Czml Model Node Transformations

<!--
  示例：CZML 平移与缩放节点
  说明：CZML 同时对同一个模型的子节点做平移与缩放，做出伸缩的机械臂
  核心逻辑：nodeTransformations.translation / scale / rotation 三类关键帧
  依赖：CesiumJS 1.121 · jsDelivr CDN
-->
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta name="robots" content="noindex,follow">
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>CZML 平移与缩放节点</title>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/cesium@1.121.0/Build/Cesium/Widgets/widgets.css">
<style>
  html,body{height:100%;margin:0}
  body{background:#0e1116;color:#e6e8ec;overflow:hidden;
       font:13px/1.6 -apple-system,"Segoe UI","PingFang SC",sans-serif}
  #c{height:100%}
  .tip{position:absolute;left:12px;top:12px;z-index:5;
       background:rgba(23,28,35,.9);border:1px solid #2a313b;border-radius:6px;
       padding:8px 12px;font-size:12px;color:#a2a9b6;max-width:320px;line-height:1.6}

  .cesium-viewer-bottom .cesium-widget-credits,.cesium-viewer-animationContainer,
  .cesium-viewer-timelineContainer{display:none!important}
</style>
</head>
<body>
<div id="c"></div>
<div class="tip">机械臂在伸长与缩短之间往复，位移和缩放都由 CZML 关键帧给出。</div>
<script src="https://cdn.jsdelivr.net/npm/cesium@1.121.0/Build/Cesium/Cesium.js"></script>
<script>
(function () {
  'use strict';

  var viewer = new Cesium.Viewer('c', {
    baseLayer: false,
    baseLayerPicker: false, geocoder: false, homeButton: false,
    sceneModePicker: false, navigationHelpButton: false,
    animation: false, timeline: false, fullscreenButton: false,
    infoBox: false, selectionIndicator: false
  });

  var scene = viewer.scene;
  scene.globe.baseColor = Cesium.Color.fromCssColorString('#1c2733');
  scene.backgroundColor = Cesium.Color.fromCssColorString('#0e1116');
  scene.skyBox.show = false;
  scene.sun.show = false;
  scene.moon.show = false;
  if (scene.skyAtmosphere) scene.skyAtmosphere.show = false;

  function glbBytes(json, bin) {
    var jb = new TextEncoder().encode(JSON.stringify(json));
    var jpad = (4 - jb.length % 4) % 4, bpad = (4 - bin.length % 4) % 4;
    var jl = jb.length + jpad, bl = bin.length + bpad;
    var out = new Uint8Array(12 + 8 + jl + 8 + bl), dv = new DataView(out.buffer);
    dv.setUint32(0, 0x46546c67, true); dv.setUint32(4, 2, true); dv.setUint32(8, out.length, true);
    dv.setUint32(12, jl, true); dv.setUint32(16, 0x4e4f534a, true); out.set(jb, 20);
    for (var i = 0; i < jpad; i++) out[20 + jb.length + i] = 0x20;
    dv.setUint32(20 + jl, bl, true); dv.setUint32(24 + jl, 0x004e4942, true); out.set(bin, 28 + jl);
    return out;
  }

  function armGlb() {
    var faces = [
      [[1, 0, 1], [1, 0, 0], [1, 1, 0], [1, 1, 1], [1, 0, 0]],
      [[0, 0, 0], [0, 0, 1], [0, 1, 1], [0, 1, 0], [-1, 0, 0]],
      [[0, 1, 1], [1, 1, 1], [1, 1, 0], [0, 1, 0], [0, 1, 0]],
      [[0, 0, 0], [1, 0, 0], [1, 0, 1], [0, 0, 1], [0, -1, 0]],
      [[0, 0, 1], [1, 0, 1], [1, 1, 1], [0, 1, 1], [0, 0, 1]],
      [[1, 0, 0], [0, 0, 0], [0, 1, 0], [1, 1, 0], [0, 0, -1]]
    ];
    var pos = [], nor = [], idx = [], base = 0;
    faces.forEach(function (f) {
      for (var i = 0; i < 4; i++) { pos.push(f[i][0], f[i][1], f[i][2]); nor.push(f[4][0], f[4][1], f[4][2]); }
      idx.push(base, base + 1, base + 2, base, base + 2, base + 3);
      base += 4;
    });
    var p = new Float32Array(pos), n = new Float32Array(nor), ix = new Uint16Array(idx);
    var pb = p.byteLength, nb = n.byteLength, ib = ix.byteLength;
    var bin = new Uint8Array(pb + nb + ib);
    bin.set(new Uint8Array(p.buffer), 0);
    bin.set(new Uint8Array(n.buffer), pb);
    bin.set(new Uint8Array(ix.buffer), pb + nb);
    var json = {
      asset: { version: '2.0' }, scene: 0, scenes: [{ nodes: [0, 1] }],
      nodes: [
        { name: 'mount', mesh: 0, scale: [1.2, 1.2, 1.2] },
        { name: 'arm', mesh: 0, translation: [0.6, 1.2, 0.6], scale: [3, 0.2, 0.2] }
      ],
      meshes: [{ primitives: [{ attributes: { POSITION: 0, NORMAL: 1 }, indices: 2, material: 0 }] }],
      materials: [{ pbrMetallicRoughness: {
        baseColorFactor: [0.45, 0.62, 0.78, 1], metallicFactor: 0.35, roughnessFactor: 0.5
      }, doubleSided: true }],
      accessors: [
        { bufferView: 0, componentType: 5126, count: 24, type: 'VEC3', min: [0, 0, 0], max: [1, 1, 1] },
        { bufferView: 1, componentType: 5126, count: 24, type: 'VEC3' },
        { bufferView: 2, componentType: 5123, count: 36, type: 'SCALAR' }
      ],
      bufferViews: [
        { buffer: 0, byteOffset: 0, byteLength: pb, target: 34962 },
        { buffer: 0, byteOffset: pb, byteLength: nb, target: 34962 },
        { buffer: 0, byteOffset: pb + nb, byteLength: ib, target: 34963 }
      ],
      buffers: [{ byteLength: pb + nb + ib }]
    };
    return new Blob([glbBytes(json, bin)], { type: 'model/gltf-binary' });
  }

  var modelUrl = URL.createObjectURL(armGlb());

  var czml = [
    {
      id: 'document', name: 'czml-node', version: '1.0',
      clock: {
        interval: '2026-10-28T00:00:00Z/2026-10-28T00:00:10Z',
        currentTime: '2026-10-28T00:00:00Z',
        multiplier: 1, range: 'LOOP_STOP'
      }
    },
    {
      id: 'robot',
      name: '机械臂',
      position: { cartographicDegrees: [116.3895, 39.9035, 0] },
      model: {
        gltf: modelUrl,
        minimumPixelSize: 60,
        runAnimations: false,
        nodeTransformations: {
          arm: {
            translation: {
              epoch: '2026-10-28T00:00:00Z',
              cartesian: [0, 0.6, 1.2, 0.6, 5, 3.4, 1.2, 0.6, 10, 0.6, 1.2, 0.6]
            },
            scale: {
              epoch: '2026-10-28T00:00:00Z',
              cartesian: [0, 3, 0.2, 0.2, 5, 5.4, 0.3, 0.3, 10, 3, 0.2, 0.2]
            }
          }
        }
      }
    }
  ];

  viewer.clock.shouldAnimate = true;
  var ds = viewer.dataSources.add(Cesium.CzmlDataSource.load(czml));
  ds.then(function (dataSource) {
    viewer.zoomTo(dataSource.entities.getById('robot'), new Cesium.HeadingPitchRange(
      Cesium.Math.toRadians(28), Cesium.Math.toRadians(-10), 110
    ));
  });
  /* 相机在数据加载完成后由 zoomTo 设置 */
})();
</script>
</body>
</html>