调整threejs类型

src/Utils.ts

@@ -1,4 +1,4 @@
-import { Object3D } from "three";
+import { Object3D, Mesh } from "three";
 import { createTemplateBoard, DrawDimension, Viewer, selectMaterial } from ".";
 
 function dispose(m: Object3D)
@@ -12,7 +12,7 @@ function dispose(m: Object3D)
 }
 
 
-let blockMeshs: THREE.Mesh[];
+let blockMeshs: Mesh[];
 let dataRelations: {
     blockMeshMap: Map<number, number>,
     meshBlockMap: Map<number, number>