Yeah, in the atmosphere editor, you have all the options in the world for changing your atmosphere setings, or you can load an entirely new atmosphere, as well, by clicking on the little file icon at the bottom right of the atmosphere editor. As for your shadows to show on your window, you have to first make sure that your sun (a directional light) is pointing at the tree, and the shadows are headed towards the window. Since this is an indoor scene, I'd just turn off shadows for the sun and use a spot on the tree, pointing it so it's casting a shadow on the window. Preview mode does cast shadows. Lighting in Vue is one of the more difficult things., but it's the same in all 3D programs. You just have to play around with it and learn from it. Not so sure why you want to turn your sun into a moon, if you can't see it. If you want it darker, you can change the setting for the brightness under the Light tab in the atmosphere editor. You can also change th ecolor of the light there, as well as ambient light levels, etc. Scene's coming along nicely. :)