Merge pull request #1236 from RaananW/arc-collision

Fixing collision with arc rotate camera

src/Cameras/babylon.arcRotateCamera.ts

@@ -392,7 +392,7 @@
             if (this.position.equals(position)) {
                 return;
             }
-            this.position = position;
+            this.position.copyFrom(position);
 
             this.rebuildAnglesAndRadius();
         }