Background

Universe Sandbox provides several options for the background to display behind the objects in the simulation. Currently, the background has no effect on the simulation itself.

## Background Menu

The Background menu allows the user to select one of several preset backgrounds from a list. This menu can be opened using the Background button in the View menu in the bottom bar.

The menu is sorted into three tabs: All, Procedural, and Textures.

Procedural backgrounds are randomly generated and resemble a two-color wispy material against a differently colored background (like a two-color nebula against the black background of space). The random seed of the background can be set in the Advanced Settings menu (see below). The following preset procedural backgrounds are available in the Background menu:

* Nebula Green
* Nebula Green Yellow
* Nebula Purple
* Nebula Red
* Nebula Red Cyan
* Space Blue
* Space Blue Green
* Space Blue Yellow
* Space Brown
* Space Mist

Texture backgrounds use a preset image or solid color. The following preset texture backgrounds are available in the Background Menu:

* Just Stars
* Milky Way Bright
* Milky Way Dark
* Milky Way Dark Galactic
* Solid Black
* Solid Dark Gray
* Solid Gray
* Solid White

## Advanced Settings

The Advanced Settings menu for backgrounds can be opened via the pencil icon in the lower right corner of each background in the Background menu.

The following settings can be adjusted in the Advanced Settings menu:

* Levels
	+ Seed
		- Represents the random seed for Procedural backgrounds. The dice icon on the right of the Seed value will generate a random seed value.
	+ Star Intensity
		- Controls the brightness of background stars
	+ Brightness
		- Controls the brightness of the background color
	+ Contrast
		- Controls the contrast of the background image
	+ Saturation
		- Controls the saturation of the background image
	+ Clamp to Horizon
		- Determines whether the procedural foreground is evenly distributed around the 3D simulation space (when off) or brighter in the x-z plane of the Simulation Grid (when on)

* Colors
	+ The dice icon to the right of the Colors label will randomize the colors of the background
	+ Base Color
		- For procedural backgrounds, the Base Color is one of three colors used to generate the background. For solid color backgrounds, the Base Color determines the color of the background. This property has no effect on backgrounds with preset images, like the Milky Way background, or the Just Stars background.
	+ Color 1
		- For procedural backgrounds, this is one of three colors used to generate the background. This property has no effect on other types of background.
	+ Color 2
		- For procedural backgrounds, this is one of three colors used to generate the background. This property has no effect on other types of background.
	+ Mode
		- Solid Color: The background is a single color, represented by Base Color
		- Stars: The background is a collection of non-simulated, distant stars against a black background
		- Texture: The background is represented by a preset image
		- Procedural: The background is randomly generated
	+ Ambient Light
		- Determines how the color of the ambient light in the situation is calculated. If set to Automatic, Universe Sandbox automatically calculates the ambient light based on the background. If set to Manual, the Manual Ambient Color is used.
	+ Manual Ambient Color
		- The color of the ambient light in the simulation. Only used when Ambient Light is set to Manual.
	+ Ambient Brightness
		- The brightness of the ambient light in the simulation.
	+ Background Rotation X
		- The rotation of the background around the x-axis of the Simulation Grid, in units of degrees
	+ Background Rotation Y
		- The rotation of the background around the y-axis of the Simulation Grid, in units of degrees
	+ Background Rotation Z
		- The rotation of the background around the z-axis of the Simulation Grid, in units of degrees