DanaProcessing

Random & noise

On this page · 6 entries

Random

  • Random(float max)
  • Random(min, max)

Uniform random float.

RandomGaussian

  • RandomGaussian() → float

Normally distributed (mean 0, standard deviation 1).

RandomSeed

  • RandomSeed(int seed)

Reseeds the shared random generator.

Noise

  • Noise(float x)
  • Noise(x, y) → float

Smooth pseudo-random value in [0, 1].

NoiseSeed · NoiseDetail

  • NoiseSeed(int seed)
  • NoiseDetail(int octaves, float falloff = 0.5f)

Reshuffles the noise permutation table, or changes octaves and falloff.

Runnable example

A complete sketch using this section. Test in Dana opens it in the IDE, or paste it into a new tab and press Run.

C#
// Random scatters, Noise flows: the same landscape, two ways.
public class Terrain : Sketch
{
    public override void Setup() => Size(600, 300);

    public override void Draw()
    {
        Background(250);
        float t = FrameCount * 0.01f;

        // Top: Random() -- jumpy.
        Stroke(200, 80, 60); NoFill();
        BeginShape();
        RandomSeed(FrameCount / 10);
        for (int x = 0; x <= Width; x += 10)
Vertex(x, 80 + Random(-40, 40));
        EndShape();

        // Bottom: Noise() -- smooth, and it moves when t changes.
        Stroke(60, 120, 200);
        BeginShape();
        for (int x = 0; x <= Width; x += 5)
Vertex(x, 220 + (Noise(x * 0.01f, t) - 0.5f) * 160);
        EndShape();

        Fill(30); NoStroke();
        Text("Random()", 10, 20);
        Text("Noise()", 10, 160);
    }
}