Document the character development toolchain in the architecture

docs/architecture.md

@@ -127,6 +127,48 @@ Contracts that keep the pipeline replaceable:
 - UI/scene art is loaded through `UiArt` with a null/neutral fallback; composed images live in `assets/images/`, not in the docs reference tree (ADR-0014).
 - CI stays offline: only committed `.glb`/`.png`/`.tres` and Godot are needed; optional AI/Blender steps are reproducible development tools.
 
+### Character development tooling
+
+Characters have two authored sources and one procedural fallback. The eight-variant
+Blender library (`assets/models/blender/npc/`) is the normal presentation path; the
+older skinned `npc_base` (`assets/models/generated/npc_base.glb`) remains a frozen
+contract and fallback; `NpcAvatar`'s procedural rig is the offline last resort.
+Blender is a developer tool only — runtime, tests and CI consume committed GLBs and
+maps.
+
+| Tool | Role | Committed artifact | Verification gate |
+| --- | --- | --- | --- |
+| `tools/npc_pipeline.py` | Builds the skinned base avatar, five-slot material maps, palette and AI-fabric preparation (`prepare`/`palette`) | `npc_base.glb`, `assets/textures/npc/*_{albedo,normal,orm}.png`, `palette.json` | `audit_glb` against the frozen 6,000-triangle / 4,000-vertex base contract |
+| `tools/blender_assets.py` | Builds/renders the library: 8 characters, 18 gear pieces, 20 props, plus `manifest.json`; stdlib `audit`/`fit`/`sheet`/`list` | `assets/models/blender/{npc,npc_gear,props}/*.glb` | Library cap 8,000 tris / 8,000 verts per character, 1,500 per gear, 4,000 per prop; grounding, UV, degenerate-triangle, attach-fit and manifest coverage checks |
+| `tools/bake_ao.py` | Bakes per-asset AO maps | `<asset>_ao.png` (256²) | Wired through `Materials.apply_ao()`/`SurfaceMaterials`; cloth/pants opt out (see below) |
+| `tools/npc_proportions.py` | Measures exported GLB rest pose (height, head, shoulders, hips, torso, limbs, feet) against the stylized guide | report / JSON in `docs/npc-proportion-audit.md` | All eight variants must stay inside the guide after a body change |
+| `tools/npc_baseline.py` | Assembles neutral-baseline sheets and before/after comparisons | `docs/blender_previews/sheet_npc_baseline*.jpg` | Human review against `docs/npc-visual-review.md` |
+| `src/test/capture_npc_baseline.gd` | Fixed-camera studio baseline, 8 variants × 6 views | local `tmp/` frames | Neutral silhouette/face/gear review |
+| `src/test/capture_npc_review.gd` | Final-context gate: 8 variants × 2 venues × day/night × 3 distances = 96 frames, crowd hidden, review-only `character_override` for the guard | local `tmp/` frames | Pre-build acceptance gate for gear fit and venue lighting |
+| `src/test/capture_realism.gd` | Venue realism stages plus a frozen portrait and surface close-ups | `docs/screens/realism/<run>/` | Optional vision judge; portrait is the only avatar-detail capture |
+
+Runtime contracts that must survive any character change:
+
+- `NpcAvatar.character_model_for(role, seed)` selects the library variant; `character_override`
+  exists only to stage roles without a spawned model (for example the guard).
+- The armature node names, `Rig/Head`, the Hip/Knee/Shoulder/Elbow/Hand proxies and the
+  **+Z visual front** are frozen; animation and `yaw_towards()` depend on them.
+- Only the five contract slots are tinted. Fixed detail materials (eyes, reflective bands,
+  rubber) stay untouched, gear is placed by `GEAR_ATTACH`, and `GEAR_OFFSETS` plus
+  `HAND_ITEM_FORWARD` are runtime attach-space corrections, not authoring changes.
+- Cloth/pants use `Materials.NPC_FABRIC_UV_SCALE` (4×) and skip the baked per-character AO;
+  skin/hair/gear keep AO. Do not reintroduce the blotchy cloth AO.
+- `apply_lod()` swaps to an impostor at 26 m; the 24-NPC budget smoke (6.94 ms, 168 meshes,
+  131,616 triangles) is the performance gate. Changing either triangle cap requires
+  re-measuring that smoke and the Web/Compatibility path.
+- Rebuild only the assets whose geometry changed (Blender GLB export is byte-nondeterministic),
+  then run `godot --headless --path . --import`; never commit a no-op full rebuild.
+
+Evidence and detailed contracts live in [`blender-assets.md`](blender-assets.md),
+[`npc-visual-review.md`](npc-visual-review.md) and
+[`npc-proportion-audit.md`](npc-proportion-audit.md); command-level usage is in
+[`asset-tooling.md`](asset-tooling.md).
+
 ### Content authoring and runtime data flow
 
 `ScenarioFactory` is the source of truth for the three authored venues. `tools/export_venues.gd`
@@ -272,6 +314,7 @@ Architecture decisions are recorded as ADRs:
 - Accessibility and localization coverage is partial; a public release needs subtitles/captions, colour-independent cues, remapping, text expansion tests and at least a documented localization workflow.
 - Unsigned macOS builds, AI asset provenance and any storefront/legal requirements are release blockers for a public release.
 - Documentation drift has already occurred (release version, implemented status and obsolete plan docs); the ownership map and roadmap must be kept current in the same change as the implementation.
+- Character quality is only partly automatable: proportions, budgets and gear fit are measured, but face realism and venue-lighting readability still need the baseline/review sheets and human sign-off after any mesh, map or material change.
 
 ## 12. Documentation Consolidation and Ownership
 
@@ -287,6 +330,8 @@ architecture document.
 | [`docs/adr/`](adr/) | Immutable decision records with context and consequences | Decision history linked from §9 |
 | [`docs/asset-tooling.md`](asset-tooling.md) | Build/audit/capture commands and pipeline usage | Operational appendix to the pipeline section |
 | [`docs/blender-assets.md`](blender-assets.md) | Blender character/gear/prop contracts and attach points | Detailed asset contract appendix |
+| [`docs/npc-visual-review.md`](npc-visual-review.md) | NPC baseline views, acceptance criteria and ranked visual gaps | Visual-QA appendix to the character tooling section |
+| [`docs/npc-proportion-audit.md`](npc-proportion-audit.md) | Measured proportions against the stylized guide | Measurement appendix to the character tooling section |
 | [`docs/getting-started.md`](getting-started.md) | Setup, commands, controls | Developer onboarding |
 | [`docs/RELEASING.md`](RELEASING.md) | Release checklist and CI/publishing steps | Deployment appendix to §7 |
 | [`docs/smoke-checklist.md`](smoke-checklist.md) | Manual verification script | QA appendix to §10 |