Multiple Synced Views

<!--
  示例：双屏同步视角
  说明：左右两个视图共享同一个相机，拖动左侧右侧同步跟随
  核心逻辑：两个 Viewer → 同一个相机状态 → postRender 同步
  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>双屏同步视角</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}

  #c{width:50%}
  #c2{position:absolute;right:0;top:0;width:50%;height:100%;
      border-left:1px solid #2a313b}
  .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">在左半边拖动或缩放，右半边的视角会同步变化。</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;

  var right = document.createElement('div');
  right.id = 'c2';
  document.body.appendChild(right);

  var options = {
    baseLayer: false,
    baseLayerPicker: false, geocoder: false, homeButton: false,
    sceneModePicker: false, navigationHelpButton: false,
    animation: false, timeline: false, fullscreenButton: false,
    infoBox: false, selectionIndicator: false
  };
  var viewer2 = new Cesium.Viewer('c2', options);

  [viewer, viewer2].forEach(function (v) {
    v.scene.globe.baseColor = Cesium.Color.fromCssColorString('#1c2733');
    v.scene.backgroundColor = Cesium.Color.fromCssColorString('#0e1116');
    v.scene.skyBox.show = false;
    v.scene.sun.show = false;
    v.scene.moon.show = false;
    if (v.scene.skyAtmosphere) v.scene.skyAtmosphere.show = false;

    for (var i = 0; i < 8; i++) {
      v.entities.add({
        position: Cesium.Cartesian3.fromDegrees(116.3852 + i * 0.0011, 39.9020, 20),
        box: {
          dimensions: new Cesium.Cartesian3(28, 24, 40),
          material: Cesium.Color.fromCssColorString('#56677d')
        }
      });
    }
  });

  /* 左视图每帧把相机状态写给右视图 */
  scene.postRender.addEventListener(function () {
    viewer2.camera.setView({
      destination: viewer.camera.positionWC,
      orientation: {
        direction: viewer.camera.directionWC,
        up: viewer.camera.upWC
      }
    });
  });
  viewer.camera.flyTo({
    destination: Cesium.Cartesian3.fromDegrees(116.3930, 39.8986, 380),
    orientation: { heading: Cesium.Math.toRadians(18), pitch: Cesium.Math.toRadians(-22), roll: 0 },
    duration: 0
  });
})();
</script>
</body>
</html>