Fix movement-hall black walls and column clipping.

Cap shared hall lights (no per-painting spots) so MeshStandard walls stay within WebGL limits, tuck classical/neoclassical details into engaged corner pilasters, and document the light budget.

Co-authored-by: Cursor <cursoragent@cursor.com>

Documentation/basics.md

@@ -299,10 +299,10 @@ Each artist has **exactly one hall**. The hall is a rectangular room sized to fi
 | Floor | Herringbone **parquet** procedural texture (`parquetFloorTexture.ts`) |
 | Wall tint | Gallery walls blend the artist’s **movement colour** into cream plaster tones |
 | Frame finish | **Unchecked** works: black moulding; **Reviewed** (`checkup_checked`): bright gold moulding at **double width** |
-| Influence lamps | A golden picture light appears **above frames** whose work has any influence-graph edge (`has_influence_links` from the API); fixture is mounted **upside down** (`InfluencePictureLamp` in `VirtualGallery.tsx`) |
+| Influence lamps | A golden picture light appears **above frames** whose work has any influence-graph edge (`has_influence_links` from the API); fixture is mounted **upside down** and is **emissive-only** (no per-frame lights — see light budget below) |
 | Curator-note plates | A small brass plate hangs **beneath frames** that have non-empty `curator_notes` |
 | Eye-level viewing | Frame centres sit at **eye height (~1.65 m)**; the camera stays **level with the floor** (no pitch up/down) |
-| Open centre | Floor and ceiling only — no columns, pedestals, or other centre objects |
+| Open centre | Floor and ceiling only — no freestanding columns or pedestals in the walkway |
 | Museum exit | Front-wall **double doors** with transom, brass hardware, sconces, marble threshold, and warm vestibule glow |
 | Shadows | **Disabled** — no Canvas shadow maps / `castShadow` (performance; flat lighting only) |
 | Hall-to-hall travel | Exit opens a panel: **Predecessors** (left) and **Successors** (right), each grouped by art movement |
@@ -338,11 +338,12 @@ Enter from the home page by clicking a **movement name** on the movement flow. F
 | Period interior | Each of the 26 seeded movements maps to a unique style in `movement-interior-styles.ts` (Italian palazzo, Baroque palace, NYC loft, white cube, etc.). Style keys use a legacy id map (`DB_ID_TO_STYLE_KEY`: gallery ids **1–26** → authored keys **27–52**, with Northern/High Renaissance swapped) so Byzantine gets the chapel, not Gothic stone |
 | Wall materials | Hi-res **procedural textures** with normal maps (`galleryProceduralTextures.ts`): real-world stone, marble, wood panelling, brick, velvet, stucco — plus **single-colour painted walls** (`painted-lime`, `painted-oil-matte`, `painted-oil-satin`, `painted-emulsion`, `painted-flat`) tinted per movement for Renaissance salons through modern white cubes |
 | Textures | Wall/floor/ceiling maps applied via `useTexturedMaterial`; movement **tints** drive painted-wall hue |
-| Windows | **Side walls only** — placed in gaps between frames (high on the wall, no overlap with paintings); style matches the movement era |
-| Lighting | Daylight from windows + ceiling track lights + ambient/sun fill |
+| Windows | **Side walls only** — placed in gaps between frames when possible; if a wall is packed, high **clerestory** windows are still added so the hall keeps daylight (`computeSideWallWindows`) |
+| Lighting | Shared hall lights only (ambient / hemisphere / directional + capped ceiling track spots + one fill per window). See **light budget** below |
+| Period details | `MovementHallDetails.tsx` — classical / neoclassical use **shallow engaged corner pilasters** (never freestanding mid-hall or proud corner shafts that cover frames) |
 | Back wall | Single wing: solid display wall. Multi-wing: **Exit double doors** → **Wing navigator** or **Exit to Timeline** |
 | Front / entrance wall | Single wing: **Exit double doors** (leave the way you entered). Multi-wing: **“Next wing →”** archway when a later wing exists |
-| Influence lamps | Same golden upside-down lamps as artist halls when `has_influence_links` is true |
+| Influence lamps | Same golden upside-down emissive fixtures as artist halls when `has_influence_links` is true |
 | Missing images | Draped canvas cover in frame |
 | Detail return | **Back to Gallery** from painting detail returns to the same wing with camera preserved; **Back to Timeline** exits the hall entirely |
 
@@ -373,6 +374,12 @@ Full guide: [tours.md](tours.md).
 
 ### Shared 3D behaviour
 
+**Light budget (critical):** Three.js forward shading cannot compile `MeshStandardMaterial` with dozens of dynamic lights. Large wings used to add **one `spotLight` per painting** (plus influence lamps), which pushed the scene to ~100–200 lights — walls, floor, and ceiling then rendered as a black void while painting canvases (`MeshBasicMaterial`) still showed. Halls therefore use **shared lighting only**: ambient / hemisphere / directional fill, a small set of ceiling track spots (`GalleryTrackLights`, capped), and **one** window spot each. Painting canvases stay unlit (`MeshBasicMaterial`); frames and influence fixtures use **emissive** accents instead of per-frame lights. Intensities are scaled for three.js physical lights (post-r155).
+
+**Period architecture:** Freestanding columns must not sit in the walkway or in the corner pocket in front of frames (hang margin is only ~0.7 m from each wall end). Classical / neoclassical details use **engaged corner pilasters** flush to the walls (`MovementHallDetails.tsx`).
+
+**Surface textures:** Procedural colour maps use sRGB; **normal maps use `NoColorSpace`** (`galleryProceduralTextures.ts`). Wrong colour space on normals breaks wall shading.
+
 **3D images** prefer local **thumbnail** files (`galleryImageUrlCandidates` in `client/src/api/client.ts`: thumb → `GET /api/paintings/:id/image?size=thumb`; full originals are **not** used for hall frames — they can be tens of MB and made large halls take ~1 minute). Remote Wikipedia fetches are too slow for realtime WebGL textures. Entering an **artist** or **movement** hall fires `POST /api/artists/:id/preload-images` or `POST /api/movements/:id/preload-images` in the **background** (does not block hall open). Texture downloads are **queued** (max 8 parallel). While a texture is loading, the frame shows the canvas cover instead of a white placeholder. A per-image deadline only releases the boot overlay counter — it does **not** permanently blank the frame if the download finishes later.
 
 **Boot overlay** (`VirtualGallery.tsx`): the center shows **“Loading gallery…”** until the WebGL canvas is ready and a short `gl.compileAsync` warm-up finishes (so entrance doors / passages do not hitch on the first turn). HDR `Environment` loads in a Suspense boundary **without** blocking the overlay. Painting textures keep loading in the background. The 3D hall stays mounted while painting detail or bio overlays are open; returning remounts the canvas when the hall becomes active again.

Documentation/data-and-images.md

@@ -278,9 +278,9 @@ To add or fix a branch, edit `MOVEMENT_LINEAGE` in that file and rebuild the cli
 
 ## Movement gallery interiors (frontend)
 
-Separate from movement lineage layout, `client/src/data/movement-interior-styles.ts` defines a **unique 3D interior** for each seeded art movement (26 styles): wall/floor/ceiling textures, trim colours, window style, and architectural details (columns, coffered ceilings, etc.). Textures are generated procedurally in `client/src/utils/galleryProceduralTextures.ts`.
+Separate from movement lineage layout, `client/src/data/movement-interior-styles.ts` defines a **unique 3D interior** for each seeded art movement (26 styles): wall/floor/ceiling textures, trim colours, window style, and architectural details (pilasters, coffered ceilings, etc.). Textures are generated procedurally in `client/src/utils/galleryProceduralTextures.ts` (colour maps in sRGB, normal maps in linear/`NoColorSpace`). Period mesh details live in `client/src/components/MovementHallDetails.tsx` — classical / neoclassical use **shallow engaged corner pilasters** so shafts never cover frames.
 
-Wing layout (up to 55 works per wing, U-shaped hang, window gap placement) lives in `client/src/utils/movementHallLayout.ts`. Visit order fills the **left wall** (first work at the entrance), then the **far/end wall**, then the **right** (last work at the entrance). The same hang applies to artist halls and guided tours. To change a movement’s look, edit its entry in `movement-interior-styles.ts` and rebuild the client.
+Wing layout (up to 55 works per wing, U-shaped hang, window gap placement with packed-wall **clerestory** fallback) lives in `client/src/utils/movementHallLayout.ts`. Visit order fills the **left wall** (first work at the entrance), then the **far/end wall**, then the **right** (last work at the entrance). The same hang applies to artist halls and guided tours. Hall lighting is **shared** (no per-painting spotlights) so `MeshStandardMaterial` walls stay within WebGL light limits — see [basics.md](basics.md) § Shared 3D behaviour. To change a movement’s look, edit its entry in `movement-interior-styles.ts` and rebuild the client.
 
 ## Historical event markers (frontend timeline)