fix(shared): 🐛 webGL2 Value Retrieval

Author: zouyaoji

packages/shared/extends/materials/MaterialExtend.ts

@@ -3,7 +3,7 @@
  * @Date: 2023-08-18 00:56:13
  * @Description: Do not edit
  * @LastEditors: zouyaoji 370681295@qq.com
- * @LastEditTime: 2023-10-31 19:38:24
+ * @LastEditTime: 2023-10-31 22:33:58
  * @FilePath: \vue-cesium\packages\shared\extends\materials\MaterialExtend.ts
  */
 
@@ -12,12 +12,13 @@ import { VcCircleWaveMaterial, VcLineFlowMaterial } from '@vue-cesium/shared/sha
 let isExtended = false
 export default class MaterialExtend {
   static extend(viewer: Cesium.Viewer) {
+    console.log('asdf', viewer)
     if (isExtended) {
       return
     }
 
     const { Material, Color, Cartesian2 } = Cesium
-    const webgl2 = (viewer as any).context?.webgl2
+    const webgl2 = viewer.scene.context?.webgl2
 
     let shaderSourceTextVcLine = VcLineFlowMaterial
     let shaderSourceTextVcCircle = VcCircleWaveMaterial