I remember in a dream I went to Mars... It started out with me in Japan then I became lucid and decided to go to the moon, however I was going to fast and flew right past it, so I went to Mars. Kind of. It was green. And there was wildlife. And giant bugs for Martians. And a Church. But it was Mars. Kind of.

So yes, it's possible, if you make your dream accurate enough, to make some sort of simulation or something.