3D Tiles Adjust Height

<!--
  示例：整体调整模型高度
  说明：15 个建筑盒体共享同一个高度偏移量，偏移由正弦函数逐帧更新
  核心逻辑：CallbackProperty 逐帧返回坐标 → offset 变量统一抬升 → postRender 驱动
  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>整体调整模型高度</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">建筑整体上下浮动 40 米。真实数据用 tileset.modelMatrix 左乘平移矩阵即可整体位移。</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 offset = 0;

  var seed = 33;
  function rnd() { seed = (seed * 9301 + 49297) % 233280; return seed / 233280; }

  for (var r = 0; r < 3; r++) {
    for (var c = 0; c < 5; c++) {
      (function (lon, lat, h, w) {
        viewer.entities.add({
          position: new Cesium.CallbackProperty(function () {
            return Cesium.Cartesian3.fromDegrees(lon, lat, h / 2 + offset);
          }, false),
          box: {
            dimensions: new Cesium.Cartesian3(w, w, h),
            material: Cesium.Color.fromCssColorString('#4b5b73'),
            outline: true,
            outlineColor: Cesium.Color.fromCssColorString('#0b0f14')
          }
        });
      })(116.3868 + c * 0.0022, 39.9038 + r * 0.0020, 14 + rnd() * 30, 20 + rnd() * 10);
    }
  }

  scene.postRender.addEventListener(function () {
    offset = Math.sin(performance.now() * 0.001) * 40;
  });

  viewer.camera.flyTo({
    destination: Cesium.Cartesian3.fromDegrees(116.3850, 39.9000, 520),
    orientation: { heading: Cesium.Math.toRadians(12), pitch: Cesium.Math.toRadians(-18), roll: 0 },
    duration: 0
  });
})();
</script>
</body>
</html>