Singularity/Library/PackageCache/com.unity.shadergraph@12.1.11/Documentation~/Simple-Noise-Node.md

Simple Noise Node

Description

Generates a simple, or Value, noise based on input UV. The scale of the generated noise is controlled by input Scale.

Ports

Name	Direction	Type	Binding	Description
UV	Input	Vector 2	UV	Input UV value
Scale	Input	Float	None	Noise scale
Out	Output	Float	None	Output value

Generated Code Example

The following example code represents one possible outcome of this node.

inline float unity_noise_randomValue (float2 uv)
{
    return frac(sin(dot(uv, float2(12.9898, 78.233)))*43758.5453);
}

inline float unity_noise_interpolate (float a, float b, float t)
{
    return (1.0-t)*a + (t*b);
}

inline float unity_valueNoise (float2 uv)
{
    float2 i = floor(uv);
    float2 f = frac(uv);
    f = f * f * (3.0 - 2.0 * f);

    uv = abs(frac(uv) - 0.5);
    float2 c0 = i + float2(0.0, 0.0);
    float2 c1 = i + float2(1.0, 0.0);
    float2 c2 = i + float2(0.0, 1.0);
    float2 c3 = i + float2(1.0, 1.0);
    float r0 = unity_noise_randomValue(c0);
    float r1 = unity_noise_randomValue(c1);
    float r2 = unity_noise_randomValue(c2);
    float r3 = unity_noise_randomValue(c3);

    float bottomOfGrid = unity_noise_interpolate(r0, r1, f.x);
    float topOfGrid = unity_noise_interpolate(r2, r3, f.x);
    float t = unity_noise_interpolate(bottomOfGrid, topOfGrid, f.y);
    return t;
}

void Unity_SimpleNoise_float(float2 UV, float Scale, out float Out)
{
    float t = 0.0;

    float freq = pow(2.0, float(0));
    float amp = pow(0.5, float(3-0));
    t += unity_valueNoise(float2(UV.x*Scale/freq, UV.y*Scale/freq))*amp;

    freq = pow(2.0, float(1));
    amp = pow(0.5, float(3-1));
    t += unity_valueNoise(float2(UV.x*Scale/freq, UV.y*Scale/freq))*amp;

    freq = pow(2.0, float(2));
    amp = pow(0.5, float(3-2));
    t += unity_valueNoise(float2(UV.x*Scale/freq, UV.y*Scale/freq))*amp;

    Out = t;
}