Show or Hide Entities

<!--
  示例：批量显示与隐藏
  说明：三排建筑按 1.4 秒切换显示，只切换父实体的 show 属性
  核心逻辑：父实体 Entity + 子实体 → parent.show = false 连带隐藏全部子实体
  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>批量显示与隐藏</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">三排建筑轮流出现，靠的是父实体上的 show 开关，而不是逐个改子实体。</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 rows = [
    { lat: 39.9056, color: '#4d86c8' },
    { lat: 39.9038, color: '#5bb08a' },
    { lat: 39.9020, color: '#d08a4e' }
  ];
  var parents = [];

  rows.forEach(function (r) {
    var parent = viewer.entities.add(new Cesium.Entity());
    parents.push(parent);
    for (var i = 0; i < 5; i++) {
      viewer.entities.add({
        parent: parent,
        position: Cesium.Cartesian3.fromDegrees(116.3862 + i * 0.0016, r.lat, 14),
        box: {
          dimensions: new Cesium.Cartesian3(11, 11, 28),
          material: Cesium.Color.fromCssColorString(r.color).withAlpha(0.9),
          outline: true,
          outlineColor: Cesium.Color.fromCssColorString('#0e1116')
        }
      });
    }
  });

  var idx = -1;
  setInterval(function () {
    idx = (idx + 1) % parents.length;
    parents.forEach(function (p, i) { p.show = (i === idx); });
  }, 1400);
  viewer.camera.flyTo({
    destination: Cesium.Cartesian3.fromDegrees(116.3905, 39.8990, 420),
    orientation: { heading: Cesium.Math.toRadians(0), pitch: Cesium.Math.toRadians(-30), roll: 0 },
    duration: 0
  });
})();
</script>
</body>
</html>