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December 18, 2020 20:32
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Ian Parberry's Exponentially Distributed Noise in C#, for Unity
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| using UnityEngine; | |
| using Random = System.Random; | |
| // Code file for 2D Perlin noise with exponentially distributed gradients. | |
| // Copyright Ian Parberry, May 2014. | |
| // | |
| // This file is made available under the GNU All-Permissive License. | |
| // | |
| // Copying and distribution of this file, with or without modification, | |
| // are permitted in any medium without royalty provided the copyright | |
| // notice and this notice are preserved. This file is offered as-is, | |
| // without any warranty. | |
| // Created by Ian Parberry, May 2014. | |
| // Last updated May 31, 2014. | |
| namespace Noise { | |
| class PerlinNoise { | |
| private static readonly float FmSqrt2 = Mathf.Sqrt(2); | |
| private const int B = 0x100; | |
| private const int BM = 0xFF; | |
| private const int N = 0x1000; | |
| private readonly float _mu; | |
| private readonly int _octaves; | |
| private readonly int[] _p = new int[B]; | |
| private readonly Vector2[] _g2 = new Vector2[B]; | |
| private readonly float[] _m = new float[B]; | |
| private readonly Random _random; | |
| public PerlinNoise(float mu, int octaves, int seed) { | |
| _mu = mu; | |
| _octaves = octaves; | |
| _random = new Random(seed); | |
| } | |
| private static float Curve(float t) { | |
| return t * t * (3.0f - 2.0f * t); | |
| } | |
| private static float Dot(float rx, float ry, Vector2 q) { | |
| return rx * q[0] + ry * q[1]; | |
| } | |
| private int Random() { | |
| return _random.Next(32767); | |
| } | |
| private void Normalize(Vector2 v) { | |
| var s = Mathf.Sqrt(v[0] * v[0] + v[1] * v[1]); | |
| v[0] /= s; | |
| v[1] /= s; | |
| } | |
| private float RandomFloat() { | |
| return 2.0F * (float) _random.NextDouble() - 1.0F; | |
| } | |
| public void Initialize() { | |
| for (var i = 0; i < _g2.Length; ++i) { | |
| _g2[i] = new Vector2(0, 0); | |
| } | |
| for (var i = 0; i < B; i++) { | |
| _g2[i][0] = RandomFloat(); | |
| _g2[i][1] = RandomFloat(); | |
| Normalize(_g2[i]); | |
| } | |
| for (var i = 0; i < B; i++) { | |
| _p[i] = i; | |
| } | |
| for (var i = B - 1; i > 0; i--) { | |
| var i1 = i; | |
| var i2 = Random() % (i + 1); | |
| var t = _p[i]; | |
| _p[i1] = _p[i2]; | |
| _p[i2] = t; | |
| } | |
| var s = 1.0F; | |
| for (var i = 0; i < B; i++) { | |
| _m[i] = s; | |
| s /= _mu; | |
| } | |
| } | |
| private float GetNoise(Vector2 vec) { | |
| Vector2 q; | |
| var t0 = vec[0] + N; | |
| var bx0 = (int) t0 & BM; | |
| var bx1 = (bx0 + 1) & BM; | |
| var rx0 = t0 - (int) t0; | |
| var rx1 = rx0 - 1.0F; | |
| var t1 = vec[1] + N; | |
| var by0 = (int) t1 & BM; | |
| var by1 = (by0 + 1) & BM; | |
| var ry0 = t1 - (int) t1; | |
| var ry1 = ry0 - 1.0F; | |
| var b00 = _p[(_p[bx0] + by0) & BM]; | |
| var b10 = _p[(_p[bx1] + by0) & BM]; | |
| var b01 = _p[(_p[bx0] + by1) & BM]; | |
| var b11 = _p[(_p[bx1] + by1) & BM]; | |
| var sx = Curve(rx0); | |
| float u; | |
| float v; | |
| q = _g2[b00]; | |
| u = _m[b00] * Dot(rx0, ry0, q); | |
| q = _g2[b10]; | |
| v = _m[b10] * Dot(rx1, ry0, q); | |
| var a = Mathf.Lerp(u, v, sx); | |
| q = _g2[b01]; | |
| u = _m[b01] * Dot(rx0, ry1, q); | |
| q = _g2[b11]; | |
| v = _m[b11] * Dot(rx1, ry1, q); | |
| var b = Mathf.Lerp(u, v, sx); | |
| var sy = Curve(ry0); | |
| return Mathf.Lerp(a, b, sy); | |
| } | |
| public float GetNoises(Vector2 position) { | |
| var result = 0.0F; | |
| var scale = 1.0F; | |
| for (var i = 0; i < _octaves; i++) { | |
| scale *= 0.5F; | |
| result += GetNoise(position) * scale; | |
| position[0] *= 2.0F; | |
| position[1] *= 2.0F; | |
| } | |
| return FmSqrt2 * result / (1.0F - scale); | |
| } | |
| } | |
| } |
Author
Hey rly cool work i tried using this noise instead of "Mathf.PerlinNoise(float a, float b)" but all i get is a full black texture, do you have any advice on getting this to work? cheers.
Author
I'd fixed it but it's been a little while, I don't recall anymore, sadly.
Yeah no problem at all, as far as i know its problably me using it wrong, but thanks anyways.
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Code adapted from here.
All credit goes to Ian Parberry.