IndieForge – Seeded 2D Perlin Noise

OVERVIEW

This package provides a deterministic, seeded 2D Perlin noise implementation intended for procedural generation in games and simulations. It's meant for those who don't really want to bother learning all the math involved. 

It converts (x, y) coordinates into smooth, natural-looking pseudo-random values. The same seed will always generate the same noise pattern, making it suitable for reproducible worlds, save/load systems, and testing.

This implementation focuses on clarity, performance, and ease of integration.

FEATURES

• Seeded and deterministic output
• Classic gradient-based Perlin noise
• Fractal Brownian Motion (fBm) support
• Lightweight and dependency-free
• Designed for real-time use
• Compatible with Unity, MonoGame, Godot (C#), and similar engines

OUTPUT RANGE

Noise(x, y) returns values approximately in the range:

-1.0 to 1.0

To convert the result to a 0–1 range:

normalized = noise * 0.5 + 0.5

SEEDS AND DETERMINISM

The generator is initialized with an integer seed.

Same seed: • Produces the same noise pattern every time

Different seed: • Produces a completely different noise pattern

Coordinates alone do not define randomness — the seed controls the permutation table used internally.

This behavior is important for: • Procedural worlds • Save/load consistency • Multiplayer synchronization • Debugging and testing

CORE METHODS

Noise(x, y)

Generates 2D Perlin noise at the given coordinates.

• Uses gradient vectors at grid corners
• Smoothly interpolates values
• Avoids visible grid artifacts

Typical usage: Sample noise at scaled coordinates (for example, x * 0.01).

Fbm(x, y, octaves, frequency, gain, lacunarity)

Generates Fractal Brownian Motion by stacking multiple layers of Perlin noise.

Each octave: • Increases frequency (adds detail) • Decreases amplitude (reduces influence)

Common values: • Octaves: 4 to 8
• Frequency: 0.005 to 0.05
• Gain: 0.45 to 0.6
• Lacunarity: 2.0

This method is commonly used for terrain heightmaps and organic patterns.

PERFORMANCE NOTES

• Uses a precomputed permutation table
• No memory allocations during sampling
• No trigonometric functions
• Safe to call frequently

For large worlds, consider caching results or sampling at chunk boundaries.

WHAT THIS CODE DOES NOT DO

• Does not place tiles
• Does not generate meshes
• Does not render graphics
• Does not manage chunks or world data

This code only produces numeric values. Interpretation is left to the user.

FILE CONTENTS

PerlinNoiseC#
ReadMe.txt

LICENSE NOTES

This source code is intended for use in personal and commercial projects.

You may:

 • Use the code in games and tools
• Modify the code
• Integrate it into larger systems

You may not: 

 • Resell or redistribute this exact source code as a standalone asset without modification

Adjust license terms as needed for your release.

Presets

Smooth terrain

• octaves: 4–5

• frequency: 0.008–0.015

• gain: 0.45

• lacunarity: 2.0

Rugged mountains

• octaves: 6–7

• frequency: 0.01–0.02

• gain: 0.6

• lacunarity: 2.0

• plus: power curve Pow(n01, 1.8–2.6)

Cloudy texture

• octaves: 5–6

• frequency: 0.03–0.07

• gain: 0.5

• lacunarity: 2.0

• keep contrast low