Pixelating shader, originally found here: https://forum.unity.com/threads/making-a-local-pixelation-image-effect-shader.183210/

v1.txt

Shader "Pixelate" {
    Properties {
        _CellSize ("Cell Size", Vector) = (0.02, 0.02, 0, 0)
    }
    SubShader {
        Tags { "RenderType"="Opaque" }
        LOD 200
       
        GrabPass { "_PixelationGrabTexture"}
       
        Pass {
            CGPROGRAM
                #pragma vertex vert
                #pragma fragment frag
                #include "UnityCG.cginc"
           
                struct v2f {
                    float4 pos : SV_POSITION;
                    float4 grabUV : TEXCOORD0;
                };
               
                float4 _CellSize;
               
                v2f vert(appdata_base v) {
                    v2f o;
                    o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
                    o.grabUV = ComputeGrabScreenPos(o.pos);
                    return o;
                }
           
                sampler2D _PixelationGrabTexture;
           
                float4 frag(v2f IN) : COLOR {
                    float2 steppedUV = IN.grabUV.xy/IN.grabUV.w;
                    steppedUV /= _CellSize.xy;
                    steppedUV = round(steppedUV);
                    steppedUV *= _CellSize.xy;
                    return tex2D(_PixelationGrabTexture, steppedUV);
                }
            ENDCG
        }
    }
}
 

v2.txt

Shader "Custom\Pixelate"
{
    Properties
    {
        _CellSize ("Cell Size", Vector) = (0.02, 0.02, 0, 0)
    }
    SubShader {
        Tags { "RenderType"="Opaque" "Queue" = "Transparent" }
        LOD 200
     
        GrabPass { "_PixelationGrabTexture"}
     
        Pass {
            CGPROGRAM
                #pragma vertex vert
                #pragma fragment frag
                #include "UnityCG.cginc"
         
                struct v2f {
                    float4 pos : SV_POSITION;
                    float4 grabUV : TEXCOORD0;
                };
             
                float4 _CellSize;
             
                v2f vert(appdata_base v) {
                    v2f o;
                    o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
                    o.grabUV = ComputeGrabScreenPos(o.pos);
                    return o;
                }
         
                sampler2D _PixelationGrabTexture;
         
                float4 frag(v2f IN) : COLOR
                {
                    float2 steppedUV = IN.grabUV.xy/IN.grabUV.w;
                    steppedUV /= _CellSize.xy;
                    steppedUV = round(steppedUV);
                    steppedUV *= _CellSize.xy;
                    return tex2D(_PixelationGrabTexture, steppedUV);
                }
            ENDCG
        }
    }
}

v3.txt

Shader "Custom/Pixelate New"
{
    Properties
    {
        _PixelSize("Pixel Size", Float) = 10
    }
 
    SubShader
    {
        Tags{ "Queue" = "Transparent" "IgnoreProjector" = "True" }
        Blend Off
        Lighting Off
        Fog{ Mode Off }
        ZWrite Off
        LOD 200
        Cull Off
 
        GrabPass{ "_GrabTexture" }
 
        Pass
        {
            CGPROGRAM
 
            #pragma vertex vert
            #pragma fragment frag
            #include "UnityCG.cginc"
 
            struct v2f
            {
                float4 pos : SV_POSITION;
                float4 uv : TEXCOORD0;
            };
 
            float _PixelSize;
 
            v2f vert(appdata_base v)
            {
                v2f o;
                o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
                o.uv = ComputeGrabScreenPos(o.pos);
                return o;
            }
 
            sampler2D _GrabTexture;
 
            float4 frag(v2f IN) : COLOR
            {
                float2 steppedUV = IN.uv.xy / IN.uv.w;
                steppedUV /= _PixelSize / _ScreenParams.xy;
                steppedUV = round(steppedUV);
                steppedUV *= _PixelSize / _ScreenParams.xy;
 
                return tex2D(_GrabTexture, steppedUV);
            }
         
            ENDCG
        }
    }
}