[Sky] [Material] used for a physically based sky. The [PhysicalSkyMaterial] uses the Preetham analytic daylight model to draw a sky based on physical properties. This results in a substantially more realistic sky than the [ProceduralSkyMaterial], but it is slightly slower and less flexible. The [PhysicalSkyMaterial] only supports one sun. The color, energy, and direction of the sun are taken from the first [DirectionalLight3D] in the scene tree. As it is based on a daylight model, the sky fades to black as the sunset ends. If you want a full day/night cycle, you will have to add a night sky by converting this to a [ShaderMaterial] and adding a night sky directly into the resulting shader. The sky's overall brightness multiplier. Higher values result in a brighter sky. Modulates the [Color] on the bottom half of the sky to represent the ground. Controls the strength of [url=https://en.wikipedia.org/wiki/Mie_scattering]Mie scattering[/url] for the sky. Mie scattering results from light colliding with larger particles (like water). On earth, Mie scattering results in a whitish color around the sun and horizon. Controls the [Color] of the [url=https://en.wikipedia.org/wiki/Mie_scattering]Mie scattering[/url] effect. While not physically accurate, this allows for the creation of alien-looking planets. Controls the direction of the [url=https://en.wikipedia.org/wiki/Mie_scattering]Mie scattering[/url]. A value of [code]1[/code] means that when light hits a particle it's passing through straight forward. A value of [code]-1[/code] means that all light is scatter backwards. [Texture2D] for the night sky. This is added to the sky, so if it is bright enough, it may be visible during the day. Controls the strength of the [url=https://en.wikipedia.org/wiki/Rayleigh_scattering]Rayleigh scattering[/url]. Rayleigh scattering results from light colliding with small particles. It is responsible for the blue color of the sky. Controls the [Color] of the [url=https://en.wikipedia.org/wiki/Rayleigh_scattering]Rayleigh scattering[/url]. While not physically accurate, this allows for the creation of alien-looking planets. For example, setting this to a red [Color] results in a Mars-looking atmosphere with a corresponding blue sunset. Sets the size of the sun disk. Default value is based on Sol's perceived size from Earth. Sets the thickness of the atmosphere. High turbidity creates a foggy-looking atmosphere, while a low turbidity results in a clearer atmosphere. If [code]true[/code], enables debanding. Debanding adds a small amount of noise which helps reduce banding that appears from the smooth changes in color in the sky.