bugs fixing

src/Lights/Shadows/babylon.shadowGenerator.ts

@@ -436,6 +436,8 @@
             if (this._boxBlurPostprocess) {
                 this._boxBlurPostprocess.dispose();
             }
+
+            this._light._shadowGenerator = null;
         }
 
         public serialize(): any {

src/Mesh/babylon.mesh.vertexData.ts

@@ -1199,7 +1199,7 @@
 
                     positions.push(position.x, position.y, position.z);
                     normals.push(normal.x, normal.y, normal.z);
-                    uvs.push(col / subdivisionsX, 1.0 - row / subdivisionsX);
+                    uvs.push(col / subdivisionsX, 1.0 - row / subdivisionsY);
                 }
             }