PQS Main Shader – Triplanar Zoom Rotation

Shader: Terrain/PQS/PQS Main Shader - Triplanar Zoom Rotation  ·  materialType = MainTriplanarZoomRotation

The PQS Material { } drives the shader that paints a body's near-surface terrain — the real, subdivided quad-sphere you see from low orbit down to the ground. This is the counterpart to the ScaledVersion materials, which paint only the distant low-LOD sphere; the PQS material takes over as the camera descends and the two are cross-faded across the fadeStart / fadeEnd altitudes. Terrain/PQS/PQS Main Shader - Triplanar Zoom Rotation is the most advanced member of the "PQS Main" family — the one stock Kerbin uses at the High terrain-detail setting.

Like the rest of the family it builds the surface procedurally and world-space triplanar — projecting tiling textures down the three world axes and blending them by the surface normal, so there are no UV seams — and it blends three textures by elevation with a separate texture on steep slopes. It departs from the others in two important ways:

• Zoom-rotation tiling instead of a near/far pair. Rather than crossfading two fixed tilings by distance, it runs a continuous cascade: as the camera pulls away, the triplanar coordinates are repeatedly scaled down by factor and rotated by factorRotation, with adjacent zoom levels blended over a factorBlendWidth band. The rotation breaks up the regular tile pattern that would otherwise become obvious as you zoom out, so a single set of textures stays convincing from the ground all the way to orbit.
• Physically-based lighting. Where the other PQS Main shaders are diffuse-only, this one is a PBR specular surface — it has a specularColor (the F0 reflectance) and pulls reflections from the scene's reflection probes, and an albedoBrightness multiplier on the surface colour.

A closely related shader, AtmosphericTriplanarZoomRotation, uses the same zoom-rotation idea without the "PQS Main" band/colour pipeline. For the distance-crossfade siblings of this shader, see Main and MainFastBlend.

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

Enabling

Select the material by setting materialType = MainTriplanarZoomRotation in the PQS { } node. The Material { } node then accepts the properties listed below.

PQS
{
    materialType = MainTriplanarZoomRotation
    Material
    {
        // Zoom-rotation tiling cascade
        factor           = 10
        factorBlendWidth = 0.1
        factorRotation   = 30

        // Colour grading and PBR lighting
        saturation       = 1
        contrast         = 1
        tintColor        = 1, 1, 1, 0
        specularColor    = 0.2, 0.2, 0.2, 0.2
        albedoBrightness = 2

        // Elevation bands (single tiling each)
        lowTex      = MyMod/PluginData/sand_color.dds
        lowBumpMap  = MyMod/PluginData/sand_normal.dds
        lowTiling   = 100000

        midTex      = MyMod/PluginData/rock_color.dds
        midBumpMap  = MyMod/PluginData/rock_normal.dds
        midTiling   = 100000

        highTex     = MyMod/PluginData/snow_color.dds
        highBumpMap = MyMod/PluginData/snow_normal.dds
        highTiling  = 100000

        // Where each band fades to the next (on normalised vertex elevation)
        lowStart  = 0
        lowEnd    = 0.3
        highStart = 0.8
        highEnd   = 1

        // Steep-slope overlay
        steepTex     = MyMod/PluginData/cliff_color.dds
        steepBumpMap = MyMod/PluginData/cliff_normal.dds
        steepPower   = 1

        // Atmospheric haze and underwater fog (only on bodies with an atmosphere)
        globalDensity    = 1
        fogColorRamp     = MyMod/PluginData/fog_ramp.dds
        oceanFogDistance = 1000
    }
}

How the surface is built

The shader is a triplanar terrain surface assembled per pixel. There is no single colour map; instead a base colour, three elevation textures, a steep overlay, and fog are combined in the following order:

1. Per-vertex colour grading — the PQS supplies a colour per vertex (COLOR.rgb, usually from a colour map or LandControl). The shader desaturates that colour toward its luma by saturation, mixes in tintColor (whose alpha is the mix amount), and scales it by contrast. The result is the base colour that the band textures then tint.
2. Three elevation bands — lowTex, midTex and highTex are blended by the vertex's normalised elevation (written into COLOR.w by the PQS height build). lowStart/lowEnd set the elevation window where the low band fades up into the mid band, and highStart/highEnd the window where the mid band fades into the high band — so low covers the bottom of the height range, mid the middle, high the top.
3. Zoom-rotation tiling — this is the shader's signature. The view distance is bracketed between consecutive powers of factor to pick a zoom level; the textures are sampled at that level's tiling and at the next level's, and the two are blended across a transition band whose width is factorBlendWidth. Each successive zoom level also rotates the triplanar coordinates by an extra factorRotation degrees, which scrambles the tile pattern so it does not read as obvious repetition as the camera pulls back. Because the triplanar coordinates are world position scaled by 10⁻⁵, the per-band tiling numbers are large (the default is 100000).
4. Steep-slope overlay — steepTex and steepBumpMap are blended over the result on steep terrain. The per-vertex steepness is multiplied by steepPower and clamped, so higher steepPower makes the cliff texture reach onto gentler slopes.
5. Normal mapping — each band and the steep overlay carry a matching DXT5nm normal map, accumulated triplanar and transformed into world space through the mesh's tangent frame. Because the zoom cascade rotates the coordinates, the normal maps rotate with them — which is why changing factorRotation shifts how relief catches the light.
6. PBR lighting — the blended albedo is scaled by albedoBrightness and lit with a physically-based specular model: specularColor is the surface's specular reflectance at normal incidence (its F0), used together with the engine's reflection probes for image-based reflections, on top of the direct light. This is the only PQS Main shader with a specular response; the rest are diffuse-only.
7. Aerial-perspective & ocean fog — on a body with an atmosphere, a distance haze is mixed in last. Its colour is read from fogColorRamp indexed by the sun angle, and its strength grows with distance and globalDensity. A second, underwater ocean fog term reads the same ramp at a different row and fades over the oceanFogDistance. On an airless body the whole fog stage is compiled out and these properties do nothing.

The triplanar projection means the band textures need no UV mapping on the mesh, but the normal mapping still needs mesh tangents, which the PQS quad-sphere provides. Because the colour, elevation and slope all come from the PQS build, the final look depends as much on your PQSMods (height, colour, LandControl) as on the textures set here.

Properties

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

1. Zoom & rotation — the tiling cascade that replaces the near/far crossfade.
2. Colour & lighting — the colour grading and the PBR specular response.
3. Elevation bands — the three height textures, their normal maps, tiling and transition windows.
4. Steep-slope overlay — the cliff texture for steep terrain.
5. Fog & opacity — the atmospheric haze ramp, ocean-fog distance and the PQS fade scalar.

Zoom & rotation

Property	Format	Description
factor	Decimal	Geometric zoom step between adjacent tiling levels — the view distance is bracketed between consecutive powers of this value. Larger values mean fewer, coarser zoom transitions across the visible range. Do not set it to 1, which collapses the cascade and locks up the game. Default 10.
factorBlendWidth	Decimal	Width of the smooth transition between adjacent zoom levels, as a fraction of one level's range (valid range 0–0.5). Small values (≈0.05) give crisp, near-discrete level changes; larger values blend them more softly. Default 0.1.
factorRotation	Decimal	Additional rotation, in degrees, applied to the triplanar coordinates at each successive zoom level. Breaks up visible tile repetition as the camera zooms out; because it rotates the normal maps too, it also shifts how surface relief catches the light. Default 30.

Colour & lighting

Property	Format	Description
saturation	Decimal	Saturation of the per-vertex colour map: 0 collapses it to greyscale (luma), 1 leaves it unchanged, higher oversaturates. Default 1.
contrast	Decimal	Contrast multiplier applied to the graded colour. Default 1.
tintColor	Color	A tint mixed into the base colour; the alpha is the mix amount (0 = no tint). Default (1, 1, 1, 0) — i.e. no tint.
specularColor	Color	Specular reflectance at normal incidence (the PBR F0 colour), used with the scene's reflection probes for the highlight and image-based reflections. Set to black to remove specular. Default (0.2, 0.2, 0.2, 0.2).
albedoBrightness	Decimal	Multiplier applied to the blended surface colour before lighting — raises or lowers the overall terrain brightness. Default 2.

Elevation bands

Each band has an albedo texture and a DXT5nm normal map, each with a single world tiling (the zoom cascade supplies the multi-scale detail). The band weights come from the vertex elevation and the four transition values at the end of the table.

Property	Format	Description
lowTex	File Path	Albedo for the low elevation band. Triplanar, world-tiled. Default "white".
lowTexScale / lowTexOffset	Vector2	Tiling and offset of lowTex.
lowTiling	Decimal	World tiling of the low albedo. Default 100000.
lowBumpMap	File Path	DXT5nm normal map for the low band. Default "bump" (flat).
lowBumpMapScale / lowBumpMapOffset	Vector2	Tiling and offset of lowBumpMap.
lowBumpTiling	Decimal	World tiling of the low normal map. Default 100000.
midTex	File Path	Albedo for the mid elevation band. Default "white".
midTexScale / midTexOffset	Vector2	Tiling and offset of midTex.
midTiling	Decimal	World tiling of the mid albedo. Default 100000.
midBumpMap	File Path	DXT5nm normal map for the mid band. Default "bump".
midBumpMapScale / midBumpMapOffset	Vector2	Tiling and offset of midBumpMap.
midBumpTiling	Decimal	World tiling of the mid normal map. Default 100000.
highTex	File Path	Albedo for the high elevation band. Default "white".
highTexScale / highTexOffset	Vector2	Tiling and offset of highTex.
highTiling	Decimal	World tiling of the high albedo. Default 100000.
highBumpMap	File Path	DXT5nm normal map for the high band. Default "bump".
highBumpMapScale / highBumpMapOffset	Vector2	Tiling and offset of highBumpMap.
highBumpTiling	Decimal	World tiling of the high normal map. Default 100000.
lowStart	Decimal	Elevation (normalised 0–1) at which the low band begins fading into the mid band. Default 0.
lowEnd	Decimal	Elevation at which the low band has fully given way to the mid band. Default 0.3.
highStart	Decimal	Elevation at which the mid band begins fading into the high band. Default 0.8.
highEnd	Decimal	Elevation at which the high band fully takes over. Default 1.

Steep-slope overlay

Property	Format	Description
steepTex	File Path	Albedo blended over steep slopes (cliffs). Default "white".
steepTexScale / steepTexOffset	Vector2	Tiling and offset of steepTex.
steepTiling	Decimal	World tiling of the steep overlay albedo. Default 100000.
steepBumpMap	File Path	DXT5nm normal map for the steep overlay. Default "bump".
steepBumpMapScale / steepBumpMapOffset	Vector2	Tiling and offset of steepBumpMap.
steepBumpTiling	Decimal	World tiling of the steep overlay normal map. Default 100000.
steepPower	Decimal	Multiplier on the vertex steepness before it is clamped to the overlay weight. Higher values push the steep texture onto gentler slopes; 0 disables it. Default 1.

Fog & opacity

Property	Format	Description
globalDensity	Decimal	Density multiplier for the aerial-perspective haze. Only has an effect on bodies with an atmosphere; higher values thicken the distance fog. Default 1.
fogColorRamp	File Path	1-D colour ramp for the fog. The aerial haze is read from it indexed by the sun angle (so the fog can be tinted differently toward and away from the sun); a second row supplies the underwater ocean-fog colour. Default "white".
fogColorRampScale / fogColorRampOffset	Vector2	Tiling and offset of the fog ramp.
oceanFogDistance	Decimal	Falloff distance (m) of the underwater ocean fog — the distance over which the surface fades into the ocean-fog colour when seen from below the waterline. Default 1000.
planetOpacity	Decimal	Opacity of the PQS material, used by KSP to fade the terrain against the scaled-space sphere across the fadeStart/fadeEnd transition. Normally left at 1. Default 1.

Notes

• These are the body's near-surface terrain materials. The body simultaneously has a ScaledVersion material for the distant sphere; KSP cross-fades between the two across the fadeStart / fadeEnd altitudes, so the two should be tuned to match where they meet.
• This is the only PQS Main shader with a specular response and an albedoBrightness control; the others (Main, Optimized, Extra, MainFastBlend, OptimizedFastBlend) are diffuse-only.
• Instead of the near/far tiling crossfade used by the other variants, detail at distance comes from the zoom-rotation cascade (factor, factorBlendWidth, factorRotation); there is consequently no powerNear/powerFar, groundTexStart/groundTexEnd, or per-band near/far tiling pair here.
• The textures are world-space triplanar, so they need no UVs and the tiling values are in world units scaled by 10⁻⁵ (hence the large defaults). The shader still requires mesh tangents for its normal mapping, which the PQS quad-sphere provides.
• The band colour, the per-vertex elevation that drives the band blend, and the slope that drives the steep overlay all come from the PQS build — your height, colour and LandControl mods shape the input this shader paints.
• The fog stage (globalDensity, fogColorRamp, oceanFogDistance) is only compiled in for bodies with an atmosphere; on an airless body it is removed entirely and those properties have no effect.
• Several shader inputs are driven by KSP at runtime and are not config properties: a floating-origin offset that keeps the world-space triplanar coordinates stable as the game shifts the origin around the craft, and the sun direction, camera altitude and viewer air density used by the fog.
• Unlike the older AtmosphericMain/AtmosphericOptimized material types, MainTriplanarZoomRotation has no Atmospheric… alias — this is the only name that selects it.