C10_Fresnel.shader

Shader "Custom/C10_Fresnel"
{
    Properties
    {
		_Color ("Color Tint", Color) = (1, 1, 1, 1)
		_FresnelScale ("Fresnel Scale", Range(0, 1)) = 0.5
		_Cubemap ("Reflection Cubemap", Cube) = "_Skybox" {}
    }
    SubShader
    {
		Tags { "RenderType"="Opaque" "Queue"="Geometry"}

        Pass { 
            Tags { "LightMode"="ForwardBase" }
            CGPROGRAM
            
            #pragma multi_compile_fwdbase
                
            #pragma vertex vert
            #pragma fragment frag
            
            #include "Lighting.cginc"
            #include "AutoLight.cginc"
            
            fixed4 _Color;
			fixed _FresnelScale;
            samplerCUBE _Cubemap;

            struct a2v {
                float4 vertex : POSITION;
                float3 normal : NORMAL;
            };
        
            struct v2f {
                float4 pos : SV_POSITION;
                float3 worldPos : TEXCOORD0;
                fixed3 worldNormal : TEXCOORD1;
                fixed3 worldViewDir : TEXCOORD2;
                fixed3 worldRefl : TEXCOORD3;
                SHADOW_COORDS(4)
            };

            v2f vert(a2v v) {
                v2f o;           
                o.pos = UnityObjectToClipPos(v.vertex);           
                o.worldNormal = UnityObjectToWorldNormal(v.normal);
                o.worldPos = mul(unity_ObjectToWorld, v.vertex).xyz;           
                o.worldViewDir = UnityWorldSpaceViewDir(o.worldPos);
				o.worldRefl = reflect(-o.worldViewDir, o.worldNormal);
                
                TRANSFER_SHADOW(o);
                
                return o;
            }

            fixed4 frag(v2f i) : SV_Target {
                fixed3 worldNormal = normalize(i.worldNormal);
                fixed3 worldLightDir = normalize(UnityWorldSpaceLightDir(i.worldPos));		
                fixed3 worldViewDir = normalize(i.worldViewDir);		
                
                fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz;
                
                fixed3 diffuse = _LightColor0.rgb * _Color.rgb * max(0, dot(worldNormal, worldLightDir));
                
				fixed3 reflection = texCUBE(_Cubemap, i.worldRefl).rgb;

                fixed3 fresnel = _FresnelScale + (1 - _FresnelScale) * pow(1 - dot(worldNormal, worldViewDir), 5);
                
                UNITY_LIGHT_ATTENUATION(atten, i, i.worldPos);
                
                // replace _ReflectAmount with saturate(fresnel)!!
                fixed3 color = ambient + lerp(diffuse, reflection, saturate(fresnel)) * atten;
                
                return fixed4(color, 1.0);
            }
            
            ENDCG
        }
    }
    FallBack "Reflective/VertexLit"
}