Czml Animated Property

<!--
  示例：CZML 的属性随时间自动变化
  要点：color 与 pixelSize 用 epoch 加采样数组声明，clock 推进时数值自动插值
  依赖：CesiumJS 1.121 · jsDelivr CDN，CZML 写在页面里，无外部数据
-->
<!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 属性动画</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%}
  .hud{position:absolute;left:12px;top:12px;z-index:5;background:rgba(23,28,35,.9);
       border:1px solid #2a313b;border-radius:6px;padding:9px 12px;font-size:12px;
       color:#a2a9b6;max-width:250px}
  .hud b{color:#e6e8ec;font-weight:600}
  .hud .row{margin-top:6px}
  .hud button{font:inherit;font-size:12px;padding:3px 9px;margin-right:4px;border-radius:4px;
       cursor:pointer;border:1px solid #343b46;background:#1d232b;color:#cfd6e2}
  .cesium-viewer-bottom .cesium-widget-credits,.cesium-viewer-animationContainer,
  .cesium-viewer-timelineContainer{display:none!important}
</style>
</head>
<body>
<div id="c"></div>
<div class="hud">
  <div><b>CZML 属性动画</b></div>
  <div class="row" id="state">属性随 clock 变化</div>
  <div class="row">
    <button id="toggle">暂停</button>
    <button id="restart">重播</button>
  </div>
  <div class="row">126 秒一轮 · 颜色 3 个关键帧</div>
</div>
<script src="https://cdn.jsdelivr.net/npm/cesium@1.121.0/Build/Cesium/Cesium.js"></script>
<script>
(function () {
  'use strict';

  var START = '2026-03-01T08:00:00Z';
  var STOP = '2026-03-01T08:02:06Z';

  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;

  /* 半径、颜色、大小的采样都以 epoch 为时间零点 */
  var czml = [
    {
      id: 'document',
      version: '1.0',
      clock: {
        interval: START + '/' + STOP,
        currentTime: START,
        multiplier: 4,
        range: 'LOOP_STOP',
        step: 'SYSTEM_CLOCK_MULTIPLIER'
      }
    },
    {
      id: 'pulse',
      name: '脉冲点',
      availability: START + '/' + STOP,
      position: { cartographicDegrees: [116.389, 39.906, 240] },
      point: {
        pixelSize: { epoch: START, number: [0, 10, 30, 30, 60, 10, 90, 30, 126, 10] },
        color: {
          epoch: START,
          rgba: [
            0, 90, 200, 255, 255,
            42, 120, 235, 255, 255,
            63, 255, 255, 255, 255,
            105, 95, 208, 168, 255,
            126, 90, 200, 255, 255
          ]
        },
        outlineColor: { rgba: [255, 255, 255, 160] },
        outlineWidth: 2
      },
      label: {
        text: '属性动画',
        font: '600 13px sans-serif',
        fillColor: { rgba: [255, 255, 255, 255] },
        pixelOffset: { cartesian2: [0, -28] }
      }
    }
  ];

  Cesium.CzmlDataSource.load(czml).then(function (ds) {
    viewer.dataSources.add(ds);
    viewer.clock.startTime = Cesium.JulianDate.fromIso8601(START);
    viewer.clock.stopTime = Cesium.JulianDate.fromIso8601(STOP);
    viewer.clock.currentTime = Cesium.JulianDate.fromIso8601(START);
    viewer.clock.multiplier = 4;
    viewer.clock.clockRange = Cesium.ClockRange.LOOP_STOP;
    viewer.clock.shouldAnimate = true;
  });

  /* 参考点位，衬托脉冲点的位置 */
  var RING = [
    [116.377, 39.906], [116.389, 39.894], [116.401, 39.906], [116.389, 39.918]
  ];
  RING.forEach(function (p) {
    viewer.entities.add({
      position: Cesium.Cartesian3.fromDegrees(p[0], p[1]),
      point: { pixelSize: 5, color: Cesium.Color.fromCssColorString('#3f5a78') }
    });
  });

  var paused = false;
  document.getElementById('toggle').addEventListener('click', function () {
    paused = !paused;
    viewer.clock.shouldAnimate = !paused;
    this.textContent = paused ? '继续' : '暂停';
    document.getElementById('state').textContent = paused ? '已暂停' : '属性随 clock 变化';
  });

  document.getElementById('restart').addEventListener('click', function () {
    viewer.clock.currentTime = Cesium.JulianDate.fromIso8601(START);
    paused = false;
    viewer.clock.shouldAnimate = true;
    document.getElementById('toggle').textContent = '暂停';
  });

  viewer.camera.flyTo({
    destination: Cesium.Cartesian3.fromDegrees(116.389, 39.890, 1900),
    orientation: {
      heading: 0,
      pitch: Cesium.Math.toRadians(-16),
      roll: 0
    },
    duration: 0
  });
})();
</script>
</body>
</html>