Document the character development toolchain in the architecture

CREDITS.md

@@ -21,6 +21,25 @@ using Blender. The `.blend` working sources are developer artifacts and are not
 shipped. The exported `.glb` files and baked AO maps are project assets; they do
 not embed third-party models or purchased asset packs.
 
+### Development-only research previews
+
+Two review sheets under `docs/blender_previews/` compare source candidates for
+the post-0.10.0 NPC variety work. They are development documentation and are not
+bundled with the game or its release packages. The underlying source models are
+kept outside version control.
+
+- [`sheet_npc_sources_research.jpg`](docs/blender_previews/sheet_npc_sources_research.jpg)
+  includes renders of **Quaternius Ultimate Modular Characters** (CC0 1.0,
+  <https://quaternius.com/>), **Kenney Blocky Characters 2.0** (CC0 1.0,
+  <https://kenney.nl/assets/blocky-characters>), and **CesiumMan** and
+  **RiggedFigure** (CC BY 4.0, © 2017 Cesium,
+  <https://github.com/KhronosGroup/glTF-Sample-Assets>).
+- [`sheet_npc_crowd_prototypes.jpg`](docs/blender_previews/sheet_npc_crowd_prototypes.jpg)
+  contains renders of project-owned generator prototypes.
+
+The CC-BY preview images are included only as development evidence. Any future
+shipped derivative of CesiumMan or RiggedFigure must keep the attribution above.
+
 The venue geometry is authored procedurally in `src/game/world_builder.gd` as a
 stylized reconstruction. The Joke Shop is a fictional stand-in for the real
 Sunset Strip block; the game does not claim endorsement by, or an exact replica

MEMORY.md

@@ -4,6 +4,23 @@ Session memory for durable decisions, state, and gotchas. Keep concise, remove o
 
 ## Decisions
 
+- **NPC model variety decision (2026-11-03, ADR-0015):** CC0 is acceptable for shipped
+  assets; CC-BY only with attribution in `CREDITS.md`; no service assets with redistribution
+  restrictions. The **procedural generator is the primary path**. Four crowd-variety specs were
+  prototyped with the existing builder (`npc_crowd_a` bun/slim/sunglasses, `npc_crowd_b`
+  bald/broad/beard/shoulder bag, `npc_crowd_c` coat/umbrella, `npc_crowd_d` hood/cup); all audit
+  clean at 4,550–5,258 tris / 4,356–5,086 verts. Prototype assets stay in
+  `tmp/npc-research/generator_proto/`; do not add them to the 0.10.0 release candidate.
+  **Quaternius is a reference, not a shipped base:** welding brings `Casual_Hoodie` from 12,518
+  to 3,199 verts and a 0.75 decimate to 2,423 verts / 4,654 tris, and its Idle/Walk clips read
+  well, but the T-pose 62-bone realistic rig/proportions do not match the arm-down 13-bone
+  contract. A contract rebuild is a no-go without a body proportion warp; a second
+  rig/animation path needs its own ADR. **MakeHuman is deferred** to a separate local pipeline:
+  the CC0 base is 19,158 verts / 36,972 tris and decimates to 3,780 / 6,468 at 0.35, but needs
+  retopology, a custom rig and project clothing. Research previews are committed under
+  `docs/blender_previews/sheet_npc_{sources_research,crowd_prototypes}.jpg`; the CC-BY entries
+  (CesiumMan/RiggedFigure, © Cesium) are attributed in `CREDITS.md` and are development-only.
+
 - **0.10.0 balance protocol:** `docs/balance-acceptance.md` defines targets and
   denominator/cohort rules for the 36 venue/difficulty/phase cells, seeds 1–100,
   access/emergency error rates and matched calm vs emergency-first comparisons.

PLAN.md

@@ -189,3 +189,4 @@ The game should feel like a tense workplace simulation with occasional crisis mo
 - A rare Bob Dobbs cameo (Easter-egg appearance; placement note in `MEMORY.md`).
 - Specific unusual NPC behaviors, such as slapping their own face, using hands as scissors, or interacting with props unexpectedly.
 - Live 3D body-camera replay; additional venues or seasonal events; real voice/dialogue audio; an image-to-mesh prop pipeline.
+- More varied NPC silhouettes (age, build, hair and outfit), using either an extended procedural character generator or a reviewed CC0/CC-BY source; the evaluation and pending decision are in `docs/npc-model-sourcing.md`.

TODO.md

@@ -181,7 +181,11 @@ verify every distribution path. This is the next minor release after the 0.9.x p
       `check_screenshots.sh` and the pinned vision judge, recording model/spend/verdicts.
 - [ ] Run the manual smoke checklist on every target and attach/link the release-candidate evidence.
 - [ ] Verify the tutorial/campaign/help text at maximum font scale and with the longest strings.
-- [ ] Remove or archive stale plans/notes and confirm no contradictory version/status claims remain.
+- [x] Remove or archive stale plans/notes and confirm no contradictory version/status claims remain.
+- [x] Document the character development toolchain in `docs/architecture.md`: base vs library
+      sources, tool/artifact/gate table, runtime attach/animation contracts and rebuild discipline.
+      (Added §5 "Character development tooling" plus risk and ownership-map updates;
+      documentation check passed.)
 
 ### Release-candidate QA and exit
 
@@ -196,6 +200,92 @@ verify every distribution path. This is the next minor release after the 0.9.x p
 - [ ] Exit: the release candidate is content-locked, externally played, legally reviewed,
       documented, reproducibly built, and approved as the 0.10.0 release candidate.
 
+## Milestone 0.11.0 — NPC model variety
+
+Goal: break the eight-character clone effect with four licence-cleared crowd-variety looks while
+keeping the frozen `npc_base` bone, tint-slot and gear-attach contract. The procedural generator is
+the primary path; Quaternius is a reviewed reference and MakeHuman is deferred to a separate local
+development pipeline. Start only after the 0.10.0 release candidate is published; this milestone
+must not delay the release.
+
+### 0.11.1 Source review and decision
+
+- [x] Research free/open-source character sources and evaluate at least three downloads against
+      the existing Blender contract. (Measured Quaternius CC0, Kenney CC0, Khronos
+      CesiumMan/RiggedFigure CC-BY and the MakeHuman CC0 base mesh; none is a drop-in.
+      Results, local preview sheet and SHA-256 provenance are in
+      `docs/npc-model-sourcing.md`.)
+- [x] Review the sourcing research with the project owner and choose Option A (procedural),
+      Option B (Quaternius CC0 intake) or Option C (MakeHuman/MPFB body pipeline); record the
+      decision in an ADR and in `MEMORY.md`. (2026-11-03: extend the procedural generator as the
+      primary path, keep Quaternius as a reviewed prototype/reference, defer MakeHuman to a
+      separate local pipeline. Recorded in ADR-0015 and `MEMORY.md`.)
+- [x] Add a source licence allow-list and provenance rule: CC0 preferred, CC-BY only with
+      attribution in `CREDITS.md`, and no service assets whose terms restrict redistribution.
+      (ADR-0015; the CC-BY research previews are attributed in `CREDITS.md`.)
+- [x] Decide whether the external preview sheet stays local under `tmp/` or is committed with
+      the required CC-BY attribution. (Committed as
+      `docs/blender_previews/sheet_npc_sources_research.jpg` with Cesium CC-BY attribution;
+      the project-owned crowd prototype sheet is also committed.)
+
+### 0.11.2 Intake and validation
+
+- [ ] Add a Blender `inspect` path that imports a GLB, applies node transforms, reports
+      tris/verts, bounds, bones, materials, UVs and skinning, and lists contract failures.
+- [ ] Add an `adapt` path for future external assets: scale/ground, weld seams, decimate, map the
+      five tint slots, and either rebuild the contract armature or record an explicit second-rig
+      contract. The Quaternius prototype showed that a contract rebuild needs a proportion warp,
+      so this is not on the 0.11.0 critical path.
+- [ ] Keep `tools/blender_assets.py audit` as the single final gate; add a regression test for the
+      intake report/adaptation using a deterministic synthetic or licence-cleared fixture.
+- [ ] Document the adapter commands and the go/no-go checks in `docs/asset-tooling.md`.
+
+### 0.11.3 One-character prototype
+
+- [x] Prototype one Quaternius CC0 variant: weld/decimate to budget and capture Idle/Walk
+      renders. (12,518 imported verts -> 3,199 after weld -> 2,423 / 4,654 tris after a 0.75
+      decimate; Idle/Walk quality is good. Preview in
+      `docs/blender_previews/sheet_npc_sources_research.jpg`.)
+- [x] Measure the prototype against the `npc_casual` controls: silhouette, rest pose, body
+      proportions and gear fit. (No-go for a contract rebuild: T-pose 62-bone realistic rig,
+      ~0.96 m hip, ~1.68 m arm span and ~0.153 m shoulder joint do not match the arm-down
+      13-bone contract. Keep as reference; a second rig/animation path needs its own ADR.)
+- [x] Make a go/no-go decision on Option B. (No-go for 0.11.0; proceed with the procedural
+      generator and keep Quaternius as a visual/style reference.)
+
+### 0.11.4 Roster and runtime
+
+- [x] Approve four crowd-variety looks (build, head silhouette, hair/beard, outer layer and
+      accessory; no clothing that labels the NPC's behaviour). (`npc_crowd_a` bun/slim/sunglasses,
+      `npc_crowd_b` bald/broad/beard/shoulder bag, `npc_crowd_c` coat/umbrella, `npc_crowd_d`
+      hood/cup; prototype sheet committed.)
+- [ ] Add the four approved specs to `CHARACTERS`, build and commit their GLBs/AO maps, and
+      update the manifest with roles and tint data. (Prototype assets are local under `tmp/`;
+      do not add them to the 0.10.0 release candidate.)
+- [ ] Replace the fixed `character_model_for()` mapping with deterministic per-role pools and add
+      tests for repeatability and duplicate avoidance.
+- [ ] Rebuild and verify gear fit for every new variant (`blender_assets.py fit` plus the runtime
+      gear checks).
+
+### 0.11.5 QA and release
+
+- [ ] Run the 24-NPC budget smoke, portrait baseline, gear fit, headless suite and a release build
+      with the expanded library.
+- [ ] Update `CREDITS.md`, `docs/development-status.md`, `docs/npc-visual-review.md` and
+      `CHANGELOG.md`; record any accepted visual limits.
+- [ ] Exit: a reviewed 12-character library passes contract audit, portrait/gear acceptance,
+      the 24-NPC budget and licence/provenance review without changing the runtime contract.
+
+### 0.11.6 Deferred MakeHuman local pipeline
+
+- [x] Evaluate the MakeHuman CC0 base mesh for a later separate local development pipeline.
+      (19,158 verts / 36,972 tris; scaled to 1.82 m; decimate 0.35 -> 3,780 verts / 6,468 tris;
+      UVs present, no normals/material groups/rig. Feasible only with retopology, a custom rig and
+      project-owned clothing; keep out of CI/build.)
+- [ ] Decide whether body-shape diversity still matters after the 12-character library lands; if
+      yes, prototype the local MPFB/MakeHuman pipeline outside the repo and commit only the final
+      CC0-derived assets with provenance.
+
 ## Future 0.x / non-blocking candidates
 
 - [ ] Live 3D body-camera replay.

docs/README.md

@@ -13,6 +13,7 @@ This folder holds the project documentation, visual references and generated QA
 - [`asset-tooling.md`](asset-tooling.md) — image/model pipelines and screenshot gates
 - [`npc-visual-review.md`](npc-visual-review.md) — NPC visual baseline, acceptance criteria and ranked gaps
 - [`npc-proportion-audit.md`](npc-proportion-audit.md) — NPC proportion ratios and stylized guide results
+- [`npc-model-sourcing.md`](npc-model-sourcing.md) — free/open-source character sources, contract evaluation and the 0.11.0 expansion plan
 - [`development-status.md`](development-status.md) — implemented features and current gaps
 - [`accessibility.md`](accessibility.md) — accessibility statement and known gaps
 - [`known-limitations.md`](known-limitations.md) — release-candidate blockers and accepted limits

docs/adr/0015-npc-model-variety-sourcing.md

@@ -0,0 +1,72 @@
+# ADR-0015: NPC model variety sourcing
+
+- **Status:** Accepted (post-0.10.0 planning)
+- **Date:** 2026-11-03
+
+## Context
+
+The library has eight skinned characters, and role/seed selection reuses them
+across the three venues. Crowds therefore repeat the same faces, builds and
+outfits. The existing contract is strict: `npc_base` mesh node, 13 named bones at
+fixed rest positions, five tint slots, front on Blender −Y and an 8,000
+triangle/vertex budget.
+
+A review compared free/open-source sources against that contract. Quaternius
+Ultimate Modular (CC0), Kenney Blocky Characters (CC0), Khronos CesiumMan and
+RiggedFigure (CC BY 4.0) and the MakeHuman base mesh (CC0) were imported and
+measured. None was a drop-in; the full results are in
+[`docs/npc-model-sourcing.md`](../npc-model-sourcing.md).
+
+## Decision
+
+1. **Ship only CC0, or CC BY with recorded attribution.** No service asset whose
+   terms restrict redistribution may be used.
+2. **Extend the project-owned procedural generator as the primary path** for
+   shipped NPC variety. The first target is four crowd-variety looks, bringing
+   the library to twelve characters.
+3. **Keep Quaternius as a reviewed reference/prototype, not a shipped base.** A
+   contract retarget is a no-go because the source is a T-pose 62-bone realistic
+   rig with substantially different proportions from the arm-down 13-bone
+   contract. A future external-rig path would need its own ADR covering its
+   skeleton, animation source and per-model gear offsets.
+4. **MakeHuman is deferred to a separate local development pipeline.** Its CC0
+   base mesh can be decimated into budget, but it needs retopology, a custom rig
+   and project-owned clothing before it is usable. It must not become a CI or
+   build dependency.
+5. **Commit research previews with attribution.** CC-BY preview images are
+   development-only and are not bundled with the game or its release packages.
+
+## Consequences
+
+### Positive
+
+- The shipped library keeps one art direction, one skeleton and one audit gate.
+- Crowd variety lands without a new runtime dependency or a second animation
+  system.
+- The licence position is simple: project-owned assets plus explicit CC-BY
+  attribution where a preview or future asset requires it.
+- The Quaternius evaluation removes a tempting but high-risk retarget from the
+  critical path.
+
+### Negative
+
+- Procedural variation is still limited by the existing face and clothing
+  vocabulary; four variants do not provide full age/body diversity.
+- Quaternius' animation set remains unused unless a second rig path is approved.
+- MakeHuman body-shape diversity is postponed.
+- External previews add a small documentation footprint that must stay out of
+  release packages.
+
+## Alternatives considered
+
+- **Retarget Quaternius onto the `npc_base` contract.** Rejected for now:
+  welding brings the geometry inside budget, but the rest pose and body
+  proportions differ enough that a contract rebuild would either distort the
+  model or require a full proportion warp.
+- **Use Quaternius' own rig and animations directly.** Deferred: attractive
+  animation quality, but it adds a second skeleton/animation path and per-model
+  gear offsets to `NpcAvatar`.
+- **Use MakeHuman as the primary body source.** Rejected for this milestone: high
+  polygon count, no rig in the base mesh and a separate authoring dependency.
+- **Use Mixamo or Ready Player Me.** Rejected: service terms are not a simple
+  free/open-source redistribution basis for shipped meshes.

docs/adr/README.md

@@ -18,3 +18,4 @@ Each ADR records the context, decision, consequences and alternatives for a dura
 - [0012-surface-materials-and-generated-props](0012-surface-materials-and-generated-props.md)
 - [0013-blender-authored-npc-characters](0013-blender-authored-npc-characters.md)
 - [0014-runtime-image-root](0014-runtime-image-root.md)
+- [0015-npc-model-variety-sourcing](0015-npc-model-variety-sourcing.md)

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 |

docs/asset-tooling.md

@@ -129,6 +129,11 @@ with colliders/avoidance and drives their emissive parts from the day/night
 cycle. The single `npc_base.glb` and primitive props remain offline fallbacks.
 Contract and integration notes: [`blender-assets.md`](blender-assets.md).
 
+Sourcing and expansion research (no external model is shipped yet):
+[`npc-model-sourcing.md`](npc-model-sourcing.md) compares Quaternius, Kenney, Khronos and
+MakeHuman sources against the character contract and records the 2026-11-03 direction
+(procedural generator first, Quaternius reference, MakeHuman deferred).
+
 | Characters | Props |
 | --- | --- |
 | ![characters](../docs/blender_previews/sheet_npc.jpg) | ![props](../docs/blender_previews/sheet_props.jpg) |

docs/blender_previews/README.md

@@ -43,6 +43,8 @@ Committed contact sheets and local Blender renders for the character, gear and p
 | <img src="security_podium.png" width="280" alt="security_podium.png"> | [`security_podium.png`](security_podium.png) |
 | <img src="sedan.png" width="280" alt="sedan.png"> | [`sedan.png`](sedan.png) |
 | <img src="sheet_npc.jpg" width="280" alt="sheet_npc.jpg"> | [`sheet_npc.jpg`](sheet_npc.jpg) |
+| <img src="sheet_npc_sources_research.jpg" width="280" alt="sheet_npc_sources_research.jpg"> | [`sheet_npc_sources_research.jpg`](sheet_npc_sources_research.jpg) |
+| <img src="sheet_npc_crowd_prototypes.jpg" width="280" alt="sheet_npc_crowd_prototypes.jpg"> | [`sheet_npc_crowd_prototypes.jpg`](sheet_npc_crowd_prototypes.jpg) |
 | <img src="sheet_npc_baseline.jpg" width="280" alt="sheet_npc_baseline.jpg"> | [`sheet_npc_baseline.jpg`](sheet_npc_baseline.jpg) |
 | <img src="sheet_npc_baseline_compare-p1.jpg" width="280" alt="sheet_npc_baseline_compare-p1.jpg"> | [`sheet_npc_baseline_compare-p1.jpg`](sheet_npc_baseline_compare-p1.jpg) |
 | <img src="sheet_npc_baseline_compare-body.jpg" width="280" alt="sheet_npc_baseline_compare-body.jpg"> | [`sheet_npc_baseline_compare-body.jpg`](sheet_npc_baseline_compare-body.jpg) |

docs/npc-model-sourcing.md

@@ -0,0 +1,308 @@
+# NPC model sourcing and expansion plan
+
+Status: **direction chosen 2026-11-03.** The procedural generator is the primary
+path, the Quaternius CC0 pack is a reviewed reference/prototype, and MakeHuman is
+deferred to a separate local development pipeline. No downloaded source model is
+committed to the game or included in a release; the committed research preview
+sheets carry the required attribution. Local evaluation files live under
+`tmp/npc-research/` (gitignored). The decision is recorded in
+[ADR-0015](adr/0015-npc-model-variety-sourcing.md).
+
+This page records the free/open-source character sources that were reviewed, how
+they behave when imported into the existing Blender tooling, and the options for
+creating a larger NPC model library. The runtime contract and current library are
+documented in [`blender-assets.md`](blender-assets.md) and
+[`npc-visual-review.md`](npc-visual-review.md).
+
+## Why this review exists
+
+The library has eight skinned characters, and `NpcAvatar.character_model_for()`
+reuses them across role families. That is enough for a release candidate, but
+crowds repeat the same faces, builds and outfits. Three venues, a 24-NPC budget
+and close-up portraits make that repetition visible.
+
+Any expansion must preserve the existing integration contract:
+
+- mesh node `npc_base` under a `Skeleton3D`;
+- bones `Head`, `HipL/R`, `KneeL/R`, `ShoulderL/R`, `ElbowL/R`, `HandL/R` plus
+  `Hips`, `Spine`, `Neck` at the contract rest positions;
+- five tint slots (`skin`, `cloth`, `pants`, `accessory`, `hair`);
+- front on Blender −Y / Godot +Z, feet near the floor, 1.6–2.1 m height;
+- at most 8,000 triangles and 8,000 glTF vertices per character;
+- gear attach points at head, back, chest and hand.
+
+The existing `audit` command is the gate. A source that looks good in a preview
+but fails `audit` is not usable without an adaptation step.
+
+## What was evaluated
+
+Blender 5.2.0 LTS (Flatpak) imported each file in background mode. Measurements
+below come from the imported scene, because external GLBs often carry node
+transforms that the project's audit (which reads accessor-local bounds) does not
+apply. "Vertices" are the imported, seam-split counts that matter for the glTF
+budget, not the source file's vertex count.
+
+| Source | Licence | Files checked | Geometry / rig | Height | Verdict |
+| --- | --- | --- | --- | --- | --- |
+| **Quaternius Ultimate Modular Men / Women** (mirrored GLB pack) | CC0 1.0 | `Casual_Hoodie.glb`, `Worker.glb`, `Casual.glb` | 5,240–6,424 tris; 10,534–12,968 verts; 62 bones; 24 animations; 4 skinned meshes on one armature | 1.80–1.87 m | **Best silhouette/outfit match.** Fails the contract: wrong bone names/rest positions, no tint slots, no `npc_base` node, vertex budget exceeded. |
+| **Kenney Blocky Characters 2.0** | CC0 1.0 | full pack (18 characters), `character-a.glb`, `character-f.glb` | 72 tris; 143 verts; static, no armature; one texture atlas per character | 2.7 m imported (needs 0.67× scale) | **Not a close-up character.** Useful as a crowd/impostor LOD or placeholder, but cannot be driven by the skeleton and has no separate face/clothing slots. |
+| **Khronos CesiumMan** | CC BY 4.0 (© Cesium) | `CesiumMan.glb` | 4,672 tris; 3,273 verts; 19-bone walk rig; 1 material/texture; 1 animation | 1.45 m | **Technical retarget test only.** One outfit and one look, wrong rig, short; works as a skinning/pose reference. Attribution is required. |
+| **Khronos RiggedFigure** | CC BY 4.0 (© Cesium) | `RiggedFigure.glb` | 256 tris; 370 verts; 19-bone walk rig; no UVs; 1 animation | 1.48 m | **Rig smoke test only.** A mannequin with no usable surface detail. |
+| **MakeHuman core base mesh / MPFB** | Core assets CC0 1.0; application AGPL/GPL | `makehuman/data/3dobjs/base.obj` | 19,158 verts; 18,486 polygons; 36,972 tris; no rig in the base mesh | ~16.9 model units before scaling | **Best body-shape diversity, highest pipeline cost.** Needs scaling, decimation/retopology and a generated rig. The MakeHuman/MPFB tool itself is not bundled. |
+
+Local review sheet (front views, not committed):
+`tmp/npc-research/previews/contact_sheet.jpg`.
+
+Rejected without downloading: Mixamo and Ready Player Me. Both are useful
+services, but their terms are not a simple free/open-source redistribution basis
+for shipped character meshes. Sketchfab, Poly Pizza and OpenGameArt can contain
+excellent CC0 work, but each asset needs a case-by-case licence and provenance
+check; they are not a consistent library source.
+
+### Measured contract failures
+
+Every example fails the unmodified `audit` contract:
+
+| Check | Quaternius | Kenney | CesiumMan | RiggedFigure | MakeHuman base |
+| --- | --- | --- | --- | --- | --- |
+| `npc_base` mesh node | no | no | no | no | no |
+| Required 13 bones | no (62 different names) | no rig | no (19 different names) | no (19 different names) | no rig |
+| Five tint slots | no | no | no | no | no |
+| ≤ 8,000 tris | yes | yes | yes | yes | no |
+| ≤ 8,000 verts | no (10.5–13k) | yes | yes | yes | no (19k) |
+| Feet on floor | yes | yes (2.7 m scale) | yes (−11 mm) | yes | no (needs scaling) |
+| Height 1.6–2.1 m | yes | no (2.7 m) | no (1.45 m) | no (1.48 m) | needs scale |
+| Skinned / UV mapped | yes / yes | no / yes | yes / yes | yes / no | no / no |
+
+The practical conclusion is that **there is no drop-in download**. External
+sources need a deliberate intake step, and the expensive part is not decimation:
+it is rebuilding or retargeting the skeleton and material slots without breaking
+the animation proxies and gear placement.
+
+The table uses Blender-imported world bounds. The stdlib `audit` reads accessor-local
+bounds and ignores node transforms, so an unapplied external GLB can fail floor/height
+checks even when the imported scene looks correct. The intake step must apply
+transforms before it measures and exports.
+
+## Options
+
+### Option A — extend the procedural generator
+
+Add more variation to `tools/blender_assets.py` rather than importing models:
+body builds, height ranges, head/face shapes, hair and facial hair, outfit
+layers, and more `CHARACTERS` specs. This keeps a single owned style, needs no
+third-party licence review, and stays inside the existing builder/audit flow.
+
+- **Strengths:** lowest integration risk, deterministic, no new dependencies.
+- **Limits:** the current face and clothing vocabulary is intentionally simple;
+  more variants may still read as the same model with a different coat.
+- **Best for:** a quick 4–8 variant expansion and filling obvious role gaps.
+
+### Option B — Quaternius CC0 intake with a contract adapter
+
+Use Quaternius meshes as silhouette/outfit donors and adapt them to the project
+contract. The visible result is a different body/clothing language from the
+current library, so the adapter must also normalise head/hand style or rebuild
+those parts.
+
+- **Strengths:** best free outfit/hair variety, animations included, CC0,
+  already close to game proportions, front axis and floor contact.
+- **Work:** weld/decimate to the vertex budget, remap materials to the five
+  slots, rebuild the armature at the contract rest positions, transfer weights,
+  repose/normalise proportions, rename the mesh node, export, audit and compare
+  in the acceptance harness.
+- **Main risk:** retargeting a 62-bone T-pose rig to the 13-bone arm-down
+  contract. Hip/knee rest heights differ substantially (Quaternius upper leg
+  starts near 0.96 m; the contract hip starts near 0.62 m), so a naive
+  nearest-bone weight transfer can produce a good still image and bad walk
+  poses. Prototype one character before committing to a roster.
+- **Best for:** a larger, visibly different library if the prototype passes the
+  portrait and walk gates.
+
+### Option C — MakeHuman/MPFB body-shape pipeline
+
+Generate a range of ages, builds and body shapes from the CC0 MakeHuman base
+mesh, then replace the head/hands and dress them with project-owned clothing.
+This is the strongest answer to "everyone has the same body", but requires an
+offline authoring step, decimation/retopology and a custom rig/weight step. It
+should be treated as a later pipeline project, not a quick content drop.
+
+## Decision and prototype outcome
+
+The project owner reviewed this page on 2026-11-03. The decision is:
+
+1. **CC0 is acceptable** for shipped character assets. CC-BY is acceptable only
+   with attribution in `CREDITS.md`; service assets whose terms restrict
+   redistribution remain excluded.
+2. **Extend the procedural generator** as the primary path, starting with
+   crowd-variety looks.
+3. **Prototype Quaternius** as a secondary source. It is not approved for
+   shipping yet; the contract-retarget result below is a no-go for the current
+   skeleton.
+4. **Use crowd variety** as the first visual goal, not role-specific costumes.
+5. **Evaluate MakeHuman for a later, separate local development pipeline.** It
+   is not part of the normal build, CI or release flow.
+6. **Commit the research previews with attribution.** The CC-BY entries are
+   listed in `CREDITS.md` and remain development-only.
+
+### Quaternius prototype
+
+The prototype used `Casual_Hoodie.glb`:
+
+- **Geometry budget is not the blocker.** Imported: 12,518 vertices / 6,206
+  triangles. After welding seam splits: 3,199 vertices / 6,206 triangles. After
+  a 0.75 decimate: 2,423 vertices / 4,654 triangles, comfortably inside the
+  library budget.
+- **Animation quality is attractive.** The imported Idle and Walk clips read
+  well at game distance, and the model brings 24 animations.
+- **The contract rest pose is the blocker.** The source is a T-pose 62-bone rig
+  with realistic proportions: upper leg starts near 0.96 m, arm span is about
+  1.68 m, and the shoulder joint sits near x = 0.153 m. The project contract is
+  an arm-down 13-bone rig with a hip near 0.62 m, a shoulder near x = 0.27 m and
+  a hand near z = 0.78 m. Rebuilding the contract armature around this mesh would
+  either distort the body substantially or require a full proportion warp.
+- **Decision:** do not retarget Quaternius to the contract now. Keep it as a
+  silhouette/style reference and, if a second rig path is ever wanted, prototype
+  it as its own animation path (its own skeleton, AnimationPlayer clips and
+  per-model gear offsets) rather than forcing it into `npc_base`. That is a
+  separate architecture decision, not an asset conversion.
+
+Preview: [`blender_previews/sheet_npc_sources_research.jpg`](blender_previews/sheet_npc_sources_research.jpg).
+
+### Generator crowd prototype
+
+Four proposed crowd specs were built with the existing generator in a temporary
+output directory. All four audit clean and stay inside the character budget:
+
+| Prototype | Look | Tris / verts | Gear |
+| --- | --- | --- | --- |
+| `npc_crowd_a` | slim, bun, sunglasses | 4,644 / 4,356 | sunglasses |
+| `npc_crowd_b` | broad, bald, beard | 4,550 / 4,453 | shoulder bag |
+| `npc_crowd_c` | average, short hair, long coat | 5,118 / 5,086 | umbrella |
+| `npc_crowd_d` | slim, short hair, hood up | 5,258 / 4,907 | cup |
+
+They vary build, head silhouette, hair/beard and outer layer while keeping the
+existing face language. They are **not in the shipped catalogue**; production
+integration belongs to milestone 0.11.4 after the 0.10.0 release candidate.
+
+Preview: [`blender_previews/sheet_npc_crowd_prototypes.jpg`](blender_previews/sheet_npc_crowd_prototypes.jpg).
+
+### MakeHuman local-pipeline evaluation
+
+The CC0 base mesh is 19,158 vertices / 18,486 polygons (36,972 triangles after
+triangulation), with 21,334 UV coordinates but no normals, material groups or
+rig. Scaling it to 1.82 m and decimating to 0.35 produced 3,780 vertices / 6,468
+triangles, which fits the geometry budget but is a collapse-decimation result,
+not production topology.
+
+MakeHuman is therefore **feasible only as a separate local body-shape pipeline**.
+The boundary for that future work is:
+
+- MPFB/MakeHuman is installed and run by a contributor, never by CI or the game
+  build.
+- Generated bodies and intermediate exports stay in `tmp/` (gitignored); the
+  CC0 base mesh is not committed.
+- The contributor scales to 1.8–1.9 m, decimates or retopologises to roughly
+  6–7k triangles, and checks the silhouette against `npc-visual-review.md`.
+- The body gets the contract armature, weights, project-owned head/hands,
+  clothing and gear; it must pass `blender_assets.py audit` and `fit`.
+- Only the final CC0-derived GLB and its provenance note are committed. The
+  application code and any non-CC0 assets stay outside the repository.
+
+This is deferred; it is not part of the 0.11.0 crowd-variety work.
+
+## Provisional NPC roster
+
+The design rule stays: clothes, props and behaviour carry the read; a model must
+not label a person as "the threat". The roster therefore adds ordinary adults
+across age, build and style, not costumes that telegraph the outcome.
+
+| Look family | Current | Proposed additions | Variation axes |
+| --- | --- | --- | --- |
+| Everyday | `npc_casual`, `npc_jacket`, `npc_coat`, `npc_hoodie`, `npc_dress` | `npc_crowd_a` (bun/slim), `npc_crowd_b` (bald/broad), `npc_crowd_c` (coat/umbrella), `npc_crowd_d` (hood/cup) | build, height, hair, facial hair, outer layer, accessory |
+| Workwear | `npc_vest`, `npc_guard` | later: second hi-vis build, venue-security build | build, height, headwear, badge/radio gear |
+| Responder | `npc_firefighter` | later: paramedic/medical responder only if the design supports it | turnout vs medical kit, build, helmet |
+| Crowd/LOD | none | optional Kenney blocky or a decimated library variant for distant crowds | silhouette and palette only |
+
+A first target is **12 library characters** (the current eight plus the four
+crowd prototypes), not twenty. That is enough to break the clone effect without
+doubling the portrait QA matrix. `character_model_for()` becomes a pool per role
+family with a deterministic seed choice; the current two-way alternation for
+guests, trespassers and threats is the template.
+
+## Implementation plan
+
+The actionable tasks live in `TODO.md` under milestone 0.11.0. The workstreams
+are:
+
+1. **Decision and licence gate.** Complete: ADR-0015, the CC0/CC-BY rule and the
+   committed preview sheets.
+2. **Generator crowd variants.** Complete as a prototype (four specs, clean
+   audit, review sheet). Production integration is pending the 0.10.0 release.
+3. **Quaternius intake.** The contract-retarget prototype is a no-go. Keep the
+   source as a reference; a second-rig/animation path would need its own ADR.
+4. **Roster build and runtime.** Add the four approved specs to `CHARACTERS`,
+   build and commit their GLBs, update the manifest, and extend the role pools.
+5. **QA and integration.** Run the 24-NPC budget, portrait baseline, gear fit,
+   headless suite and release build. Record provenance and any accepted limits.
+   Only then update `CHANGELOG.md` and `docs/development-status.md`.
+
+### Adapter notes
+
+- Apply node transforms before measuring or exporting. CesiumMan imports with a
+  Z-up root and an `Icosphere` helper object; exclude helpers, not just the mesh
+  names, when measuring.
+- Weld duplicate seam vertices before decimating. Quaternius' 12k imported
+  vertices are mostly UV/normal splits; the underlying surface is much smaller,
+  but the glTF budget counts the splits after export.
+- Decimate to a target below 8,000 tris/verts, then re-unwrap only if the
+  existing UVs cannot survive the material remap. The current library uses
+  smart projection at 80° to keep islands large.
+- Map materials by semantic role, not by source name. A source "Purple" or
+  "Worker_Vest" needs an explicit mapping to `cloth`, `pants`, `skin`, `hair` or
+  `accessory`; do not rely on colour heuristics.
+- Keep the face direction unambiguous. The front is Blender −Y; verify it with
+  a capture, not by guessing from the source file.
+- For any future external-rig path, do not silently add a second skeleton format
+  to `NpcAvatar`. Record the per-model skeleton, animation source and gear
+  offsets as an explicit contract.
+
+## Review outcome
+
+The project owner answered the review questions on 2026-11-03:
+
+| Question | Answer |
+| --- | --- |
+| Are third-party CC0 characters acceptable? | Yes. |
+| Which direction? | Prototype Quaternius and extend the procedural generator. |
+| Which looks first? | Crowd variety. |
+| Should MakeHuman be pursued? | Evaluate it for a later, separate local development pipeline. |
+| Commit the previews? | Yes, with CC-BY attribution. |
+
+## Downloaded example provenance
+
+Source models were downloaded on 2026-11-03 and kept out of version control. The two
+research preview sheets are committed under `docs/blender_previews/`; the CC-BY
+attribution is recorded in `CREDITS.md`.
+
+| File | Source | SHA-256 |
+| --- | --- | --- |
+| `quaternius/Casual_Hoodie.glb` | `raw.githubusercontent.com/LuanDucate/Ducz.CharacterCreator/HEAD/public/models/Male/Casual_Hoodie.glb` (Quaternius CC0) | `f5b722199f7628b24550989af4230f65d5230727df9c326fd2b3e360effe5249` |
+| `quaternius/Worker.glb` | same mirror, `Male/Worker.glb` | `8d0f454336c2effc5c08f63a177af3a82d1a7af025ca9588b40e4c90c4703534` |
+| `quaternius/Casual.glb` | same mirror, `Female/Casual.glb` | `bc2d84fba249ebaa0629cb9d133ad37234196e4b8004aa205a6397abed04e05c` |
+| `kenney_blocky_characters.zip` | `kenney.nl/assets/blocky-characters` | `5e123859aa0c1598342b600c6db197024a1d63eb9ec531398b310725f589887e` |
+| `khronos/CesiumMan.glb` | `github.com/KhronosGroup/glTF-Sample-Assets` | `b7001eaeea8254bd44773bcd247e78696d94169388fbb2a1800fc69434e777d9` |
+| `khronos/RiggedFigure.glb` | same repository | `d6be85417d3e256861ee733eea6916093a7af7c79c16366181fd8abcaeb38cf5` |
+| `makehuman/base.obj` | `github.com/makehumancommunity/makehuman/blob/master/makehuman/data/3dobjs/base.obj` | `8e761e6624b8f54536409135d1636da63b32486a90d4897f84e121d144f6fb4c` |
+
+Source terms:
+
+- Quaternius packs are CC0 1.0 according to the pack page and the mirror's
+  credits. The mirror is a convenience download; the original pack page is
+  <https://quaternius.com/packs/ultimatemodularcharacters.html>.
+- Kenney Blocky Characters 2.0 is CC0 1.0; the pack's `License.txt` is included
+  in the download.
+- CesiumMan and RiggedFigure are CC BY 4.0, © 2017 Cesium. If any derivative is
+  committed or shipped, the attribution must be added to `CREDITS.md`.
+- MakeHuman core assets are CC0 per `LICENSE.ASSETS.md`; the application source
+  is AGPL and is not bundled.