# Background Editor

Opens via Editors › Background Editor.

Controls the visual environment that surrounds the mission: background bitmap layers, suns, nebula, skybox, ambient lighting, and stars.

## Background slots

A mission can define multiple backgrounds. The left drop-down selects the active background; the one currently loaded into the scene and visible in the viewport. Use Add and Remove to create or delete slots. Swap exchanges all data (bitmaps, suns, flags) between the two selected backgrounds. The Import button lets you pull backgrounds from another mission file.

## Bitmaps

Full-sphere background images composited behind the scene. Use Add to open a gallery and pick a new bitmap, Change to replace the selected one (also gallery), and Delete to remove it. You can also use the drop-down next to the list for a quicker replacement without the gallery. Select a bitmap in the list to edit its properties:

Field | Description
--- | ---
Pitch / Bank / Heading | Orientation of the bitmap on the sphere.
Scale X / Y | Stretches the bitmap horizontally and vertically.
Divisions | Number of mesh subdivisions (1–5) used when rendering the bitmap. Higher values improve perspective correction at the cost of slightly more geometry. Only the vertical (Y) axis division is currently active in the engine.

## Suns

Works the same as Bitmaps; Add, Change (gallery), Delete, and a quick-change drop-down. Bank is omitted since suns are circular. Select a sun in the list to edit:

Field | Description
--- | ---
Pitch / Heading | Position of the sun in the sky. This also determines the direction of dynamic lighting cast on ships.
Scale | Uniform size of the sun flare/glow image.

Save angles in correct format - a legacy checkbox that should always be checked for new missions. It controls whether pitch/bank/heading angles are saved using the modern coordinate convention or the older one. Unchecking it is only relevant when maintaining compatibility with very old mission files.

## Full Nebula

Enables the FS2-style nebula environment. When active, the mission takes place inside a gas cloud with fog, particle poofs, and optional lightning. This is not the same as the volumetric nebula renderer. For that see Volumetric Nebula.

Field | Description
--- | ---
Pattern | The background texture file used for the nebula environment.
Range | AWACS and targeting range multiplier inside the nebula. Lower values reduce how far sensors can detect targets.
Lightning Storm | Selects the lightning storm type active in the nebula, or `<None>` for no lightning.
Poofs | A list of cloud puff particle types defined in the tables. Check the ones you want active in the nebula.
Ship Trails | Toggles engine contrail streaks left by ships moving through the nebula clouds.
Visibility at 1000m | Fraction (0–1, inclusive) of light that survives 1000 meters of fog. Smaller values produce thicker fog. Zero is allowed (fully opaque).
Fog Near Distance | Distance from the camera, in meters, where fog begins. Must be greater than zero.
Skybox Clip Distance | Maximum render distance for the skybox in fog, in meters. 0 disables skybox fog.
Fog Clip Distance | Maximum render distance for the scene in fog, in meters. 0 disables scene fog.
Display background bitmaps in nebula | When checked, background bitmaps defined in the Bitmaps section are still visible through the nebula. Uncheck to let the nebula obscure them completely.
Override Fog Palette | When checked, uses the RGB values specified here as the fog color instead of the nebula's default palette.

## Ambient Light

Sets the global ambient light color applied to all ship and object surfaces. Use the RGB sliders to tint the ambient fill.

## Skybox

Renders a POF model as a full-environment backdrop, replacing the default procedural starfield. Select the POF file and set Pitch / Bank / Heading to rotate it. Leave the file field blank for no skybox.

The rendering flags control how the model is drawn:

Flag | Effect
--- | ---
No Lighting | Disables dynamic and ambient lighting on the skybox.
All Transparent | Renders the model fully transparent.
No Z-buffer | Disables depth buffer writes so the skybox always renders behind everything else.
No Cull | Renders both front- and back-facing polygons.
No Glowmaps | Disables glow/emission map rendering on the model.
Force Clamp | Forces texture coordinate clamping rather than wrapping.

The default flags for a new skybox are No Z-buffer, No Cull, All Transparent, and No Lighting, which is the correct setup for most cases.

## Misc

Field | Description
--- | ---
Number of Stars | Count of procedurally placed background stars. These may not be visible when a skybox is in use.
Takes place in subspace | Loads the subspace tunnel effect for the entire mission.
Environment map | Texture used for environment-mapped reflections and lighting on ship surfaces.
Lighting profile | Selects the lighting profile from the tables to apply to the mission.

## Old Nebula

A legacy FS1-style nebula system. These settings are read and written for backwards compatibility with old mission files, but the renderer that drew them was removed.