A demonstration of Halton Sequencing Quasirandom Noise

HaltonSequencer.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

// Note that the Halton bases must consist of coprime integers.

// Learn more about the Halton sequence: https://en.wikipedia.org/wiki/Halton_sequence
// Learn more about low discrepancy sequences: https://en.wikipedia.org/wiki/Low-discrepancy_sequence
// Learn more about coprime numbers: https://en.wikipedia.org/wiki/Coprime_integers

public class HaltonSequencer : MonoBehaviour
{
	[Header("Texture Generator")]
	public bool generateHaltonTexture;

	[Header("Demo")]
	public bool generateHaltonSamples;
	public float rate = 0.2f;
	public GameObject haltonSample;
	private float t = 0;
	private int index = 1;
	public float boxDimension = 5f;

	private void OnValidate()
	{
		if (generateHaltonTexture)
		{
			GenerateHaltonTexture();
			generateHaltonTexture = false;
		}

		if (generateHaltonSamples)
		{
			t = Time.time;
		}
	}

	private void Update()
	{
		if (generateHaltonSamples)
		{
			if(Time.time - t > rate)
			{
				float x = (Halton(2, index) - 0.5f) * boxDimension;
				float y = (Halton(3, index) - 0.5f) * boxDimension;
				float z = (Halton(5, index) - 0.5f) * boxDimension;
				
				Instantiate(haltonSample, new Vector3(x, z, y), Quaternion.identity);
				
				index++;
				t = Time.time;
			}
		}
	}


	private float Halton(int b, int index)
	{
		float result = 0.0f;
		float f = 1.0f;

		while (index > 0)
		{
			f = f / (float)b;
			result += f * (float)(index % b);
			index = index / b;
		}

		return result;
	}

	private void GenerateHaltonTexture(int baseR = 2, int baseG = 3, int baseB = 5, int baseA = 7, int maxIndex = 256)
	{
		Texture2D t = new Texture2D(maxIndex, 1, TextureFormat.RGBA32, false);

		Color[] c = new Color[maxIndex];
		for (int x = 0; x < maxIndex; x++)
		{
			float r = Halton(baseR, x + 30);
			float g = Halton(baseG, x + 30);
			float b = Halton(baseB, x + 30);
			float a = Halton(baseA, x + 30);
			c[x] = new Color(r, g, b, a);
		}

		t.SetPixels(c);
		t.Apply();

		byte[] encodedTexture = t.EncodeToPNG();
		System.IO.File.WriteAllBytes(Application.dataPath + "/halton.png", encodedTexture);
	}


	private void OnGUI()
	{
		GUI.Label(new Rect(0, 0, 300, 100), "Index: " + index);
	}

	private void OnDrawGizmos()
	{
		Gizmos.DrawWireCube(Vector3.zero, Vector3.one * 5);
	}
}