One problem I think you're going to face is the fact that you're using an atmospheric tool that can make some things reallly challenging. For instance, I'm going to guess the ground we're seeing in your image is the ground plane generated by the atmosphere tool. This may reduce your control. You can add another infinite plane to the scene to do more stuff and lower the ground plane in the atmosphere control. Turning off the light through transparency will darken the inside of your buildings but again, I suspect your insides are too light because of the atmosphere. While the atmosphere you're using does have great aspects to it, the side effects are aggravating. You might try using no atmosphere and using a backdrop image for your skies and such. So far, the model and textures look great. I think you're on a great track! -Kix

-Kix