Partial Ellipsoids

<!--
  示例：局部椭球
  说明：三个被切掉一块的椭球，分别用内外半径与角度范围做出空心和开口
  核心逻辑：ellipsoid.innerRadii → minimumClock / maximumClock → minimumCone / maximumCone
  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>局部椭球</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">开口范围用弧度表示，内外半径相同就是实心球壳。</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;

  function ball(dx, radii, inner, clockRange, coneRange, color) {
    viewer.entities.add({
      position: Cesium.Cartesian3.fromDegrees(116.386 + dx, 39.9046, 60),
      ellipsoid: {
        radii: radii,
        innerRadii: inner,
        minimumClock: clockRange[0],
        maximumClock: clockRange[1],
        minimumCone: coneRange[0],
        maximumCone: coneRange[1],
        material: Cesium.Color.fromCssColorString(color).withAlpha(0.75),
        outline: true,
        outlineColor: Cesium.Color.fromCssColorString('#0e1116')
      }
    });
  }

  var R = new Cesium.Cartesian3(40, 40, 40);
  var IR = new Cesium.Cartesian3(26, 26, 26);

  /* 完整球壳 */
  ball(0, R, IR, [0, Cesium.Math.TWO_PI], [0, Cesium.Math.PI], '#4d86c8');
  /* 上半部 */
  ball(0.0034, R, IR, [0, Cesium.Math.TWO_PI], [0, Cesium.Math.PI_OVER_TWO], '#5bb08a');
  /* 四分之一开口 */
  ball(0.0068, R, new Cesium.Cartesian3(26, 26, 26),
       [0, Cesium.Math.PI_OVER_TWO], [Cesium.Math.PI_OVER_FOUR, Cesium.Math.PI_OVER_TWO], '#d08a4e');
  viewer.camera.flyTo({
    destination: Cesium.Cartesian3.fromDegrees(116.3935, 39.9006, 190),
    orientation: { heading: Cesium.Math.toRadians(-20), pitch: Cesium.Math.toRadians(-10), roll: 0 },
    duration: 0
  });
})();
</script>
</body>
</html>