I wish I could do that. Or at least consistently do that, as I have some limited ability. I dream kind of like I'm half-blind all the time despite having perfectly good vision IRL-I had exactly ONE instant of a vivid dream when I was much younger, then went 'Whoa!' and exited out of that mode. I'm not sure this is inhibiting my ability to Lucidly dream, despite the obvious disadvantage; among the few times I've hijacked a dream plot gave me flight in the middle of a race, and I usually can corral the direction of the 'plot,' but I'm not able to really Lucidly dream and I can't really control the setting as much as I'd like. I've got to try that for real, though.