Demo 52 - Checkerboard

Shader "Custom/PostRenderingCheckerboard"
{
    Properties
    {
        _MainTex ("Texture", 2D) = "white" {}
        _Color ("Color", color) = (1, 1, 1, 1)
        [PowerSlider(2.0)] _Val ("Size", Range(0.0, 1)) = 0
    }

    SubShader
    {
        Pass
        {
            CGPROGRAM
            #pragma vertex vert_img
            #pragma fragment frag
            #include "UnityCG.cginc"

            sampler2D _MainTex;
            fixed4 _Color;
            half _Val;

            fixed4 frag(v2f_img i) : SV_Target {
                float2 val = floor(i.pos.xy * _Val) * 0.5;

                if(frac(val.x + val.y) > 0)
                    return _Color;

                return tex2D(_MainTex, i.uv);
            }

            ENDCG
        }
    }
}