71 lines
2.0 KiB
Markdown
71 lines
2.0 KiB
Markdown
|
# 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**.
|
||
|
|
|
||
|
|
## 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;
|
||
|
|
}
|
||
|
|
```
|