https://www.linkedin.com/pulse/inverse-shader-unity-seyed-morteza-kamali/

#Unity #CG #HLSL #Shader

https://80.lv/articles/river-editor-water-simulation-in-real-time/

#Water #Shader

https://www.linkedin.com/pulse/what-hell-arctangent-shader-seyed-morteza-kamali/
#Unity #hlsl #shader

https://www.linkedin.com/pulse/tunnel-effect-seyed-morteza-kamali/

#Unity #hlsl #shader

Convolution matrix

In image processing, a kernel, convolution matrix, or mask is a small matrix. It is used for blurring, sharpening, embossing, edge detection, and more. This is accomplished by doing a convolution between a kernel and an image.

Shader "Convolution"
{
Properties
{
_MainTex ("Texture", 2D) = "white" {}
}
SubShader
{
// No culling or depth
Cull Off ZWrite Off ZTest Always

Pass
{
CGPROGRAM

#pragma vertex vert
#pragma fragment frag

#include "UnityCG.cginc"

struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
};

struct v2f
{
float2 uv : TEXCOORD0;
float4 vertex : SV_POSITION;
};

v2f vert (appdata v)
{
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.uv = v.uv;
return o;
}

sampler2D _MainTex;
float4 _MainTex_TexelSize;

float3x3 GetData(int channel, sampler2D tex, float2 uv, float4 size)
{
float3x3 mat;
for (int y=-1; y<2; y++)
{
for(int x=-1; x<2; x++)
{
mat[x+1][y+1]=tex2D(tex, uv + float2(x*size.x, y*size.y))[channel];
}
}
return mat;
}
float3x3 GetMean(float3x3 matr, float3x3 matg, float3x3 matb)
{
float3x3 mat;
for (int y=0; y<3; y++)
{
for(int x=0; x<3; x++)
{
mat[x][y] = (matr[x][y] + matg[x][y] + matb[x][y]) / 3.0;
}
}
return mat;
}

float Convolve(float3x3 kernel, float3x3 pixels, float denom, float offset)
{
float res = 0.0;
for (int y=0; y<3; y++)
{
for(int x=0; x<3; x++)
{
res += kernel[2-x][2-y]*pixels[x][y];
}
}

return res;
}

fixed4 frag (v2f i) : SV_Target
{
float3x3 kerIdentity = float3x3 ( -1.0, -1.0, -1.0,
-1.0, 8.0, -1.0,
-1.0, -1.0, -1.0);

float3x3 kerEmboss = float3x3 (2.0, 0.0, 0.0,
0.0, -1.0, 0.0,
0.0, 0.0, -1.0);

float3x3 kerSharpness = float3x3 (-1.0, -1.0, -1.0,
-1.0, 9.0, -1.0,
-1.0, -1.0, -1.0);

float3x3 kerGausBlur = float3x3 (1.0, 2.0, 1.0,
2.0, 4.0, 2.0,
1.0, 2.0, 1.0);

float3x3 kerEdgeDetect = float3x3 ( -1.0, -1.0, -1.0,
-1.0, 8.0, -1.0,
-1.0, -1.0, -1.0);

float3x3 matr = GetData(0, _MainTex, i.uv, _MainTex_TexelSize);
float3x3 matg = GetData(1, _MainTex, i.uv, _MainTex_TexelSize);
float3x3 matb = GetData(2, _MainTex, i.uv, _MainTex_TexelSize);
float3x3 mata = GetMean(matr, matg, matb);


// kernel
float4 gl_FragColor = float4(Convolve(kerEdgeDetect,matr,1.0,0.0),
Convolve(kerEdgeDetect,matg,1.0,0.0),
Convolve(kerEdgeDetect,matb,1.0,0.0),
1.0);

return gl_FragColor;
}
ENDCG
}
}
}

// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'

Shader "Shaders 102/Simple Box Blur"
{
Properties
{
_MainTex ("Texture", 2D) = "white" {}
}
SubShader
{
Blend SrcAlpha OneMinusSrcAlpha


Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag

#include "UnityCG.cginc"

struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
};

struct v2f
{
float2 uv : TEXCOORD0;
float4 vertex : SV_POSITION;
};

v2f vert (appdata v)
{
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.uv = v.uv;
return o;
}

sampler2D _MainTex;
float4 _MainTex_TexelSize;

float4 box(sampler2D tex, float2 uv, float4 size)
{
float4 c = tex2D(tex, uv + float2(-size.x, size.y)) + tex2D(tex, uv + float2(0, size.y)) + tex2D(tex, uv + float2(size.x, size.y)) +
tex2D(tex, uv + float2(-size.x, 0)) + tex2D(tex, uv + float2(0, 0)) + tex2D(tex, uv + float2(size.x, 0)) +
tex2D(tex, uv + float2(-size.x, -size.y)) + tex2D(tex, uv + float2(0, -size.y)) + tex2D(tex, uv + float2(size.x, -size.y));

return c / 9;
}

float4 frag (v2f i) : SV_Target
{
float4 col = box(_MainTex, i.uv, _MainTex_TexelSize);
return col;
}
ENDCG
}
}
}