# Simple Noise Node

## Description

Generates a simple, or [Value](https://en.wikipedia.org/wiki/Value_noise), noise based on input **UV**. The scale of the generated noise is controlled by input **Scale**.

You can also choose to use two different hashing methods for calculating the noise. As of Unity version 2021.2, the Simple Noise node defaults to the **Deterministic** hash, to ensure consistent results for noise generation across platforms.

## 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 |

## Controls

| Name        | Type           | Options  | Description |
|:------------ |:-------------|:-----|:---|
| Hash Type      | Dropdown | Deterministic, LegacySine | Selects the hash function used to generate random numbers for noise generation. |

## 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;
}
```