Welcome to Dreamviews!

It's certainly possible to change your dream, through means of teleportation (changing the location entirely). You can also dismiss or summon certain people/characters. Anything is possible in a lucid dream; dreams are not bound by anything except your confidence and expectations. With a bit of practice, you'll be able to step through a door/mirror into a rainforest or crater. All it takes is knowing fully that the location you want will be on the other side. Visualizing it helps, too.