3D Tiles Bim

<!--
  示例：BIM 建筑的逐层呈现
  说明：八层楼体自下而上逐层显示，一层停 0.9 秒，全部出现后重置
  核心逻辑：盒体按层高堆叠 → entity.show 控制显隐 → setTimeout 推进楼层
  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>BIM 建筑的逐层呈现</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">楼层自下而上出现，全部显示后清空重来。真实 BIM 数据用楼层属性过滤或裁剪平面剖切。</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 floorCount = 8, floorH = 4;
  var palette = ['#3f4d62', '#47566d', '#4f5f78', '#576883'];
  var floors = [];

  for (var i = 0; i < floorCount; i++) {
    var e = viewer.entities.add({
      position: Cesium.Cartesian3.fromDegrees(116.391, 39.907, i * floorH + floorH / 2),
      box: {
        dimensions: new Cesium.Cartesian3(26, 20, floorH * 0.92),
        material: Cesium.Color.fromCssColorString(palette[i % palette.length]),
        outline: true,
        outlineColor: Cesium.Color.fromCssColorString('#0b0f14')
      },
      show: false
    });
    floors.push(e);
  }

  var idx = 0;
  function next() {
    if (idx < floors.length) {
      floors[idx].show = true;
      idx++;
      setTimeout(next, 900);
    } else {
      setTimeout(function () { floors.forEach(function (f) { f.show = false; }); idx = 0; next(); }, 2600);
    }
  }
  next();

  viewer.camera.flyTo({
    destination: Cesium.Cartesian3.fromDegrees(116.3862, 39.9008, 190),
    orientation: { heading: Cesium.Math.toRadians(38), pitch: Cesium.Math.toRadians(-10), roll: 0 },
    duration: 0
  });
})();
</script>
</body>
</html>