koobas.hobune.stream
I am new to shaders and I want to write a shader to get erosion in a binary image.
Best Answer
It's fairly simple, just use the Image Effect Shader template and change the part in the end to this:
sampler2D _MainTex;
float4 _MainTex_TexelSize;
fixed4 frag (v2f i) : SV_Target
{
float2 o = _MainTex_TexelSize.xy;
float v = 0;
v += tex2D(_MainTex, i.uv + float2( 1, 1) * o);
v += tex2D(_MainTex, i.uv + float2( 1, 0) * o);
v += tex2D(_MainTex, i.uv + float2( 1, -1) * o);
v += tex2D(_MainTex, i.uv + float2( 0, 1) * o);
v += tex2D(_MainTex, i.uv + float2( 0, 0) * o);
v += tex2D(_MainTex, i.uv + float2( 0, -1) * o);
v += tex2D(_MainTex, i.uv + float2(-1, 1) * o);
v += tex2D(_MainTex, i.uv + float2(-1, 0) * o);
v += tex2D(_MainTex, i.uv + float2(-1, -1) * o);
return v == 9 ? 1 : 0;
}
Basically _MainTex_TexelSize.xy is the size of each pixel on the main texture. We sample the texture in a 3x3-grid around the pixel we are currently shading and only return 1 if all 9 pixels are 1.
I tried this code. But ins$$anonymous$$d of edges getting eroded, they are getting enhanced. Do you know the reason why?
