Vividness is somewhat related to lucidity according to some oneironauts. Their argument is that the more aware you are of the dream world, the more detailed and vivid things will look to you, because you can shift awareness and engage your senses more deeply into perceiving your surrounding.

But TheSkies may have a point, loads of times you'll get more vividness out an ordinary dream rather than a lucid (at least for non-expert people I'd say :p)