Singularity/Library/PackageCache/com.unity.shadergraph@12.1.11/Documentation~/Gradient-Noise-Node.md
2024-05-06 11:45:45 -07:00

1.5 KiB

Gradient Noise Node

Description

Generates a gradient, or Perlin, 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.

float2 unity_gradientNoise_dir(float2 p)
{
    p = p % 289;
    float x = (34 * p.x + 1) * p.x % 289 + p.y;
    x = (34 * x + 1) * x % 289;
    x = frac(x / 41) * 2 - 1;
    return normalize(float2(x - floor(x + 0.5), abs(x) - 0.5));
}

float unity_gradientNoise(float2 p)
{
    float2 ip = floor(p);
    float2 fp = frac(p);
    float d00 = dot(unity_gradientNoise_dir(ip), fp);
    float d01 = dot(unity_gradientNoise_dir(ip + float2(0, 1)), fp - float2(0, 1));
    float d10 = dot(unity_gradientNoise_dir(ip + float2(1, 0)), fp - float2(1, 0));
    float d11 = dot(unity_gradientNoise_dir(ip + float2(1, 1)), fp - float2(1, 1));
    fp = fp * fp * fp * (fp * (fp * 6 - 15) + 10);
    return lerp(lerp(d00, d01, fp.y), lerp(d10, d11, fp.y), fp.x);
}

void Unity_GradientNoise_float(float2 UV, float Scale, out float Out)
{
    Out = unity_gradientNoise(UV * Scale) + 0.5;
}