Unityのシェーダーで、ランダムディザリングを改造し、適当に偏ったモザイクをつくりました。
Shader "dither"
{
Properties
{
_MainTex ("Texture", 2D) = "white" {}
_Split("_Split",range(1,10)) = 1
}
SubShader
{
Tags { "RenderType"="Opaque" }
LOD 100
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
// make fog work
#pragma multi_compile_fog
#include "UnityCG.cginc"
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
};
struct v2f
{
float2 uv : TEXCOORD0;
UNITY_FOG_COORDS(1)
float4 vertex : SV_POSITION;
};
sampler2D _MainTex;
float _Split;
float4 _MainTex_ST;
v2f vert (appdata v)
{
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.uv = TRANSFORM_TEX(v.uv, _MainTex);
UNITY_TRANSFER_FOG(o,o.vertex);
return o;
}
float rand(float2 co) {
float a = frac(dot(co, float2(2.067390879775102, 12.451168662908249))) - 0.5;
float s = a * (6.182785114200511 + a * a * (-38.026512460676566 + a * a * 53.392573080032137));
float t = frac(s * 43758.5453);
return t;
}
fixed4 frag (v2f i) : SV_Target
{
float split = pow( 2, floor( _Split ) );
float2 offset = float2( 0, floor( _Time.z * split ) );
float r = rand( floor( i.uv * split + offset ) / split );
float size = split * floor( abs(r) * 25 + 2 );
float2 uvv = floor( i.uv * size ) / size;
// sample the texture
fixed4 col = tex2D(_MainTex, uvv);
col.x = step( rand( uvv ), col.x );
col.y = step( rand( uvv ), col.y );
col.z = step( rand( uvv ), col.z );
return col;
}
ENDCG
}
}
}