Density Functions

Source: Decompiled from HytaleServer.jar (pre-release 2026.02.05-9ce2783f7)

Density functions are the computational graph core of Hytale's V2 world generation system. There are 68 registered density function types in AssetManager.java, each representing a node in a directed acyclic graph (DAG). Every node takes zero or more inputs and produces a single double output value. These graphs define terrain shape, material selection, prop placement thresholds, and more.

At generation time, the graph is evaluated per-position: each density function receives a Density.Context containing the current sampling coordinates and related state, and returns a scalar value. Complex terrain is built by composing simple nodes -- noise generators feed into math operations, which feed into clamps and curves, which ultimately produce the terrain density field.

Common Fields

All density function assets inherit shared base fields from DensityAsset.ABSTRACT_CODEC:

Field	Type	Required	Default	Description
`Inputs`	`DensityAsset[]`	No	`[]`	Child density inputs -- the upstream nodes in the graph
`Skip`	`boolean`	No	`false`	If `true`, the function is disabled and returns a constant `0.0`
`ExportAs`	`string`	No	`null`	Name to register this density under for the Export/Import reuse system

Every concrete density type adds its own fields on top of these three. The Inputs array ordering matters -- many types reference inputs by index (e.g., Mix uses inputs[0] as a, inputs[1] as b, inputs[2] as factor).

Density.Context

The context object passed to all density functions at evaluation time:

Field	Type	Description
`position`	`Vector3d`	Current sampling position in world space
`densityAnchor`	`Vector3d`	Anchor point for relative/anchored calculations
`positionsAnchor`	`Vector3d`	Positions-based anchor (used by Positions* types)
`switchState`	`int`	Current switch state hash for conditional branching
`distanceFromCellWall`	`double`	Distance from the nearest cell wall boundary
`terrainDensityProvider`	`TerrainDensityProvider`	Provider for querying terrain density at arbitrary positions
`distanceToBiomeEdge`	`int`	Distance (in blocks) to the nearest biome edge

Coordinate transform nodes (Scale, Slider, Rotator, etc.) modify the position in the context before passing it to their child input, effectively transforming the coordinate space of the sub-graph.

Type Reference

Noise Generators

Four noise function types that sample procedural noise fields. These are leaf nodes with no density inputs.

`SimplexNoise2D`

2D simplex noise sampled at (x, z). Ignores Y coordinate.

Field	Type	Default	Description
`Lacunarity`	`double`	`1.0`	Frequency multiplier between octaves
`Persistence`	`double`	`1.0`	Amplitude multiplier between octaves
`Scale`	`double`	`1.0`	Base frequency scale
`Octaves`	`int`	`1`	Number of noise octaves
`Seed`	`string`	`"A"`	Seed string for deterministic generation

Inputs: 0

{
  "Type": "SimplexNoise2D",
  "Seed": "terrain_height",
  "Scale": 0.003,
  "Octaves": 4,
  "Lacunarity": 2.0,
  "Persistence": 0.5
}

`SimplexNoise3D`

3D simplex noise sampled at (x, y, z) with independent XZ and Y scaling.

Field	Type	Default	Description
`Lacunarity`	`double`	`1.0`	Frequency multiplier between octaves
`Persistence`	`double`	`1.0`	Amplitude multiplier between octaves
`ScaleXZ`	`double`	`1.0`	Horizontal frequency scale
`ScaleY`	`double`	`1.0`	Vertical frequency scale
`Octaves`	`int`	`1`	Number of noise octaves
`Seed`	`string`	`"A"`	Seed string for deterministic generation

Inputs: 0

{
  "Type": "SimplexNoise3D",
  "Seed": "caves_3d",
  "ScaleXZ": 0.02,
  "ScaleY": 0.04,
  "Octaves": 3,
  "Lacunarity": 2.0,
  "Persistence": 0.45
}

`CellNoise2D`

2D cellular/Voronoi noise. Returns values based on the selected ReturnType (distance to cell center, cell value, etc.).

Field	Type	Default	Description
`ScaleX`	`double`	`1.0`	Horizontal X frequency scale
`ScaleZ`	`double`	`1.0`	Horizontal Z frequency scale
`Jitter`	`double`	`0.5`	Cell point randomization amount
`Octaves`	`int`	`1`	Number of noise octaves
`Seed`	`string`	`"A"`	Seed string for deterministic generation
`ReturnType`	`ReturnTypeAsset`	—	Determines what value the cell noise returns (see ReturnType Assets)

Inputs: 0

{
  "Type": "CellNoise2D",
  "Seed": "biome_regions",
  "ScaleX": 0.005,
  "ScaleZ": 0.005,
  "Jitter": 0.45,
  "Octaves": 1,
  "ReturnType": {
    "Type": "Distance"
  }
}

`CellNoise3D`

3D cellular/Voronoi noise with independent X, Y, Z scaling.

Field	Type	Default	Description
`ScaleX`	`double`	`1.0`	X frequency scale
`ScaleY`	`double`	`1.0`	Y frequency scale
`ScaleZ`	`double`	`1.0`	Z frequency scale
`Jitter`	`double`	`0.5`	Cell point randomization amount
`Octaves`	`int`	`1`	Number of noise octaves
`Seed`	`string`	`"A"`	Seed string for deterministic generation
`ReturnType`	`ReturnTypeAsset`	—	Determines what value the cell noise returns (see ReturnType Assets)

Inputs: 0

{
  "Type": "CellNoise3D",
  "Seed": "ore_pockets",
  "ScaleX": 0.1,
  "ScaleY": 0.15,
  "ScaleZ": 0.1,
  "Jitter": 0.5,
  "Octaves": 1,
  "ReturnType": {
    "Type": "CellValue"
  }
}

Math Operations

Nine types for arithmetic operations on density values.

`Constant`

Returns a fixed value. The simplest density node.

Field	Type	Default	Description
`Value`	`double`	required	The constant value to return

Inputs: 0

{
  "Type": "Constant",
  "Value": 64.0
}

`Sum`

Adds all input values together. Accepts a variable number of inputs.

Inputs: Variable (sums all)

{
  "Type": "Sum",
  "Inputs": [
    { "Type": "SimplexNoise2D", "Seed": "base", "Scale": 0.005 },
    { "Type": "Constant", "Value": 100.0 }
  ]
}

`Multiplier`

Multiplies all input values together. Accepts a variable number of inputs.

Inputs: Variable (multiplies all)

{
  "Type": "Multiplier",
  "Inputs": [
    { "Type": "SimplexNoise2D", "Seed": "amp", "Scale": 0.001 },
    { "Type": "Constant", "Value": 50.0 }
  ]
}

`Abs`

Returns the absolute value of the input.

Inputs: 1

{
  "Type": "Abs",
  "Inputs": [
    { "Type": "SimplexNoise3D", "Seed": "ridges", "ScaleXZ": 0.01, "ScaleY": 0.02 }
  ]
}

`Inverter`

Negates the input value (multiplies by -1).

Inputs: 1

{
  "Type": "Inverter",
  "Inputs": [
    { "Type": "YValue" }
  ]
}

`Sqrt`

Returns the square root of the input value.

Inputs: 1

{
  "Type": "Sqrt",
  "Inputs": [
    { "Type": "Distance" }
  ]
}

`Pow`

Raises the input to the specified exponent.

Field	Type	Default	Description
`Exponent`	`double`	`1.0`	The power to raise the input to

Inputs: 1

{
  "Type": "Pow",
  "Exponent": 2.0,
  "Inputs": [
    { "Type": "SimplexNoise2D", "Seed": "terrain", "Scale": 0.01 }
  ]
}

`OffsetConstant`

Legacy constant representing an offset value. Returns a fixed constant. Retained for backward compatibility.

Inputs: 0

{
  "Type": "OffsetConstant"
}

`AmplitudeConstant`

Legacy constant representing an amplitude value. Returns a fixed constant. Retained for backward compatibility.

Inputs: 0

{
  "Type": "AmplitudeConstant"
}

Clamping & Range

Ten types for constraining and selecting value ranges.

`Clamp`

Clamps the input value between WallA and WallB.

Field	Type	Default	Description
`WallA`	`double`	—	Lower bound
`WallB`	`double`	—	Upper bound

Inputs: 1

{
  "Type": "Clamp",
  "WallA": 0.0,
  "WallB": 1.0,
  "Inputs": [
    { "Type": "SimplexNoise2D", "Seed": "mask", "Scale": 0.01 }
  ]
}

`SmoothClamp`

Smooth (differentiable) clamping with a configurable smoothing range at the boundaries.

Field	Type	Default	Description
`WallA`	`double`	`-1.0`	Lower bound
`WallB`	`double`	`1.0`	Upper bound
`Range`	`double`	`0.01`	Smoothing transition range at the clamp boundaries

Inputs: 1

{
  "Type": "SmoothClamp",
  "WallA": -1.0,
  "WallB": 1.0,
  "Range": 0.1,
  "Inputs": [
    { "Type": "SimplexNoise3D", "Seed": "smooth_terrain", "ScaleXZ": 0.01, "ScaleY": 0.02 }
  ]
}

`Floor`

Applies a hard lower limit. Values below Limit are set to Limit.

Field	Type	Default	Description
`Limit`	`double`	`0.0`	Minimum allowed value

Inputs: 1

{
  "Type": "Floor",
  "Limit": 0.0,
  "Inputs": [
    { "Type": "SimplexNoise2D", "Seed": "height", "Scale": 0.003 }
  ]
}

`SmoothFloor`

Smooth lower limit with a gradual transition zone.

Field	Type	Default	Description
`Limit`	`double`	—	Minimum allowed value
`SmoothRange`	`double`	`1.0`	Transition distance below the limit

Inputs: 1

{
  "Type": "SmoothFloor",
  "Limit": 0.0,
  "SmoothRange": 2.0,
  "Inputs": [
    { "Type": "Sum", "Inputs": [] }
  ]
}

`Ceiling`

Applies a hard upper limit. Values above Limit are set to Limit.

Field	Type	Default	Description
`Limit`	`double`	—	Maximum allowed value

Inputs: 1

{
  "Type": "Ceiling",
  "Limit": 200.0,
  "Inputs": [
    { "Type": "YValue" }
  ]
}

`SmoothCeiling`

Smooth upper limit with a gradual transition zone.

Field	Type	Default	Description
`Limit`	`double`	—	Maximum allowed value
`SmoothRange`	`double`	`1.0`	Transition distance above the limit

Inputs: 1

{
  "Type": "SmoothCeiling",
  "Limit": 256.0,
  "SmoothRange": 4.0,
  "Inputs": [
    { "Type": "YValue" }
  ]
}

`Min`

Returns the minimum value from all inputs. Accepts a variable number of inputs.

Inputs: Variable

{
  "Type": "Min",
  "Inputs": [
    { "Type": "SimplexNoise2D", "Seed": "a", "Scale": 0.01 },
    { "Type": "SimplexNoise2D", "Seed": "b", "Scale": 0.02 }
  ]
}

`SmoothMin`

Smooth minimum of two inputs with a configurable blending range (polynomial smooth min).

Field	Type	Default	Description
`Range`	`double`	`1.0`	Blending distance between the two values

Inputs: 2

{
  "Type": "SmoothMin",
  "Range": 4.0,
  "Inputs": [
    { "Type": "Distance" },
    { "Type": "Constant", "Value": 10.0 }
  ]
}

`Max`

Returns the maximum value from all inputs. Accepts a variable number of inputs.

Inputs: Variable

{
  "Type": "Max",
  "Inputs": [
    { "Type": "SimplexNoise2D", "Seed": "a", "Scale": 0.01 },
    { "Type": "Constant", "Value": 0.0 }
  ]
}

`SmoothMax`

Smooth maximum of two inputs with a configurable blending range.

Field	Type	Default	Description
`Range`	`double`	`1.0`	Blending distance between the two values

Inputs: 2

{
  "Type": "SmoothMax",
  "Range": 2.0,
  "Inputs": [
    { "Type": "Terrain" },
    { "Type": "Constant", "Value": -5.0 }
  ]
}

Mapping & Remapping

Three types for transforming value ranges.

`Normalizer`

Linearly remaps a value from one range to another.

Field	Type	Default	Description
`FromMin`	`double`	`0.0`	Source range minimum
`FromMax`	`double`	`1.0`	Source range maximum
`ToMin`	`double`	`0.0`	Target range minimum
`ToMax`	`double`	`1.0`	Target range maximum

Inputs: 1

{
  "Type": "Normalizer",
  "FromMin": -1.0,
  "FromMax": 1.0,
  "ToMin": 0.0,
  "ToMax": 100.0,
  "Inputs": [
    { "Type": "SimplexNoise2D", "Seed": "height", "Scale": 0.005 }
  ]
}

`CurveMapper`

Remaps the input value through an arbitrary curve defined by a CurveAsset.

Field	Type	Default	Description
`Curve`	`CurveAsset`	—	The curve used to remap the input value

Inputs: 1

{
  "Type": "CurveMapper",
  "Curve": {
    "Type": "SimpleCurve",
    "Points": [
      [0.0, 0.0],
      [0.5, 0.8],
      [1.0, 1.0]
    ]
  },
  "Inputs": [
    { "Type": "SimplexNoise2D", "Seed": "contour", "Scale": 0.003 }
  ]
}

`Offset` / `Amplitude`

Legacy remapping types. Apply a Y-dependent function for offset or amplitude modification.

Field	Type	Default	Description
`FunctionForY`	`NodeFunctionYOutAsset`	—	Y-axis dependent function applied to the input

Inputs: 1 each

{
  "Type": "Offset",
  "FunctionForY": { "Type": "Linear", "Slope": 0.5, "Intercept": 64.0 },
  "Inputs": [
    { "Type": "SimplexNoise2D", "Seed": "base", "Scale": 0.005 }
  ]
}

Mixing & Blending

Two types for blending between density values.

`Mix`

Linear interpolation (lerp) between two values. Input 0 is a, input 1 is b, input 2 is the factor (0.0 returns a, 1.0 returns b).

Inputs: 3 (a, b, factor)

{
  "Type": "Mix",
  "Inputs": [
    { "Type": "SimplexNoise2D", "Seed": "plains", "Scale": 0.003 },
    { "Type": "SimplexNoise2D", "Seed": "mountains", "Scale": 0.001 },
    { "Type": "SimplexNoise2D", "Seed": "blend", "Scale": 0.0005 }
  ]
}

`MultiMix`

Piecewise linear blending across multiple inputs using keyed breakpoints. Each key defines a threshold value; the density smoothly transitions between adjacent inputs as the first input crosses key boundaries.

Field	Type	Default	Description
`Keys`	`KeyAsset[]`	—	Array of key breakpoints defining the piecewise transitions

Inputs: Variable (one per segment)

{
  "Type": "MultiMix",
  "Keys": [
    { "Value": 0.0 },
    { "Value": 0.33 },
    { "Value": 0.66 },
    { "Value": 1.0 }
  ],
  "Inputs": [
    { "Type": "SimplexNoise2D", "Seed": "selector", "Scale": 0.001 },
    { "Type": "Constant", "Value": 60.0 },
    { "Type": "Constant", "Value": 80.0 },
    { "Type": "Constant", "Value": 120.0 }
  ]
}

Coordinate Transforms

Seven types for transforming the coordinate space before evaluating child inputs.

`Scale`

Scales the sampling coordinates by independent per-axis factors.

Field	Type	Default	Description
`ScaleX`	`double`	`1.0`	X-axis scale factor
`ScaleY`	`double`	`1.0`	Y-axis scale factor
`ScaleZ`	`double`	`1.0`	Z-axis scale factor

Inputs: 1

{
  "Type": "Scale",
  "ScaleX": 2.0,
  "ScaleY": 0.5,
  "ScaleZ": 2.0,
  "Inputs": [
    { "Type": "SimplexNoise3D", "Seed": "detail", "ScaleXZ": 0.1, "ScaleY": 0.1 }
  ]
}

`Slider`

Translates (offsets) the sampling coordinates by a fixed amount per axis.

Field	Type	Default	Description
`SlideX`	`double`	`0.0`	X-axis offset
`SlideY`	`double`	`0.0`	Y-axis offset
`SlideZ`	`double`	`0.0`	Z-axis offset

Inputs: 1

{
  "Type": "Slider",
  "SlideY": -64.0,
  "Inputs": [
    { "Type": "SimplexNoise3D", "Seed": "shifted", "ScaleXZ": 0.02, "ScaleY": 0.02 }
  ]
}

`Rotator`

Rotates the coordinate space by redefining the Y axis and applying a spin angle.

Field	Type	Default	Description
`NewYAxis`	`Vector3d`	—	The new Y-axis direction vector
`SpinAngle`	`double`	—	Rotation angle (radians) around the new Y axis

Inputs: 1

{
  "Type": "Rotator",
  "NewYAxis": [0.0, 1.0, 0.0],
  "SpinAngle": 0.785,
  "Inputs": [
    { "Type": "SimplexNoise3D", "Seed": "rotated", "ScaleXZ": 0.01, "ScaleY": 0.01 }
  ]
}

`Anchor`

Switches the sampling position to use the density anchor point from the context, enabling relative-to-anchor calculations.

Field	Type	Default	Description
`Reversed`	`boolean`	`false`	If `true`, inverts the anchor direction

Inputs: 1

{
  "Type": "Anchor",
  "Reversed": false,
  "Inputs": [
    { "Type": "Distance" }
  ]
}

`XOverride`

Overrides the X coordinate of the sampling position with a fixed value.

Field	Type	Default	Description
`Value`	`double`	—	The fixed X coordinate value

Inputs: 1

{
  "Type": "XOverride",
  "Value": 0.0,
  "Inputs": [
    { "Type": "SimplexNoise2D", "Seed": "stripe", "Scale": 0.01 }
  ]
}

`YOverride`

Overrides the Y coordinate of the sampling position with a fixed value.

Field	Type	Default	Description
`Value`	`double`	—	The fixed Y coordinate value

Inputs: 1

{
  "Type": "YOverride",
  "Value": 64.0,
  "Inputs": [
    { "Type": "SimplexNoise3D", "Seed": "flat_sample", "ScaleXZ": 0.01, "ScaleY": 0.01 }
  ]
}

`ZOverride`

Overrides the Z coordinate of the sampling position with a fixed value.

Field	Type	Default	Description
`Value`	`double`	—	The fixed Z coordinate value

Inputs: 1

{
  "Type": "ZOverride",
  "Value": 0.0,
  "Inputs": [
    { "Type": "SimplexNoise2D", "Seed": "column", "Scale": 0.01 }
  ]
}

Warping

Three types for spatially distorting the coordinate space of a child density function.

`GradientWarp`

Warps the sampling position along the gradient of a secondary density field. Displaces coordinates in the direction of steepest change, creating organic distortions.

Field	Type	Default	Description
`SampleRange`	`double`	`1.0`	Distance used to compute the gradient via finite differences
`WarpFactor`	`double`	`1.0`	Strength multiplier for the warp displacement
`2D`	`boolean`	—	If `true`, performs 2D gradient warp (XZ only)
`YFor2D`	`double`	—	Fixed Y value used when `2D` is `true`

Inputs: 2 (input 0 = density to warp, input 1 = gradient source field)

{
  "Type": "GradientWarp",
  "SampleRange": 2.0,
  "WarpFactor": 8.0,
  "2D": false,
  "Inputs": [
    { "Type": "SimplexNoise3D", "Seed": "base", "ScaleXZ": 0.01, "ScaleY": 0.01 },
    { "Type": "SimplexNoise3D", "Seed": "warp_field", "ScaleXZ": 0.005, "ScaleY": 0.005 }
  ]
}

`FastGradientWarp`

A performance-optimized gradient warp using built-in noise generation. Avoids the need for a separate gradient source input.

Field	Type	Default	Description
`WarpScale`	`float`	`1.0`	Scale of the warp noise field
`WarpOctaves`	`int`	`1`	Number of noise octaves for the warp field
`WarpLacunarity`	`float`	`2.0`	Lacunarity of the warp noise
`WarpPersistence`	`float`	`0.5`	Persistence of the warp noise
`WarpFactor`	`float`	`1.0`	Strength multiplier for the displacement
`Seed`	`string`	`"A"`	Seed string for the internal warp noise

Inputs: 1

{
  "Type": "FastGradientWarp",
  "WarpScale": 0.01,
  "WarpOctaves": 2,
  "WarpFactor": 5.0,
  "Seed": "fast_warp",
  "Inputs": [
    { "Type": "SimplexNoise2D", "Seed": "terrain", "Scale": 0.005 }
  ]
}

`VectorWarp`

Warps the sampling position by a fixed direction vector scaled by a secondary density field.

Field	Type	Default	Description
`WarpFactor`	`double`	`1.0`	Strength multiplier for the displacement
`WarpVector`	`Vector3d`	—	Direction vector of the warp displacement

Inputs: 2 (input 0 = density to warp, input 1 = warp magnitude source)

{
  "Type": "VectorWarp",
  "WarpFactor": 3.0,
  "WarpVector": [1.0, 0.0, 0.0],
  "Inputs": [
    { "Type": "SimplexNoise3D", "Seed": "base", "ScaleXZ": 0.02, "ScaleY": 0.02 },
    { "Type": "SimplexNoise2D", "Seed": "warp_amount", "Scale": 0.005 }
  ]
}

Shape Primitives

Nine types that generate density fields based on geometric distance calculations. These are leaf nodes (no density inputs) that compute distance from the origin or anchor point to define shapes.

`Distance`

Spherical distance from the origin (or anchor). Returns a value based on the Euclidean distance, remapped through an optional curve.

Field	Type	Default	Description
`Curve`	`CurveAsset`	—	Curve to remap the raw distance value

Inputs: 0

{
  "Type": "Distance",
  "Curve": {
    "Type": "SimpleCurve",
    "Points": [[0.0, 1.0], [10.0, 0.0]]
  }
}

`Cube`

Cubic distance from the origin. Uses the maximum absolute coordinate component (Chebyshev distance) to define a cube shape.

Field	Type	Default	Description
`Curve`	`CurveAsset`	—	Curve to remap the raw distance value

Inputs: 0

{
  "Type": "Cube",
  "Curve": {
    "Type": "SimpleCurve",
    "Points": [[0.0, 1.0], [5.0, 0.0]]
  }
}

`Ellipsoid`

Ellipsoidal distance with per-axis scaling and optional rotation.

Field	Type	Default	Description
`Curve`	`CurveAsset`	—	Curve to remap the raw distance value
`Scale`	`Vector3d`	`[1, 1, 1]`	Per-axis scale factors defining the ellipsoid radii
`NewYAxis`	`Vector3d`	`[0, 1, 0]`	Reorientation of the Y axis
`Spin`	`double`	—	Rotation angle around the new Y axis

Inputs: 0

{
  "Type": "Ellipsoid",
  "Scale": [10.0, 5.0, 10.0],
  "NewYAxis": [0.0, 1.0, 0.0],
  "Spin": 0.0,
  "Curve": {
    "Type": "SimpleCurve",
    "Points": [[0.0, 1.0], [1.0, 0.0]]
  }
}

`Cuboid`

Oriented box shape with per-axis scaling and rotation.

Field	Type	Default	Description
`Curve`	`CurveAsset`	—	Curve to remap the raw distance value
`Scale`	`Vector3d`	`[1, 1, 1]`	Per-axis scale factors defining the cuboid dimensions
`NewYAxis`	`Vector3d`	`[0, 1, 0]`	Reorientation of the Y axis
`Spin`	`double`	—	Rotation angle around the new Y axis

Inputs: 0

{
  "Type": "Cuboid",
  "Scale": [8.0, 4.0, 8.0],
  "NewYAxis": [0.0, 1.0, 0.0],
  "Spin": 0.5,
  "Curve": {
    "Type": "SimpleCurve",
    "Points": [[0.0, 1.0], [1.0, 0.0]]
  }
}

`Cylinder`

Cylindrical shape with separate radial and axial curves for independent falloff control.

Field	Type	Default	Description
`RadialCurve`	`CurveAsset`	—	Curve controlling radial (cross-section) falloff
`AxialCurve`	`CurveAsset`	—	Curve controlling axial (along-length) falloff
`NewYAxis`	`Vector3d`	`[0, 1, 0]`	Orientation axis of the cylinder
`Spin`	`double`	—	Rotation angle around the cylinder axis

Inputs: 0

{
  "Type": "Cylinder",
  "NewYAxis": [0.0, 1.0, 0.0],
  "Spin": 0.0,
  "RadialCurve": {
    "Type": "SimpleCurve",
    "Points": [[0.0, 1.0], [5.0, 0.0]]
  },
  "AxialCurve": {
    "Type": "SimpleCurve",
    "Points": [[0.0, 1.0], [10.0, 0.0]]
  }
}

`Plane`

Density based on signed distance to an infinite plane.

Field	Type	Default	Description
`Curve`	`CurveAsset`	—	Curve to remap the signed distance
`IsAnchored`	`boolean`	—	If `true`, the plane passes through the density anchor
`PlaneNormal`	`Vector3d`	`[0, 1, 0]`	Normal vector defining the plane orientation

Inputs: 0

{
  "Type": "Plane",
  "IsAnchored": true,
  "PlaneNormal": [0.0, 1.0, 0.0],
  "Curve": {
    "Type": "SimpleCurve",
    "Points": [[-10.0, 1.0], [0.0, 0.5], [10.0, 0.0]]
  }
}

`Axis`

Density based on distance from an infinite line (axis).

Field	Type	Default	Description
`Curve`	`CurveAsset`	—	Curve to remap the distance
`IsAnchored`	`boolean`	—	If `true`, the axis passes through the density anchor
`Axis`	`Vector3d`	`[0, 1, 0]`	Direction vector of the axis

Inputs: 0

{
  "Type": "Axis",
  "IsAnchored": true,
  "Axis": [0.0, 1.0, 0.0],
  "Curve": {
    "Type": "SimpleCurve",
    "Points": [[0.0, 1.0], [8.0, 0.0]]
  }
}

`Shell`

Generates a shell shape based on angle and distance curves, useful for creating shell-like or petal-like forms.

Field	Type	Default	Description
`Axis`	`Vector3d`	—	Central axis of the shell
`Mirror`	`boolean`	—	If `true`, mirrors the shape across the axis
`AngleCurve`	`CurveAsset`	—	Curve defining the angular profile
`DistanceCurve`	`CurveAsset`	—	Curve defining the distance-based falloff

Inputs: 0

{
  "Type": "Shell",
  "Axis": [0.0, 1.0, 0.0],
  "Mirror": true,
  "AngleCurve": {
    "Type": "SimpleCurve",
    "Points": [[0.0, 1.0], [3.14, 0.0]]
  },
  "DistanceCurve": {
    "Type": "SimpleCurve",
    "Points": [[0.0, 1.0], [5.0, 0.0]]
  }
}

`Angle`

Returns the angle between a reference vector and either a vector provider output or a fixed direction.

Field	Type	Default	Description
`VectorProvider`	`VectorProviderAsset`	—	Provides the reference vector
`Vector`	`Vector3d`	—	Fixed comparison vector
`IsAxis`	`boolean`	—	If `true`, computes the angle relative to an axis rather than a direction

Inputs: 0

{
  "Type": "Angle",
  "Vector": [0.0, 1.0, 0.0],
  "IsAxis": false,
  "VectorProvider": {
    "Type": "Constant",
    "Value": [1.0, 0.0, 0.0]
  }
}

Coordinate Accessors

Three types that directly return one of the current sampling coordinates.

`XValue`

Returns the X coordinate of the current sampling position.

Inputs: 0

{
  "Type": "XValue"
}

`YValue`

Returns the Y coordinate of the current sampling position.

Inputs: 0

{
  "Type": "YValue"
}

`ZValue`

Returns the Z coordinate of the current sampling position.

Inputs: 0

{
  "Type": "ZValue"
}

Context Accessors

Four types that read values from the Density.Context rather than computing them.

`Terrain`

Returns the terrain density at the current sampling position by querying the context's terrainDensityProvider.

Inputs: 0

{
  "Type": "Terrain"
}

`BaseHeight`

Returns the base terrain height for the current column, optionally as a distance from the sampling position.

Field	Type	Default	Description
`BaseHeightName`	`string`	—	Name identifier for the base height source
`Distance`	`boolean`	—	If `true`, returns distance from sampling Y to the base height; if `false`, returns the raw height value

Inputs: 0

{
  "Type": "BaseHeight",
  "BaseHeightName": "surface",
  "Distance": true
}

`CellWallDistance`

Returns the distanceFromCellWall value from the context. Useful for creating features that respond to cell/Voronoi boundaries.

Inputs: 0

{
  "Type": "CellWallDistance"
}

`DistanceToBiomeEdge`

Returns the distanceToBiomeEdge value from the context. Useful for biome transition blending.

Inputs: 0

{
  "Type": "DistanceToBiomeEdge"
}

Gradient

One type for computing directional gradients of density fields.

`Gradient`

Computes the directional derivative (gradient) of the input density along a specified axis direction using finite differences.

Field	Type	Default	Description
`Axis`	`Vector3d`	`[0, 1, 0]`	Direction along which to compute the gradient
`SampleRange`	`double`	`1.0`	Distance between the two sample points for finite differences

Inputs: 1

{
  "Type": "Gradient",
  "Axis": [0.0, 1.0, 0.0],
  "SampleRange": 1.0,
  "Inputs": [
    { "Type": "Terrain" }
  ]
}

Caching

Three types for caching density evaluation results to avoid redundant computation.

`Cache`

Caches the most recently evaluated positions and their results. Provides a simple LRU-style cache.

Field	Type	Default	Description
`Capacity`	`int`	`3`	Number of cached position/result pairs

Inputs: 1

{
  "Type": "Cache",
  "Capacity": 8,
  "Inputs": [
    { "Type": "SimplexNoise3D", "Seed": "expensive", "ScaleXZ": 0.001, "ScaleY": 0.001, "Octaves": 6 }
  ]
}

`Cache2D`

Deprecated. 2D position cache that only considers the (x, z) coordinates. Retained for backward compatibility.

Inputs: 1

{
  "Type": "Cache2D",
  "Inputs": [
    { "Type": "SimplexNoise2D", "Seed": "height_cache", "Scale": 0.005 }
  ]
}

`YSampled`

Vertical interpolation optimization. Samples the input at regular Y intervals and interpolates between them, significantly reducing evaluation cost for densities that vary smoothly along the Y axis.

Field	Type	Default	Description
`SampleDistance`	`double`	`4.0`	Vertical distance between sample points
`SampleOffset`	`double`	`0.0`	Vertical offset for the sampling grid

Inputs: 1

{
  "Type": "YSampled",
  "SampleDistance": 4.0,
  "SampleOffset": 0.0,
  "Inputs": [
    { "Type": "SimplexNoise3D", "Seed": "terrain_3d", "ScaleXZ": 0.01, "ScaleY": 0.02 }
  ]
}

Conditional

Two types for branching the density graph based on runtime state.

`Switch`

Selects one of several child density functions based on the current switchState in the context. Each case maps a state hash to an input index.

Field	Type	Default	Description
`SwitchCases`	`SwitchCaseAsset[]`	—	Array of case definitions mapping state hashes to input indices

Inputs: Variable (one per case)

{
  "Type": "Switch",
  "SwitchCases": [
    { "State": "plains", "InputIndex": 0 },
    { "State": "mountains", "InputIndex": 1 },
    { "State": "ocean", "InputIndex": 2 }
  ],
  "Inputs": [
    { "Type": "Constant", "Value": 64.0 },
    { "Type": "Constant", "Value": 128.0 },
    { "Type": "Constant", "Value": 32.0 }
  ]
}

`SwitchState`

Sets the switchState in the context before evaluating the child input. Used to configure downstream Switch nodes.

Field	Type	Default	Description
`SwitchState`	`string`	—	State string that is hashed and set as the current switch state

Inputs: 1

{
  "Type": "SwitchState",
  "SwitchState": "mountains",
  "Inputs": [
    { "Type": "Switch", "SwitchCases": [] }
  ]
}

Positions-Based

Four types that operate using the positions-based anchor and context for cell-noise-driven generation systems.

`PositionsCellNoise`

Generates density based on cell noise position data. Integrates with the positions-based pipeline where candidate positions are generated from cell noise patterns.

Inputs: Variable

{
  "Type": "PositionsCellNoise"
}

`Positions3D`

3D position-based density evaluation. Samples density at positions defined by the positions anchor system.

Inputs: Variable

{
  "Type": "Positions3D"
}

`PositionsPinch`

Applies a spatial pinch effect, compressing or expanding space toward/away from a point. Used for creating organic deformations in position-based generation.

Inputs: Variable

{
  "Type": "PositionsPinch"
}

`PositionsTwist`

Applies a spatial twist effect, rotating space progressively along an axis. Used for creating spiraling or twisted formations.

Inputs: Variable

{
  "Type": "PositionsTwist"
}

Import / Export / Pipeline

Three types for composing and reusing density graphs.

`Exported`

Wraps a density function for export. The wrapped density is registered under its ExportAs name and cached with SingleInstance optimization -- meaning the density is built once and shared across all references.

Inputs: 1

{
  "Type": "Exported",
  "ExportAs": "shared_terrain_noise",
  "Inputs": [
    {
      "Type": "SimplexNoise2D",
      "Seed": "terrain",
      "Scale": 0.003,
      "Octaves": 4,
      "Lacunarity": 2.0,
      "Persistence": 0.5
    }
  ]
}

`Imported`

References a previously exported density function by name. At build time, the imported density resolves to the SingleInstance-cached version of the exported density.

Field	Type	Default	Description
`Name`	`string`	—	Name of the exported density to import

Inputs: 0

{
  "Type": "Imported",
  "Name": "shared_terrain_noise"
}

`Pipeline`

A complex composition node that chains density functions in a sequential pipeline. Each stage of the pipeline can modify or build upon the previous stage's output.

Inputs: Variable

{
  "Type": "Pipeline",
  "Inputs": [
    { "Type": "SimplexNoise2D", "Seed": "base_height", "Scale": 0.003 },
    { "Type": "Normalizer", "FromMin": -1.0, "FromMax": 1.0, "ToMin": 40.0, "ToMax": 120.0 },
    { "Type": "Cache", "Capacity": 4 }
  ]
}

Export / Import System

Any density function can set the ExportAs field (from DensityAsset.ABSTRACT_CODEC) to register itself under a name string. Other density functions anywhere in the graph can then use the Imported type with that name to reference the same density.

The ExportedDensityAsset class adds SingleInstance caching optimization: the density is built exactly once during the build phase and the same runtime instance is shared across all import references. This is critical for performance when the same expensive noise function or density sub-graph is used by multiple biomes or terrain layers.

{
  "Type": "Sum",
  "Inputs": [
    {
      "Type": "SimplexNoise2D",
      "Seed": "continent",
      "Scale": 0.0005,
      "Octaves": 6,
      "ExportAs": "continent_noise"
    },
    {
      "Type": "Multiplier",
      "Inputs": [
        { "Type": "Imported", "Name": "continent_noise" },
        { "Type": "Constant", "Value": 80.0 }
      ]
    }
  ]
}

ReturnType Assets

Cell noise functions (CellNoise2D, CellNoise3D) use a ReturnType field to select what value the noise returns. There are 10 registered return type assets:

Type String	Description
`CellValue`	Returns the random value assigned to the nearest cell
`Curve`	Returns a curve-remapped value
`Distance`	Returns the distance to the nearest cell point
`Distance2`	Returns the distance to the second-nearest cell point
`Distance2Add`	Returns `Distance + Distance2`
`Distance2Sub`	Returns `Distance2 - Distance` (creates cell edge patterns)
`Distance2Mul`	Returns `Distance * Distance2`
`Distance2Div`	Returns `Distance / Distance2`
`Imported`	References an exported return type
`Density`	Uses a density function to compute the return value

{
  "Type": "CellNoise2D",
  "Seed": "edge_detect",
  "ScaleX": 0.01,
  "ScaleZ": 0.01,
  "ReturnType": {
    "Type": "Distance2Sub"
  }
}

DistanceFunction Assets

Cell noise calculations support 2 registered distance function types that define the distance metric used:

Type String	Description
`Euclidean`	Standard Euclidean distance (`sqrt(dx^2 + dy^2 + dz^2)`)
`Manhattan`	Manhattan/taxicab distance (`

{
  "ReturnType": {
    "Type": "Distance",
    "DistanceFunction": {
      "Type": "Manhattan"
    }
  }
}

Complete Type Summary

Category	Count	Types
Noise Generators	4	`SimplexNoise2D`, `SimplexNoise3D`, `CellNoise2D`, `CellNoise3D`
Math Operations	9	`Constant`, `Sum`, `Multiplier`, `Abs`, `Inverter`, `Sqrt`, `Pow`, `OffsetConstant`, `AmplitudeConstant`
Clamping & Range	10	`Clamp`, `SmoothClamp`, `Floor`, `SmoothFloor`, `Ceiling`, `SmoothCeiling`, `Min`, `SmoothMin`, `Max`, `SmoothMax`
Mapping & Remapping	3	`Normalizer`, `CurveMapper`, `Offset`/`Amplitude`
Mixing & Blending	2	`Mix`, `MultiMix`
Coordinate Transforms	7	`Scale`, `Slider`, `Rotator`, `Anchor`, `XOverride`, `YOverride`, `ZOverride`
Warping	3	`GradientWarp`, `FastGradientWarp`, `VectorWarp`
Shape Primitives	9	`Distance`, `Cube`, `Ellipsoid`, `Cuboid`, `Cylinder`, `Plane`, `Axis`, `Shell`, `Angle`
Coordinate Accessors	3	`XValue`, `YValue`, `ZValue`
Context Accessors	4	`Terrain`, `BaseHeight`, `CellWallDistance`, `DistanceToBiomeEdge`
Gradient	1	`Gradient`
Caching	3	`Cache`, `Cache2D`, `YSampled`
Conditional	2	`Switch`, `SwitchState`
Positions-Based	4	`PositionsCellNoise`, `Positions3D`, `PositionsPinch`, `PositionsTwist`
Import/Export/Pipeline	3	`Exported`, `Imported`, `Pipeline`
Total	68

Source files: AssetManager.java, DensityAsset.java, Density.java, SimplexNoise2dDensityAsset.java, SimplexNoise3dDensityAsset.java, CellNoise2dDensityAsset.java, CellNoise3dDensityAsset.java, ConstantDensityAsset.java, SumDensityAsset.java, MultiplierDensityAsset.java, AbsDensityAsset.java, InverterDensityAsset.java, SqrtDensityAsset.java, PowDensityAsset.java, ClampDensityAsset.java, SmoothClampDensityAsset.java, FloorDensityAsset.java, SmoothFloorDensityAsset.java, CeilingDensityAsset.java, SmoothCeilingDensityAsset.java, MinDensityAsset.java, SmoothMinDensityAsset.java, MaxDensityAsset.java, SmoothMaxDensityAsset.java, NormalizerDensityAsset.java, CurveMapperDensityAsset.java, MixDensityAsset.java, MultiMixDensityAsset.java, ScaleDensityAsset.java, SliderDensityAsset.java, RotatorDensityAsset.java, AnchorDensityAsset.java, GradientWarpDensityAsset.java, FastGradientWarpDensityAsset.java, VectorWarpDensityAsset.java, DistanceDensityAsset.java, CubeDensityAsset.java, EllipsoidDensityAsset.java, CuboidDensityAsset.java, CylinderDensityAsset.java, PlaneDensityAsset.java, AxisDensityAsset.java, ShellDensityAsset.java, AngleDensityAsset.java, GradientDensityAsset.java, CacheDensityAsset.java, YSampledDensityAsset.java, SwitchDensityAsset.java, SwitchStateDensityAsset.java, ExportedDensityAsset.java, ImportedDensityAsset.java, PipelineDensityAsset.java, ReturnTypeAsset.java, DistanceFunctionAsset.java

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Density Functions

Common Fields

Density.Context

Type Reference

Noise Generators

SimplexNoise2D

SimplexNoise3D

CellNoise2D

CellNoise3D

Math Operations

Constant

Sum

Multiplier

Abs

Inverter

Sqrt

Pow

OffsetConstant

AmplitudeConstant

Clamping & Range

Clamp

SmoothClamp

Floor

SmoothFloor

Ceiling

SmoothCeiling

Min

SmoothMin

Max

SmoothMax

Mapping & Remapping

Normalizer

CurveMapper

Offset / Amplitude

Mixing & Blending

Mix

MultiMix

Coordinate Transforms

Scale

Slider

Rotator

Anchor

XOverride

YOverride

ZOverride

Warping

GradientWarp

FastGradientWarp

VectorWarp

Shape Primitives

Distance

Cube

Ellipsoid

Cuboid

Cylinder

Plane

Axis

Shell

Angle

Coordinate Accessors

XValue

YValue

ZValue

Context Accessors

Terrain

BaseHeight

CellWallDistance

DistanceToBiomeEdge

Gradient

Gradient

Caching

Cache

Cache2D

YSampled

`SimplexNoise2D`

`SimplexNoise3D`

`CellNoise2D`

`CellNoise3D`

`Constant`

`Sum`

`Multiplier`

`Abs`

`Inverter`

`Sqrt`

`Pow`

`OffsetConstant`

`AmplitudeConstant`

`Clamp`

`SmoothClamp`

`Floor`

`SmoothFloor`

`Ceiling`

`SmoothCeiling`

`Min`

`SmoothMin`

`Max`

`SmoothMax`

`Normalizer`

`CurveMapper`

`Offset` / `Amplitude`

`Mix`

`MultiMix`

`Scale`

`Slider`

`Rotator`

`Anchor`

`XOverride`

`YOverride`

`ZOverride`

`GradientWarp`

`FastGradientWarp`

`VectorWarp`

`Distance`

`Cube`

`Ellipsoid`

`Cuboid`

`Cylinder`

`Plane`

`Axis`

`Shell`

`Angle`

`XValue`

`YValue`

`ZValue`

`Terrain`

`BaseHeight`

`CellWallDistance`

`DistanceToBiomeEdge`

`Gradient`

`Cache`

`Cache2D`

`YSampled`

`Switch`

`SwitchState`

`PositionsCellNoise`

`Positions3D`

`PositionsPinch`

`PositionsTwist`

`Exported`

`Imported`

`Pipeline`