Vacuum Material

Shader: Terrain/Scaled Planet (Simple)

The Vacuum Material { } drives the Terrain/Scaled Planet (Simple) shader — the plainest of the scaled-space planet shaders, and the type used by most airless bodies in the stock system. It paints the planet's distant, low-LOD sphere from a single colour map and lights it with a standard Blinn-Phong specular model.

In the stock KittopiaTech dumps, the bodies set to type = Vacuum are Moho, Gilly, the Mun, Minmus, Ike, Dres, Vall, Tylo, Bop, and Pol. It is not, however, used by every airless body: Eeloo has no atmosphere yet is set to AtmosphericStandard.

It is the airless counterpart to the Atmospheric material: both build the surface the same way, but the atmospheric shader (Terrain/Scaled Planet (RimAerial)) adds a view-angle rim glow for the atmosphere's limb, whereas this one has no rim at all. If your body builds its appearance procedurally from cloud bands instead of a painted map, see the Gas Giant material.

We shall first see how to enable the material, then how the shader lights the surface, and finally discuss each group of properties in turn.

Enabling

Select the vacuum material by setting type = Vacuum in the ScaledVersion { } node. The Material { } node then accepts the properties listed below.

ScaledVersion
{
    type = Vacuum
    Material
    {
        // Surface maps
        texture = MyMod/PluginData/Mun_color.dds
        normals = MyMod/PluginData/Mun_normal.dds

        // Colour and specular response
        color     = 1, 1, 1, 1
        specColor = 0.5, 0.5, 0.5, 1
        shininess = 0.078125

        // Resource-scanner overlay (optional)
        resourceMap = MyMod/PluginData/Mun_resources.dds
    }
}

How the surface is lit

The vacuum shader is essentially Unity's BumpedSpecular (Blinn-Phong) lighting with three KSP-specific pieces layered on top:

1. Colour and gloss — texture is the colour map. Its RGB channels are the surface albedo (multiplied by color), and its alpha channel is a per-pixel specular intensity mask: bright areas catch the sun's highlight strongly, dark areas stay matte. This lets a single texture vary glossiness across the surface (e.g. shiny crater glass against dull regolith).
2. Surface relief — normals is a tangent-space normal map that perturbs the lighting per pixel, so the body keeps fine surface detail when viewed from orbit even though the scaled-space mesh is smooth.
3. Resource overlay — resourceMap is the resource-scanner overlay. It is composited additively (rgb × a) on top of the lit surface, so the default all-black map contributes nothing and it only shows once a scan reveals it.

The highlight itself is shaped by specColor (its tint) and shininess (how tight it is). There is no atmosphere, emission, or rim term — what you paint is what you get, lit by the local star.

Properties

The properties fall into four groups, which we shall take in turn:

1. Surface maps — the colour and normal textures that define the body's appearance.
2. Colour and specular — the tints and highlight sharpness applied during lighting.
3. Resource overlay — the optional scanner map composited on top.
4. Opacity — the scaled-space fade scalar.

Surface maps

Property	Format	Description
texture	File Path	The scaled-space colour map. RGB = surface albedo (multiplied by color); alpha = per-pixel specular intensity mask. Also accepts the alias mainTex. Default "white".
mainTexScale / mainTexOffset	Vector2	Tiling and offset of the colour map.
normals	File Path	Tangent-space normal map, stored in DXT5nm packing (X in the alpha channel, Y in green, Z reconstructed). Also accepts the alias bumpMap. Default "bump" (flat).
bumpMapScale / bumpMapOffset	Vector2	Tiling and offset of the normal map.

Colour and specular

Property	Format	Description
color	Color	Master diffuse tint multiplied into the colour map's RGB before lighting. The alpha is unused. Default (1, 1, 1, 1).
specColor	Color	Specular highlight tint, scaled by the star's light colour and further modulated by the colour map's alpha mask. Set to black to disable specular entirely. Default (0.5, 0.5, 0.5, 1).
shininess	Decimal	Highlight sharpness. The value maps to a Blinn-Phong specular exponent of shininess × 128 — smaller values give a broad, soft highlight, larger values a tight, sharp one. The shader declares the valid range as [0.03, 1]. Default 0.078125.

Resource overlay

Property	Format	Description
resourceMap	File Path	Resource-scanner overlay texture, composited additively as rgb × a over the lit surface. Default "black" (contributes nothing).
resourceMapScale / resourceMapOffset	Vector2	Tiling and offset of the resource map.

Opacity

Property	Format	Description
opacity	Decimal	Master opacity of the scaled-space material, range [0, 1]. Default 1.

Notes

• opacity is marked [PerRendererData] and is driven at runtime by the scaled-space fader, which cross-fades the body between its scaled-space and local (PQS) representations as the camera crosses the fadeStart and fadeEnd altitudes. A static config value is therefore normally left at its default of 1.
• resourceMap is likewise [PerRendererData]: KSP's surface-resource visualisation layer sets it per-renderer when a scan is active. The default black texture means no overlay is shown.
• The shader requires mesh tangents for its normal mapping — the scaled mesh Kopernicus generates already provides them. A custom mesh without tangents will render with broken normals.
• If the shader fails to compile on the target platform it falls back to Unity's Standard shader.