The animation that I'm going to explain can also be used as background when we make a movie animation, or as a background of a game.
When creating background, I sometime use spheres or cylinders environments. But more often I use a sphere and a cylinder-shaped object. Sphere typically used when texture is used in the form of image of the sky or clouds. While the cylinders are used when the edges of the texture of the mountains or trees.
For Animation architecture, I suggest using a cylinder, Since the camera wont be looking up to high. In fact, sometimes the camera aims from above to the roof. But if the animation is more directed to the game, the camera may be aiming to every direction, for that,I suggest using sphere background.
Tip: Use the wide texture (panorama), in order to get wider eye view. Also, choose one that hue and saturation can be set into the atmosphere of night and day.