Arcgis Elevation Terrain

<!--
  示例：用自定义高程地形提供者生成山脉
  说明：CustomHeightmapTerrainProvider 按瓦片回调返回高度数组，地形完全由数学函数算出，不请求任何地形服务
  核心逻辑：tileXYToRectangle 取经纬度范围 → 正弦叠加算高程 → Float32Array 交给 provider → 赋给 terrainProvider
  依赖：CesiumJS 1.121 · jsDelivr CDN，无 DEM 数据与 ion Token
-->
<!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>代码生成高程地形</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%}
  .hud{position:absolute;left:12px;top:12px;z-index:5;background:rgba(23,28,35,.9);
       border:1px solid #2a313b;border-radius:6px;padding:9px 12px;font-size:12px;
       color:#a2a9b6;max-width:260px}
  .hud b{color:#e6e8ec;font-weight:600}
  .hud .row{margin-top:7px}
  input[type=range]{width:100%}
  .cesium-viewer-bottom .cesium-widget-credits,.cesium-viewer-animationContainer,
  .cesium-viewer-timelineContainer{display:none!important}
</style>
</head>
<body>
<div id="c"></div>
<div class="hud">
  <div><b>程序化高程地形</b></div>
  <div class="row">采样 32 × 32，按瓦片实时计算</div>
  <div class="row">高程振幅 <span id="ampVal">1400</span> 米</div>
  <div class="row"><input id="amp" type="range" min="200" max="3000" step="100" value="1400"></div>
  <div class="row">黄色折线表示贴地效果</div>
</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('#243040');
  scene.backgroundColor = Cesium.Color.fromCssColorString('#0e1116');
  scene.skyBox.show = false;
  scene.moon.show = false;
  if (scene.skyAtmosphere) scene.skyAtmosphere.show = false;
  scene.globe.enableLighting = true;

  var scheme = new Cesium.GeographicTilingScheme();
  var W = 32;
  var H = 32;
  var amplitude = 1400;

  /* ---------- 每个瓦片按经纬度算高度，返回 Float32Array ---------- */
  function heights(x, y, level) {
    var rect = scheme.tileXYToRectangle(x, y, level);
    var out = new Float32Array(W * H);

    for (var j = 0; j < H; j++) {
      for (var i = 0; i < W; i++) {
        var lon = Cesium.Math.toDegrees(
          rect.west + (rect.east - rect.west) * (i + 0.5) / W
        );
        var lat = Cesium.Math.toDegrees(
          rect.south + (rect.north - rect.south) * (j + 0.5) / H
        );

        var h = amplitude *
              Math.sin(lon * 0.9) * Math.cos(lat * 0.8) * 0.6 +
              700 * Math.sin(lon * 2.7 + 1.2) * Math.sin(lat * 2.1) +
              260 * Math.cos(lon * 6.1) * Math.sin(lat * 5.3) +
              amplitude * 0.35;

        out[j * W + i] = Math.max(-120, h);
      }
    }
    return out;
  }

  var terrain = new Cesium.CustomHeightmapTerrainProvider({
    width: W,
    height: H,
    tilingScheme: scheme,
    callback: heights
  });

  viewer.terrainProvider = terrain;

  /* 一条贴地的折线，用来看地形是否真的起伏 */
  var linePositions = [];
  for (var d = 0; d < 6; d++) {
    linePositions.push(100 + d * 2.4, 30 + Math.sin(d) * 1.6, 0);
  }
  viewer.entities.add({
    polyline: {
      positions: Cesium.Cartesian3.fromDegreesArrayHeights(linePositions),
      width: 3,
      clampToGround: true,
      material: Cesium.Color.fromCssColorString('#ffd166')
    }
  });

  document.getElementById('amp').addEventListener('input', function () {
    amplitude = parseInt(this.value, 10);
    document.getElementById('ampVal').textContent = amplitude;
    viewer.terrainProvider = new Cesium.CustomHeightmapTerrainProvider({
      width: W,
      height: H,
      tilingScheme: scheme,
      callback: heights
    });
  });

  viewer.camera.flyTo({
    destination: Cesium.Cartesian3.fromDegrees(101, 31.5, 1120000),
    orientation: {
      heading: Cesium.Math.toRadians(8),
      pitch: Cesium.Math.toRadians(-38),
      roll: 0
    },
    duration: 0
  });
})();
</script>
</body>
</html>