Add movement artist filter modal and fix large-hall texture blanks

Clicking a movement opens ArtistFilterModal to choose artists before the gallery. Large halls no longer permanently blank frames when texture loads exceed the overlay deadline; fall back thumb to full to on-demand API.

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

Documentation/API.md

@@ -373,9 +373,38 @@ Artists belonging to a single movement.
 
 ---
 
+## `GET /api/movements/:id/artists-summary`
+
+Lightweight artist list for the **movement gallery entry filter** modal (portraits + painting counts).
+
+**Response** — array of:
+
+```json
+{
+  "id": 6,
+  "name": "Andrei Rublev",
+  "birth_year": 1360,
+  "death_year": 1430,
+  "portrait_path": "portraits/...",
+  "portrait_thumb_path": "portraits/thumbs/...",
+  "portrait_cache_key": 1710000000000,
+  "portrait_thumb_cache_key": 1710000000000,
+  "painting_count": 12
+}
+```
+
+| Field | Meaning |
+|-------|---------|
+| `painting_count` | Number of paintings by this artist (any movement filter is by `artists.movement_id`) |
+| `portrait_*_cache_key` | File mtimes for cache-busting (from `enrichArtistRow`) |
+
+Ordered by `birth_year`, then name. Localized when `?lang=` / locale headers request a non-default locale.
+
+---
+
 ## `GET /api/movements/:id/gallery`
 
-Full **movement gallery** payload for the 3D movement wings view (opened by clicking a movement name on the home page).
+Full **movement gallery** payload for the 3D movement wings view (opened by clicking a movement name on the home page, after the artist-filter modal).
 
 **Response**
 

Documentation/basics.md

@@ -8,7 +8,7 @@ The app is organised as a **drill-down hierarchy**:
 
 1. **Timeline** — historical eras (Ancient → Contemporary) with definite or fuzzy date boundaries.
 2. **Movement flow** — art movements as curved SVG streams on the same year axis; documented predecessor→successor branches; portrait thumbnails placed along each stream.
-3. **3D gallery** — one personal hall per artist, a **movement gallery** (click a movement name), or a **guided tour** hall (timeline → **Tours**): period-themed or tour wings of up to ~55 works, U-shaped hang (left → end wall → right).
+3. **3D gallery** — one personal hall per artist, a **movement gallery** (click a movement name → artist filter → hall), or a **guided tour** hall (timeline → **Tours**): period-themed or tour wings of up to ~55 works, U-shaped hang (left → end wall → right).
 4. **Painting detail** — full work in the centre, *Influenced By* on the left, *Influenced* on the right (paintings, artists, or movements), optional **curator notes** and **art-history notes** with image markers, prev/next catalog browsing, optional fullscreen, link to artist biography.
 5. **Artist biography** — portrait, lifespan, movement, and Wikipedia-sourced intro text (`bio_short` / `bio_full`). With debug mode on, the same image-audit panel as painting detail (portrait search, **Checked** / **Fix it** / **More** / **Clear** / **Upload**).
 
@@ -209,9 +209,9 @@ Pan, zoom, and era/event click-to-zoom only update **local** `viewStart` / `view
 |--------|------|
 | Overlay **“Loading art history…”** | Until the first catalog fetch (`bounds` + `timeline` + `artists`) completes |
 | Bottom banner **“Loading portraits…”** | While artist portrait thumbnails are still downloading on the movement flow (timeline stays interactive) |
-| Overlay **“Opening artist/movement gallery…”** | Between clicking a portrait/movement and the 3D hall data being ready |
+| Overlay **“Opening artist/movement gallery…”** / **“Loading artists…”** | Between clicking a portrait/movement and the 3D hall (or artist-filter modal) data being ready |
 | Overlay **“Loading gallery…”** | While the 3D canvas initializes, HDR Environment settles, or door/hall shaders warm up after the hall opens (painting images continue loading after the overlay dismisses) |
-| Overlay **“Loading paintings…”** | While wall painting textures are still downloading / uploading to the GPU |
+| Overlay **“Loading paintings…”** | Brief counter while wall painting textures start downloading; large halls (e.g. Byzantine) keep loading after the overlay dismisses — a slow image no longer permanently blanks the frame |
 | Overlay **“Restoring gallery…”** | Briefly after WebGL context loss while the canvas remounts |
 
 View updates are **batched to one commit per animation frame** via `createViewChangeScheduler()` in `timelineView.ts` (`HomePage.tsx` → `handleViewChange`), so rapid scroll-wheel events do not flood React with separate renders.
@@ -272,7 +272,7 @@ Each artist appears as a **portrait circle** on their movement’s stream row:
 | Scroll wheel anywhere on flow canvas | Zoom (same year range as timeline; works over portraits and labels too) |
 | Drag on flow canvas | Pan |
 | Click portrait | Open artist biography |
-| Click **movement name** (label on stream) | Open **movement gallery** for that movement |
+| Click **movement name** (label on stream) | Open the **artist filter** modal for that movement, then the movement gallery |
 
 **Zoom/pan performance:** The movement canvas uses a **capture-phase** wheel listener so scroll zoom works even when the cursor is over a portrait. While scrolling or dragging, a short **interaction mode** (~120 ms after the last input) draws simplified solid SVG strokes and temporarily hides portrait/label DOM so zoom stays responsive; full stream styling and portraits return when you stop.
 
@@ -326,11 +326,11 @@ Predecessors and successors come from **`painting_influence_sources`** (painting
 
 ### Movement galleries
 
-Enter from the home page by clicking a **movement name** on the movement flow (`MovementBands.tsx` → `GET /api/movements/:id/gallery`).
+Enter from the home page by clicking a **movement name** on the movement flow. First a centered **artist filter** modal (`ArtistFilterModal.tsx`) loads `GET /api/movements/:id/artists-summary` (portrait, lifespan, painting count). All artists are selected by default; deselect any to exclude their works, then **Enter gallery**. The client loads `GET /api/movements/:id/gallery` and filters paintings to the selected artist IDs before opening `VirtualGallery`.
 
 | Rule | Implementation |
 |------|----------------|
-| One gallery per movement | All paintings by artists in that movement, sorted chronologically |
+| One gallery per movement | Paintings by **selected** artists in that movement, sorted chronologically |
 | Wings | Catalog split into wings of up to **55 works** (`movementHallLayout.ts`); large movements (e.g. Baroque) use multiple wings |
 | Paintings on walls | **Left, end, and right** — single-wing halls keep the far wall solid (full span); multi-wing halls hang end-wall works on panels beside the back exit |
 | Wall order | Same U-shaped hang as artist halls (left → end → right) |
@@ -373,9 +373,9 @@ Full guide: [tours.md](tours.md).
 
 ### Shared 3D behaviour
 
-**3D images** use locally cached files only (`galleryImageUrl` in `client/src/api/client.ts`). Remote fetches are too slow for realtime WebGL textures; the client calls `POST /api/artists/:id/preload-images` or `POST /api/movements/:id/preload-images` automatically when entering an **artist** or **movement** hall (public routes — link disk files and regenerate missing thumbs). While a texture is loading, the frame shows the canvas cover instead of a white placeholder.
+**3D images** prefer local thumbnail files (`galleryImageUrlCandidates` in `client/src/api/client.ts`: thumb → full → `GET /api/paintings/:id/image?size=thumb`). Remote Wikipedia fetches are too slow for realtime WebGL textures; the client calls `POST /api/artists/:id/preload-images` or `POST /api/movements/:id/preload-images` automatically when entering an **artist** or **movement** hall (public routes — link disk files and regenerate missing thumbs). 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 (important for large halls such as Byzantine).
 
-**Boot overlay** (`VirtualGallery.tsx`): the center shows **“Loading gallery…”** until the WebGL canvas is ready, HDR `Environment` has settled (or timed out / failed), and a one-shot `gl.compileAsync` warm-up finishes so entrance doors / passages (often frustum-culled at spawn) do not hitch on the first turn. Painting textures keep loading in the background (prefer thumbnails; per-image timeouts; GPU upload after decode) so large halls (50+ works) are not stuck on the overlay. Env and shader warm-up also have short timeouts. The 3D hall stays mounted while painting detail or bio overlays are open; returning remounts the canvas when the hall becomes active again.
+**Boot overlay** (`VirtualGallery.tsx`): the center shows **“Loading gallery…”** until the WebGL canvas is ready, HDR `Environment` has settled (or timed out / failed), and a one-shot `gl.compileAsync` warm-up finishes so entrance doors / passages (often frustum-culled at spawn) do not hitch on the first turn. Painting textures keep loading in the background (prefer thumbnails; fallback to full / on-demand API; GPU upload after decode) so large halls (50+ works) are not stuck on the overlay. Env and shader warm-up also have short timeouts. The 3D hall stays mounted while painting detail or bio overlays are open; returning remounts the canvas when the hall becomes active again.
 
 **WebGL context-loss recovery:** on some GPUs/drivers (notably certain Chrome setups) the browser can drop the WebGL context right after entering a hall, which would otherwise leave a permanent dark window. `VirtualGallery.tsx` listens for `webglcontextlost` / `webglcontextrestored`, calls `preventDefault()` so the browser can restore the context, and remounts the `<Canvas>` with a fresh context (a **“Restoring gallery…”** overlay shows briefly). The network-loaded HDR `Environment` map is wrapped in an error boundary so, if it fails to load, the hall still renders without reflections instead of unmounting the whole scene.
 

client/src/api/client.ts

@@ -5,6 +5,7 @@ import type {
   Artist,
   ArtistDetail,
   MovementGalleryDetail,
+  ArtistSummary,
   Painting,
   PaintingDetail,
   ArtistNavigation,
@@ -176,6 +177,30 @@ export function galleryImageUrl(
   return null;
 }
 
+/** Ordered texture URL candidates for a hall frame (thumb → full → on-demand API). */
+export function galleryImageUrlCandidates(
+  painting: {
+    id?: number;
+    thumbnail_path?: string | null;
+    image_path?: string | null;
+    image_cache_key?: number | null;
+    thumbnail_cache_key?: number | null;
+  },
+  sessionRevision?: number | null
+): string[] {
+  const revision = paintingImageRevision(painting, sessionRevision);
+  const urls: string[] = [];
+  const push = (u: string | null | undefined) => {
+    if (u && !urls.includes(u)) urls.push(u);
+  };
+  if (painting.thumbnail_path) push(imageUrl(painting.thumbnail_path, revision));
+  if (painting.image_path) push(imageUrl(painting.image_path, revision));
+  if (painting.id != null) {
+    push(`/api/paintings/${painting.id}/image?size=thumb`);
+  }
+  return urls;
+}
+
 export function galleryImageUrlWithRevision(
   painting: {
     id?: number;
@@ -458,6 +483,9 @@ export const api = {
 
   getMovementGallery: (id: number) => fetchJson<MovementGalleryDetail>(localizedPath(`${API}/movements/${id}/gallery`)),
 
+  getMovementArtistsSummary: (id: number) =>
+    fetchJson<ArtistSummary[]>(localizedPath(`${API}/movements/${id}/artists-summary`)),
+
   getArtistNavigation: (id: number) =>
     fetchJson<ArtistNavigation>(localizedPath(`${API}/artists/${id}/navigation`)),
 

client/src/components/ArtistFilterModal.css

@@ -0,0 +1,229 @@
+.artist-filter-backdrop {
+  position: fixed;
+  inset: 0;
+  z-index: 200;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  background: rgba(0, 0, 0, 0.65);
+  padding: 16px;
+}
+
+.artist-filter-modal {
+  width: min(100%, 720px);
+  max-height: min(90vh, 640px);
+  display: flex;
+  flex-direction: column;
+  border-radius: 10px;
+  border: 1px solid rgba(201, 169, 110, 0.35);
+  background: linear-gradient(180deg, #1a1a2e 0%, #12121f 100%);
+  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.55);
+}
+
+.artist-filter-header {
+  padding: 20px 24px 12px;
+  flex-shrink: 0;
+}
+
+.artist-filter-header h2 {
+  margin: 0 0 6px;
+  font-family: 'Georgia', serif;
+  font-size: 22px;
+  color: #e8d5b5;
+}
+
+.artist-filter-subtitle {
+  margin: 0;
+  font-size: 13px;
+  color: rgba(201, 169, 110, 0.7);
+}
+
+.artist-filter-toolbar {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 12px;
+  padding: 0 24px 12px;
+  flex-shrink: 0;
+}
+
+.artist-filter-toggle-all {
+  border: none;
+  background: transparent;
+  color: rgba(255, 220, 160, 0.9);
+  font-size: 13px;
+  cursor: pointer;
+  text-decoration: underline;
+  text-underline-offset: 2px;
+}
+
+.artist-filter-toggle-all:hover {
+  color: #ffe8c0;
+}
+
+.artist-filter-count {
+  font-size: 12px;
+  color: rgba(201, 169, 110, 0.65);
+}
+
+.artist-filter-grid {
+  flex: 1;
+  overflow-y: auto;
+  display: grid;
+  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
+  gap: 12px;
+  padding: 4px 24px 16px;
+}
+
+.artist-filter-card {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: 4px;
+  padding: 12px 8px;
+  border-radius: 8px;
+  border: 1px solid rgba(201, 169, 110, 0.2);
+  background: rgba(0, 0, 0, 0.25);
+  cursor: pointer;
+  text-align: center;
+  transition: border-color 0.15s, background 0.15s, opacity 0.15s;
+}
+
+.artist-filter-card:hover {
+  border-color: rgba(255, 220, 160, 0.45);
+  background: rgba(0, 0, 0, 0.35);
+}
+
+.artist-filter-card-selected {
+  border-color: rgba(255, 220, 160, 0.55);
+  background: rgba(255, 220, 160, 0.08);
+}
+
+.artist-filter-card:not(.artist-filter-card-selected) {
+  opacity: 0.55;
+}
+
+.artist-filter-portrait-wrap {
+  position: relative;
+  width: 56px;
+  height: 56px;
+  margin-bottom: 4px;
+}
+
+.artist-filter-portrait {
+  width: 56px;
+  height: 56px;
+  border-radius: 50%;
+  object-fit: cover;
+  border: 2px solid rgba(201, 169, 110, 0.4);
+}
+
+.artist-filter-portrait-placeholder {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  background: rgba(201, 169, 110, 0.15);
+  color: rgba(232, 213, 181, 0.6);
+  font-size: 20px;
+  font-family: 'Georgia', serif;
+}
+
+.artist-filter-check {
+  position: absolute;
+  right: -2px;
+  bottom: -2px;
+  width: 20px;
+  height: 20px;
+  border-radius: 50%;
+  background: rgba(255, 220, 160, 0.95);
+  color: #1a1a2e;
+  font-size: 12px;
+  font-weight: 700;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  line-height: 1;
+}
+
+.artist-filter-card:not(.artist-filter-card-selected) .artist-filter-check {
+  background: rgba(0, 0, 0, 0.5);
+  border: 1px solid rgba(201, 169, 110, 0.35);
+  color: transparent;
+}
+
+.artist-filter-name {
+  font-family: 'Georgia', serif;
+  font-size: 13px;
+  font-weight: 600;
+  color: #e8d5b5;
+  line-height: 1.25;
+}
+
+.artist-filter-years {
+  font-size: 11px;
+  color: rgba(201, 169, 110, 0.75);
+}
+
+.artist-filter-paintings {
+  font-size: 11px;
+  color: rgba(201, 169, 110, 0.55);
+}
+
+.artist-filter-footer {
+  display: flex;
+  justify-content: flex-end;
+  gap: 10px;
+  padding: 16px 24px 20px;
+  border-top: 1px solid rgba(201, 169, 110, 0.15);
+  flex-shrink: 0;
+}
+
+.artist-filter-cancel,
+.artist-filter-proceed {
+  padding: 10px 18px;
+  border-radius: 6px;
+  font-size: 14px;
+  cursor: pointer;
+}
+
+.artist-filter-cancel {
+  border: 1px solid rgba(201, 169, 110, 0.35);
+  background: transparent;
+  color: rgba(232, 213, 181, 0.85);
+}
+
+.artist-filter-cancel:hover {
+  background: rgba(201, 169, 110, 0.1);
+}
+
+.artist-filter-proceed {
+  border: none;
+  background: linear-gradient(180deg, #c9a96e 0%, #a88b4a 100%);
+  color: #1a1a2e;
+  font-weight: 600;
+}
+
+.artist-filter-proceed:hover:not(:disabled) {
+  filter: brightness(1.08);
+}
+
+.artist-filter-proceed:disabled {
+  opacity: 0.45;
+  cursor: not-allowed;
+}
+
+@media (max-width: 480px) {
+  .artist-filter-grid {
+    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
+    gap: 8px;
+    padding-left: 16px;
+    padding-right: 16px;
+  }
+
+  .artist-filter-header,
+  .artist-filter-toolbar,
+  .artist-filter-footer {
+    padding-left: 16px;
+    padding-right: 16px;
+  }
+}

client/src/components/ArtistFilterModal.tsx

@@ -0,0 +1,171 @@
+import { useEffect, useMemo, useState } from 'react';
+import type { ArtistSummary } from '../types';
+import { portraitThumbUrl, portraitUrl } from '../api/client';
+import { useQueuedImageSrc } from '../hooks/useQueuedImageSrc';
+import './ArtistFilterModal.css';
+
+interface Props {
+  open: boolean;
+  movementName: string;
+  artists: ArtistSummary[];
+  portraitRevisions?: Record<number, number>;
+  onProceed: (selectedIds: Set<number>) => void;
+  onClose: () => void;
+}
+
+function formatLifespan(birth: number | null, death: number | null): string {
+  const b = birth != null ? String(birth) : '?';
+  const d = death != null ? String(death) : '?';
+  return `${b}–${d}`;
+}
+
+function paintingCountLabel(count: number): string {
+  return count === 1 ? '1 painting' : `${count} paintings`;
+}
+
+function ArtistFilterPortrait({
+  artist,
+  revision,
+}: {
+  artist: ArtistSummary;
+  revision?: number;
+}) {
+  const thumbSrc =
+    artist.portrait_thumb_path || artist.portrait_path
+      ? portraitThumbUrl(artist, revision)
+      : null;
+  const fullSrc = artist.portrait_path
+    ? portraitUrl(artist.portrait_path, revision ?? artist.portrait_cache_key)
+    : null;
+  const [srcIndex, setSrcIndex] = useState(0);
+  const candidates = [thumbSrc, fullSrc].filter((s, i, arr): s is string => Boolean(s) && arr.indexOf(s) === i);
+  const requested = candidates[srcIndex] ?? null;
+  const queuedSrc = useQueuedImageSrc(requested);
+
+  useEffect(() => {
+    setSrcIndex(0);
+  }, [thumbSrc, fullSrc]);
+
+  if (!queuedSrc) {
+    return (
+      <span className="artist-filter-portrait artist-filter-portrait-placeholder" aria-hidden>
+        ?
+      </span>
+    );
+  }
+
+  return (
+    <img
+      src={queuedSrc}
+      alt=""
+      className="artist-filter-portrait"
+      onError={() => {
+        setSrcIndex((i) => (i + 1 < candidates.length ? i + 1 : candidates.length));
+      }}
+    />
+  );
+}
+
+export default function ArtistFilterModal({
+  open,
+  movementName,
+  artists,
+  portraitRevisions,
+  onProceed,
+  onClose,
+}: Props) {
+  const allIds = useMemo(() => new Set(artists.map((a) => a.id)), [artists]);
+  const [selected, setSelected] = useState<Set<number>>(() => new Set(allIds));
+
+  useEffect(() => {
+    if (open) {
+      setSelected(new Set(artists.map((a) => a.id)));
+    }
+  }, [open, artists]);
+
+  if (!open) return null;
+
+  const allSelected = selected.size === artists.length && artists.length > 0;
+  const noneSelected = selected.size === 0;
+
+  const toggleArtist = (id: number) => {
+    setSelected((prev) => {
+      const next = new Set(prev);
+      if (next.has(id)) next.delete(id);
+      else next.add(id);
+      return next;
+    });
+  };
+
+  const toggleAll = () => {
+    setSelected(allSelected ? new Set() : new Set(allIds));
+  };
+
+  return (
+    <div className="artist-filter-backdrop" onMouseDown={onClose}>
+      <div
+        className="artist-filter-modal"
+        role="dialog"
+        aria-labelledby="artist-filter-title"
+        aria-modal="true"
+        onMouseDown={(e) => e.stopPropagation()}
+      >
+        <header className="artist-filter-header">
+          <h2 id="artist-filter-title">{movementName}</h2>
+          <p className="artist-filter-subtitle">Choose artists to include in the gallery hall</p>
+        </header>
+
+        <div className="artist-filter-toolbar">
+          <button type="button" className="artist-filter-toggle-all" onClick={toggleAll}>
+            {allSelected ? 'Deselect all' : 'Select all'}
+          </button>
+          <span className="artist-filter-count">
+            {selected.size} of {artists.length} selected
+          </span>
+        </div>
+
+        <div className="artist-filter-grid">
+          {artists.map((artist) => {
+            const isSelected = selected.has(artist.id);
+            return (
+              <button
+                key={artist.id}
+                type="button"
+                className={`artist-filter-card${isSelected ? ' artist-filter-card-selected' : ''}`}
+                onClick={() => toggleArtist(artist.id)}
+                aria-pressed={isSelected}
+              >
+                <span className="artist-filter-portrait-wrap">
+                  <ArtistFilterPortrait
+                    artist={artist}
+                    revision={portraitRevisions?.[artist.id]}
+                  />
+                  <span className="artist-filter-check" aria-hidden>
+                    {isSelected ? '✓' : ''}
+                  </span>
+                </span>
+                <span className="artist-filter-name">{artist.name}</span>
+                <span className="artist-filter-years">{formatLifespan(artist.birth_year, artist.death_year)}</span>
+                <span className="artist-filter-paintings">{paintingCountLabel(artist.painting_count)}</span>
+              </button>
+            );
+          })}
+        </div>
+
+        <footer className="artist-filter-footer">
+          <button type="button" className="artist-filter-cancel" onClick={onClose}>
+            Cancel
+          </button>
+          <button
+            type="button"
+            className="artist-filter-proceed"
+            disabled={noneSelected}
+            onClick={() => onProceed(new Set(selected))}
+          >
+            Enter gallery
+          </button>
+        </footer>
+      </div>
+    </div>
+  );
+}

client/src/components/VirtualGallery.tsx

@@ -12,7 +12,7 @@ import type {
   MovementArtistGroup,
   TourGalleryDetail,
 } from '../types';
-import { galleryImageUrlWithRevision, imageUrl, api } from '../api/client';
+import { galleryImageUrlCandidates, imageUrl, api } from '../api/client';
 import { comparePaintingsChronological, paintingHasCuratorNotes, paintingHasInfluenceLinks, paintingWallCaption } from '../utils/paintingUtils';
 import { cloneSurfaceTexture, getSurfaceTexture } from '../utils/galleryProceduralTextures';
 import { resolveMovementInteriorStyle, type MovementInteriorStyle, type GalleryWindowSpec } from '../data/movement-interior-styles';
@@ -647,20 +647,32 @@ function CanvasCover({
   );
 }
 
-function usePaintingTexture(url: string | null) {
+function usePaintingTexture(urls: string[] | string | null) {
+  const candidates = useMemo(() => {
+    const list = Array.isArray(urls) ? urls.filter(Boolean) : urls ? [urls] : [];
+    return list;
+  }, [Array.isArray(urls) ? urls.join('|') : urls ?? '']);
+  const candidateKey = candidates.join('|');
+  const [urlIndex, setUrlIndex] = useState(0);
+  const url = candidates[urlIndex] ?? null;
   const [texture, setTexture] = useState<THREE.Texture | null>(null);
-  const [failed, setFailed] = useState(!url);
+  const [failed, setFailed] = useState(candidates.length === 0);
   const textureLoad = useContext(GalleryTextureLoadContext);
   const { gl } = useThree();
 
+  useEffect(() => {
+    setUrlIndex(0);
+  }, [candidateKey]);
+
   useEffect(() => {
     if (!url) {
       setTexture(null);
-      setFailed(true);
+      setFailed(candidates.length === 0 || urlIndex >= candidates.length);
       return;
     }
 
     setFailed(false);
+    setTexture(null);
     let disposed = false;
     let loaded: THREE.Texture | null = null;
     let settled = false;
@@ -674,9 +686,12 @@ function usePaintingTexture(url: string | null) {
     };
 
     textureLoad?.begin();
+    // Release the loading overlay after a deadline, but do NOT mark the texture
+    // failed — large halls (e.g. Byzantine, 45 works) queue behind ~6 browser
+    // connections and often finish after 10s. Marking failed permanently left
+    // blank canvases even when the image arrived later.
     const loadTimeout = window.setTimeout(() => {
       if (settled || disposed) return;
-      setFailed(true);
       finish();
     }, TEXTURE_LOAD_TIMEOUT_MS);
 
@@ -692,17 +707,21 @@ function usePaintingTexture(url: string | null) {
         const img = tex.image as HTMLImageElement | undefined;
         if (!img || img.width < 4 || img.height < 4) {
           tex.dispose();
-          setFailed(true);
           finish();
+          if (!disposed) {
+            if (urlIndex + 1 < candidates.length) setUrlIndex((i) => i + 1);
+            else setFailed(true);
+          }
           return;
         }
         loaded = tex;
         tex.colorSpace = THREE.SRGBColorSpace;
         tex.anisotropy = 4;
-        // Release the hall overlay counter before GPU upload — large halls
-        // (50+ works) otherwise stay on "Loading paintings…" for a long time.
         finish();
-        if (!disposed) setTexture(tex);
+        if (!disposed) {
+          setFailed(false);
+          setTexture(tex);
+        }
         try {
           if (!disposed) gl.initTexture(tex);
         } catch {
@@ -713,7 +732,10 @@ function usePaintingTexture(url: string | null) {
       () => {
         window.clearTimeout(loadTimeout);
         finish();
-        if (!disposed) setFailed(true);
+        if (!disposed) {
+          if (urlIndex + 1 < candidates.length) setUrlIndex((i) => i + 1);
+          else setFailed(true);
+        }
       }
     );
 
@@ -724,7 +746,7 @@ function usePaintingTexture(url: string | null) {
       loaded?.dispose();
       setTexture(null);
     };
-  }, [url, textureLoad, gl]);
+  }, [url, urlIndex, candidates.length, textureLoad, gl]);
 
   return { texture, failed };
 }
@@ -877,8 +899,8 @@ function PaintingFrame({
   const reviewed = paintingIsReviewed(painting);
   const { matBorder, rail, depth: frameDepth } = frameDimsForReviewed(reviewed);
   const hasImage = paintingHasGalleryImage(painting);
-  const url = hasImage ? galleryImageUrlWithRevision(painting, imageRevision) : null;
+  const urls = hasImage ? galleryImageUrlCandidates(painting, imageRevision) : [];
-  const { texture, failed } = usePaintingTexture(url);
+  const { texture, failed } = usePaintingTexture(urls);
   const showImage = hasImage && !failed && !!texture;
   const showCanvas = !showImage;
   const hasInfluenceLinks = paintingHasInfluenceLinks(painting);

client/src/pages/HomePage.tsx

@@ -12,12 +12,14 @@ import InfluencesPage from '../pages/InfluencesPage';
 import ToursPage from '../pages/ToursPage';
 import UsersPage from '../pages/UsersPage';
 import CuratorLoginModal from '../components/CuratorLoginModal';
+import ArtistFilterModal from '../components/ArtistFilterModal';
 import ToursPopup from '../components/ToursPopup';
 import CatalogSearchBar from '../components/CatalogSearchBar';
 import LocaleSwitcher from '../components/LocaleSwitcher';
 import GalleryLoadingMarker from '../components/GalleryLoadingMarker';
 import '../components/CatalogSearchBar.css';
 import '../components/CuratorLoginModal.css';
+import '../components/ArtistFilterModal.css';
 import '../components/ToursPopup.css';
 import '../components/LocaleSwitcher.css';
 import '../pages/TranslationsPage.css';
@@ -34,6 +36,7 @@ import type {
   PaintingDetail,
   MovementGalleryDetail,
   TourGalleryDetail,
+  ArtistSummary,
 } from '../types';
 import { createViewChangeScheduler } from '../utils/timelineView';
 import { sortArtistPaintingsChronological } from '../utils/paintingUtils';
@@ -178,6 +181,11 @@ export default function HomePage() {
   const [loginOpen, setLoginOpen] = useState(false);
   const [loginRedirect, setLoginRedirect] = useState<CuratorLoginRedirect>(null);
   const [toursPopupOpen, setToursPopupOpen] = useState(false);
+  const [artistFilterModal, setArtistFilterModal] = useState<{
+    movementId: number;
+    movementName: string;
+    artists: ArtistSummary[];
+  } | null>(null);
   const effectiveDebugMode = debugMode && canImages;
   const [galleryRevision, setGalleryRevision] = useState(0);
   const viewRef = useRef(view);
@@ -639,11 +647,43 @@ export default function HomePage() {
   };
 
   const handleMovementClick = async (movementId: number) => {
+    setGalleryEntryLoading('Loading artists…');
+    try {
+      const artists = await api.getMovementArtistsSummary(movementId);
+      if (artists.length === 0) {
+        setError('No artists in this movement.');
+        return;
+      }
+      const movement = timelineData.movements.find((m) => m.id === movementId);
+      setArtistFilterModal({
+        movementId,
+        movementName: movement?.name ?? 'Movement',
+        artists,
+      });
+    } catch {
+      setError('Failed to load movement artists.');
+    } finally {
+      setGalleryEntryLoading(null);
+    }
+  };
+
+  const handleArtistFilterProceed = async (selectedIds: Set<number>) => {
+    if (!artistFilterModal) return;
+    const { movementId } = artistFilterModal;
+    setArtistFilterModal(null);
     setGalleryEntryLoading('Opening movement gallery…');
     try {
       await api.preloadMovementImages(movementId).catch(() => undefined);
       const data = await api.getMovementGallery(movementId);
-      openMovementGallery(movementId, data);
+      const filtered: MovementGalleryDetail = {
+        ...data,
+        paintings: data.paintings.filter((p) => selectedIds.has(Number(p.artist_id))),
+      };
+      if (filtered.paintings.length === 0) {
+        setError('No paintings for the selected artists.');
+        return;
+      }
+      openMovementGallery(movementId, filtered);
     } catch {
       setError('Failed to load movement gallery.');
     } finally {
@@ -1117,6 +1157,17 @@ export default function HomePage() {
         onSelectTour={(tourId) => void handleSelectPublishedTour(tourId)}
       />
 
+      {artistFilterModal && (
+        <ArtistFilterModal
+          open
+          movementName={artistFilterModal.movementName}
+          artists={artistFilterModal.artists}
+          portraitRevisions={portraitRevisions}
+          onClose={() => setArtistFilterModal(null)}
+          onProceed={(selectedIds) => void handleArtistFilterProceed(selectedIds)}
+        />
+      )}
+
       {view.type === 'timeline' && (
         <div className="home-page">
           <header className="site-header">

client/src/types/index.ts

@@ -136,6 +136,19 @@ export interface MovementGalleryDetail {
   paintings: Painting[];
 }
 
+/** Artist row for movement gallery entry filter (portraits + painting counts). */
+export interface ArtistSummary {
+  id: number;
+  name: string;
+  birth_year: number | null;
+  death_year: number | null;
+  portrait_path: string | null;
+  portrait_thumb_path?: string | null;
+  portrait_cache_key?: number | null;
+  portrait_thumb_cache_key?: number | null;
+  painting_count: number;
+}
+
 export interface TourSummary {
   id: number;
   title: string;

server/index.js

@@ -335,6 +335,29 @@ app.get('/api/movements/:id/gallery', async (req, res) => {
   }
 });
 
+// Artists for a movement with painting counts (for gallery entry filter modal)
+app.get('/api/movements/:id/artists-summary', async (req, res) => {
+  try {
+    const { id } = req.params;
+    const result = await pool.query(
+      `SELECT a.id, a.name, a.birth_year, a.death_year, a.portrait_path, a.portrait_thumb_path,
+              COUNT(p.id)::int AS painting_count
+       FROM artists a
+       LEFT JOIN paintings p ON p.artist_id = a.id
+       WHERE a.movement_id = $1
+       GROUP BY a.id
+       ORDER BY a.birth_year NULLS LAST, a.name`,
+      [id]
+    );
+    const { locale, statuses } = localeContext(req);
+    const localized = await localizeArtists(result.rows, locale, statuses);
+    res.json(localized.map(enrichArtistRow));
+  } catch (err) {
+    console.error(err);
+    res.status(500).json({ error: 'Failed to fetch movement artists summary' });
+  }
+});
+
 // Artists for a movement in a time range
 app.get('/api/movements/:id/artists', async (req, res) => {
   try {