3D Tiles Feature Picking

<!--
  示例：要素拾取与属性查询
  说明：16 栋建筑各带四条属性，点击后在左下角浮层显示
  核心逻辑：entity.properties 挂数据 → ScreenSpaceEventHandler 监听左键 → scene.pick → getValue
  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>要素拾取与属性查询</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}
  .info{position:absolute;left:12px;bottom:12px;z-index:6;background:rgba(23,28,35,.92);
       border:1px solid #2a313b;border-radius:6px;padding:8px 12px;font-size:12px;
       color:#a2a9b6;line-height:1.8;max-width:220px}
  .info b{color:#e6e8ec}
</style>
</head>
<body>
<div id="c"></div>
<div class="tip">点任意建筑，左下角显示它的编号、类型、高度与体量。点空白处浮层关闭。</div>
<div id="info" class="info">点击任意一栋建筑</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 seed = 17;
  function rnd() { seed = (seed * 9301 + 49297) % 233280; return seed / 233280; }

  var palette = ['#4d7cff', '#3ecf8e', '#ffb44d', '#a78bfa'];
  var kinds = ['办公', '住宅', '商业', '配套'];

  for (var i = 0; i < 16; i++) {
    var lon = 116.3868 + (i % 4) * 0.0026;
    var lat = 39.9036 + Math.floor(i / 4) * 0.0024;
    var h = 18 + rnd() * 48;
    var kind = kinds[i % kinds.length];
    viewer.entities.add({
      position: Cesium.Cartesian3.fromDegrees(lon, lat, h / 2),
      box: {
        dimensions: new Cesium.Cartesian3(28, 26, h),
        material: Cesium.Color.fromCssColorString(palette[i % palette.length]).withAlpha(0.85),
        outline: true,
        outlineColor: Cesium.Color.WHITE.withAlpha(0.3)
      },
      properties: {
        name: 'B-' + (i + 1),
        kind: kind,
        height: Math.round(h) + ' 米',
        area: Math.round(28 * 26 * h / 1000) + ' 千立方米'
      }
    });
  }

  var info = document.getElementById('info');
  var handler = new Cesium.ScreenSpaceEventHandler(scene.canvas);
  handler.setInputAction(function (click) {
    var picked = scene.pick(click.position);
    if (!picked || !picked.id) {
      info.style.display = 'none';
      return;
    }
    var p = picked.id.properties;
    info.style.display = 'block';
    info.innerHTML =
      '<b>' + p.name.getValue() + '</b><br>' +
      '类型：' + p.kind.getValue() + '<br>' +
      '高度：' + p.height.getValue() + '<br>' +
      '体量：' + p.area.getValue();
  }, Cesium.ScreenSpaceEventType.LEFT_CLICK);

  viewer.camera.flyTo({
    destination: Cesium.Cartesian3.fromDegrees(116.3925, 39.8990, 760),
    orientation: { heading: Cesium.Math.toRadians(6), pitch: Cesium.Math.toRadians(-30), roll: 0 },
    duration: 0
  });
})();
</script>
</body>
</html>