Near the surface of the Earth, STK displays a uniform blue or black sky. Applying a global cloud texture through the Globe Manager, at best, might add a few wispy white streaks.There is a way to improve this through the use of a 'Sky Dome' model file. A Sky Dome model is a hemisphere with a texture of the sky mapped onto it.
To add a Sky Dome model, create a facility at or near the center of your scene and replace the default facility model with a Sky Dome model.
Two models, Sky_Dome_Dark.zip and Sky_Dome_Blue.zip, are attached.
STK with no Sky Dome Sky Dome Blue Sky Dome Dark
Sky Domes need to be very large and are only visible from the inside. Looking at it from the outside, straight down, you will see a ring. Scale it to 3 or 4 to insure that it is outside of your scene. At a scale of 4, the Sky Dome will be slightly smaller than the Earth. Since the Earth is round and the bottom of the Sky Dome is flat, you need to apply a Z Translation Offset to move the bottom edge below the horizon.If your are using terrain, it may be clipped if the dome is too small. If you are visualizing satellites, they may be cut off by the dome, or fly under the clouds. That would look bad.
Sky_Dome_Blue is a partly cloudy sky that looks nearly the same from all angles. Sky_Dome_Dark shows a wider variety of weather. Applying a Z Rotational Offset will allow you to rotate this dome to the desired weather pattern for your scene.
The domes included here use four seamless textures that are 1024 x 1024. Mapped to the model, the combined image area is 4096 x 1024, a ratio of 4:1. The models themselves are in our original MDL format. As such, you can use these as templates for making other domes by replacing the imagery.