Add object visibility states to Object States

Object States seem to store only the position information of objects. It would be very useful if they could also remember the visibility / hidden state of objects.

For example, in one camera view, I may need a tree behind the camera to cast foreground shadows. But in another view, that same tree may need to be hidden because it blocks the composition.

Another example: I may want to show two different crowd activity states within the same scene.

If Object States could store whether specific objects are visible or hidden, it would make scene management much more flexible.