PerlinSeaWave.c

// Each #kernel tells which function to compile; you can have many kernels
#pragma kernel PerlinSea
#include "noiseSimplex.cginc"
// Create a RenderTexture with enableRandomWrite flag and set it
// with cs.SetTexture
RWStructuredBuffer<float3> _Positions;
uint _Resolution;
float _Amplitude;
float _Speed;
float _Time;
float _Step;

//return 0~1 value
float GetPerlinNoise(float2 uv, float time){
    return snoise(float2(uv.x,uv.y+(time * 0.5)));
}

//set the position according to the perlin noise
float3 PerlinWaveFunction(float2 uv, float t){
    float3 pos;
    pos.x = uv.x;
    pos.y = ((GetPerlinNoise(uv, t)+0.5) * 2 - 1) *  _Amplitude;
    // pos.y = sin(PI * (uv.x + uv.y + t));
    pos.z = uv.y;
    return pos;
}

//return the float2 which range is from -1 to  1
float2 GetUV(uint3 id){
    float2 uv = (id.xy + 0.5) * _Step - 1.0;
    return uv;
}

//set the _Position array by given id and pos
void SetPosition(uint3 id ,float3 pos){
    if (id.x < _Resolution && id.y < _Resolution){
        _Positions[id.x + id.y * _Resolution] = pos;
    }
}

//main thread 
[numthreads(8,8,1)]
void PerlinSea (uint3 id : SV_DispatchThreadID)
{
    // TODO: insert actual code here!
    float2 uv = GetUV(id);
    SetPosition(id, PerlinWaveFunction(uv, _Time));

}