Czml Polygon Intervals

<!--
  示例：CZML 多边形按时间分段显示与换色
  说明：availability 决定对象在不在，material 的 color 数组按 interval 换色，中间留空档测试消失
  核心逻辑：CzmlDataSource.load → clock 往返播放 → 观察颜色与显示状态切换
  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 多边形分时段</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%}
  .cesium-viewer-bottom .cesium-widget-credits,.cesium-viewer-animationContainer,
  .cesium-viewer-timelineContainer{display:none!important}
</style>
</head>
<body>
<div id="c"></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.moon.show = false;
  if (scene.skyAtmosphere) scene.skyAtmosphere.show = false;

  var start = Cesium.JulianDate.fromIso8601('2026-10-28T00:00:00Z');
  var stop = Cesium.JulianDate.addSeconds(start, 90, new Cesium.JulianDate());

  viewer.clock.startTime = start.clone();
  viewer.clock.stopTime = stop.clone();
  viewer.clock.currentTime = start.clone();
  viewer.clock.clockRange = Cesium.ClockRange.LOOP_STOP;
  viewer.clock.multiplier = 2;
  viewer.clock.shouldAnimate = true;

  var data = [
    {
      id: 'document',
      name: '多边形分时段',
      version: '1.0',
      clock: {
        interval: '2026-10-28T00:00:00Z/2026-10-28T00:01:30Z',
        currentTime: '2026-10-28T00:00:00Z',
        multiplier: 2,
        range: 'LOOP_STOP'
      }
    },
    {
      id: 'stage-polygon',
      name: '分时段多边形',
      availability: '2026-10-28T00:00:00Z/2026-10-28T00:01:30Z',
      position: { cartographicDegrees: [116.392, 39.900, 0] },
      polygon: {
        positions: {
          cartographicDegrees: [
            116.356, 39.882, 0,
            116.428, 39.884, 0,
            116.430, 39.922, 0,
            116.354, 39.918, 0
          ]
        },
        height: 0,
        material: {
          solidColor: {
            color: [
              { interval: '2026-10-28T00:00:00Z/2026-10-28T00:00:30Z', rgba: [77, 155, 255, 165] },
              { interval: '2026-10-28T00:00:30Z/2026-10-28T00:00:55Z', rgba: [241, 196, 90, 165] },
              { interval: '2026-10-28T00:00:55Z/2026-10-28T00:01:20Z', rgba: [228, 92, 122, 165] },
              { interval: '2026-10-28T00:01:20Z/2026-10-28T00:01:30Z', rgba: [57, 192, 160, 165] }
            ]
          }
        },
        outline: true,
        outlineColor: { rgba: [225, 238, 252, 230] }
      }
    },
    {
      id: 'caption',
      position: { cartographicDegrees: [116.392, 39.878, 0] },
      label: {
        text: '蓝 0-30s · 黄 30-55s · 红 55-80s · 绿 80-90s',
        font: '500 13px "Microsoft YaHei", sans-serif',
        fillColor: { rgba: [216, 230, 246, 255] },
        disableDepthTestDistance: Number.POSITIVE_INFINITY
      }
    }
  ];

  Cesium.CzmlDataSource.load(data).then(function (ds) {
    viewer.dataSources.add(ds);
  });

  viewer.camera.flyTo({
    destination: Cesium.Cartesian3.fromDegrees(116.392, 39.862, 14000),
    orientation: {
      heading: 0,
      pitch: Cesium.Math.toRadians(-46),
      roll: 0
    },
    duration: 0
  });
})();
</script>
</body>
</html>