_check_srcdoc.js

    import * as THREE from 'three';
    import { OrbitControls } from 'three/addons/controls/OrbitControls.js';
    import { GLTFLoader } from 'three/addons/loaders/GLTFLoader.js';
    // Spark (gaussian-splat renderer) is loaded lazily via ensureSpark() — only the
    // dojo-scene splat path needs it, so its unpkg module stays off the boot path.
    window.__viewerBooted = true;   // core ESM imports resolved; the head watchdog stands down

    const SMPLX_HEIGHT = 1.7;
    const data = JSON.parse(document.getElementById('motion-data').textContent);
    const characters = JSON.parse(document.getElementById('char-data').textContent);
    const cfg = JSON.parse(document.getElementById('viewer-cfg').textContent);
    // The id of the clip currently on screen (kept current on every switch) so
    // the on-screen label can show it. Hoisted here (above setCreatorLabel) to
    // avoid a temporal-dead-zone throw when the boot label renders.
    let curId = (cfg.currentId && cfg.currentId.indexOf('kata:') !== 0 ? cfg.currentId : '')
      || (data ? data.id : '') || '';
    function decodeFloat32(b64) {
      const bin = atob(b64);
      const bytes = new Uint8Array(bin.length);
      for (let i = 0; i < bin.length; i++) bytes[i] = bin.charCodeAt(i);
      return new Float32Array(bytes.buffer);
    }
    function decodeBytes(b64) {
      const bin = atob(b64);
      const bytes = new Uint8Array(bin.length);
      for (let i = 0; i < bin.length; i++) bytes[i] = bin.charCodeAt(i);
      return bytes;
    }
    const app = document.getElementById('app');
    const scene = new THREE.Scene();
    const defaultBackground = new THREE.Color(0x151719);
    scene.background = defaultBackground.clone();
    let dojoTexture = null;
    let dojoEnv = null;
    function makePanoramaFloorMaterial(tex) {
      return new THREE.ShaderMaterial({
        uniforms: {
          pano: { value: tex },
          origin: { value: new THREE.Vector3(0.0, 1.35, 0.0) },
        },
        vertexShader: `
          varying vec3 vWorldPos;
          void main() {
            vec4 world = modelMatrix * vec4(position, 1.0);
            vWorldPos = world.xyz;
            gl_Position = projectionMatrix * viewMatrix * world;
          }
        `,
        fragmentShader: `
          precision highp float;
          uniform sampler2D pano;
          uniform vec3 origin;
          varying vec3 vWorldPos;
          const float PI = 3.141592653589793;
          void main() {
            vec3 dir = normalize(vWorldPos - origin);
            float u = atan(dir.z, dir.x) / (2.0 * PI) + 0.5;
            float v = asin(clamp(dir.y, -1.0, 1.0)) / PI + 0.5;
            vec3 color = texture2D(pano, vec2(u, v)).rgb;
            gl_FragColor = vec4(color * 1.08, 1.0);
          }
        `,
        side: THREE.DoubleSide,
      });
    }
    function clearDojoScene() {
      if (dojoEnv) {
        scene.remove(dojoEnv);
        dojoEnv.traverse((o) => {
          if (o.geometry) o.geometry.dispose();
          if (o.material) {
            if (Array.isArray(o.material)) o.material.forEach((m) => m.dispose());
            else o.material.dispose();
          }
        });
        dojoEnv = null;
      }
      if (dojoTexture) {
        dojoTexture.dispose();
        dojoTexture = null;
      }
      scene.background = defaultBackground.clone();
      if (typeof floor !== 'undefined') floor.visible = true;
    }
    function applyDojoScene(src, settings) {
      if (!src) { clearDojoScene(); return; }
      applyDojoRoomSettings(settings);
      new THREE.TextureLoader().load(src, (tex) => {
        clearDojoScene();
        applyDojoRoomSettings(settings);
        tex.colorSpace = THREE.SRGBColorSpace;
        dojoTexture = tex;
        scene.background = defaultBackground.clone();
        if (typeof floor !== 'undefined') floor.visible = false;

        dojoEnv = new THREE.Group();
        dojoEnv.name = 'dojo-environment';

        // Finite world-space panorama shell. Unlike scene.background, this is real
        // geometry, so camera translation/dolly creates visible scale/parallax.
        const shellGeo = new THREE.SphereGeometry(5.8, 64, 32);
        shellGeo.scale(-1, 1, 1);
        const shellMat = new THREE.MeshBasicMaterial({ map: tex, side: THREE.FrontSide, depthWrite: false });
        const shell = new THREE.Mesh(shellGeo, shellMat);
        shell.position.set(0, 1.35, 0);
        shell.renderOrder = -10;
        dojoEnv.add(shell);

        const floorGeo = new THREE.PlaneGeometry(8.5, 8.5, 24, 24);
        const floorMat = makePanoramaFloorMaterial(tex);
        const roomFloor = new THREE.Mesh(floorGeo, floorMat);
        roomFloor.rotation.x = -Math.PI / 2;
        roomFloor.position.y = -0.012;
        dojoEnv.add(roomFloor);

        const wallMat = new THREE.MeshStandardMaterial({
          color: 0x3b3028,
          roughness: 0.9,
          metalness: 0.0,
          transparent: true,
          opacity: 0.42,
          side: THREE.DoubleSide,
        });
        const backWall = new THREE.Mesh(new THREE.PlaneGeometry(8.5, 3.7), wallMat.clone());
        backWall.position.set(0, 1.85, -4.15);
        dojoEnv.add(backWall);
        const leftWall = new THREE.Mesh(new THREE.PlaneGeometry(8.2, 3.7), wallMat.clone());
        leftWall.position.set(-4.15, 1.85, 0);
        leftWall.rotation.y = Math.PI / 2;
        dojoEnv.add(leftWall);
        const rightWall = new THREE.Mesh(new THREE.PlaneGeometry(8.2, 3.7), wallMat.clone());
        rightWall.position.set(4.15, 1.85, 0);
        rightWall.rotation.y = -Math.PI / 2;
        dojoEnv.add(rightWall);
        wallMat.dispose();

        scene.add(dojoEnv);
        applyDojoRoomSettings(settings);
      }, undefined, (err) => {
        console.error('dojo scene load failed', err);
      });
    }

    let disposed = false;   // set on teardown to stop the loop + free the GL context
    const renderer = new THREE.WebGLRenderer({ antialias: false, powerPreference: 'high-performance' });
    renderer.setPixelRatio(Math.min(window.devicePixelRatio || 1, 1.5));
    renderer.outputColorSpace = THREE.SRGBColorSpace;
    app.appendChild(renderer.domElement);
    // Spark renderer is created on first splat use (dojo scenes only) — see ensureSpark().
    // This keeps the heavy unpkg spark module off the viewer's critical boot path.
    let spark = null;
    async function ensureSpark() {
      const mod = await import('@sparkjsdev/spark');
      if (!spark) { spark = new mod.SparkRenderer({ renderer }); scene.add(spark); }
      return mod;
    }
    let dojoSplatRoot = null;
    let dojoSplatHelper = null;
    let dojoSplatObjectUrl = null;
    // Room size is the dojo FLOOR FOOTPRINT in world metres — the same units as the
    // ~1.7m character (SMPLX_HEIGHT). fitDojoSplat normalises every splat to this span,
    // so the character/room proportion is fixed: 6.5m ≈ 3.8 character-heights across
    // (the character spans ~26% of the floor — a believable small dojo).
    let dojoRoomSize = 6.5;
    let dojoRoomHeight = 3.2;
    let dojoSplatBaseBounds = null;
    const dojoFloorSurfaceY = 0.0;
    const dojoFloorThickness = 0.025;
    function postDojoStatus(text) {
      try { parent.postMessage({ kind: 'dojo-status', text }, '*'); } catch (e) {}
    }
    function applyDojoRoomSettings(settings) {
      settings = settings || {};
      dojoRoomSize = Math.max(1.0, Number(settings.room_size || settings.roomSize || dojoRoomSize) || dojoRoomSize);
      dojoRoomHeight = Math.max(1.0, Number(settings.room_height || settings.roomHeight || dojoRoomHeight) || dojoRoomHeight);
      if (dojoSplatRoot) fitDojoSplat();
      if (dojoEnv) dojoEnv.scale.set(dojoRoomSize / 8.5, dojoRoomHeight / 3.2, dojoRoomSize / 8.5);
      if (!dojoSplatRoot) resizeFloorGrid(dojoRoomSize);
    }
    function percentile(values, q) {
      if (!values || !values.length) return 0;
      const sorted = values.slice().sort((a, b) => a - b);
      const idx = Math.min(sorted.length - 1, Math.max(0, (sorted.length - 1) * q));
      const lo = Math.floor(idx);
      const hi = Math.ceil(idx);
      const t = idx - lo;
      return sorted[lo] * (1 - t) + sorted[hi] * t;
    }
    function resizeFloorGrid(size) {
      if (typeof floor === 'undefined') return;
      const gridSize = Math.max(1.0, Number(size) || dojoRoomSize);
      floor.scale.set(gridSize, 1, gridSize);
    }
    function estimateSplatFloor(localX, localY, localZ, robust) {
      if (!localY || !localY.length || !robust) return percentile(localY || [0], 0.02);
      const yLow = percentile(localY, 0.02);
      const yHigh = percentile(localY, 0.55);
      const span = Math.max(0.001, yHigh - yLow);
      const bins = 56;
      const stats = Array.from({ length: bins }, () => ({
        count: 0,
        minX: Infinity,
        maxX: -Infinity,
        minZ: Infinity,
        maxZ: -Infinity,
        sumY: 0,
      }));
      const padX = robust.sizeX * 0.15;
      const padZ = robust.sizeZ * 0.15;
      for (let i = 0; i < localY.length; i++) {
        const y = localY[i];
        const x = localX[i];
        const z = localZ[i];
        if (y < yLow || y > yHigh) continue;
        if (x < robust.minX - padX || x > robust.maxX + padX || z < robust.minZ - padZ || z > robust.maxZ + padZ) continue;
        const idx = Math.min(bins - 1, Math.max(0, Math.floor(((y - yLow) / span) * bins)));
        const s = stats[idx];
        s.count += 1;
        s.sumY += y;
        s.minX = Math.min(s.minX, x);
        s.maxX = Math.max(s.maxX, x);
        s.minZ = Math.min(s.minZ, z);
        s.maxZ = Math.max(s.maxZ, z);
      }
      let best = null;
      let bestScore = -Infinity;
      for (let i = 0; i < stats.length; i++) {
        const s = stats[i];
        if (s.count < 12) continue;
        const coverX = Math.min(1, Math.max(0, (s.maxX - s.minX) / robust.sizeX));
        const coverZ = Math.min(1, Math.max(0, (s.maxZ - s.minZ) / robust.sizeZ));
        const coverage = Math.sqrt(Math.max(0.001, coverX * coverZ));
        // Prefer dense, broad, lower horizontal bands. This rejects small outlier
        // clusters while avoiding upper wall/ceiling bands with similar density.
        const lowerBias = 1.0 - (i / bins) * 0.35;
        const score = s.count * coverage * lowerBias;
        if (score > bestScore) {
          bestScore = score;
          best = { y: s.sumY / s.count, count: s.count, coverage, index: i };
        }
      }
      if (!best) return percentile(localY, 0.08);
      return best.y;
    }
    async function splatPayloadBuffer(value) {
      if (!value) return '';
      const response = await fetch(value);
      if (!response.ok) throw new Error('PLY fetch failed: ' + response.status + ' ' + response.statusText);
      return await response.arrayBuffer();
    }
    function parsePlyBounds(buffer) {
      const bytes = new Uint8Array(buffer);
      const scanLimit = Math.min(bytes.length, 16384);
      let headerEnd = -1;
      for (let i = 0; i < scanLimit - 10; i++) {
        if (bytes[i] === 10 && bytes[i + 1] === 101 && bytes[i + 2] === 110 && bytes[i + 3] === 100 && bytes[i + 4] === 95 && bytes[i + 5] === 104 && bytes[i + 6] === 101 && bytes[i + 7] === 97 && bytes[i + 8] === 100 && bytes[i + 9] === 101 && bytes[i + 10] === 114) {
          headerEnd = i + 11;
          if (bytes[headerEnd] === 13 && bytes[headerEnd + 1] === 10) headerEnd += 2;
          else if (bytes[headerEnd] === 10) headerEnd += 1;
          break;
        }
      }
      if (headerEnd < 0) return null;
      const header = new TextDecoder('ascii').decode(bytes.slice(0, headerEnd));
      const lines = header.split(/\r?\n/);
      const formatLine = lines.find((line) => line.startsWith('format ')) || '';
      const isAscii = formatLine.indexOf('ascii') >= 0;
      const isBinaryLittle = formatLine.indexOf('binary_little_endian') >= 0;
      let vertexCount = 0;
      const props = [];
      let inVertex = false;
      for (const line of lines) {
        const parts = line.trim().split(/\s+/);
        if (parts[0] === 'element') {
          inVertex = parts[1] === 'vertex';
          if (inVertex) vertexCount = Number(parts[2]) || 0;
        } else if (inVertex && parts[0] === 'property' && parts.length >= 3) {
          props.push({ type: parts[1], name: parts[2] });
        }
      }
      const xIndex = props.findIndex((p) => p.name === 'x');
      const yIndex = props.findIndex((p) => p.name === 'y');
      const zIndex = props.findIndex((p) => p.name === 'z');
      if (!vertexCount || xIndex < 0 || yIndex < 0 || zIndex < 0) return null;
      const min = [Infinity, Infinity, Infinity];
      const max = [-Infinity, -Infinity, -Infinity];
      const localX = [];
      const localY = [];
      const localZ = [];
      const add = (x, y, z) => {
        if (![x, y, z].every(Number.isFinite)) return;
        min[0] = Math.min(min[0], x); min[1] = Math.min(min[1], y); min[2] = Math.min(min[2], z);
        max[0] = Math.max(max[0], x); max[1] = Math.max(max[1], y); max[2] = Math.max(max[2], z);
        // Match the viewer transforms below: splat yaw Y=PI/2, root X=PI.
        localX.push(z);
        localY.push(-y);
        localZ.push(x);
      };
      if (isAscii) {
        const body = new TextDecoder('utf-8').decode(bytes.slice(headerEnd));
        const rows = body.split(/\r?\n/);
        for (let i = 0; i < Math.min(vertexCount, rows.length); i++) {
          const vals = rows[i].trim().split(/\s+/).map(Number);
          add(vals[xIndex], vals[yIndex], vals[zIndex]);
        }
      } else if (isBinaryLittle) {
        const sizeOf = (type) => (type === 'double' || type === 'float64' ? 8 : type === 'uchar' || type === 'uint8' || type === 'char' || type === 'int8' ? 1 : type === 'ushort' || type === 'uint16' || type === 'short' || type === 'int16' ? 2 : 4);
        const readers = {
          float: (dv, o) => dv.getFloat32(o, true),
          float32: (dv, o) => dv.getFloat32(o, true),
          double: (dv, o) => dv.getFloat64(o, true),
          float64: (dv, o) => dv.getFloat64(o, true),
          uchar: (dv, o) => dv.getUint8(o),
          uint8: (dv, o) => dv.getUint8(o),
          char: (dv, o) => dv.getInt8(o),
          int8: (dv, o) => dv.getInt8(o),
          ushort: (dv, o) => dv.getUint16(o, true),
          uint16: (dv, o) => dv.getUint16(o, true),
          short: (dv, o) => dv.getInt16(o, true),
          int16: (dv, o) => dv.getInt16(o, true),
          uint: (dv, o) => dv.getUint32(o, true),
          uint32: (dv, o) => dv.getUint32(o, true),
          int: (dv, o) => dv.getInt32(o, true),
          int32: (dv, o) => dv.getInt32(o, true),
        };
        const stride = props.reduce((n, p) => n + sizeOf(p.type), 0);
        const offsets = [];
        let off = 0;
        for (const p of props) { offsets.push(off); off += sizeOf(p.type); }
        const dv = new DataView(buffer);
        for (let i = 0; i < vertexCount; i++) {
          const base = headerEnd + i * stride;
          if (base + stride > buffer.byteLength) break;
          const read = (idx) => (readers[props[idx].type] || readers.float)(dv, base + offsets[idx]);
          add(read(xIndex), read(yIndex), read(zIndex));
        }
      } else {
        return null;
      }
      if (!min.every(Number.isFinite) || !max.every(Number.isFinite)) return null;
      const size = [max[0] - min[0], max[1] - min[1], max[2] - min[2]];
      const robust = {
        minX: percentile(localX, 0.05),
        maxX: percentile(localX, 0.95),
        minZ: percentile(localZ, 0.05),
        maxZ: percentile(localZ, 0.95),
      };
      robust.sizeX = Math.max(0.001, robust.maxX - robust.minX);
      robust.sizeZ = Math.max(0.001, robust.maxZ - robust.minZ);
      robust.footprint = Math.max(robust.sizeX, robust.sizeZ);
      robust.floorY = estimateSplatFloor(localX, localY, localZ, robust);
      robust.floorP02 = percentile(localY, 0.02);
      return { min, max, size, maxDim: Math.max(size[0], size[1], size[2]), robust };
    }
    function clearDojoSplat() {
      if (dojoSplatHelper) {
        scene.remove(dojoSplatHelper);
        if (dojoSplatHelper.geometry) dojoSplatHelper.geometry.dispose();
        if (dojoSplatHelper.material) dojoSplatHelper.material.dispose();
        dojoSplatHelper = null;
      }
      if (dojoSplatRoot) {
        scene.remove(dojoSplatRoot);
        _dojoSplatGrow = null;
        dojoSplatRoot.traverse((o) => {
          // SplatMesh.dispose() frees its packed splats so the Spark renderer stops
          // drawing it (removing it from the scene graph alone doesn't — Spark caches).
          if (typeof o.dispose === 'function') o.dispose();
          if (o.geometry) o.geometry.dispose();
          if (o.material) {
            if (Array.isArray(o.material)) o.material.forEach((m) => m.dispose());
            else o.material.dispose();
          }
        });
        dojoSplatRoot = null;
      }
      if (dojoSplatObjectUrl) {
        URL.revokeObjectURL(dojoSplatObjectUrl);
        dojoSplatObjectUrl = null;
      }
      dojoSplatBaseBounds = null;
      // Tear the Spark renderer down so it stops drawing the removed splat (it caches
      // accumulated splats independently of the scene graph). ensureSpark() rebuilds it
      // for the next dojo splat.
      if (spark) {
        try { scene.remove(spark); if (typeof spark.dispose === 'function') spark.dispose(); } catch (e) {}
        spark = null;
      }
    }
    // Animate the splat scaling up from ~0 to its fit scale on first load, so it grows
    // in instead of popping. Ticked each frame by _dojoSplatGrowTick.
    let _dojoSplatGrow = null;
    function _dojoSplatGrowTick(dt) {
      if (!_dojoSplatGrow || !dojoSplatRoot) return;
      _dojoSplatGrow.t += dt;
      const k = Math.min(1, _dojoSplatGrow.t / _dojoSplatGrow.dur);
      const e = 1 - Math.pow(1 - k, 3);   // easeOutCubic
      dojoSplatRoot.scale.setScalar(Math.max(0.0001, _dojoSplatGrow.to * e));
      if (k >= 1) _dojoSplatGrow = null;
    }
    function fitDojoSplat(attempt = 0, grow = false) {
      if (!dojoSplatRoot) return;
      const robust = dojoSplatBaseBounds && dojoSplatBaseBounds.robust ? dojoSplatBaseBounds.robust : null;
      const rawMax = robust && robust.footprint > 0 ? robust.footprint : (dojoSplatBaseBounds && dojoSplatBaseBounds.maxDim > 0 ? dojoSplatBaseBounds.maxDim : 1.0);
      // Normalise the splat footprint to `dojoRoomSize` metres so it stays proportional
      // to the ~SMPLX_HEIGHT-tall character (room span ≈ dojoRoomSize / 1.7 body-heights).
      const target = Math.max(SMPLX_HEIGHT * 1.5, dojoRoomSize);
      const scale = target / rawMax;
      const localFloorY = robust ? robust.floorY : 0;
      const localCenterX = robust ? (robust.minX + robust.maxX) * 0.5 : 0;
      const localCenterZ = robust ? (robust.minZ + robust.maxZ) * 0.5 : 0;
      const floorY = (dojoFloorSurfaceY - dojoFloorThickness) - localFloorY * scale;
      if (grow) { _dojoSplatGrow = { t: 0, dur: 0.7, to: scale }; dojoSplatRoot.scale.setScalar(0.0001); }
      else { _dojoSplatGrow = null; dojoSplatRoot.scale.setScalar(scale); }
      dojoSplatRoot.position.set(-localCenterX * scale, floorY, -localCenterZ * scale);
      dojoSplatRoot.updateMatrixWorld(true);
      resizeFloorGrid(rawMax * scale);
      const raw = dojoSplatBaseBounds && dojoSplatBaseBounds.size ? dojoSplatBaseBounds.size : [rawMax, rawMax, rawMax];
      const footprint = robust ? (robust.sizeX.toFixed(2) + ' x ' + robust.sizeZ.toFixed(2)) : rawMax.toFixed(2);
      const floorP02 = robust && robust.floorP02 != null ? robust.floorP02.toFixed(2) : 'n/a';
      postDojoStatus('Splat loaded in viewer. Raw bounds ' + raw.map((v) => v.toFixed(2)).join(' x ') + 'm, robust footprint ' + footprint + 'm, floor band ' + localFloorY.toFixed(2) + 'm (p02 ' + floorP02 + 'm), scale ' + scale.toFixed(2) + 'x.');
    }
    async function applyDojoSplat(url, settings) {
      if (!url) { clearDojoSplat(); postDojoStatus('Splat cleared.'); return; }
      clearDojoSplat();
      applyDojoRoomSettings(settings);
      postDojoStatus('Loading splat in viewer...');
      try {
        const buffer = await splatPayloadBuffer(url);
        dojoSplatBaseBounds = parsePlyBounds(buffer);
        if (dojoSplatObjectUrl) URL.revokeObjectURL(dojoSplatObjectUrl);
        dojoSplatObjectUrl = URL.createObjectURL(new Blob([buffer], { type: 'application/octet-stream' }));
        const loadUrl = dojoSplatObjectUrl;
        const sparkMod = await ensureSpark();
        const packedSplats = await new sparkMod.SplatLoader().loadAsync(loadUrl);
        const splat = new sparkMod.SplatMesh({ packedSplats });
        dojoSplatRoot = new THREE.Group();
        dojoSplatRoot.name = 'dojo-splat';
        dojoSplatRoot.add(splat);
        splat.rotation.y = Math.PI / 2;
        dojoSplatRoot.rotation.x = Math.PI;
        dojoSplatRoot.scale.setScalar(1.0);
        dojoSplatRoot.position.set(0.95, 0.05, -0.85);
        scene.add(dojoSplatRoot);
        fitDojoSplat(0, true);   // grow in from ~0 so the splat doesn't pop
      } catch (err) {
        console.error('dojo splat load failed', err);
        postDojoStatus('Splat load failed: ' + (err && err.message ? err.message : err));
      }
    }

    const camera = new THREE.PerspectiveCamera(45, 1, 0.01, 200);
    const controls = new OrbitControls(camera, renderer.domElement);
    controls.enableDamping = true;

    // --- Move placement: overlay a move's END pose as a draggable figure. Tap the
    //     ground to move it (sets the 2D root), swipe across it to rotate. Reports
    //     {kind:'place-update', tx, tz, rot} so the composer updates the move. ---
    let placeGroup = null, placePosed = null, placeParents = null, placeTx = 0, placeTz = 0, placeRot = 0, placeHitMesh = null, placeMoveHit = null, placeRotHit = null;
    let placeBaseTx = 0, placeBaseTz = 0, placeBaseHeading = 0;   // world transform of the move's START
    let placeStartPosed = null, placeStartGroup = null, placeStartVis = false, placeEndVis = true, placeEndSkel = null;
    const _placeRay = new THREE.Raycaster();
    const _placePlane = new THREE.Plane(new THREE.Vector3(0, 1, 0), 0);
    const _placeNDC = new THREE.Vector2(), _placeHit = new THREE.Vector3();
    let _placeDrag = null;
    function placeApply() {
      if (!placeGroup) return;
      // Compose the move's local (tx,tz,rot) onto the START-of-move world transform, so
      // the overlay sits where the move ends in the kata (not at the origin).
      const bh = placeBaseHeading, c = Math.cos(bh), s = Math.sin(bh);
      placeGroup.position.set(placeTx * c + placeTz * s + placeBaseTx, 0, -placeTx * s + placeTz * c + placeBaseTz);
      placeGroup.rotation.y = bh + placeRot * Math.PI / 180;
    }
    // Build a colored skeleton (lines + joint dots) group from a posed-joint array.
    function _placeSkel(posed, color) {
      const grp = new THREE.Group();
      const segs = [];
      for (let i = 0; i < posed.length; i++) { const p = placeParents[i]; if (p < 0) continue; segs.push(posed[p], posed[i]); }
      const arr = new Float32Array(segs.length * 3);
      for (let i = 0; i < segs.length; i++) { arr[i*3] = segs[i][0]; arr[i*3+1] = segs[i][1]; arr[i*3+2] = segs[i][2]; }
      const g = new THREE.BufferGeometry(); g.setAttribute('position', new THREE.BufferAttribute(arr, 3));
      const lines = new THREE.LineSegments(g, new THREE.LineBasicMaterial({ color, depthTest: false, transparent: true, opacity: 0.96 })); lines.renderOrder = 999; grp.add(lines);
      const dotG = new THREE.SphereGeometry(0.022, 6, 6), dotM = new THREE.MeshBasicMaterial({ color, depthTest: false });
      for (const j of posed) { const d = new THREE.Mesh(dotG, dotM); d.position.set(j[0], j[1], j[2]); d.renderOrder = 999; grp.add(d); }
      return grp;
    }
    // Animate a group's scale toward show/hide so skeletons grow/shrink (no pop).
    const _placeAnims = new Map();   // obj -> target scale
    function placeSetVisible(obj, show) { if (!obj) return; if (show) obj.visible = true; _placeAnims.set(obj, { target: show ? 1 : 0 }); }
    function _placeAnimTick() {
      if (!_placeAnims.size) return;
      for (const [obj, st] of _placeAnims) {
        if (!obj.parent) { _placeAnims.delete(obj); continue; }
        const cur = obj.scale.x, next = cur + (st.target - cur) * 0.28;
        if (Math.abs(next - st.target) < 0.012) { obj.scale.setScalar(st.target || 0.0001); if (st.target === 0) obj.visible = false; _placeAnims.delete(obj); }
        else obj.scale.setScalar(next);
      }
    }
    function placeBuild() {
      if (placeGroup) { scene.remove(placeGroup); placeGroup = null; }
      if (placeStartGroup) { scene.remove(placeStartGroup); placeStartGroup = null; }
      _placeAnims.clear();
      // Container holding the END skeleton + the gizmos. The container stays visible so
      // the pose CONTROLS (ring/knob) remain even when the skeleton is hidden.
      placeGroup = new THREE.Group();
      placeEndSkel = _placeSkel(placePosed, 0xe8736a);   // RED end-pose skeleton (toggle)
      placeEndSkel.scale.setScalar(0.0001); placeEndSkel.visible = placeEndVis; placeGroup.add(placeEndSkel);
      // Ground gizmos: green ring at the feet = drag to MOVE; red knob out front = ROTATE.
      const moveDisc = new THREE.Mesh(new THREE.CircleGeometry(0.30, 36), new THREE.MeshBasicMaterial({ color: 0x5fb98c, side: THREE.DoubleSide, depthTest: false, transparent: true, opacity: 0.38 }));
      moveDisc.rotation.x = -Math.PI / 2; moveDisc.position.y = 0.012; moveDisc.renderOrder = 997; placeGroup.add(moveDisc); placeMoveHit = moveDisc;
      const moveRing = new THREE.Mesh(new THREE.RingGeometry(0.30, 0.35, 36), new THREE.MeshBasicMaterial({ color: 0x9fe6c0, side: THREE.DoubleSide, depthTest: false, transparent: true, opacity: 0.95 }));
      moveRing.rotation.x = -Math.PI / 2; moveRing.position.y = 0.013; moveRing.renderOrder = 998; placeGroup.add(moveRing);
      const stemG = new THREE.BufferGeometry(); stemG.setAttribute('position', new THREE.BufferAttribute(new Float32Array([0, 0.013, 0, 0, 0.013, 0.52]), 3));
      placeGroup.add(new THREE.LineSegments(stemG, new THREE.LineBasicMaterial({ color: 0xe8736a, depthTest: false, transparent: true, opacity: 0.85 })));
      const rotKnob = new THREE.Mesh(new THREE.SphereGeometry(0.09, 16, 12), new THREE.MeshBasicMaterial({ color: 0xe8736a, depthTest: false }));
      rotKnob.position.set(0, 0.013, 0.52); rotKnob.renderOrder = 999; placeGroup.add(rotKnob); placeRotHit = rotKnob;   // y on the stem line so it hits the sphere center
      scene.add(placeGroup);
      placeSetVisible(placeEndSkel, placeEndVis);   // grow the skeleton in
      // START pose skeleton (GREEN) at the move's start (the base transform), hidden by default.
      if (placeStartPosed && placeStartPosed.length) {
        placeStartGroup = _placeSkel(placeStartPosed, 0x5fb98c);
        placeStartGroup.position.set(placeBaseTx, 0, placeBaseTz);
        placeStartGroup.rotation.y = placeBaseHeading;
        placeStartGroup.scale.setScalar(0.0001); placeStartGroup.visible = placeStartVis;
        scene.add(placeStartGroup);
        placeSetVisible(placeStartGroup, placeStartVis);
      }
      placeApply();
    }
    function placeShow(posed, startPosed, parents, tx, tz, rot, base, startVis, endVis) {
      placePosed = posed; placeStartPosed = startPosed || null; placeParents = parents; placeTx = tx; placeTz = tz; placeRot = rot;
      placeBaseTx = (base && base.x) || 0; placeBaseTz = (base && base.z) || 0; placeBaseHeading = (base && base.heading) || 0;
      placeStartVis = !!startVis; placeEndVis = (endVis !== false);
      placeBuild();
    }
    function placeHide() {
      if (placeGroup) { scene.remove(placeGroup); placeGroup = null; }
      if (placeStartGroup) { scene.remove(placeStartGroup); placeStartGroup = null; }
      placePosed = null; placeStartPosed = null; placeHitMesh = null; placeMoveHit = null; placeRotHit = null; controls.enabled = true;
    }
    function _placeNDCfrom(cx, cy) { const r = renderer.domElement.getBoundingClientRect(); _placeNDC.x = ((cx - r.left) / r.width) * 2 - 1; _placeNDC.y = -((cy - r.top) / r.height) * 2 + 1; _placeRay.setFromCamera(_placeNDC, camera); }
    function placeOverFigure(cx, cy) { if (!placeHitMesh) return false; _placeNDCfrom(cx, cy); return _placeRay.intersectObject(placeHitMesh, false).length > 0; }
    function placeGround(cx, cy) { _placeNDCfrom(cx, cy); return _placeRay.ray.intersectPlane(_placePlane, _placeHit) ? _placeHit : null; }
    // Place gizmos: pointerdown on the MOVE ring → drag to translate; on the ROTATE knob
    // → drag around to turn. Anywhere else the camera orbits (the figure body is inert).
    renderer.domElement.addEventListener('pointerdown', (e) => {
      if (!placeGroup) return;
      _placeNDCfrom(e.clientX, e.clientY);
      const onRot = placeRotHit && _placeRay.intersectObject(placeRotHit, false).length > 0;
      const onMove = !onRot && placeMoveHit && _placeRay.intersectObject(placeMoveHit, false).length > 0;
      if (onRot || onMove) {
        const g = placeGround(e.clientX, e.clientY); const wp = placeGroup.position;
        _placeDrag = { mode: onRot ? 'rot' : 'move', ox: g ? (wp.x - g.x) : 0, oz: g ? (wp.z - g.z) : 0 };   // world offset
        controls.enabled = false;   // dragging a gizmo, not the camera
      } else { _placeDrag = null; }
    });
    renderer.domElement.addEventListener('pointermove', (e) => {
      if (!placeGroup || !_placeDrag) return;
      const hit = placeGround(e.clientX, e.clientY); if (!hit) return;
      const bh = placeBaseHeading, c = Math.cos(bh), s = Math.sin(bh);
      if (_placeDrag.mode === 'move') {
        const dx = (hit.x + _placeDrag.ox) - placeBaseTx, dz = (hit.z + _placeDrag.oz) - placeBaseTz;   // desired world → local
        placeTx = dx * c - dz * s; placeTz = dx * s + dz * c;
      } else {
        const cx = placeGroup.position.x, cz = placeGroup.position.z;   // face the figure toward the pointer
        placeRot = (Math.atan2(hit.x - cx, hit.z - cz) - bh) * 180 / Math.PI;
      }
      placeApply(); postParent({ kind: 'place-update', tx: placeTx, tz: placeTz, rot: placeRot });
    });
    function _placeEnd() { controls.enabled = true; _placeDrag = null; }
    renderer.domElement.addEventListener('pointerup', _placeEnd);
    renderer.domElement.addEventListener('pointercancel', _placeEnd);

    // Brighter, lighter-bottomed hemisphere so downward-facing surfaces (a shadowed
    // face in a guard pose) aren't near-black; key + a front fill so faces read.
    scene.add(new THREE.HemisphereLight(0xffffff, 0x6a7078, 2.7));
    const dir = new THREE.DirectionalLight(0xffffff, 2.1);
    dir.position.set(3, 5, 2);
    scene.add(dir);
    const fill = new THREE.DirectionalLight(0xffffff, 0.85);   // front fill toward the camera
    fill.position.set(-2, 3, 5);
    scene.add(fill);

    const floor = new THREE.GridHelper(1, 20, 0x42f6ff, 0x1aa6b8);
    floor.position.y = dojoFloorSurfaceY;
    floor.scale.set(dojoRoomSize, 1, dojoRoomSize);
    scene.add(floor);

    // Motion arrays are swapped in only for clips with this viewer's joint count.
    let jointData = decodeFloat32(data.joint_data_b64);
    let quatData = data.quat_data_b64 ? decodeFloat32(data.quat_data_b64) : null;
    let rootData = data.root_data_b64 ? decodeFloat32(data.root_data_b64) : null;
    let nFrames = data.preview_frames || 0;
    let fps = data.preview_fps || data.fps || 30;
    const parents = data.parents;
    const boneNames = data.bone_names || [];
    const nJoints = data.num_joints || 0;

    // --- Procedural skeleton (joints + bones + root trail), grouped for toggling.
    const skel = new THREE.Group();
    scene.add(skel);

    // Camera framing + root-trail geometry, recomputed from the CURRENT clip
    // (frame count and extents change between clips).
    const rootPathGeo = new THREE.BufferGeometry();
    skel.add(new THREE.Line(rootPathGeo, new THREE.LineBasicMaterial({ color: 0x7dd3fc })));
    function frameCamera() {
      let minX = Infinity, minY = Infinity, minZ = Infinity, maxX = -Infinity, maxY = -Infinity, maxZ = -Infinity;
      for (let i = 0; i < jointData.length; i += 3) {
        const x = jointData[i], y = jointData[i + 1], z = jointData[i + 2];
        if (x < minX) minX = x; if (x > maxX) maxX = x;
        if (y < minY) minY = y; if (y > maxY) maxY = y;
        if (z < minZ) minZ = z; if (z > maxZ) maxZ = z;
      }
      const box = new THREE.Box3(new THREE.Vector3(minX, minY, minZ), new THREE.Vector3(maxX, maxY, maxZ));
      const center = new THREE.Vector3(), size = new THREE.Vector3();
      box.getCenter(center); box.getSize(size);
      const radius = Math.max(size.x, size.y, size.z, 1);
      controls.target.copy(center);
      camera.position.set(center.x + radius * 0.9, center.y + radius * 0.55, center.z + radius * 1.8);
      camera.near = Math.max(radius / 1000, 0.01);
      camera.far = radius * 20;
      camera.updateProjectionMatrix();
      const rp = new Float32Array(nFrames * 3);
      for (let f = 0; f < nFrames; f++) {
        const src = f * nJoints * 3;
        rp[f * 3] = jointData[src]; rp[f * 3 + 1] = 0.02; rp[f * 3 + 2] = jointData[src + 2];
      }
      rootPathGeo.setAttribute('position', new THREE.BufferAttribute(rp, 3));
      rootPathGeo.computeBoundingSphere();
    }

    const cameraLockBtn = document.getElementById('camera-lock');
    let cameraLocked = true;
    const cameraFocus = new THREE.Vector3();
    const previousCameraFocus = new THREE.Vector3();
    const cameraFocusDelta = new THREE.Vector3();
    const lockedCameraOffset = new THREE.Vector3(1.55, 0.72, 2.85);
    function frameFocus(f, out) {
      const safeFrame = Math.max(0, Math.min(nFrames - 1, f || 0));
      const o = safeFrame * nJoints * 3;
      out.set(jointData[o] || 0, jointData[o + 1] || 0.9, jointData[o + 2] || 0);
      return out;
    }
    function setLockedCameraView() {
      frameFocus(frame, cameraFocus);
      controls.target.copy(cameraFocus);
      camera.position.copy(cameraFocus).add(lockedCameraOffset);
      previousCameraFocus.copy(cameraFocus);
      controls.update();
    }
    function syncCameraLock(jump = false) {
      if (!cameraLocked || !nFrames || !nJoints) return;
      if (_camAnim) { frameFocus(frame, previousCameraFocus); return; }   // a fly is in progress — don't fight it
      frameFocus(frame, cameraFocus);
      if (jump) {
        setLockedCameraView();
        return;
      }
      cameraFocusDelta.copy(cameraFocus).sub(previousCameraFocus);
      camera.position.add(cameraFocusDelta);
      controls.target.add(cameraFocusDelta);
      previousCameraFocus.copy(cameraFocus);
    }
    function updateCameraLockButton() {
      cameraLockBtn.innerHTML = cameraLocked ? '&#128274;' : '&#128275;';
      cameraLockBtn.title = cameraLocked ? 'Camera locked to character' : 'Camera unlocked';
      cameraLockBtn.setAttribute('aria-label', cameraLockBtn.title);
    }
    cameraLockBtn.onclick = () => {
      cameraLocked = !cameraLocked;
      if (cameraLocked) setLockedCameraView();
      updateCameraLockButton();
    };
    updateCameraLockButton();
    // Center + frame the FULL body (head→feet) at the current frame. The open sidebar is
    // accounted for by the existing view offset (applyViewOffset), so the body is centered
    // in the still-visible area. Driven by the parent's center/lock button.
    // Eased camera fly so loading a stance/move GLIDES into frame instead of popping.
    let _camAnim = null;
    function flyCameraTo(pos, look, dur) { _camAnim = { p0: camera.position.clone(), p1: pos.clone(), t0: controls.target.clone(), t1: look.clone(), t: 0, dur: dur || 0.5 }; }
    function _camAnimTick(dt) {
      if (!_camAnim) return;
      _camAnim.t += dt;
      const k = Math.min(1, _camAnim.t / _camAnim.dur);
      const e = k < 0.5 ? 2 * k * k : 1 - Math.pow(-2 * k + 2, 2) / 2;   // easeInOutQuad
      camera.position.lerpVectors(_camAnim.p0, _camAnim.p1, e);
      controls.target.lerpVectors(_camAnim.t0, _camAnim.t1, e);
      if (k >= 1) _camAnim = null;
    }
    const _frameDir = new THREE.Vector3(0.04, 0.22, 2.9).normalize();   // near-frontal, camera further left + lower
    // Frame the WHOLE body (head→feet) with a roomy margin, centered in the visible area
    // (the open drawer is accounted for by applyViewOffset). smooth=true glides there.
    function centerFullBody(smooth) {
      if (!nFrames || !nJoints) return;
      let minY = Infinity, maxY = -Infinity;
      const base = Math.max(0, Math.min(nFrames - 1, frame)) * nJoints * 3;
      for (let i = 0; i < nJoints; i++) { const y = jointData[base + i * 3 + 1]; if (y < minY) minY = y; if (y > maxY) maxY = y; }
      const bh = Math.max((maxY - minY) || 1.6, 1.2);
      frameFocus(frame, previousCameraFocus);                 // pelvis → smooth follow deltas
      const look = previousCameraFocus.clone(); look.y = (minY + maxY) / 2;   // focus = body center
      const fov = (camera.fov || 45) * Math.PI / 180;
      const dist = (bh / (2 * Math.tan(fov / 2))) * 2.9 + 1.0;   // fit full height + extra margin (zoomed out more)
      const pos = look.clone().addScaledVector(_frameDir, dist);
      if (smooth) flyCameraTo(pos, look, 0.5);
      else { camera.position.copy(pos); controls.target.copy(look); controls.update(); }
      applyViewOffset();
    }

    const childCounts = parents.map(() => 0);
    parents.forEach(p => { if (p >= 0) childCounts[p] += 1; });
    const jointGeo = new THREE.SphereGeometry(0.018, 10, 6);
    const jointMat = new THREE.MeshStandardMaterial({ color: 0xd7dde5, roughness: 0.55 });
    const jointMesh = new THREE.InstancedMesh(jointGeo, jointMat, nJoints);
    jointMesh.instanceMatrix.setUsage(THREE.DynamicDrawUsage);
    jointMesh.frustumCulled = false;
    for (let i = 0; i < nJoints; i++) {
      const color = i === 0 ? 0x7dd3fc : (childCounts[i] === 0 ? 0xfacc15 : 0xd7dde5);
      jointMesh.setColorAt(i, new THREE.Color(color));
    }
    if (jointMesh.instanceColor) jointMesh.instanceColor.needsUpdate = true;
    skel.add(jointMesh);

    const edges = [];
    for (let i = 0; i < nJoints; i++) {
      if (parents[i] < 0) continue;
      edges.push([i, parents[i]]);
    }
    const edgePositions = new Float32Array(edges.length * 2 * 3);
    const edgeGeo = new THREE.BufferGeometry();
    edgeGeo.setAttribute('position', new THREE.BufferAttribute(edgePositions, 3));
    edgeGeo.attributes.position.setUsage(THREE.DynamicDrawUsage);
    const edgeLines = new THREE.LineSegments(edgeGeo, new THREE.LineBasicMaterial({ color: 0xaeb7c2 }));
    edgeLines.frustumCulled = false;
    skel.add(edgeLines);
    const dummy = new THREE.Object3D();

    // Skeleton OVERLAY: draw the true joint bones on top of the mesh character
    // (x-ray) so the actual pose is readable as it plays. Toggled in the menu.
    let skelOverlay = false;
    function applySkelOverlayStyle() {
      // Bright + depth-tested-off so bones show THROUGH the character when overlaying.
      const xray = skelOverlay && mode !== 'skeleton';
      edgeLines.material.color.set(xray ? 0x39ff14 : 0xaeb7c2);
      edgeLines.material.depthTest = !xray;
      jointMat.depthTest = !xray;
      jointMat.color.set(xray ? 0x39ff14 : 0xd7dde5);
      edgeLines.renderOrder = jointMesh.renderOrder = xray ? 999 : 0;
      jointMat.needsUpdate = true;
    }
    // RED reference-pose skeleton (viser-style constraint skeleton): the STATIC
    // target pose a seeded clip was generated to start from. Drawn alongside the
    // green overlay so you can see the generated frame 0 land on it (and peel away).
    const refEdgePositions = new Float32Array(edges.length * 2 * 3);
    const refEdgeGeo = new THREE.BufferGeometry();
    refEdgeGeo.setAttribute('position', new THREE.BufferAttribute(refEdgePositions, 3));
    const refEdges = new THREE.LineSegments(refEdgeGeo, new THREE.LineBasicMaterial({
      color: 0xff3b3b, depthTest: false, transparent: true, opacity: 0.9 }));
    refEdges.renderOrder = 998; refEdges.frustumCulled = false; refEdges.visible = false;
    scene.add(refEdges);
    let hasReference = false;
    function setReferencePose(ref) {
      // ref: flat [nJoints*3] array (re-rooted to XZ origin, same frame as clip f0).
      hasReference = Array.isArray(ref) && ref.length === nJoints * 3;
      if (hasReference) {
        let k = 0;
        for (const [i, p] of edges) {
          refEdgePositions[k++] = ref[p*3]; refEdgePositions[k++] = ref[p*3+1]; refEdgePositions[k++] = ref[p*3+2];
          refEdgePositions[k++] = ref[i*3]; refEdgePositions[k++] = ref[i*3+1]; refEdgePositions[k++] = ref[i*3+2];
        }
        refEdgeGeo.attributes.position.needsUpdate = true;
      }
      refEdges.visible = hasReference && skelOverlay;
    }
    setReferencePose((typeof data !== 'undefined' && data && data.reference_pose) || null);

    // RED NEXT-TARGET skeleton for a KATA: a single static red pose at the NEXT
    // upcoming checkpoint (the most-expressive frame of the upcoming move). As the
    // green skeleton advances past a checkpoint, the red jumps to the next one —
    // less noisy than showing every target at once.
    let targetFramesArr = [];
    const targetPos = new Float32Array(edges.length * 2 * 3);
    const targetGeo = new THREE.BufferGeometry();
    targetGeo.setAttribute('position', new THREE.BufferAttribute(targetPos, 3));
    const targetEdges = new THREE.LineSegments(targetGeo, new THREE.LineBasicMaterial({
      color: 0xff3b3b, depthTest: false, transparent: true, opacity: 0.75 }));
    targetEdges.renderOrder = 997; targetEdges.frustumCulled = false; targetEdges.visible = false;
    scene.add(targetEdges);
    function setTargetPoses(frames) {
      targetFramesArr = (Array.isArray(frames) ? frames.filter((f) => f >= 0 && f < nFrames) : []).sort((a, b) => a - b);
      updateNextTarget(frame);
    }
    function updateNextTarget(curFrame) {
      if (!targetFramesArr.length || !skelOverlay || !jointData) { targetEdges.visible = false; return; }
      // next checkpoint strictly ahead; wrap to the first when past the last (loop).
      let f = targetFramesArr.find((t) => t > curFrame);
      if (f === undefined) f = targetFramesArr[0];
      const base = f * nJoints * 3; let k = 0;
      for (const [i, p] of edges) {
        targetPos[k++] = jointData[base + p*3]; targetPos[k++] = jointData[base + p*3+1]; targetPos[k++] = jointData[base + p*3+2];
        targetPos[k++] = jointData[base + i*3]; targetPos[k++] = jointData[base + i*3+1]; targetPos[k++] = jointData[base + i*3+2];
      }
      targetGeo.attributes.position.needsUpdate = true;
      targetEdges.visible = true;
    }

    const skelOverlayBox = document.getElementById('skel-overlay');
    if (skelOverlayBox) skelOverlayBox.addEventListener('change', () => {
      skelOverlay = skelOverlayBox.checked;
      skel.visible = skelOverlay || mode === 'skeleton';
      refEdges.visible = hasReference && skelOverlay;
      updateNextTarget(frame);
      applySkelOverlayStyle();
      setSkeletonFrame(frame);     // populate bone positions immediately
    });

    // --- Rest-mode retargeter: drive a skinned rig from the clip's world quats.
    // Ported from kimodo-motion-api web/src/animator.js (alignMode='rest'):
    //   Q_target_world = Q_kimodo_world . Q_bone_rest_world
    //   Q_target_local = Q_parent_world^-1 . Q_target_world
    class Animator {
      constructor(skinned, mapping, opts) {
        this.mapping = mapping;
        this.scale = opts.scale;
        this.groundOffsetY = opts.groundOffsetY;
        this.norm = (n) => n.replace(/[.:]/g, '');
        this.bonesByName = {};
        for (const b of skinned.skeleton.bones) this.bonesByName[this.norm(b.name)] = b;
        skinned.updateMatrixWorld(true);
        this.restQ = new Map();
        const p = new THREE.Vector3(), q = new THREE.Quaternion(), s = new THREE.Vector3();
        for (const b of skinned.skeleton.bones) { b.matrixWorld.decompose(p, q, s); this.restQ.set(b.name, q.clone()); }
        this.pelvis = this.bonesByName[this.norm(mapping.pelvis || '')] || null;
        this.pairs = [];
        this._qk = new THREE.Quaternion(); this._qw = new THREE.Quaternion();
        this._qp = new THREE.Quaternion(); this._tp = new THREE.Vector3(); this._ts = new THREE.Vector3();
      }
      resolve(names) {
        this.pairs = [];
        for (let i = 0; i < names.length; i++) {
          const tName = this.mapping[names[i]];
          if (!tName) continue;
          const bone = this.bonesByName[this.norm(tName)];
          if (!bone) continue;
          this.pairs.push({ idx: i, bone, restQ: this.restQ.get(bone.name) });
        }
        console.log('[retarget] resolved ' + this.pairs.length + ' of ' + names.length + ' joints');
      }
      applyFrame(quats, root, f) {
        if (!quats) return;
        for (const { idx, bone, restQ } of this.pairs) {
          const o = f * nJoints * 4 + idx * 4;
          this._qk.set(quats[o], quats[o + 1], quats[o + 2], quats[o + 3]);
          this._qw.copy(this._qk).multiply(restQ);
          if (bone.parent) {
            bone.parent.matrixWorld.decompose(this._tp, this._qp, this._ts);
            this._qp.invert();
            bone.quaternion.copy(this._qp).multiply(this._qw);
          } else {
            bone.quaternion.copy(this._qw);
          }
          bone.updateMatrixWorld(true);
        }
        if (this.pelvis && root) {
          const s = this.scale;
          this.pelvis.position.set(root[f * 3] * s, root[f * 3 + 1] * s - this.groundOffsetY, root[f * 3 + 2] * s);
        }
      }
    }

    const charCache = {};
    let character = null;   // { root, anim }
    let mode = 'skeleton';

    // Map a skin atlas (e.g. the decompiled s&box citizen skin) onto a character's
    // body materials. One shared UV atlas covers the whole body; skip eye/mouth
    // sub-materials (their own UVs). flipY=false = glTF UV convention.
    // The material color multiplies the texture — a warm pinkish "wiener" tint pushes
    // the pale skin toward sausage. Set to 0xffffff to disable the tint.
    const SAUSAGE_TINT = 0x8f6549;
    const _charTexLoader = new THREE.TextureLoader();
    _charTexLoader.setCrossOrigin('anonymous');
    function applyCharSkin(root, url) {
      const tex = _charTexLoader.load(url);
      tex.colorSpace = THREE.SRGBColorSpace;
      tex.flipY = false;
      tex.anisotropy = renderer.capabilities.getMaxAnisotropy();
      root.traverse(o => {
        if (!o.isMesh && !o.isSkinnedMesh) return;
        const mats = Array.isArray(o.material) ? o.material : [o.material];
        for (const m of mats) {
          if (!m) continue;
          const name = (m.name || o.name || '').toLowerCase();
          if (/eye|mouth|teeth|tongue|brow|lash|cornea/.test(name)) continue;
          m.map = tex;
          if (m.color) m.color.setHex(SAUSAGE_TINT);   // warm sausage tint multiplies the skin atlas
          if (m.metalness !== undefined) m.metalness = 0;   // skin is non-metal; metallic PBR w/o envMap renders black
          if (m.roughness !== undefined) m.roughness = Math.max(m.roughness, 0.7);
          m.needsUpdate = true;
        }
      });
    }

    // Network loads on the boot/reveal path must never HANG: a stalled CDN request
    // (socket opens, no response) never rejects, so a bare `await loadAsync` would leave
    // the viewer stuck on the spinner with NO character. Bound each GLB fetch with a
    // timeout (+ optional retry) so a stall fails fast and we fall back gracefully
    // (skeleton for the body, skip-the-garment for clothing) instead of blanking forever.
    function loadGltfTimed(loader, url, ms, tries) {
      ms = ms || 12000; tries = Math.max(1, tries || 1);
      const once = () => new Promise((resolve, reject) => {
        let settled = false;
        const timer = setTimeout(() => { if (!settled) { settled = true; reject(new Error('gltf timeout: ' + url)); } }, ms);
        loader.loadAsync(url).then(
          (g) => { if (!settled) { settled = true; clearTimeout(timer); resolve(g); } },
          (e) => { if (!settled) { settled = true; clearTimeout(timer); reject(e); } }
        );
      });
      let p = once();
      for (let i = 1; i < tries; i++) p = p.catch(() => once());   // retry a transient stall/error
      return p;
    }

    async function buildCharacter(entry) {
      const loader = new GLTFLoader();
      // Prefer the hosted GLB URL — the browser caches it across iframe rebuilds, so
      // re-rendering the viewer doesn't re-download or re-ship the mesh. Fall back to an
      // inline base64 blob if a character still embeds one. Timed + retried so a stalled
      // CDN fetch fails fast (-> skeleton) rather than hanging the viewer blank.
      const gltf = entry.glb_url
        ? await loadGltfTimed(loader, entry.glb_url, 12000, 2)
        : await loader.parseAsync(decodeBytes(entry.glb_b64).buffer, '');
      const root = gltf.scene;
      root.scale.setScalar(entry.scale || 1.0);
      let skinned = null;
      root.traverse(o => { if (o.isSkinnedMesh) { if (!skinned) skinned = o; o.frustumCulled = false; } });
      if (!skinned) throw new Error('GLB has no skinned mesh');
      if (entry.texture) applyCharSkin(root, entry.texture);   // map the s&box skin atlas onto the body
      root.visible = false;
      scene.add(root);
      root.updateMatrixWorld(true);
      const bb = new THREE.Box3().setFromObject(root);
      const groundOffsetY = -bb.min.y;
      root.position.y += groundOffsetY;
      const charHeight = (bb.max.y - bb.min.y) || 1;
      const anim = new Animator(skinned, entry.mapping, { scale: charHeight / SMPLX_HEIGHT, groundOffsetY });
      anim.resolve(boneNames);
      return { root, anim, skinned, dressed: false };
    }

    // --- Clothing: garments are skinned GLBs rigged to the SAME citizen bone_N
    // skeleton. Wear one by name-matching its bones to the citizen's and copying
    // the citizen's bone transforms onto them each frame (syncClothing), so the
    // garment deforms with the body. Ported from kata.js attach/detach/sync.
    const clothLoader = new GLTFLoader();
    const worn = new Map();          // slot -> garment id (intent, persists)
    const wornAttached = new Map();  // slot -> { scene, pairs }
    const slotSelects = {};
    for (const [slot, id] of Object.entries(cfg.defaultClothing || {})) worn.set(slot, id);

    function detachGarment(slot) {
      const a = wornAttached.get(slot);
      if (!a) return;
      if (character) character.root.remove(a.scene);
      a.scene.traverse(o => { if (o.isMesh && o.geometry) o.geometry.dispose(); });
      wornAttached.delete(slot);
    }
    async function attachGarment(slot, item) {
      detachGarment(slot);
      if (!character || !character.skinned) return;
      const sc = (await loadGltfTimed(clothLoader, item.url, 9000, 1)).scene;
      let mesh = null;
      sc.traverse(o => { if (o.isSkinnedMesh) { if (!mesh) mesh = o; o.frustumCulled = false; } });
      if (!mesh) return;
      mesh.renderOrder = item.layer || 1;
      const cit = new Map(character.skinned.skeleton.bones.map(b => [b.name, b]));
      const pairs = mesh.skeleton.bones.map(jb => ({ j: jb, c: cit.get(jb.name) })).filter(p => p.c);
      character.root.add(sc);
      wornAttached.set(slot, { scene: sc, pairs });
    }
    // Returns true only if EVERY worn garment attached. A stalled/failed garment
    // returns false so the caller can decline to reveal a half-dressed character.
    async function applyWorn() {
      for (const s of [...wornAttached.keys()]) detachGarment(s);
      let allOk = true;
      for (const [slot, id] of worn) {
        const item = cfg.clothing.find(c => c.id === id);
        if (!item) continue;
        try { await attachGarment(slot, item); }
        catch (e) { console.warn('clothing load failed', id, e); allOk = false; }
      }
      return allOk;
    }
    function syncClothing() {
      for (const { pairs } of wornAttached.values())
        for (const { j, c } of pairs) { j.quaternion.copy(c.quaternion); j.position.copy(c.position); j.scale.copy(c.scale); }
    }

    const playBtn = document.getElementById('play');
    const scrub = document.getElementById('scrub');
    const frameLabel = document.getElementById('frame');
    const speed = document.getElementById('speed');
    const characterSel = document.getElementById('character');
    const menuBtn = document.getElementById('menu-btn');
    const menu = document.getElementById('menu');
    menuBtn.onclick = () => menu.classList.toggle('open');
    const creatorLabel = document.getElementById('creator-label');
    function truncateText(value, maxLen) {
      const text = String(value || '').replace(/\s+/g, ' ').trim();
      return text.length > maxLen ? text.slice(0, Math.max(0, maxLen - 1)).trimEnd() + '...' : text;
    }
    function appendSpan(parent, cls, text) {
      const span = document.createElement('span');
      span.className = cls;
      span.textContent = text;
      parent.appendChild(span);
    }
    // Always reflect the clip currently on screen. Do NOT fall back to cfg.*
    // (the initially-rendered clip's creator) -- on a picker switch that would
    // leave a named author stuck on a subsequently-loaded anonymous clip.
    function setCreatorLabel(source) {
      const username = (source && source.created_by) || '';
      const name = (source && source.created_by_name) || username;
      const prompt = truncateText((source && source.prompt) || '', 72);
      // The clip id lets you point precisely at the animation on screen. Prefer
      // the payload's own id, else the canonically-tracked curId.
      const cid = (source && source.id) || (typeof curId !== 'undefined' ? curId : '') || '';
      if (!username && !prompt && !cid) {
        creatorLabel.style.display = 'none';
        creatorLabel.textContent = '';
        return;
      }
      creatorLabel.textContent = '';
      if (cid) {
        const idSpan = document.createElement('span');
        idSpan.className = 'creator-id';
        idSpan.textContent = cid;
        idSpan.title = 'Click to copy clip id';
        idSpan.style.cursor = 'pointer';
        idSpan.onclick = () => { try { navigator.clipboard.writeText(cid); idSpan.classList.add('copied'); setTimeout(() => idSpan.classList.remove('copied'), 900); } catch (e) {} };
        creatorLabel.appendChild(idSpan);
      }
      if (username) {
        if (cid) appendSpan(creatorLabel, 'creator-sep', '/');
        appendSpan(creatorLabel, 'creator-by', 'made by ');
        appendSpan(creatorLabel, 'creator-name', name || username);
      }
      if (prompt) {
        if (username || cid) appendSpan(creatorLabel, 'creator-sep', '/');
        appendSpan(creatorLabel, 'creator-prompt', prompt);
      }
      creatorLabel.title = `${cid ? `[${cid}] ` : ''}${username ? `Made by @${username}` : 'Anonymous animation'}${prompt ? `: ${prompt}` : ''}`;
      creatorLabel.style.display = 'block';
    }
    setCreatorLabel(data);
    const loadingEl = document.getElementById('loading');
    const showLoading = () => loadingEl.classList.add('on');
    const hideLoading = () => loadingEl.classList.remove('on');
    const toastEl = document.getElementById('viewer-toast');
    let _toastTimer = null;
    function showToast(msg, ms) {
      if (!toastEl) return;
      toastEl.textContent = msg;
      toastEl.classList.add('on');
      if (_toastTimer) clearTimeout(_toastTimer);
      _toastTimer = setTimeout(() => toastEl.classList.remove('on'), ms || 7000);
    }
    // Status text was removed from the UI; this sink keeps existing status
    // assignments harmless (still visible in the console).
    const info = { set textContent(v) { try { console.log('[viewer]', v); } catch (e) {} } };
    scrub.max = Math.max(0, nFrames - 1);

    // Populate the display-model picker. The Citizen mapping is SMPL-X-22 only;
    // SOMA-77 clips still render as the procedural skeleton so finger chains are visible.
    for (const c of characters) {
      if (c.id !== 'skeleton' && (!quatData || nJoints !== 22)) continue;
      const opt = document.createElement('option');
      opt.value = c.id;
      opt.textContent = c.label;
      characterSel.appendChild(opt);
    }
    characterSel.value = 'skeleton';

    let frame = 0;
    let playing = true;
    let elapsedFrames = 0;
    let last = performance.now();

    function setSkeletonFrame(f) {
      const base = f * nJoints * 3;
      for (let i = 0; i < nJoints; i++) {
        const o = base + i * 3;
        dummy.position.set(jointData[o], jointData[o + 1], jointData[o + 2]);
        dummy.updateMatrix();
        jointMesh.setMatrixAt(i, dummy.matrix);
      }
      jointMesh.instanceMatrix.needsUpdate = true;
      let k = 0;
      for (const [i, p] of edges) {
        const po = base + p * 3;
        const io = base + i * 3;
        edgePositions[k++] = jointData[po];
        edgePositions[k++] = jointData[po + 1];
        edgePositions[k++] = jointData[po + 2];
        edgePositions[k++] = jointData[io];
        edgePositions[k++] = jointData[io + 1];
        edgePositions[k++] = jointData[io + 2];
      }
      edgeGeo.attributes.position.needsUpdate = true;
    }

    function showFrame(idx) {
      frame = ((idx % nFrames) + nFrames) % nFrames;
      if (mode === 'skeleton' || skelOverlay) setSkeletonFrame(frame);
      if (skelOverlay) updateNextTarget(frame);   // advance the red next-target skeleton
      if (mode !== 'skeleton' && character) {
        character.anim.applyFrame(quatData, rootData, frame);
        syncClothing();
      }
      syncCameraLock();
      scrub.value = String(frame);
      frameLabel.textContent = `${frame + 1} / ${nFrames}`;
    }

    const clothingRows = document.getElementById('clothing-rows');

    characterSel.onchange = async () => {
      const id = characterSel.value;
      if (id === 'skeleton') {
        mode = 'skeleton';
        skel.visible = true;
        applySkelOverlayStyle();
        if (character) character.root.visible = false;
        clothingRows.style.display = 'none';
        showFrame(frame);
        return;
      }
      const entry = characters.find(c => c.id === id);
      if (!entry) {
        characterSel.value = 'skeleton';
        mode = 'skeleton';
        skel.visible = true;
        if (character) character.root.visible = false;
        clothingRows.style.display = 'none';
        showFrame(frame);
        return;
      }
      info.textContent = `Loading ${entry.label}...`;
      if (character) character.root.visible = false;
      skel.visible = skelOverlay;
      showLoading();
      try {
        if (!charCache[id]) charCache[id] = await buildCharacter(entry);
        character = charCache[id];
        mode = id;
        showFrame(frame);                 // pose body + clothing while still HIDDEN
        // Dress FULLY before revealing — we never show a half-dressed citizen. If the
        // mesh or any garment stalls/fails (buildCharacter throws, or applyWorn returns
        // false), fall through to the catch: keep the skeleton and toast the user that a
        // refresh may be needed, rather than revealing an undressed/broken character.
        const dressed = character.dressed || await applyWorn();
        if (!dressed) throw new Error('clothing did not finish loading');
        character.dressed = true;
        character.root.visible = true;    // reveal the finished, fully-dressed character
        skel.visible = skelOverlay;
        applySkelOverlayStyle();           // x-ray the overlay bones over the mesh
        clothingRows.style.display = Object.keys(slotSelects).length ? '' : 'none';
        info.textContent = `${entry.label} - ${character.anim.pairs.length} joints retargeted`;
      } catch (e) {
        console.error(e);
        // Don't show the partially-loaded character — fall back to the skeleton (motion
        // still plays) and notify that a refresh may be needed to load the character.
        if (character) character.root.visible = false;
        info.textContent = `Could not load ${entry.label} — refresh to retry`;
        characterSel.value = 'skeleton';
        mode = 'skeleton';
        skel.visible = true;
        clothingRows.style.display = 'none';
        showFrame(frame);
        showToast('Couldn’t fully load the character — refresh the page to try again.');
      } finally {
        hideLoading();
      }
    };

    // Wardrobe dropdowns: one per clothing slot (None + the garments in that slot).
    // Changing one attaches/detaches live when a character is shown.
    async function onWardrobeChange(slot, id) {
      if (id) worn.set(slot, id); else worn.delete(slot);
      if (mode === 'skeleton' || !character) return;
      const item = id ? cfg.clothing.find(c => c.id === id) : null;
      if (item) await attachGarment(slot, item); else detachGarment(slot);
    }
    (function buildWardrobe() {
      const bySlot = {};
      for (const g of (cfg.clothing || [])) (bySlot[g.slot] = bySlot[g.slot] || []).push(g);
      let any = false;
      for (const [slot, label] of Object.entries(cfg.slots || {})) {
        const items = bySlot[slot];
        if (!items || !items.length) continue;
        if (!any) {
          const hdr = document.createElement('div');
          hdr.className = 'mhdr';
          hdr.textContent = 'Clothing';
          clothingRows.appendChild(hdr);
          any = true;
        }
        const row = document.createElement('div');
        row.className = 'mrow';
        const lab = document.createElement('span');
        lab.className = 'mlab';
        lab.textContent = label;
        const sel = document.createElement('select');
        const none = document.createElement('option');
        none.value = ''; none.textContent = 'None';
        sel.appendChild(none);
        for (const g of items) {
          const o = document.createElement('option');
          o.value = g.id; o.textContent = g.label;
          sel.appendChild(o);
        }
        sel.value = worn.get(slot) || '';
        sel.onchange = () => onWardrobeChange(slot, sel.value);
        slotSelects[slot] = sel;
        row.appendChild(lab); row.appendChild(sel);
        clothingRows.appendChild(row);
      }
    })();
    clothingRows.style.display = 'none';

    // --- In-viewer animation picker: fetch any clip's compact preview by URL and
    // swap the motion arrays without reloading the page when the joint count matches.
    const animSel = document.getElementById('animation');
    const animLabels = new Map((cfg.animations || []).map((a) => [a.id, a.label]));
    // currentId may be a 'kata:<root>' selector (auto-play a kata); curId (hoisted
    // above) stays a real clip id (or '' for a composite kata) for messages/label.
    function postParent(payload) { try { parent.postMessage(payload, '*'); } catch (e) {} }
    // The camera is framed ONCE per editing session (the first motion that loads), then
    // left alone as the user browses stances / edits moves. `keepCamera` payloads ask to
    // preserve the current view; a `camera-reframe` message re-arms the one-shot centering.
    let _didInitialFrame = false;
    function loadMotion(p) {
      // Skip clips with a different joint count rather than render them garbled.
      if ((p.num_joints || 0) !== nJoints) {
        console.warn('skipping clip: ' + (p.num_joints || 0) + ' joints, viewer expects ' + nJoints);
        return;
      }
      jointData = decodeFloat32(p.joint_data_b64);
      quatData = p.quat_data_b64 ? decodeFloat32(p.quat_data_b64) : null;
      rootData = p.root_data_b64 ? decodeFloat32(p.root_data_b64) : null;
      nFrames = p.preview_frames || 0;
      fps = p.preview_fps || p.fps || 30;
      scrub.max = Math.max(0, nFrames - 1);
      frame = 0; elapsedFrames = 0; last = performance.now();
      const _wasPos = camera.position.clone(), _wasTgt = controls.target.clone();   // previous view
      frameCamera();                                  // near/far + root-path geometry
      camera.position.copy(_wasPos); controls.target.copy(_wasTgt);   // restore the prior view
      if (p.keepCamera && _didInitialFrame) {
        // Keep the existing (already-framed) camera — just re-apply the drawer offset.
        controls.update(); applyViewOffset();
      } else {
        centerFullBody(true);                         // one-shot full-body framing (accounts for the drawer)
        _didInitialFrame = true;
      }
      showFrame(0);
      setCreatorLabel(p);
      setReferencePose(p.reference_pose || null);   // red target-pose skeleton (seeded clips)
      setTargetPoses(p.target_frames || null);      // red target skeletons at each kata seam
    }
    // Katas first (play the whole stitched sequence), then single moves. Kata
    // option values are prefixed 'kata:' and carry their spine path of clip ids.
    const kataIds = new Map();
    for (const k of (cfg.katas || [])) kataIds.set(k.root, k.ids || []);
    // (Re)build the picker options, optionally filtered by a query that matches
    // either the clip id or the visible label (case-insensitive). Native <select>
    // can't hide <option>s reliably, so we rebuild the list on each keystroke.
    function renderAnimOptions(q) {
      const query = (q || '').trim().toLowerCase();
      const match = (id, label) => !query
        || (id || '').toLowerCase().includes(query)
        || (label || '').toLowerCase().includes(query);
      const prev = animSel.value;
      animSel.textContent = '';
      let shown = 0;
      const katas = (cfg.katas || []).filter(k => match('kata:' + k.root, k.label));
      if (katas.length) {
        const kg = document.createElement('optgroup');
        kg.label = '▶ Katas (full sequence)';
        for (const k of katas) {
          const opt = document.createElement('option');
          opt.value = 'kata:' + k.root;
          opt.textContent = k.label + ' · ' + k.count + ' moves';
          kg.appendChild(opt); shown++;
        }
        animSel.appendChild(kg);
      }
      const anims = (cfg.animations || []).filter(a => match(a.id, a.label));
      if (anims.length) {
        const ag = document.createElement('optgroup');
        ag.label = 'Single moves';
        for (const a of anims) {
          const opt = document.createElement('option');
          // Lead with a short id chunk (the 6 hex chars after 'kmd_') so a picker
          // entry can be matched to a specific clip id; full id shows in the label.
          const shortId = (a.id || '').replace(/^kmd_/, '').slice(0, 6);
          opt.value = a.id; opt.textContent = (shortId ? shortId + ' · ' : '') + a.label;
          ag.appendChild(opt); shown++;
        }
        animSel.appendChild(ag);
      }
      if (!shown) {
        const opt = document.createElement('option');
        opt.value = ''; opt.disabled = true; opt.textContent = 'no matches';
        animSel.appendChild(opt);
      }
      // Keep the current selection if it's still visible after filtering.
      if (prev && [...animSel.options].some(o => o.value === prev)) animSel.value = prev;
    }
    renderAnimOptions('');
    const animFilter = document.getElementById('anim-filter');
    if (animFilter) animFilter.addEventListener('input', () => renderAnimOptions(animFilter.value));
    if (cfg.currentId) animSel.value = cfg.currentId;
    // Default-to-kata: if the picker is pointed at a kata, auto-play the whole
    // stitched sequence once the viewer has booted.
    if (animSel.value && animSel.value.indexOf('kata:') === 0) {
      setTimeout(() => { if (animSel.value.indexOf('kata:') === 0) animSel.onchange(); }, 60);
    }
    animSel.onchange = async () => {
      const id = animSel.value;
      if (!id) return;
      if (id.startsWith('kata:')) {
        // Whole kata: the parent drawer stitches the path client-side and posts
        // the result back as a 'load-payload'. Just request it here.
        const root = id.slice(5);
        const ids = kataIds.get(root) || [];
        if (ids.length) { showLoading(); postParent({ kind: 'play-kata', ids, label: animSel.options[animSel.selectedIndex].textContent }); }
        return;
      }
      if (!cfg.previewBase) return;
      showLoading();
      try {
        const r = await fetch(`${cfg.previewBase}/${encodeURIComponent(id)}.json`);
        if (!r.ok) throw new Error('HTTP ' + r.status);
        const payload = await r.json();
        if (!payload.prompt) payload.prompt = animLabels.get(id) || '';
        // Set the id BEFORE rendering so the on-screen label shows this clip's id
        // (not the previously-loaded one).
        payload.id = payload.id || id;
        curId = id;
        loadMotion(payload);
        // In-place clip switch (same iframe): only the highlight needs updating.
        // NOT 'kimodo-preview-ready' -- that would re-trigger clothing/actions work.
        postParent({ kind: 'kimodo-clip-changed', id: curId });
      } catch (err) {
        console.error('animation load failed', err);
      } finally {
        hideLoading();
      }
    };

    // Model + clothing are chosen in the page-level controls, which post
    // {kind:'model'|'clothing', ...} to drive the hidden controls' apply logic.
    window.addEventListener('message', (e) => {
      const m = e.data || {};
      if (m.kind === 'model') {
        const nextModel = [...characterSel.options].some(o => o.value === m.value) ? m.value : 'skeleton';
        characterSel.value = nextModel || 'skeleton';
        characterSel.onchange();
      } else if (m.kind === 'clothing') {
        const sel = slotSelects[m.slot];
        if (sel) sel.value = m.value || '';
        onWardrobeChange(m.slot, m.value || '');
      } else if (m.kind === 'load-animation' && m.id) {
        // Actions drawer asked to play a specific clip: reuse the picker path.
        animSel.value = m.id;
        animSel.onchange();
      } else if (m.kind === 'load-payload' && m.payload) {
        // Kata drawer / picker stitched a path client-side: play the arrays directly.
        curId = m.payload.id || '';
        loadMotion(m.payload);
        hideLoading();
        postParent({ kind: 'kimodo-clip-changed', id: curId });
      } else if (m.kind === 'viewport-inset') {
        // A left drawer is covering the left `left` px of the canvas — shift the
        // rendered scene right so the character stays centered in the visible area.
        viewportInsetLeft = Math.max(0, Number(m.left) || 0);
        applyViewOffset();
      } else if (m.kind === 'dojo-scene') {
        const scenePayload = m.scene || {};
        const img = m.image || scenePayload.image || scenePayload.panorama_image || '';
        const splat = m.splat || scenePayload.splat || scenePayload.splat_url || '';
        const settings = { room_size: scenePayload.room_size, room_height: scenePayload.room_height };
        const renderMode = scenePayload.render_mode || scenePayload.mode || (splat ? 'splat' : 'panorama');
        if (renderMode === 'splat' && splat) {
          if (scenePayload.use_panorama_skybox && img) applyDojoScene(img, settings);
          else clearDojoScene();
          applyDojoSplat(splat, settings);
        } else if (img) {
          clearDojoSplat();
          applyDojoScene(img, settings);
        }
      } else if (m.kind === 'dojo-room-settings') {
        applyDojoRoomSettings(m.settings || {});
      } else if (m.kind === 'dojo-clear') {
        clearDojoScene();
        clearDojoSplat();
      } else if (m.kind === 'place-pose') {
        placeShow(m.posed, m.startPosed, m.parents, m.tx || 0, m.tz || 0, m.rot || 0, m.base, m.startVis, m.endVis);
      } else if (m.kind === 'place-vis') {
        // Grow/shrink the SKELETONS only; the gizmos (pose controls) stay put.
        if (typeof m.start === 'boolean') { placeStartVis = m.start; placeSetVisible(placeStartGroup, m.start); }
        if (typeof m.end === 'boolean') { placeEndVis = m.end; placeSetVisible(placeEndSkel, m.end); }
      } else if (m.kind === 'place-clear') {
        placeHide();
      } else if (m.kind === 'transport') {
        // Action card play-row drives the viewer's playback.
        if (m.action === 'play' || (m.action === 'toggle' && !playing)) {
          playing = true; playBtn.textContent = 'Pause'; elapsedFrames = frame; last = performance.now();
        } else if (m.action === 'pause' || (m.action === 'toggle' && playing)) {
          playing = false; playBtn.textContent = 'Play';
        } else if (m.action === 'seek' && typeof m.frame === 'number') {
          playing = false; playBtn.textContent = 'Play'; elapsedFrames = m.frame; showFrame(m.frame);
        }
      } else if (m.kind === 'camera-lock') {
        // Parent center/lock button: center + frame the full body and follow, or free.
        cameraLocked = !!m.on;
        if (cameraLocked) centerFullBody(true);
        updateCameraLockButton();
      } else if (m.kind === 'camera-reframe') {
        // Re-arm the one-shot framing so the NEXT motion load re-centers (new session).
        _didInitialFrame = false;
      }
    });

    playBtn.onclick = () => {
      playing = !playing;
      playBtn.textContent = playing ? 'Pause' : 'Play';
      elapsedFrames = frame;
      last = performance.now();
    };
    scrub.oninput = () => {
      playing = false;
      playBtn.textContent = 'Play';
      elapsedFrames = Number(scrub.value);
      showFrame(elapsedFrames);
    };

    // When a left drawer covers `viewportInsetLeft` px, offset the projection so the
    // world center maps to the middle of the still-visible region (right of the
    // drawer) — the character appears centered again. 0 = no drawer = clear offset.
    let viewportInsetLeft = 0;
    function applyViewOffset() {
      // Do NOT compensate for the sidebar — just center the character in the full canvas
      // (looks fine with the bar shown or hidden, and avoids the off-center artifacts a
      // projection shift introduced).
      camera.clearViewOffset();
      camera.updateProjectionMatrix();
    }
    function resize() {
      const w = app.clientWidth || 1;
      const h = app.clientHeight || 1;
      renderer.setSize(w, h, false);
      camera.aspect = w / h;
      applyViewOffset();   // re-applies the drawer offset (or clears) + updateProjectionMatrix
    }
    window.addEventListener('resize', resize);
    resize();
    frameCamera();
    centerFullBody(false);   // initial full-body framing (immediate, no fly)

    // Decide the starting model BEFORE the first render so the skeleton never
    // flashes when the citizen is the default: hide the skeleton up front and
    // let the citizen appear once it's built (clothing streams in after).
    const startCharacter = (quatData && nJoints === 22 && cfg.defaultCharacter && characters.some(c => c.id === cfg.defaultCharacter))
      ? cfg.defaultCharacter : 'skeleton';
    if (startCharacter !== 'skeleton') {
      skel.visible = false;
      characterSel.value = startCharacter;
      characterSel.onchange();
    } else {
      showFrame(0);
    }

    // Tell the parent the viewer is ready (with the clip id) so the Actions
    // drawer can refresh + know which clip is showing.
    postParent({ kind: 'kimodo-preview-ready', id: curId });

    let lastPost = 0;
    function tick(now) {
      if (disposed) return;
      const dt = Math.min(0.1, (now - last) / 1000);
      last = now;
      if (playing && nFrames > 1) {
        elapsedFrames += dt * fps * Number(speed.value);
        const target = Math.floor(elapsedFrames) % nFrames;
        if (target !== frame) showFrame(target);
      }
      // Stream playback state to the parent so a card's play-row can track it.
      if (now - lastPost > 120) {
        lastPost = now;
        postParent({ kind: 'kimodo-frame', id: curId, frame, playing, num_frames: nFrames });
      }
      _camAnimTick(dt);   // glide the camera into a new framing
      _placeAnimTick();   // grow/shrink place skeletons
      _dojoSplatGrowTick(dt);   // grow the dojo splat in on first load
      controls.update();
      renderer.render(scene, camera);
      requestAnimationFrame(tick);
    }
    requestAnimationFrame(tick);

    // Gradio replaces this whole iframe on each (re)render. Without releasing the
    // WebGL context the browser accumulates them and eventually blocks new ones
    // ("Web page caused context loss and was blocked"). Stop the loop and free the
    // GPU context the moment this iframe is torn down.
    function teardownViewer() {
      if (disposed) return;
      disposed = true;
      try { controls.dispose(); } catch (e) {}
      try { renderer.forceContextLoss(); } catch (e) {}
      try { renderer.dispose(); } catch (e) {}
    }
    window.addEventListener('pagehide', teardownViewer);
    window.addEventListener('beforeunload', teardownViewer);