高光遮罩MaskTexture

高光遮罩的原理可以简单的理解为：漫反射叠加上一个采样过遮罩纹理的高光次幂

Shader "Unlit/UnlitShader_MaskTexture"
{
    Properties
    {
        _MainTex        ("Texture"       ,2D)              = "white" {} 
        _NormalMap      ("NormalMap"     ,2D)               = "bump"{}  
        _SpecularMask   ("SpecularMask"  ,2D)               = "white"{}  
        _Color          ("Color"         ,Color)            = (1.0,1.0,1.0,1.0) 
        _Specular       ("Specular"      ,Color)       = (1.0,1.0,1.0,1.0) 
        _BumpScale      ("BumpScale"     ,Range(0.0,20.0))   = 1.0 
        _SpecularScale  ("_SpecularScale",Range(0.0,10.0))  = 1.0 
        _Gloss          ("Gloss"         ,Range(0.0,256.0)) = 20
    }
    SubShader
    {
        Tags { "RenderType"="Opaque" }

        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag

            #include "UnityCG.cginc"
            #include "Lighting.cginc"

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

            struct VertexInput
            {
                float4 vertex : POSITION;
                float3 normal : NORMAL;
                float4 tangent : TANGENT;
                float2 uv : TEXCOORD0;
            };

            struct VertexOutput
            {
                float4 pos : SV_POSITION;
                float2 uv : TEXCOORD0;
                float3 lDir : TEXCOORD1;
                float3 vDir : TEXCOORD2;
            };

            VertexOutput vert (VertexInput v)
            {
                VertexOutput o;
                o.pos = UnityObjectToClipPos(v.vertex);
                o.uv.xy = v.uv.xy * _MainTex_ST.xy + _MainTex_ST.zw;
                TANGENT_SPACE_ROTATION;
                o.lDir = mul(rotation,ObjSpaceLightDir(v.vertex)).xyz;
                o.vDir = mul(rotation,ObjSpaceViewDir(v.vertex)).xyz;

                return o;
            }

            fixed4 frag (VertexOutput i) : SV_Target
            {
                fixed3 lDirTS = normalize(i.lDir);
                fixed3 vDirTS = normalize(i.vDir);
                fixed3 nDirTS = UnpackNormal(tex2D(_NormalMap ,i.uv));
                fixed3 hDir = normalize(lDirTS + vDirTS);

                fixed3 ndotlTS = dot(nDirTS,lDirTS);
                fixed3 ndoth = dot(nDirTS,hDir);
                nDirTS.xy *= _BumpScale;
                nDirTS.z = sqrt(1.0 - saturate(dot(nDirTS.xy,nDirTS.xy)));

                fixed3 albedo = tex2D(_MainTex,i.uv).rgb * _Color.rgb;
                fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz * albedo;
                fixed3 diffuse = _LightColor0.rgb * albedo * max(0.0,ndotlTS);
                fixed specularMask = tex2D(_SpecularMask,i.uv).r * _SpecularScale;
                fixed3 specular = _LightColor0.rgb * _Specular.rgb * pow(max(0,ndoth) , _Gloss) * specularMask;

                return fixed4(ambient + diffuse + specular ,1.0);
            }
            ENDCG
        }
    }
    FallBack"Specular"
}

标签：遮罩,高光,1.0,MainTex,uv,fixed3,xy,MaskTexture,nDirTS
来源： https://blog.csdn.net/qq_43933700/article/details/120788837