _sample_terrain(world, camera_position)
+		var typed_camera_position = GODOT_WORLD_POSITION_SCRIPT.new(
+			camera_position.x,
+			camera_position.y,
+			camera_position.z
+		)
+		var terrain_sample: Dictionary = render_facade.call(
+			"renderer_ground_query_snapshot",
+			typed_camera_position
+		)
 		terrain_sample["name"] = checkpoint.get("name", "checkpoint")
 		terrain_sample["camera_y"] = camera_position.y
 		if terrain_sample.has("terrain_height"):
@@ -94,137 +100,6 @@ func _run_async() -> void:
 	quit(1 if failed else 0)
 
 
-func _sample_terrain(world: Node3D, world_position: Vector3) -> Dictionary:
-	var tile_coordinate := _adt_tile_vector2i(world_position)
-	var tile_states: Dictionary = world.get("_tile_states")
-	var highest_terrain_height := -INF
-	var intersected_tile_key := ""
-	var ready_mesh_count := 0
-	for tile_y in range(tile_coordinate.y - 1, tile_coordinate.y + 2):
-		for tile_x in range(tile_coordinate.x - 1, tile_coordinate.x + 2):
-			var tile_key := "%d_%d" % [tile_x, tile_y]
-			if not tile_states.has(tile_key):
-				continue
-			var state: Dictionary = tile_states[tile_key]
-			var terrain_height_variant = _intersect_terrain_state(state, world_position)
-			if terrain_height_variant == null:
-				continue
-			ready_mesh_count += 1
-			var terrain_height := float(terrain_height_variant)
-			if terrain_height > highest_terrain_height:
-				highest_terrain_height = terrain_height
-				intersected_tile_key = tile_key
-	if not is_finite(highest_terrain_height):
-		var missing_result := {
-			"status": "no_intersection" if ready_mesh_count > 0 else "mesh_not_ready",
-			"tile": "%d_%d" % [tile_coordinate.x, tile_coordinate.y],
-		}
-		missing_result.merge(_tile_runtime_diagnostic(world, String(missing_result.tile), world_position), true)
-		if bool(missing_result.get("quality_mesh_present", false)) or bool(missing_result.get("tile_lod_mesh_present", false)):
-			missing_result["status"] = "no_intersection"
-			missing_result.merge(_nearest_terrain_sample(world, world_position), true)
-			if missing_result.get("nearest_sample_distance", null) != null:
-				missing_result["status"] = "sampled_nearby"
-				missing_result["terrain_height"] = float(missing_result.nearest_sample_height)
-		return missing_result
-	return {
-		"status": "sampled",
-		"tile": intersected_tile_key,
-		"terrain_height": highest_terrain_height,
-	}
-
-
-func _intersect_terrain_state(state: Dictionary, world_position: Vector3):
-	var terrain_mesh: Mesh = state.get("quality_terrain_mesh", null)
-	if terrain_mesh == null:
-		terrain_mesh = state.get("tile_lod_mesh", null)
-	if terrain_mesh == null:
-		return null
-	var triangle_mesh := terrain_mesh.generate_triangle_mesh()
-	if triangle_mesh == null:
-		return null
-	var tile_root := state.get("root", null) as Node3D
-	if tile_root == null:
-		return null
-	var inverse_transform := tile_root.global_transform.affine_inverse()
-	var local_ray_origin := inverse_transform * Vector3(world_position.x, RAY_HEIGHT, world_position.z)
-	var local_ray_direction := inverse_transform.basis * Vector3.DOWN
-	var intersection: Dictionary = triangle_mesh.intersect_ray(local_ray_origin, local_ray_direction)
-	if intersection.is_empty():
-		return null
-	var local_hit: Vector3 = intersection.get("position", Vector3.ZERO)
-	var world_hit := tile_root.global_transform * local_hit
-	return world_hit.y
-
-
-func _tile_runtime_diagnostic(world: Node3D, tile_key: String, world_position: Vector3) -> Dictionary:
-	var available_tiles: Dictionary = world.get("_available_tiles")
-	var loading_tasks: Dictionary = world.get("_tile_loading_tasks")
-	var tile_states: Dictionary = world.get("_tile_states")
-	var load_queue: Array = world.get("_tile_load_queue")
-	var queued_index := -1
-	for index in load_queue.size():
-		var request: Dictionary = load_queue[index]
-		if String(request.get("key", "")) == tile_key:
-			queued_index = index
-			break
-	var diagnostic := {
-		"available": available_tiles.has(tile_key),
-		"queued_index": queued_index,
-		"loading": loading_tasks.has(tile_key),
-		"state_present": tile_states.has(tile_key),
-		"load_queue_size": load_queue.size(),
-	}
-	if tile_states.has(tile_key):
-		var state: Dictionary = tile_states[tile_key]
-		var quality_mesh: Mesh = state.get("quality_terrain_mesh", null)
-		var tile_lod_mesh: Mesh = state.get("tile_lod_mesh", null)
-		diagnostic["quality_mesh_present"] = quality_mesh != null
-		diagnostic["tile_lod_mesh_present"] = tile_lod_mesh != null
-		diagnostic["quality_source"] = String(state.get("quality_terrain_source", ""))
-		diagnostic["tile_lod"] = int(state.get("tile_lod", -1))
-		var tile_root := state.get("root", null) as Node3D
-		if tile_root != null:
-			var local_position := tile_root.global_transform.affine_inverse() * world_position
-			diagnostic["tile_root_position"] = _vector3_array(tile_root.global_position)
-			diagnostic["probe_local_position"] = _vector3_array(local_position)
-		var diagnostic_mesh := quality_mesh if quality_mesh != null else tile_lod_mesh
-		if diagnostic_mesh != null:
-			var mesh_aabb := diagnostic_mesh.get_aabb()
-			diagnostic["mesh_aabb_position"] = _vector3_array(mesh_aabb.position)
-			diagnostic["mesh_aabb_size"] = _vector3_array(mesh_aabb.size)
-	return diagnostic
-
-
-func _nearest_terrain_sample(world: Node3D, world_position: Vector3) -> Dictionary:
-	var tile_states: Dictionary = world.get("_tile_states")
-	for radius in [2.0, 5.0, 10.0, 20.0, 40.0]:
-		for offset in [Vector2(radius, 0.0), Vector2(-radius, 0.0), Vector2(0.0, radius), Vector2(0.0, -radius)]:
-			var sample_position := world_position + Vector3(offset.x, 0.0, offset.y)
-			var sample_tile := _adt_tile_vector2i(sample_position)
-			var sample_key := "%d_%d" % [sample_tile.x, sample_tile.y]
-			if not tile_states.has(sample_key):
-				continue
-			var height_variant = _intersect_terrain_state(tile_states[sample_key], sample_position)
-			if height_variant != null:
-				return {
-					"nearest_sample_distance": radius,
-					"nearest_sample_height": float(height_variant),
-					"nearest_sample_tile": sample_key,
-				}
-	return {"nearest_sample_distance": null}
-
-
-func _adt_tile_vector2i(world_position: Vector3) -> Vector2i:
-	var typed_world_position = GODOT_WORLD_POSITION_SCRIPT.new(world_position.x, world_position.y, world_position.z)
-	var tile_coordinate = COORDINATE_MAPPER_SCRIPT.godot_to_adt_tile(typed_world_position)
-	return Vector2i(tile_coordinate.tile_x, tile_coordinate.tile_y)
-
-
-func _vector3_array(value: Vector3) -> Array[float]:
-	return [value.x, value.y, value.z]
-
-
 func _vector3(value_variant) -> Vector3:
 	if not (value_variant is Array) or value_variant.size() != 3:
 		return Vector3.ZERO

src/tools/verify_coordinate_conversion_boundaries.gd

@@ -23,7 +23,6 @@ const REQUIRED_MAPPER_CALLS := {
 	"res://src/render/streaming/streaming_target_planner.gd": ["godot_to_adt_tile", "godot_to_adt_tile_local"],
 	"res://src/scenes/player/third_person_wow_controller.gd": ["adt_tile_local_to_godot"],
 	"res://src/gameplay/terrain/adt_terrain_query.gd": ["godot_to_adt_tile", "godot_to_adt_tile_local", "adt_tile_local_to_chunk"],
-	"res://src/tools/probe_render_terrain_height.gd": ["godot_to_adt_tile"],
 }
 
 
@@ -61,7 +60,7 @@ func _initialize() -> void:
 		quit(1)
 		return
 
-	print("COORDINATE_CONVERSION_BOUNDARIES PASS files=%d native_boundary=1 oracle=1 consumers=6 classifier_cases=6" % source_paths.size())
+	print("COORDINATE_CONVERSION_BOUNDARIES PASS files=%d native_boundary=1 oracle=1 consumers=5 classifier_cases=6" % source_paths.size())
 	quit(0)
 
 

src/tools/verify_renderer_internal_access.gd

@@ -5,6 +5,9 @@ extends SceneTree
 const STREAMING_WORLD_LOADER_PATH := "res://src/scenes/streaming/streaming_world_loader.gd"
 const GAMEPLAY_ROOT := "res://src/gameplay"
 const SOURCE_ROOTS: Array[String] = ["res://src", "res://addons"]
+const RENDERER_DIAGNOSTIC_PATHS: Array[String] = [
+	"res://src/tools/probe_render_terrain_height.gd",
+]
 
 
 func _initialize() -> void:
@@ -20,6 +23,8 @@ func _initialize() -> void:
 		consumer_paths_by_path[gameplay_path] = true
 	for editor_source_path in editor_source_paths:
 		consumer_paths_by_path[editor_source_path] = true
+	for renderer_diagnostic_path in RENDERER_DIAGNOSTIC_PATHS:
+		consumer_paths_by_path[renderer_diagnostic_path] = true
 
 	for consumer_path_variant in consumer_paths_by_path:
 		var consumer_path := String(consumer_path_variant)
@@ -33,10 +38,11 @@ func _initialize() -> void:
 		quit(1)
 		return
 
-	print("RENDERER_INTERNAL_ACCESS PASS private_symbols=%d gameplay=%d editor_sources=%d" % [
+	print("RENDERER_INTERNAL_ACCESS PASS private_symbols=%d gameplay=%d editor_sources=%d renderer_tools=%d" % [
 		private_renderer_symbols.size(),
 		gameplay_paths.size(),
 		editor_source_paths.size(),
+		RENDERER_DIAGNOSTIC_PATHS.size(),
 	])
 	quit(0)
 

src/tools/verify_world_render_facade.gd

@@ -5,6 +5,7 @@ extends SceneTree
 const WORLD_RENDER_FACADE_SCRIPT := preload("res://src/render/world_render_facade.gd")
 const GODOT_WORLD_POSITION_SCRIPT := preload("res://src/domain/coordinates/godot_world_position.gd")
 const STREAMING_FOCUS_SCRIPT := preload("res://src/domain/streaming/streaming_focus.gd")
+const RENDERED_GROUND_SAMPLE_SCRIPT := preload("res://src/render/terrain/rendered_ground_sample.gd")
 
 const RUNTIME_SCENE_PATHS: Array[String] = [
 	"res://src/scenes/streaming/eastern_kingdoms_streaming.tscn",
@@ -15,12 +16,19 @@ const TOOL_PATHS: Array[String] = [
 	"res://src/tools/probe_render_camera_occluders.gd",
 	"res://src/tools/probe_render_terrain_height.gd",
 ]
+const STREAMING_WORLD_LOADER_PATH := "res://src/scenes/streaming/streaming_world_loader.gd"
 
 
 class StreamingWorldLoaderDouble extends Node:
 	var current_focus: StreamingFocus
 	var refresh_count := 0
 	var metrics := {"tiles": 2, "queues": {"tile": 1}}
+	var ground_sample: RefCounted = RENDERED_GROUND_SAMPLE_SCRIPT.available(42.25)
+	var ground_snapshot := {
+		"status": "sampled",
+		"terrain_height": 42.25,
+		"diagnostic": {"state_present": true},
+	}
 
 	func set_streaming_focus(streaming_focus: StreamingFocus) -> void:
 		current_focus = streaming_focus
@@ -32,9 +40,16 @@ class StreamingWorldLoaderDouble extends Node:
 	func render_baseline_snapshot() -> Dictionary:
 		return metrics
 
+	func sample_rendered_ground_height(_godot_world_position: GodotWorldPosition) -> RefCounted:
+		return ground_sample
+
+	func render_ground_query_snapshot(_godot_world_position: GodotWorldPosition) -> Dictionary:
+		return ground_snapshot
+
 
 func _initialize() -> void:
 	var failures: Array[String] = []
+	_verify_rendered_ground_sample_contract(failures)
 	await _verify_delegation_and_snapshot_isolation(failures)
 	_verify_repository_wiring(failures)
 
@@ -44,10 +59,26 @@ func _initialize() -> void:
 		quit(1)
 		return
 
-	print("WORLD_RENDER_FACADE PASS delegation=3 runtime_scenes=2 tools=3")
+	print("WORLD_RENDER_FACADE PASS delegation=5 ground_contract=2 runtime_scenes=2 tools=3")
 	quit(0)
 
 
+func _verify_rendered_ground_sample_contract(failures: Array[String]) -> void:
+	var non_finite_sample = RENDERED_GROUND_SAMPLE_SCRIPT.available(INF)
+	_expect_true(not non_finite_sample.is_available, "non-finite rendered ground is unavailable", failures)
+	_expect_true(
+		non_finite_sample.failure_code == &"render_terrain_height_not_finite",
+		"non-finite rendered ground failure code",
+		failures
+	)
+	var default_unavailable_sample = RENDERED_GROUND_SAMPLE_SCRIPT.unavailable(&"")
+	_expect_true(
+		default_unavailable_sample.failure_code == &"render_terrain_unavailable",
+		"empty rendered ground failure code normalizes",
+		failures
+	)
+
+
 func _verify_delegation_and_snapshot_isolation(failures: Array[String]) -> void:
 	var test_root := Node.new()
 	var loader := StreamingWorldLoaderDouble.new()
@@ -82,6 +113,24 @@ func _verify_delegation_and_snapshot_isolation(failures: Array[String]) -> void:
 	(snapshot["queues"] as Dictionary)["tile"] = 999
 	_expect_true(int(loader.metrics.tiles) == 2, "top-level metrics are detached", failures)
 	_expect_true(int(loader.metrics.queues.tile) == 1, "nested metrics are detached", failures)
+
+	var query_position = GODOT_WORLD_POSITION_SCRIPT.new(100.0, 200.0, 300.0)
+	var ground_sample: RefCounted = facade.sample_ground_height(query_position)
+	_expect_true(ground_sample.is_available, "rendered ground sample delegates", failures)
+	_expect_near(ground_sample.height_units, 42.25, "rendered ground height", failures)
+	loader.ground_sample = RENDERED_GROUND_SAMPLE_SCRIPT.unavailable(&"render_terrain_mesh_not_ready")
+	var unavailable_ground_sample: RefCounted = facade.sample_ground_height(query_position)
+	_expect_true(not unavailable_ground_sample.is_available, "unavailable ground sample delegates", failures)
+	_expect_true(
+		unavailable_ground_sample.failure_code == &"render_terrain_mesh_not_ready",
+		"ground failure code delegates",
+		failures
+	)
+	var ground_snapshot: Dictionary = facade.renderer_ground_query_snapshot(query_position)
+	ground_snapshot["terrain_height"] = 999.0
+	(ground_snapshot["diagnostic"] as Dictionary)["state_present"] = false
+	_expect_near(float(loader.ground_snapshot.terrain_height), 42.25, "ground snapshot top-level detached", failures)
+	_expect_true(bool(loader.ground_snapshot.diagnostic.state_present), "ground snapshot nested detached", failures)
 	test_root.queue_free()
 
 
@@ -98,6 +147,44 @@ func _verify_repository_wiring(failures: Array[String]) -> void:
 		_expect_true(not tool_source.contains('world.call("refresh_streaming_focus"'), "%s avoids direct streamer refresh" % tool_path, failures)
 		_expect_true(not tool_source.contains('world.set("streaming_focus_source_path"'), "%s avoids direct streamer focus config" % tool_path, failures)
 
+	var terrain_probe_source := _read_text("res://src/tools/probe_render_terrain_height.gd", failures)
+	_expect_true(
+		terrain_probe_source.contains('"renderer_ground_query_snapshot"'),
+		"terrain probe delegates ground diagnostics",
+		failures
+	)
+	_expect_true(
+		not terrain_probe_source.contains('world.get("_'),
+		"terrain probe avoids private streamer state",
+		failures
+	)
+	for forbidden_probe_text in [
+		"_tile_states",
+		"_tile_load_queue",
+		"_tile_loading_tasks",
+		"_available_tiles",
+		"generate_triangle_mesh",
+	]:
+		_expect_true(
+			not terrain_probe_source.contains(forbidden_probe_text),
+			"terrain probe omits %s" % forbidden_probe_text,
+			failures
+		)
+
+	var loader_source := _read_text(STREAMING_WORLD_LOADER_PATH, failures)
+	for required_loader_text in [
+		"func sample_rendered_ground_height(godot_world_position: GodotWorldPosition)",
+		"func render_ground_query_snapshot(godot_world_position: GodotWorldPosition)",
+		"RENDER_GROUND_QUERY_RAY_HEIGHT_UNITS := 5000.0",
+		"for radius_units in [2.0, 5.0, 10.0, 20.0, 40.0]",
+		"generate_triangle_mesh()",
+	]:
+		_expect_true(
+			loader_source.contains(required_loader_text),
+			"streamer ground query retains %s" % required_loader_text,
+			failures
+		)
+
 
 func _read_text(path: String, failures: Array[String]) -> String:
 	var file := FileAccess.open(path, FileAccess.READ)