遮罩纹理_MaskTexture

Shader "Unlit/MaskTexture"
{
    Properties
    {
        _Color ("Color Tint", Color) = (1, 1, 1, 1)
        _MainTex ("Main Tex", 2D) = "white" {}
        _BumpMap ("Normal Map", 2D) = "bump" {}
        _BumpScale("Bump Scale", Float) = 1.0
        _SpecularMask ("Specular Mask", 2D) = "white" {}
        _SpecularScale ("Specular Scale", Float) = 1.0
        _Specular ("Specular", Color) = (1, 1, 1, 1)
        _Gloss ("Gloss", Range(8.0, 256)) = 20

    }
    SubShader
    {
        Tags { "LightMode"="ForwardBase" }

        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #include "Lighting.cginc"

            fixed4 _Color;
            sampler2D _MainTex;
            float4 _MainTex_ST;
            sampler2D _BumpMap;
            float _BumpScale;
            sampler2D _SpecularMask;
            float _SpecularScale;
            fixed4 _Specular;
            float _Gloss;

            struct a2v{

                float4 vertex : POSITION;
                float3 normal : NORMAL;
                float4 tangent : TANGENT;
                float4 texcoord : TEXCOORD0;
            };

            struct v2f{

                float4 pos:SV_POSITION;
                float2 uv : TEXCOORD0;
                float3 lightDir :TEXCOORD1;
                float3 viewDir :TEXCOORD2;

            };

            v2f vert (a2v v)
            {
                v2f o;
                o.pos = UnityObjectToClipPos(v.vertex);

                o.uv.xy = v.texcoord.xy * _MainTex_ST.xy + _MainTex_ST.zw;


                TANGENT_SPACE_ROTATION;

                o.lightDir = mul(rotation,ObjSpaceLightDir(v.vertex)).xyz;
                o.viewDir = mul(rotation, ObjSpaceViewDir(v.vertex)).xyz;
                
                return o;

            }                                       

            fixed4 frag(v2f i) :SV_Target
            {
                 fixed3 tangentLightDir = normalize(i.lightDir);
                 fixed3 tangentViewDir = normalize(i.viewDir);
            
                fixed3 tangentNormal = UnpackNormal(tex2D(_BumpMap,i.uv));

                tangentNormal.xy *= _BumpScale;

                tangentNormal.z = sqrt(1.0- saturate(dot(tangentNormal.xy,tangentNormal.xy)));

                fixed3 albedo = tex2D(_MainTex, i.uv).rgb * _Color.rgb;

                fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz * albedo;

                fixed3 diffuse = _LightColor0.rgb * albedo * max(0, dot(tangentNormal, tangentLightDir));
                
                fixed3 halfDir = normalize(tangentLightDir + tangentViewDir);
                
                fixed3 specularMask = tex2D(_SpecularMask,i.uv).r* _SpecularScale;

                fixed3 specular = _LightColor0.rgb *albedo* pow(max(0, dot(tangentNormal, halfDir)),_Gloss)*specularMask;

                return fixed4(ambient + diffuse + specular, 1.0);

            }
             
            ENDCG
        }
            
        
        }

    FallBack "Specular"
}