Perlin Noise (Flowgraph Node)

Overview

Node Name: Perlin Noise
Category: repeat_instant
File: extensions/flowgraph/nodes/util/perlinNoise.lua

Generates coherent random numbers using Perlin noise. Produces smooth, natural-looking random values suitable for procedural content.

Pin Schema

Input Pins

Pin	Type	Default	Description
`flow`	flow	-	Input flow
`value`	number	-	Input seed value (e.g., time or distance)
`octaves`	number (hidden)	6	Number of detail levels
`amplitude`	number (hidden)	128	Output value range
`frequency`	number (hidden)	4	Detail density per octave
`normalize`	bool (hidden)	false	Normalize output to -0.5 to 0.5 range
`randomStartSeed`	bool (hidden)	true	Randomize seed each run for varied patterns

Output Pins

Pin	Type	Description
`flow`	flow	Output flow
`value`	number	The generated noise value

Internals

Key Methods

Method	Description
`init()`	Initializes graph data, debug settings, scale range
`drawCustomProperties()`	Provides "Smooth preset" and "Natural preset" buttons
`drawMiddle(builder, style)`	Renders a debug graph of recent output values
`_executionStarted()`	Initializes permutation table, sets random start seed
`work()`	Computes octave Perlin noise from input value, maintains debug graph
`OctavePerlin(x, y, z, octaves, amplitude, frequency)`	Multi-octave noise accumulator
`noise(x, y, z)`	Core Perlin noise function using permutation hash
`grad(hash, x, y, z)`	Gradient function using dot product lookup
`fade(t)`	Smoothstep fade: `6t⁵ - 15t⁴ + 10t³`
`lerp(t, a, b)`	Linear interpolation

Presets

Preset	Frequency	Amplitude	Octaves
Smooth	0.15	64	1
Natural	0.5	128	6

Debug

When data.debug is true, the node displays a scrolling graph of the last 1000 output values in the editor.

How It Works

On execution start, builds the permutation table (classic Perlin noise permutation) and optionally generates a random start seed.
Each frame, computes OctavePerlin(randomStartSeed + inputValue, 0, 0, ...).
Octave noise sums multiple noise passes at increasing frequency and decreasing amplitude.
Core noise() function hashes unit cube coordinates and interpolates gradients using the fade function.
If normalize is enabled, divides the result by the maximum possible value to produce -0.5 to 0.5 range.

Usage Example

-- Generate smooth terrain-like variation:
-- [Timer] → elapsed → value → [Perlin Noise] octaves=6, frequency=0.5
--                                → value → [Scale] → [Set Terrain Height]

-- Use for vehicle body sway animation:
-- [Frame Counter] → count → value → [Perlin Noise] preset=Smooth
--                                     → value → [Apply Camera Offset]

Key Dependencies

bit (bit32) - bitwise operations for permutation hash
Classic Perlin noise permutation table (Ken Perlin's reference implementation)

Overview

Node Name: Perlin Noise
Category: repeat_instant
File: extensions/flowgraph/nodes/util/perlinNoise.lua

Generates coherent random numbers using Perlin noise. Produces smooth, natural-looking random values suitable for procedural content.

Pin Schema

Input Pins

Pin	Type	Default	Description
`flow`	flow	-	Input flow
`value`	number	-	Input seed value (e.g., time or distance)
`octaves`	number (hidden)	6	Number of detail levels
`amplitude`	number (hidden)	128	Output value range
`frequency`	number (hidden)	4	Detail density per octave
`normalize`	bool (hidden)	false	Normalize output to -0.5 to 0.5 range
`randomStartSeed`	bool (hidden)	true	Randomize seed each run for varied patterns

Output Pins

Pin	Type	Description
`flow`	flow	Output flow
`value`	number	The generated noise value

Internals

Key Methods

Method	Description
`init()`	Initializes graph data, debug settings, scale range
`drawCustomProperties()`	Provides "Smooth preset" and "Natural preset" buttons
`drawMiddle(builder, style)`	Renders a debug graph of recent output values
`_executionStarted()`	Initializes permutation table, sets random start seed
`work()`	Computes octave Perlin noise from input value, maintains debug graph
`OctavePerlin(x, y, z, octaves, amplitude, frequency)`	Multi-octave noise accumulator
`noise(x, y, z)`	Core Perlin noise function using permutation hash
`grad(hash, x, y, z)`	Gradient function using dot product lookup
`fade(t)`	Smoothstep fade: `6t⁵ - 15t⁴ + 10t³`
`lerp(t, a, b)`	Linear interpolation

Presets

Preset	Frequency	Amplitude	Octaves
Smooth	0.15	64	1
Natural	0.5	128	6

Debug

When data.debug is true, the node displays a scrolling graph of the last 1000 output values in the editor.

How It Works

On execution start, builds the permutation table (classic Perlin noise permutation) and optionally generates a random start seed.
Each frame, computes OctavePerlin(randomStartSeed + inputValue, 0, 0, ...).
Octave noise sums multiple noise passes at increasing frequency and decreasing amplitude.
Core noise() function hashes unit cube coordinates and interpolates gradients using the fade function.
If normalize is enabled, divides the result by the maximum possible value to produce -0.5 to 0.5 range.

Usage Example

-- Generate smooth terrain-like variation:
-- [Timer] → elapsed → value → [Perlin Noise] octaves=6, frequency=0.5
--                                → value → [Scale] → [Set Terrain Height]

-- Use for vehicle body sway animation:
-- [Frame Counter] → count → value → [Perlin Noise] preset=Smooth
--                                     → value → [Apply Camera Offset]

Key Dependencies

bit (bit32) - bitwise operations for permutation hash
Classic Perlin noise permutation table (Ken Perlin's reference implementation)

Perlin Noise (Flowgraph Node)

Overview

Pin Schema

Input Pins

Output Pins

Internals

Key Methods

Presets

Debug

How It Works

Usage Example

Key Dependencies

See Also

On this page

Perlin Noise (Flowgraph Node)

Overview

Pin Schema

Input Pins

Output Pins

Internals

Key Methods

Presets

Debug

How It Works

Usage Example

Key Dependencies

See Also

On this page