rnd(M03): add rendered ground query facade

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.
-`StreamingWorldLoader` remains the internal scene implementation while later M03
-packages add environment, entity-visual and ground-query contracts.
+Runtime, capture and probe callers use `WorldRenderFacade` for focus, metrics and
+rendered-ground diagnostics. `StreamingWorldLoader` remains the internal scene
+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
-  that reads tile readiness/terrain internals; it is excluded from the gameplay/
-  EditorPlugin gate until equivalent ground-query and readiness facade contracts exist.
+- Rendered-ground sampling generates a triangle mesh on demand and retains the
+  historical nearby seam fallback. It is appropriate for diagnostics, not a
+  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