Shader "AIGame/HomeExplorerCutout"
{
    Properties
    {
        _MainTex ("Tex", 2D) = "white" {}
        _Key ("Key", Color) = (1, 0, 1, 1)
    }
    SubShader
    {
        Tags { "Queue"="Transparent" "RenderType"="Transparent" "IgnoreProjector"="True" }
        Blend SrcAlpha OneMinusSrcAlpha
        ZWrite Off
        Cull Off
        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #include "UnityCG.cginc"
            sampler2D _MainTex;
            float4 _Key;
            struct appdata { float4 vertex : POSITION; float2 uv : TEXCOORD0; };
            struct v2f { float4 vertex : SV_POSITION; float2 uv : TEXCOORD0; };
            v2f vert(appdata v) { v2f o; o.vertex = UnityObjectToClipPos(v.vertex); o.uv = v.uv; return o; }
            fixed4 frag(v2f i) : SV_Target
            {
                fixed4 c = tex2D(_MainTex, i.uv);
                float d = distance(c.rgb, _Key.rgb);
                c.a = smoothstep(0.18, 0.42, d);
                if (c.a < 0.02) discard;
                return c;
            }
            ENDCG
        }
    }
}