From d0823b76283b2cd3c7ce5883bd791381ed7da992 Mon Sep 17 00:00:00 2001
From: jessikitty <jess.rogerson.29@outlook.com>
Date: Thu, 30 Jul 2026 10:10:31 +1000
Subject: [PATCH] characters editor: per-part placement panel with
 TransformControls gizmo + synced numeric fields, model-default/per-ghost
 scope toggle, rebuilt inline build-from-parts dialog (edit/delete models)

---
 public/admin/characters.html | 344 ++++++++++++++++++++++++++++++-----
 1 file changed, 299 insertions(+), 45 deletions(-)

diff --git a/public/admin/characters.html b/public/admin/characters.html
index 78dd745..5827463 100644
--- a/public/admin/characters.html
+++ b/public/admin/characters.html
@@ -12,11 +12,12 @@
 <script type="module">
 import * as THREE from 'three';
 import { OrbitControls } from 'three/addons/controls/OrbitControls.js';
-import { buildGhost } from '/js/ghosts/loader.js';
+import { TransformControls } from 'three/addons/controls/TransformControls.js';
+import { buildGhost, PART_KEYS, normalizePart, mergePart } from '/js/ghosts/loader.js';
 import { api, requireAuth, styles, nav } from './admin.js';
 
 document.head.insertAdjacentHTML('beforeend', `<style>${styles}
-  #wrap { display:grid; grid-template-columns: 260px 1fr 300px; height:calc(100vh - 44px); }
+  #wrap { display:grid; grid-template-columns: 240px 1fr 320px; height:calc(100vh - 44px); }
   #list { background:#0d1226; overflow:auto; padding:8px; }
   #list .gh { padding:6px 9px; border-radius:6px; cursor:pointer; font-size:.82rem; display:flex; gap:7px; align-items:center; }
   #list .gh:hover { background:#1a2244; }
@@ -34,6 +35,8 @@ document.head.insertAdjacentHTML('beforeend', `<style>${styles}
   .row input, .row select { flex:1; min-width:0; }
   .row input[type=color] { padding:1px; height:26px; }
   .row input[type=range] { padding:0; }
+  .row.tri input { width:0; flex:1; text-align:center; }
+  .row.tri label { width:60px; }
   .assets { display:flex; flex-wrap:wrap; gap:6px; margin:6px 0; }
   .asset { background:#0d1226; border-radius:6px; padding:5px 8px; font-size:.72rem; display:flex; gap:6px; align-items:center; }
   .asset img { width:26px; height:26px; object-fit:cover; border-radius:3px; }
@@ -41,6 +44,17 @@ document.head.insertAdjacentHTML('beforeend', `<style>${styles}
   .badge { font-size:.7rem; opacity:.62; line-height:1.45; }
   .drop { border:1px dashed #2a3a6e; border-radius:8px; padding:10px; text-align:center; font-size:.75rem; opacity:.8; }
   .drop.over { border-color:#51eaf1; background:#141c3a; }
+  .parttabs { display:flex; flex-wrap:wrap; gap:4px; margin:6px 0; }
+  .parttab { padding:3px 9px; border-radius:6px; font-size:.72rem; cursor:pointer; background:#0d1226; border:1px solid #2a3a6e; }
+  .parttab.active { background:#2a3a6e; border-color:#51eaf1; color:#cfe6ff; }
+  .parttab.absent { opacity:.4; cursor:default; }
+  .parttab .m { color:#51eaf1; margin-left:4px; font-size:.62rem; }
+  .seg { display:flex; gap:0; margin:6px 0; border:1px solid #2a3a6e; border-radius:6px; overflow:hidden; }
+  .seg button { flex:1; border-radius:0; background:#0d1226; font-size:.72rem; padding:5px; }
+  .seg button.on { background:#2a3a6e; color:#51eaf1; }
+  .minibtn { padding:3px 8px; font-size:.7rem; }
+  #overlay { position:absolute; left:10px; bottom:10px; font-size:.72rem; background:rgba(6,8,15,.6); padding:6px 10px; border-radius:8px; max-width:60%; }
+  #gizhint { position:absolute; right:10px; top:10px; font-size:.72rem; background:rgba(6,8,15,.7); padding:6px 10px; border-radius:8px; display:none; }
 </style>`);
 await requireAuth();
 
@@ -50,8 +64,8 @@ app.innerHTML = `${nav('characters')}
 <div id="wrap">
   <div id="list"><input class="search" id="search" placeholder="Search ghosts…"><div id="ghosts"></div></div>
   <div id="stage"><canvas id="gl"></canvas>
-    <div style="position:absolute;left:10px;bottom:10px;font-size:.72rem;background:rgba(6,8,15,.6);padding:6px 10px;border-radius:8px">
-      Live preview · drag to orbit · changes apply to all viewers on Save</div></div>
+    <div id="overlay">Live preview · drag to orbit · changes apply to all viewers on Save</div>
+    <div id="gizhint"></div></div>
   <div id="side"></div>
 </div>`;
 
@@ -60,6 +74,7 @@ const gdata = await api('/api/ghosts');
 const ghosts = gdata.ghosts;
 const gradients = gdata.gradients.gradients || gdata.gradients;
 let manifest = await api('/api/models');
+manifest.models ||= [];
 let assets = await api('/api/assets');
 let chars = await api('/api/characters');
 chars.byId ||= {}; chars.defaults ||= {};
@@ -68,6 +83,10 @@ const baseHeight = scene.ghostHeightCm ?? 4;
 
 let selId = ghosts[0]?.id;
 let filter = '';
+let activePart = null;          // which part key the gizmo/fields target
+let partScope = 'model';        // 'model' (shared default) | 'ghost' (this ghost's override)
+let gizmoMode = 'translate';    // 'translate' | 'rotate'
+let modelsDirty = false;        // model manifest changed but not yet PUT
 
 // ---------- preview ----------
 const cvs = document.getElementById('gl');
@@ -83,19 +102,63 @@ const orbit = new OrbitControls(cam, cvs);
 orbit.target.set(0, 2.2, 0);
 const grid = new THREE.GridHelper(20, 20, 0x2a3a6e, 0x151b36); scn.add(grid);
 
+// Gizmo for direct part manipulation, attached to a part's node inside the preview.
+const gizmo = new TransformControls(cam, cvs);
+gizmo.setSize(0.7);
+gizmo.addEventListener('dragging-changed', e => orbit.enabled = !e.value);
+gizmo.addEventListener('objectChange', onGizmoMove);
+scn.add(gizmo);
+
 let previewObj = null;
-async function refreshPreview() {
+let partNodes = {};             // partKey -> Object3D holding that part
+
+async function refreshPreview(keepGizmo = false) {
+  const priorPart = activePart;
+  if (gizmo.object) gizmo.detach();
   if (previewObj) { scn.remove(previewObj); previewObj = null; }
+  partNodes = {};
   const g = ghosts.find(x => x.id === selId);
   if (!g) return;
   previewObj = await buildGhost(g, gradients, manifest, chars);
   previewObj.userData.setHeight(baseHeight);
   scn.add(previewObj);
+
+  previewObj.traverse(o => { if (o.userData && o.userData.partKey) partNodes[o.userData.partKey] = o; });
+
   const h = chars.byId[selId]?.heightCm || baseHeight;
   orbit.target.set(0, h / 2, 0);
-  cam.position.set(0, h * 0.75, h * 3);
+  if (!keepGizmo) cam.position.set(0, h * 0.75, h * 3);
+  if (keepGizmo && priorPart && partNodes[priorPart]) attachGizmo(priorPart);
 }
 
+function attachGizmo(key) {
+  const node = partNodes[key];
+  const hint = document.getElementById('gizhint');
+  if (!node) { gizmo.detach(); if (hint) hint.style.display = 'none'; return; }
+  gizmo.setMode(gizmoMode);
+  gizmo.attach(node);
+  if (hint) {
+    hint.style.display = 'block';
+    hint.textContent = `${key} · ${gizmoMode} · ${partScope === 'model' ? 'model default' : 'this ghost'}`;
+  }
+}
+
+// When the gizmo is dragged, read the node transform and persist it.
+function onGizmoMove() {
+  if (!activePart) return;
+  const node = gizmo.object;
+  if (!node) return;
+  writePartTransform(activePart, {
+    offset: [round(node.position.x), round(node.position.y), round(node.position.z)],
+    rotation: [round(THREE.MathUtils.radToDeg(node.rotation.x)),
+               round(THREE.MathUtils.radToDeg(node.rotation.y)),
+               round(THREE.MathUtils.radToDeg(node.rotation.z))],
+    scale: round(node.scale.x),
+  });
+  syncPartFields();
+}
+const round = v => Math.round(v * 1000) / 1000;
+
 function fit() {
   renderer.setSize(cvs.clientWidth, cvs.clientHeight, false);
   cam.aspect = cvs.clientWidth / cvs.clientHeight; cam.updateProjectionMatrix();
@@ -103,7 +166,8 @@ function fit() {
 new ResizeObserver(fit).observe(cvs);
 (function loop(t) {
   requestAnimationFrame(loop);
-  if (previewObj) { previewObj.userData.tick(t / 1000); previewObj.rotation.y += 0.004; }
+  // Don't auto-spin while placing a part — rotation makes the gizmo unusable.
+  if (previewObj) { previewObj.userData.tick(t / 1000); if (!activePart) previewObj.rotation.y += 0.004; }
   orbit.update(); renderer.render(scn, cam);
 })(0);
 
@@ -116,22 +180,57 @@ function renderList() {
       <span class="dot" style="background:${COLORS[g.color]}"></span>${g.name}
       ${chars.byId[g.id] ? '<span class="cust">●</span>' : ''}</div>`).join('');
   document.querySelectorAll('.gh').forEach(el => el.onclick = async () => {
-    selId = el.dataset.id; renderList(); renderSide(); await refreshPreview();
+    selId = el.dataset.id; activePart = null; gizmo.detach();
+    if (previewObj) previewObj.rotation.y = 0;
+    renderList(); renderSide(); await refreshPreview();
   });
 }
 document.getElementById('search').oninput = e => { filter = e.target.value; renderList(); };
 
-// ---------- side panel ----------
+// ---------- override helpers ----------
 const side = document.getElementById('side');
 const ov = () => (chars.byId[selId] ||= {});
 const cur = (k, dflt) => { const v = chars.byId[selId]?.[k]; return v != null ? v : (chars.defaults[k] != null ? chars.defaults[k] : dflt); };
 
+function activeModel() {
+  const id = cur('modelId', '');
+  const models = manifest.models || [];
+  if (!models.length) return null;
+  return (id && models.find(m => m.id === id)) || models[0];
+}
+
+/* Effective transform for a part = model default, plus ghost override when that scope is active. */
+function effectivePart(key) {
+  const model = activeModel();
+  if (!model || !model.parts || !model.parts[key]) return null;
+  const ghostOv = chars.byId[selId]?.partOverrides?.[key];
+  return mergePart(model.parts[key], partScope === 'ghost' ? ghostOv : null);
+}
+
+/* Persist a transform into whichever scope is active. */
+function writePartTransform(key, tf) {
+  const model = activeModel();
+  if (!model) return;
+  if (partScope === 'model') {
+    const base = normalizePart(model.parts[key]) || { url: model.parts[key] };
+    model.parts[key] = { url: base.url, offset: tf.offset, rotation: tf.rotation, scale: tf.scale };
+    modelsDirty = true; setSaveDirty();
+  } else {
+    const o = ov();
+    o.partOverrides ||= {};
+    o.partOverrides[key] = { ...(o.partOverrides[key] || {}), ...tf };
+  }
+}
+
+// ---------- side panel ----------
 function renderSide() {
   const g = ghosts.find(x => x.id === selId);
   if (!g) { side.innerHTML = ''; return; }
   const grad = gradients[g.color] || gradients.Blue;
   const models = (manifest.models || []);
   const textures = assets.assets.filter(a => a.kind === 'texture');
+  const model = activeModel();
+  const hasParts = model && model.parts && Object.keys(model.parts).length;
 
   side.innerHTML = `
     <h2>${g.name}</h2>
@@ -148,16 +247,19 @@ function renderSide() {
     <div class="row"><label>extra scale</label>
       <input type="number" step="0.05" min="0.05" id="scale" value="${cur('scale', 1)}"></div>
 
+    ${hasParts ? partPlacementSection(model, g) : `<div class="badge" style="margin-top:8px">
+      This ghost uses the ${model ? 'model’s single mesh' : 'procedural wisp'} — build a multi-part model (Assets box) to place parts individually.</div>`}
+
     <h2>Appearance</h2>
     <div class="row"><label>opacity</label>
       <input type="range" min="0.1" max="1" step="0.02" id="opacity" value="${cur('opacity', 0.92)}">
       <span id="opv" style="width:32px;font-size:.72rem">${(+cur('opacity', 0.92)).toFixed(2)}</span></div>
     <div class="row"><label>top colour</label>
       <input type="color" id="topColor" value="${cur('topColor', grad.top)}">
-      <button id="resetTop">reset</button></div>
+      <button id="resetTop" class="minibtn">reset</button></div>
     <div class="row"><label>bottom</label>
       <input type="color" id="bottomColor" value="${cur('bottomColor', grad.bottom)}">
-      <button id="resetBottom">reset</button></div>
+      <button id="resetBottom" class="minibtn">reset</button></div>
 
     <h2>Textures</h2>
     <div class="badge">Front-projected decals — no UV mapping needed. Use PNGs with transparency.</div>
@@ -178,9 +280,112 @@ function renderSide() {
       <button id="clearChar" class="danger">Reset this ghost</button>
       <button id="applyAll">Apply to all</button>
     </div>
-    <button id="save" class="primary" style="width:100%;padding:10px;margin-top:8px">Save characters</button>
+    <button id="save" class="primary" style="width:100%;padding:10px;margin-top:8px">Save characters${modelsDirty ? ' + model' : ''}</button>
     <div id="status" class="badge" style="margin-top:6px"></div>`;
 
+  bindCommon();
+  if (hasParts) bindPartPlacement(model);
+}
+
+function partPlacementSection(model, g) {
+  const present = PART_KEYS.filter(k => model.parts[k]);
+  if (!activePart || !model.parts[activePart]) activePart = present[0] || null;
+  const p = activePart ? effectivePart(activePart) : null;
+  const ghostHasOv = !!(activePart && chars.byId[selId]?.partOverrides?.[activePart]);
+
+  return `
+    <h2>Part placement</h2>
+    <div class="seg" id="scopeSeg">
+      <button data-scope="model" class="${partScope === 'model' ? 'on' : ''}">Model default</button>
+      <button data-scope="ghost" class="${partScope === 'ghost' ? 'on' : ''}">This ghost${ghostHasOv ? ' ●' : ''}</button>
+    </div>
+    <div class="badge">${partScope === 'model'
+      ? 'Editing the shared model — affects every ghost using it.'
+      : 'Editing only ' + g.name + ' — layered over the model default.'}</div>
+    <div class="parttabs" id="partTabs">
+      ${PART_KEYS.map(k => `<span class="parttab ${k === activePart ? 'active' : ''} ${model.parts[k] ? '' : 'absent'}" data-part="${k}">
+        ${k}${chars.byId[selId]?.partOverrides?.[k] ? '<span class="m">●</span>' : ''}</span>`).join('')}
+    </div>
+    ${!activePart ? '<div class="badge">No parts in this model.</div>' : `
+    <div class="seg" id="modeSeg">
+      <button data-mode="translate" class="${gizmoMode === 'translate' ? 'on' : ''}">Move</button>
+      <button data-mode="rotate" class="${gizmoMode === 'rotate' ? 'on' : ''}">Rotate</button>
+    </div>
+    <div class="row tri"><label>offset</label>
+      <input type="number" step="0.05" id="pofx" value="${p.offset[0]}" title="X">
+      <input type="number" step="0.05" id="pofy" value="${p.offset[1]}" title="Y">
+      <input type="number" step="0.05" id="pofz" value="${p.offset[2]}" title="Z"></div>
+    <div class="row tri"><label>rotation°</label>
+      <input type="number" step="5" id="prox" value="${p.rotation[0]}" title="X">
+      <input type="number" step="5" id="proy" value="${p.rotation[1]}" title="Y">
+      <input type="number" step="5" id="proz" value="${p.rotation[2]}" title="Z"></div>
+    <div class="row"><label>part scale</label>
+      <input type="number" step="0.02" min="0.02" id="pscale" value="${p.scale}"></div>
+    <div class="row">
+      <button id="partReset" class="minibtn danger">Reset ${partScope === 'ghost' ? 'override' : 'part'}</button>
+      <span class="badge">drag the gizmo or type values</span>
+    </div>`}`;
+}
+
+function bindPartPlacement(model) {
+  document.querySelectorAll('#scopeSeg button').forEach(b => b.onclick = () => {
+    partScope = b.dataset.scope; renderSide();
+    if (activePart) attachGizmo(activePart);
+  });
+  document.querySelectorAll('#partTabs .parttab').forEach(el => el.onclick = () => {
+    const k = el.dataset.part;
+    if (!model.parts[k]) return;
+    activePart = k; renderSide(); attachGizmo(k);
+  });
+  document.querySelectorAll('#modeSeg button').forEach(b => b.onclick = () => {
+    gizmoMode = b.dataset.mode;
+    document.querySelectorAll('#modeSeg button').forEach(x => x.classList.toggle('on', x === b));
+    if (activePart) attachGizmo(activePart);
+  });
+  if (!activePart) return;
+
+  const readFields = () => ({
+    offset: [num('pofx'), num('pofy'), num('pofz')],
+    rotation: [num('prox'), num('proy'), num('proz')],
+    scale: num('pscale', 1),
+  });
+  const onField = async () => { writePartTransform(activePart, readFields()); await refreshPreview(true); };
+  ['pofx','pofy','pofz','prox','proy','proz','pscale'].forEach(id => {
+    const el = document.getElementById(id); if (el) el.oninput = onField;
+  });
+  document.getElementById('partReset').onclick = async () => {
+    if (partScope === 'ghost') {
+      const po = chars.byId[selId]?.partOverrides;
+      if (po) { delete po[activePart]; if (!Object.keys(po).length) delete ov().partOverrides; }
+      if (!Object.keys(chars.byId[selId] || {}).length) delete chars.byId[selId];
+    } else {
+      const base = normalizePart(model.parts[activePart]);
+      if (base) { model.parts[activePart] = base.url; modelsDirty = true; setSaveDirty(); }
+    }
+    renderSide(); await refreshPreview(true);
+  };
+
+  if (partNodes[activePart]) attachGizmo(activePart);
+}
+
+const num = (id, dflt = 0) => { const v = parseFloat(document.getElementById(id)?.value); return Number.isFinite(v) ? v : dflt; };
+
+function syncPartFields() {
+  if (!activePart) return;
+  const p = effectivePart(activePart);
+  if (!p) return;
+  const set = (id, v) => { const el = document.getElementById(id); if (el && document.activeElement !== el) el.value = v; };
+  set('pofx', p.offset[0]); set('pofy', p.offset[1]); set('pofz', p.offset[2]);
+  set('prox', p.rotation[0]); set('proy', p.rotation[1]); set('proz', p.rotation[2]);
+  set('pscale', p.scale);
+}
+
+function setSaveDirty() {
+  const s = document.getElementById('save');
+  if (s) s.textContent = 'Save characters + model';
+}
+
+function bindCommon() {
   const bind = (id, key, transform = v => v) => {
     const el = document.getElementById(id);
     if (!el) return;
@@ -189,7 +394,8 @@ function renderSide() {
       if (v === '' || v == null) delete ov()[key]; else ov()[key] = v;
       if (id === 'opacity') document.getElementById('opv').textContent = (+v).toFixed(2);
       if (!Object.keys(chars.byId[selId] || {}).length) delete chars.byId[selId];
-      await refreshPreview(); renderList();
+      if (id === 'modelId') { activePart = null; renderSide(); }
+      await refreshPreview(id !== 'modelId'); renderList();
     };
   };
   bind('modelId', 'modelId');
@@ -202,27 +408,32 @@ function renderSide() {
   bind('torsoTextureUrl', 'torsoTextureUrl');
   for (const k of ['faceY', 'faceSize', 'torsoY', 'torsoSize']) bind(k, k, v => parseFloat(v));
 
-  document.getElementById('resetTop').onclick = async () => { delete ov().topColor; await refreshPreview(); renderSide(); };
-  document.getElementById('resetBottom').onclick = async () => { delete ov().bottomColor; await refreshPreview(); renderSide(); };
+  document.getElementById('resetTop').onclick = async () => { delete ov().topColor; await refreshPreview(true); renderSide(); };
+  document.getElementById('resetBottom').onclick = async () => { delete ov().bottomColor; await refreshPreview(true); renderSide(); };
   document.getElementById('clearChar').onclick = async () => {
-    delete chars.byId[selId]; await refreshPreview(); renderList(); renderSide();
+    delete chars.byId[selId]; activePart = null; await refreshPreview(); renderList(); renderSide();
   };
   document.getElementById('applyAll').onclick = async () => {
     const src = { ...(chars.byId[selId] || {}) };
-    delete src.faceTextureUrl;                       // per-ghost faces stay per-ghost
+    delete src.faceTextureUrl;            // per-ghost faces stay per-ghost
+    delete src.partOverrides;             // per-ghost nudges stay per-ghost
     if (!confirm('Apply this ghost\'s model/appearance settings as the default for every ghost?')) return;
     chars.defaults = { ...chars.defaults, ...src };
     renderList(); renderSide();
   };
-  document.getElementById('save').onclick = async () => {
-    const st = document.getElementById('status');
-    try { chars = await api('/api/characters', 'PUT', chars); chars.byId ||= {}; chars.defaults ||= {};
-      st.textContent = 'Saved ' + new Date().toLocaleTimeString(); renderList();
-    } catch (e) { st.textContent = 'Save failed: ' + e.message; }
-  };
+  document.getElementById('save').onclick = onSave;
 }
 
-// ---------- asset manager (bottom of list column) ----------
+async function onSave() {
+  const st = document.getElementById('status');
+  try {
+    if (modelsDirty) { manifest = await api('/api/models', 'PUT', manifest); manifest.models ||= []; modelsDirty = false; }
+    chars = await api('/api/characters', 'PUT', chars); chars.byId ||= {}; chars.defaults ||= {};
+    st.textContent = 'Saved ' + new Date().toLocaleTimeString(); renderList(); renderSide();
+  } catch (e) { st.textContent = 'Save failed: ' + e.message; }
+}
+
+// ---------- asset manager ----------
 function renderAssets() {
   const models = assets.assets.filter(a => a.kind === 'model');
   const textures = assets.assets.filter(a => a.kind === 'texture');
@@ -243,7 +454,7 @@ function renderAssets() {
     <div class="badge">Textures (${textures.length})</div>
     <div class="assets">${textures.map(a => `<span class="asset"><img src="${a.url}">${a.name}
       <button data-delasset="${a.id}" class="danger">✕</button></span>`).join('') || '<span class="badge">none</span>'}</div>
-    ${models.length ? `<button id="buildModel" style="width:100%;margin-top:6px">Build model from parts…</button>` : ''}`;
+    <button id="buildModel" style="width:100%;margin-top:6px">${manifest.models.length ? 'Build / edit model…' : 'Build model from parts…'}</button>`;
 
   const drop = document.getElementById('drop');
   drop.ondragover = e => { e.preventDefault(); drop.classList.add('over'); };
@@ -255,8 +466,7 @@ function renderAssets() {
     await api('/api/assets/' + b.dataset.delasset, 'DELETE');
     assets = await api('/api/assets'); renderAssets(); renderSide(); await refreshPreview();
   });
-  const bm = document.getElementById('buildModel');
-  if (bm) bm.onclick = buildModelDialog;
+  document.getElementById('buildModel').onclick = () => openBuilder(activeModel()?.id || null);
 }
 
 async function upload(files) {
@@ -276,25 +486,69 @@ async function upload(files) {
   renderAssets(); renderSide();
 }
 
-/* Assemble uploaded OBJ parts into a named model in the manifest. */
-async function buildModelDialog() {
+// ---------- inline model builder (replaces sequential prompts) ----------
+let builderEl = null;
+function openBuilder(editId = null) {
   const objs = assets.assets.filter(a => a.kind === 'model' && a.name.toLowerCase().endsWith('.obj'));
-  if (!objs.length) return alert('Upload some .obj parts first.');
-  const id = prompt('Model name (e.g. minifig):', 'minifig');
-  if (!id) return;
-  const parts = {};
-  for (const key of ['legs', 'torso', 'head', 'headpiece']) {
-    const list = objs.map((o, i) => `${i}: ${o.name}`).join('\n');
-    const pick = prompt(`Which file is the ${key}? (number, or blank to skip)\n\n${list}`, '');
-    if (pick === null) return;
-    if (pick.trim() !== '' && objs[+pick]) parts[key] = objs[+pick].url;
-  }
-  if (!Object.keys(parts).length) return alert('No parts chosen.');
-  manifest.models = (manifest.models || []).filter(m => m.id !== id);
-  manifest.models.push({ id, scale: 1, parts });
-  manifest = await api('/api/models', 'PUT', manifest);
-  renderSide(); await refreshPreview();
-  alert(`Model "${id}" created — pick it in the Model dropdown.`);
+  if (!objs.length) return alert('Upload some .obj parts first (drop them in the Assets box).');
+  const existing = editId ? manifest.models.find(m => m.id === editId) : null;
+
+  if (builderEl) builderEl.remove();
+  builderEl = document.createElement('div');
+  builderEl.style.cssText = 'position:fixed;inset:0;background:rgba(4,6,14,.72);display:flex;align-items:center;justify-content:center;z-index:50';
+  const partsInit = existing ? existing.parts : {};
+  const urlToIdx = entry => { const u = typeof entry === 'string' ? entry : entry?.url; return objs.findIndex(o => o.url === u); };
+
+  builderEl.innerHTML = `<div style="background:#111730;border:1px solid #2a3a6e;border-radius:12px;padding:18px;width:420px;max-width:92vw;max-height:88vh;overflow:auto">
+    <h2 style="margin:0 0 4px;color:#8fb8ff;font-size:1rem">${existing ? 'Edit model' : 'Build model from parts'}</h2>
+    <div class="badge" style="margin-bottom:10px">Assign an uploaded .obj to each slot. Leave a slot as “— none —” to skip it. Fine placement is tuned afterward in the Part placement panel.</div>
+    <div class="row"><label>model id</label>
+      <input id="bmId" value="${existing ? existing.id : ''}" placeholder="e.g. minifig" ${existing ? 'readonly' : ''}></div>
+    ${PART_KEYS.map(k => `<div class="row"><label>${k}</label>
+      <select data-slot="${k}"><option value="">— none —</option>
+        ${objs.map((o, i) => `<option value="${i}" ${urlToIdx(partsInit[k]) === i ? 'selected' : ''}>${o.name}</option>`).join('')}
+      </select></div>`).join('')}
+    <div class="row"><label>base scale</label>
+      <input type="number" step="0.05" min="0.05" id="bmScale" value="${existing?.scale ?? 1}"></div>
+    <div class="row" style="justify-content:flex-end;margin-top:12px">
+      ${existing ? `<button id="bmDelete" class="danger">Delete</button>` : ''}
+      <button id="bmCancel">Cancel</button>
+      <button id="bmSave" class="primary">${existing ? 'Update' : 'Create'}</button>
+    </div>
+    <div class="badge" id="bmStatus" style="margin-top:6px"></div>
+  </div>`;
+  document.body.appendChild(builderEl);
+
+  document.getElementById('bmCancel').onclick = () => { builderEl.remove(); builderEl = null; };
+  const del = document.getElementById('bmDelete');
+  if (del) del.onclick = async () => {
+    if (!confirm(`Delete model "${existing.id}"? Ghosts using it fall back to the first model / wisp.`)) return;
+    manifest.models = manifest.models.filter(m => m.id !== existing.id);
+    manifest = await api('/api/models', 'PUT', manifest); manifest.models ||= [];
+    builderEl.remove(); builderEl = null; renderAssets(); renderSide(); await refreshPreview();
+  };
+  document.getElementById('bmSave').onclick = async () => {
+    const status = document.getElementById('bmStatus');
+    const id = document.getElementById('bmId').value.trim();
+    if (!id) return status.textContent = 'Give the model an id.';
+    const newParts = {};
+    document.querySelectorAll('[data-slot]').forEach(sel => {
+      if (sel.value !== '' && objs[+sel.value]) {
+        const url = objs[+sel.value].url;
+        const prev = existing?.parts?.[sel.dataset.slot];   // keep placement if the file is unchanged
+        newParts[sel.dataset.slot] = (prev && normalizePart(prev)?.url === url) ? prev : url;
+      }
+    });
+    if (!Object.keys(newParts).length) return status.textContent = 'Pick at least one part.';
+    const scale = parseFloat(document.getElementById('bmScale').value) || 1;
+    manifest.models = manifest.models.filter(m => m.id !== id);
+    manifest.models.push({ id, scale, parts: newParts });
+    manifest = await api('/api/models', 'PUT', manifest); manifest.models ||= [];
+    ov().modelId = id;
+    if (!Object.keys(chars.byId[selId] || {}).length) delete chars.byId[selId];
+    builderEl.remove(); builderEl = null;
+    activePart = null; renderAssets(); renderList(); renderSide(); await refreshPreview();
+  };
 }
 
 renderList(); renderSide(); renderAssets(); fit(); await refreshPreview();