Shader "Custom/Wet"
{
  Properties
  {
    
  }
  SubShader
  {
    Tags { "Queue"="Transparent" }
    // LOD 100
    Blend One One
    ZWrite Off
    // Cull Off

    Pass
    {
      CGPROGRAM
      #pragma vertex vert
      #pragma fragment frag
      #pragma multi_compile_instancing
      #pragma target 3.5

      // #include "UnityCG.cginc"
      #include "UnityStandardBRDF.cginc"

      struct appdata
      {
        float4 vertex : POSITION;
        UNITY_VERTEX_INPUT_INSTANCE_ID
        fixed3 normal : NORMAL;
      };

      struct v2f
      {
        float4 vertex : SV_POSITION;
        fixed3 normal : TEXCOORD1;
        fixed4 color : COLOR;
      };

      sampler2D _MainTex;
      float4 _MainTex_ST;

      v2f vert (appdata v)
      {
        v2f o;
        UNITY_SETUP_INSTANCE_ID(v);
        o.vertex = UnityObjectToClipPos(v.vertex);
        o.normal = UnityObjectToWorldNormal(v.normal);

        fixed4 base = fixed4(1, 1, 1, 1);
        fixed3 worldPos = mul(unity_ObjectToWorld, v.vertex).xyz;
        fixed3 viewDir = normalize(UnityWorldSpaceViewDir(worldPos));
        // o.color = base * clamp(dot(o.normal, -viewDir), 0, 0.2);

        // Rim lighting
        fixed rim = 1.0 - saturate(dot (normalize(viewDir), o.normal));
        o.color = base * rim * rim * 0.2;

        return o;
      }

      fixed4 frag (v2f i) : SV_Target
      {
        return i.color;
      }
      ENDCG
    }
  }
}