Specular + Metallic Shader

Question

Как в Unity Standard Shader есть «Specular Highlights», но в то же время «Metallic»?

Я пытаюсь сделать то же самое, но не могу понять.Пока у меня есть:

// Upgrade NOTE: replaced '_World2Object' with 'unity_WorldToObject'
// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'

Shader "Custom/MetallicHighlights" {
    Properties {
        _Color ("Color", Color) = (1, 1, 1, 1)
        _MainTex ("Albedo", 2D) = "white" {}

        _GlossMapScale ("Smoothness", Range(0.0, 1.0)) = 0.0
        _MetallicFactor("Metallic Factor", Range(0.0, 1.0)) = 0
        _MetallicGlossMap ("Metallic", 2D) = "gloss" {}
    }
    SubShader {
        Tags { "RenderType"="Opaque" }
        LOD 200

        CGPROGRAM
        // Physically based Standard lighting model, and enable shadows on all light types
        // And generate the shadow pass with instancing support
        #pragma surface surf Standard fullforwardshadows addshadow

        // Use shader model 3.0 target, to get nicer looking lighting
        #pragma target 3.0

        struct Input {
            float4 color: Color;
            float2 uv_MainTex;
            float3 viewDir;
        };

        sampler2D _MainTex;
        sampler2D _MetallicGlossMap;
        fixed4 _Color;
        half _GlossMapScale;
        half _MetallicFactor;

        void surf (Input IN, inout SurfaceOutputStandard o) {
            // Albedo comes from a texture tinted by color
            fixed4 albedo = tex2D (_MainTex, IN.uv_MainTex) * _Color;
            o.Albedo = albedo.rgb;
            o.Alpha = albedo.a;

            half rim = _RimCap - saturate(dot(normalize(IN.viewDir), o.Normal));
            o.Emission = _RimColor.rgb * pow(rim, _RimIntensity);

            // Metallic and smoothness come from slider variables
            // o.Metallic = _MetallicFactor;
            // o.Smoothness = _GlossMapScale;

            fixed4 metal_colour = tex2D(_MetallicGlossMap, IN.uv_MainTex);
            o.Metallic = metal_colour.r * _MetallicFactor;
            o.Smoothness = metal_colour.a * _GlossMapScale;
        }
        ENDCG
    }
    FallBack "Diffuse"
}

, но когда я проверяю шейдер Unity Standard, я замечаю, что у него есть «Metallic» (слайдер + текстура), а также «Specular Highlight» (флажок) и «Reflections» (флажок) для «Параметры рендеринга вперед» ..

Как именно они это делают?Если я использую SurfaceOutputStandardSpecular, то я теряю опцию Metallic в структуре.

Есть идеи?

Answer 1

Должно работать:

// Upgrade NOTE: replaced '_World2Object' with 'unity_WorldToObject'
// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'

Shader "Custom/MetallicHighlights" {
    Properties {
        _Color ("Color", Color) = (1, 1, 1, 1)
        _MainTex ("Albedo", 2D) = "white" {}

        _GlossMapScale ("Smoothness", Range(0.0, 1.0)) = 0.0
        _MetallicFactor("Metallic Factor", Range(0.0, 1.0)) = 0
        _MetallicGlossMap ("Metallic", 2D) = "gloss" {}
        [ToggleOff] _SpecularHighlights("Specular Highlights", Float) = 1.0
    }
    SubShader {
        Tags { "RenderType"="Opaque" }
        LOD 200

        CGPROGRAM
        // Physically based Standard lighting model, and enable shadows on all light types
        // And generate the shadow pass with instancing support
        #pragma surface surf Standard fullforwardshadows addshadow
        #pragma shader_feature _SPECULARHIGHLIGHTS_OFF

        // Use shader model 3.0 target, to get nicer looking lighting
        #pragma target 3.0

        struct Input {
            float4 color: Color;
            float2 uv_MainTex;
            float3 viewDir;
        };

        sampler2D _MainTex;
        sampler2D _MetallicGlossMap;
        fixed4 _Color;
        half _GlossMapScale;
        half _MetallicFactor;

        void surf (Input IN, inout SurfaceOutputStandard o) {
            // Albedo comes from a texture tinted by color
            fixed4 albedo = tex2D (_MainTex, IN.uv_MainTex) * _Color;
            o.Albedo = albedo.rgb;
            o.Alpha = albedo.a;

            half rim = _RimCap - saturate(dot(normalize(IN.viewDir), o.Normal));
            o.Emission = _RimColor.rgb * pow(rim, _RimIntensity);

            // Metallic and smoothness come from slider variables
            // o.Metallic = _MetallicFactor;
            // o.Smoothness = _GlossMapScale;

            fixed4 metal_colour = tex2D(_MetallicGlossMap, IN.uv_MainTex);
            o.Metallic = metal_colour.r * _MetallicFactor;
            o.Smoothness = metal_colour.a * _GlossMapScale;
        }
        ENDCG
    }
    FallBack "Diffuse"
}