Sky Environment

In Unity, the default sky is the gradient blue color. You can change it though changing the gradient color or texturizing it.

Rendering Sky

Click Window, Lighting, Settings on the toolbar to set the parameter for rendering the sky.
On Lightmapping Settings, you can also set the Ambient Occlusion to reinforce the details of the lighted object.
On Other Settings, you can set the Fog switch and edit its parameters.
- Color : Set the fog color, and its default is gray.
- Mode : Set the fog spreading mode, including LInear, Exponential, and Exponential Squared.
- Density : Set the fog concentration ranging from 0 (minimum) to 1 (maximum). In general, you can increase or decrease it by 0.01 unit.
On Other Settings, you can also set Halo Texture, Halo Strength, Flare Strength, Flare Fade Speed, and Spot Cookie.
On Environment,
- [Option] You can download the asset package from the asset store, for exmple, Classic Skybox, etc.
- Skybox Material : You can change the sky texture, for example, skybox, etc. The texture consists of six different texture images.
- Sun Source : Set the light source represents the sun source. In general, usually set the Directional Light as the sun source.

You can also download the dynamic skybox which is based on different time peroids during the day.