Resolution Scaling

<!--
  示例：渲染分辨率缩放
  说明：把渲染分辨率降到 50% 再升回 100%，画质与帧率同步变化
  核心逻辑：viewer.resolutionScale → useBrowserRecommendedResolution → 逐级切换
  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>渲染分辨率缩放</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">画面在清晰与发虚之间循环，这是渲染分辨率在变，画布尺寸没有变。</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;

  viewer.resolutionScale = 1.0;
  viewer.useBrowserRecommendedResolution = false;
  scene.debugShowFramesPerSecond = true;

  /* 一些细节密集的楼群，缩放后差异明显 */
  for (var i = 0; i < 20; i++) {
    for (var j = 0; j < 14; j++) {
      var h = 14 + ((i + j * 3) % 7) * 7;
      viewer.entities.add({
        position: Cesium.Cartesian3.fromDegrees(
          116.3846 + i * 0.0006, 39.9010 + j * 0.0006, h / 2
        ),
        box: {
          dimensions: new Cesium.Cartesian3(18, 16, h),
          material: Cesium.Color.fromHsl(0.58, 0.28, 0.32 + (i % 4) * 0.05)
        }
      });
    }
  }

  var levels = [1.0, 0.5, 0.35];
  var idx = 0;
  setInterval(function () {
    idx = (idx + 1) % levels.length;
    viewer.resolutionScale = levels[idx];
  }, 3500);
  viewer.camera.flyTo({
    destination: Cesium.Cartesian3.fromDegrees(116.3980, 39.8950, 620),
    orientation: { heading: Cesium.Math.toRadians(24), pitch: Cesium.Math.toRadians(-22), roll: 0 },
    duration: 0
  });
})();
</script>
</body>
</html>