Web Map Tile Service with Time

<!--
  示例：带时间的 WMTS 图层
  说明：按时间维度切换影像，时钟推进时图层内容随之变化
  核心逻辑：两帧离线影像 → 时钟推进 → 按时间切换图层显隐
  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>带时间的 WMTS 图层</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">时钟在走，影像按时间切换；真实 WMTS 用 time 参数让服务端返回对应时次。</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 frameImage(hue) {
    var W = 512, H = 384;
    var c = document.createElement('canvas');
    c.width = W; c.height = H;
    var ctx = c.getContext('2d');
    ctx.fillStyle = 'hsl(' + hue + ',30%,18%)';
    ctx.fillRect(0, 0, W, H);
    for (var i = 0; i < 90; i++) {
      ctx.fillStyle = 'hsla(' + hue + ',70%,60%,' + (0.15 + Math.random() * 0.5) + ')';
      var x = Math.random() * W, y = Math.random() * H;
      ctx.beginPath();
      ctx.ellipse(x, y, 14 + Math.random() * 40, 8 + Math.random() * 20, 0.6, 0, Math.PI * 2);
      ctx.fill();
    }
    return c.toDataURL('image/png');
  }

  var rect = Cesium.Rectangle.fromDegrees(115.9, 39.5, 116.9, 40.2);
  var frames = [frameImage(205), frameImage(28), frameImage(120)];
  var layers = [];

  for (var i = 0; i < frames.length; i++) {
    layers.push(viewer.imageryLayers.addImageryProvider(
      new Cesium.SingleTileImageryProvider({ url: frames[i], rectangle: rect })
    ));
  }

  /* 三个时次轮流显示，每 3 秒切一帧 */
  var index = 0, elapsed = 0;
  scene.preRender.addEventListener(function (s, t) {
    elapsed += 1 / 60;
    if (elapsed < 3) return;
    elapsed = 0;
    index = (index + 1) % layers.length;
    for (var k = 0; k < layers.length; k++) { layers[k].show = (k === index); }
  });
  viewer.camera.flyTo({
    destination: Cesium.Rectangle.fromDegrees(115.9, 39.5, 116.9, 40.2),
    duration: 0
  });
})();
</script>
</body>
</html>