message: fix viewer when center is given
diff: @@ -149,7 +149,7 @@ class BaseViewer(Viewer):
  self.dynamic_world_x_range[1] += (diffy - diffx)/2
  else:
  center = self.center
  - # self._update_world_dynamic_range(center)
  + self._update_world_dynamic_range(center)
  def _update_world_dynamic_range(self, center):
  aspect_ratio = self.get_aspect_ratio()
  