add SkyBox and GroundSkyBox

modules/exts/SkyBox.js → modules/exts/GroundSkyBox.js

   }
 `
 
-class SkyBox extends Cesium.SkyBox {
+class GroundSkyBox extends Cesium.SkyBox {
   constructor(options = {}) {
     super(options)
-    this.offsetAngle = options?.offsetAngle || 90
+    this.offsetAngle = options?.offsetAngle
   }
 
   update(frameState, useHdr) {
   }
 }
 
-export default SkyBox
+export default GroundSkyBox

modules/exts/index.js

  * @Date: 2021-02-21 17:51:00
  */
 
-export { default as SkyBox } from './SkyBox'
+export { default as GroundSkyBox } from './GroundSkyBox'

modules/thirdpart/index.js

   Cartesian2: Cesium.Cartesian2,
   Cartesian3: Cesium.Cartesian3,
   SceneMode: Cesium.SceneMode,
+  SkyBox: Cesium.SkyBox,
+  Color: Cesium.Color,
+  Rect: Cesium.Rectangle,
+  ShadowMode: Cesium.ShadowMode,
+  JulianDate: Cesium.JulianDate,
   HeightReference: Cesium.HeightReference,
   HorizontalOrigin: Cesium.HorizontalOrigin,
   VerticalOrigin: Cesium.VerticalOrigin,
+  CallbackProperty: Cesium.CallbackProperty,
   ClassificationType: Cesium.ClassificationType,
-  ShadowMode: Cesium.ShadowMode,
   TilesetStyle: Cesium.Cesium3DTileStyle,
-  CallbackProperty: Cesium.CallbackProperty,
-  JulianDate: Cesium.JulianDate,
-  Color: Cesium.Color,
-  Rect: Cesium.Rectangle,
   GeographicTilingScheme: Cesium.GeographicTilingScheme,
   WebMercatorTilingScheme: Cesium.WebMercatorTilingScheme,
   ColorMaterialProperty: Cesium.ColorMaterialProperty,

packages/core/src/components.js

 /**
  * exts
  */
-import { SkyBox } from '@dc-modules/exts'
+import { GroundSkyBox } from '@dc-modules/exts'
 
 /**
  * thirdPart
   /**
    * exts
    */
-  SkyBox,
+  GroundSkyBox,
   /**
    * thirdPart
    */