Cesium 太阳光晕

1. 基于后处理实现
2. 位置动态跟随太阳实际位置
3. 可以动态改变颜色

    viewer.camera.flyTo({
      destination: { "x": -2471386.549378386, "y": 4838798.836366257, "z": 3329936.5717575867 },
      duration: 0,
      orientation: {
        heading: Cesium.Math.toRadians(120),
        pitch: Cesium.Math.toRadians(-10),
        roll: 6.2831850130093905
      }
    });

    effect = new SunFlareEffect(viewer)