I think the computers can only &quot;express&quot; (input or output) in terms of a 2D image, whereas it seems to me that human dreaming is in terms of abstract thoughts. We&#x27;re not really dreaming in 3D, but dreaming in perception. If we could train a computer on 3D scenes in the same manner, it would be able to express its dreams in 3D, but we don&#x27;t have the data to feed it.