法线贴图 在之前学习过了，我们使用法线贴图在低分辨率的模型上 模拟 高分辨率的效果。
Unity中 通过 UnpackNormal 函数 来使用法线贴图。
之前学习法线贴图的记录
Unity Shaders and Effects Cookbook (2-5) 如何使用法线贴图
这一节讲的是 在Cubemap 上使用法线贴图。模拟凹凸效果。
最终效果如图
一起来做吧。
首先搭建好场景，和上一节一样。
导入法线贴图
创建材质 、Shader 。
复制上一节的 Shader 就行。然后修改成下面的内容。
Shader "CookBookShaders/Chapt4-4/Cubemap_NormalMap" { Properties { _MainTint("Diffuse Color",Color)=(1,1,1,1) _MainTex ("Base (RGB)", 2D) = "white" {} _NormalMap("Normal Map",2D) = "bump"{} _Cubemap("Cubemap",CUBE)=""{} _ReflAmount("Reflection Amount",Range(0,1))=0.5 } SubShader { Tags { "RenderType"="Opaque" } LOD 200 CGPROGRAM #pragma surface surf Lambert float4 _MainTint; sampler2D _MainTex; sampler2D _NormalMap; samplerCUBE _Cubemap; float _ReflAmount; struct Input { float2 uv_MainTex; float2 uv_NormalMap; float3 worldRefl; INTERNAL_DATA }; void surf (Input IN, inout SurfaceOutput o) { half4 c = tex2D (_MainTex, IN.uv_MainTex); //从法线贴图中提取法线信息，UnpackNormal这个函数在 CGInclude 文件夹中的Lighting中。 float3 normals=UnpackNormal(tex2D(_NormalMap,IN.uv_NormalMap)); o.Normal=normals; //上面使用法线贴图中的法线数据 替代了 原来的法线数据。 //法线被修改了，就不能 直接用原来的 内置属性 worldRefl 这个反射向量，而是要通过 WorldReflectionVector(IN,o.Normal)来获取。 //使用WorldReflectionVector 获得 基于法线贴图中的反射向量的 世界反射向量 o.Emission = texCUBE(_Cubemap,WorldReflectionVector(IN,o.Normal)).rgb * _ReflAmount; o.Albedo = c.rgb * _MainTint; o.Alpha = c.a; } ENDCG } FallBack "Diffuse"}和上一节的Shader 相比，修改了如下几处：
1、在 Properties 属性块中添加了法线贴图
_NormalMap("Normal Map",2D) = "bump"{}然后在 SubShader 中添加对应的变量
sampler2D _NormalMap;2、在 Input 中 添加了 法线贴图的UV，以及一个奇怪的字段 INTERNAL_DATA
struct Input { float2 uv_MainTex; float2 uv_NormalMap; float3 worldRefl; INTERNAL_DATA };uv_NormalMap 是用来读取 法线贴图数据的。
转自http://blog.csdn.net/huutu http://www.thisisgame.com.cn
INTERNAL_DATA
书上有两点解释
A：通过在Input 中添加 INTERNAL_DATA ，我们就可以访问由法线贴图修改后的表面法线。
这个很奇怪，为什么要添加 INTERNAL_DATA，才可以访问由法线贴图修改后的表面法线？上次学习法线贴图的时候可没有这个东西。
习惯性到 CGIncludes 里面去查找，发现并没有 INTERNAL_DATA 。
在官方文档
http://docs.unity3d.com/Manual/SL-SurfaceShaderExamples.html找到这一句话
If you want to do reflections that are affected by normal maps, it needs to be slightly more involved: INTERNAL_DATA needs to be added to the Input structure, and WorldReflectionVector function used to compute per-pixel reflection vector after you’ve written the Normal output.
就是说计算世界反射向量的时候 使用了法线贴图就要加上 这个。
谷歌一下，发现网友说在 生成的代码中能看出来，然后就查看生成的代码
Shader "CookBookShaders/Chapt4-4/Cubemap_NormalMap" { Properties { _MainTint("Diffuse Color",Color)=(1,1,1,1) _MainTex ("Base (RGB)", 2D) = "white" {} _NormalMap("Normal Map",2D) = "bump"{} _Cubemap("Cubemap",CUBE)=""{} _ReflAmount("Reflection Amount",Range(0,1))=0.5 } SubShader { Tags { "RenderType"="Opaque" } LOD 200 // ------------------------------------------------------------ // Surface shader code generated out of a CGPROGRAM block: // ---- forward rendering base pass: Pass { Name "FORWARD" Tags { "LightMode" = "ForwardBase" }CGPROGRAM// compile directives#pragma vertex vert_surf#pragma fragment frag_surf#pragma multi_compile_fwdbase#include "HLSLSupport.cginc"#include "UnityShaderVariables.cginc"#define UNITY_PASS_FORWARDBASE#include "UnityCG.cginc"#include "Lighting.cginc"#include "AutoLight.cginc"#define INTERNAL_DATA half3 TtoW0; half3 TtoW1; half3 TtoW2;#define WorldReflectionVector(data,normal) reflect (data.worldRefl, half3(dot(data.TtoW0,normal), dot(data.TtoW1,normal), dot(data.TtoW2,normal)))#define WorldNormalVector(data,normal) fixed3(dot(data.TtoW0,normal), dot(data.TtoW1,normal), dot(data.TtoW2,normal))// Original surface shader snippet:#line 18 ""#ifdef DUMMY_PREPROCESSOR_TO_WORK_AROUND_HLSL_COMPILER_LINE_HANDLING#endif //#pragma surface surf Lambert float4 _MainTint; sampler2D _MainTex; sampler2D _NormalMap; samplerCUBE _Cubemap; float _ReflAmount; struct Input { float2 uv_MainTex; float2 uv_NormalMap; float3 worldRefl; INTERNAL_DATA }; void surf (Input IN, inout SurfaceOutput o) { half4 c = tex2D (_MainTex, IN.uv_MainTex); //从法线贴图中提取法线信息，UnpackNormal这个函数在 CGInclude 文件夹中的Lighting中。 float3 normals=UnpackNormal(tex2D(_NormalMap,IN.uv_NormalMap)); o.Normal=normals; //上面使用法线贴图中的法线数据 替代了 原来的法线数据。 //法线被修改了，就不能 直接用原来的 内置属性 worldRefl 这个反射向量，而是要通过 WorldReflectionVector(IN,o.Normal)来获取。 //使用WorldReflectionVector 获得 基于法线贴图中的反射向量的 世界反射向量 o.Emission = texCUBE(_Cubemap,WorldReflectionVector(IN,o.Normal)).rgb * _ReflAmount; o.Albedo = c.rgb * _MainTint; o.Alpha = c.a; } // vertex-to-fragment interpolation data#ifdef LIGHTMAP_OFFstruct v2f_surf { float4 pos : SV_POSITION; float4 pack0 : TEXCOORD0; fixed4 TtoW0 : TEXCOORD1; fixed4 TtoW1 : TEXCOORD2; fixed4 TtoW2 : TEXCOORD3; fixed3 lightDir : TEXCOORD4; fixed3 vlight : TEXCOORD5; LIGHTING_COORDS(6,7)};#endif#ifndef LIGHTMAP_OFFstruct v2f_surf { float4 pos : SV_POSITION; float4 pack0 : TEXCOORD0; fixed4 TtoW0 : TEXCOORD1; fixed4 TtoW1 : TEXCOORD2; fixed4 TtoW2 : TEXCOORD3; float2 lmap : TEXCOORD4; LIGHTING_COORDS(5,6)};#endif#ifndef LIGHTMAP_OFFfloat4 unity_LightmapST;#endiffloat4 _MainTex_ST;float4 _NormalMap_ST;// vertex shaderv2f_surf vert_surf (appdata_full v) { v2f_surf o; o.pos = mul (UNITY_MATRIX_MVP, v.vertex); o.pack0.xy = TRANSFORM_TEX(v.texcoord, _MainTex); o.pack0.zw = TRANSFORM_TEX(v.texcoord, _NormalMap); float3 viewDir = -ObjSpaceViewDir(v.vertex); float3 worldRefl = mul ((float3x3)_Object2World, viewDir); TANGENT_SPACE_ROTATION; o.TtoW0 = float4(mul(rotation, _Object2World[0].xyz), worldRefl.x)*unity_Scale.w; o.TtoW1 = float4(mul(rotation, _Object2World[1].xyz), worldRefl.y)*unity_Scale.w; o.TtoW2 = float4(mul(rotation, _Object2World[2].xyz), worldRefl.z)*unity_Scale.w; #ifndef LIGHTMAP_OFF o.lmap.xy = v.texcoord1.xy * unity_LightmapST.xy + unity_LightmapST.zw; #endif float3 worldN = mul((float3x3)_Object2World, SCALED_NORMAL); float3 lightDir = mul (rotation, ObjSpaceLightDir(v.vertex)); #ifdef LIGHTMAP_OFF o.lightDir = lightDir; #endif // SH/ambient and vertex lights #ifdef LIGHTMAP_OFF float3 shlight = ShadeSH9 (float4(worldN,1.0)); o.vlight = shlight; #ifdef VERTEXLIGHT_ON float3 worldPos = mul(_Object2World, v.vertex).xyz; o.vlight += Shade4PointLights ( unity_4LightPosX0, unity_4LightPosY0, unity_4LightPosZ0, unity_LightColor[0].rgb, unity_LightColor[1].rgb, unity_LightColor[2].rgb, unity_LightColor[3].rgb, unity_4LightAtten0, worldPos, worldN ); #endif // VERTEXLIGHT_ON #endif // LIGHTMAP_OFF // pass lighting information to pixel shader TRANSFER_VERTEX_TO_FRAGMENT(o); return o;}#ifndef LIGHTMAP_OFFsampler2D unity_Lightmap;#ifndef DIRLIGHTMAP_OFFsampler2D unity_LightmapInd;#endif#endif// fragment shaderfixed4 frag_surf (v2f_surf IN) : SV_Target { // prepare and unpack data #ifdef UNITY_COMPILER_HLSL Input surfIN = (Input)0; #else Input surfIN; #endif surfIN.uv_MainTex = IN.pack0.xy; surfIN.uv_NormalMap = IN.pack0.zw; surfIN.worldRefl = float3(IN.TtoW0.w, IN.TtoW1.w, IN.TtoW2.w); surfIN.TtoW0 = IN.TtoW0.xyz; surfIN.TtoW1 = IN.TtoW1.xyz; surfIN.TtoW2 = IN.TtoW2.xyz; #ifdef UNITY_COMPILER_HLSL SurfaceOutput o = (SurfaceOutput)0; #else SurfaceOutput o; #endif o.Albedo = 0.0; o.Emission = 0.0; o.Specular = 0.0; o.Alpha = 0.0; o.Gloss = 0.0; // call surface function surf (surfIN, o); // compute lighting & shadowing factor fixed atten = LIGHT_ATTENUATION(IN); fixed4 c = 0; // realtime lighting: call lighting function #ifdef LIGHTMAP_OFF c = LightingLambert (o, IN.lightDir, atten); #endif // LIGHTMAP_OFF || DIRLIGHTMAP_OFF #ifdef LIGHTMAP_OFF c.rgb += o.Albedo * IN.vlight; #endif // LIGHTMAP_OFF // lightmaps: #ifndef LIGHTMAP_OFF #ifndef DIRLIGHTMAP_OFF // directional lightmaps fixed4 lmtex = tex2D(unity_Lightmap, IN.lmap.xy); fixed4 lmIndTex = tex2D(unity_LightmapInd, IN.lmap.xy); half3 lm = LightingLambert_DirLightmap(o, lmtex, lmIndTex, 1).rgb; #else // !DIRLIGHTMAP_OFF // single lightmap fixed4 lmtex = tex2D(unity_Lightmap, IN.lmap.xy); fixed3 lm = DecodeLightmap (lmtex); #endif // !DIRLIGHTMAP_OFF // combine lightmaps with realtime shadows #ifdef SHADOWS_SCREEN #if defined(UNITY_NO_RGBM) c.rgb += o.Albedo * min(lm, atten*2); #else c.rgb += o.Albedo * max(min(lm,(atten*2)*lmtex.rgb), lm*atten); #endif #else // SHADOWS_SCREEN c.rgb += o.Albedo * lm; #endif // SHADOWS_SCREEN c.a = o.Alpha; #endif // LIGHTMAP_OFF c.rgb += o.Emission; return c;}ENDCG} // ---- forward rendering additive lights pass: Pass { Name "FORWARD" Tags { "LightMode" = "ForwardAdd" } ZWrite Off Blend One One Fog { Color (0,0,0,0) }CGPROGRAM// compile directives#pragma vertex vert_surf#pragma fragment frag_surf#pragma multi_compile_fwdadd#include "HLSLSupport.cginc"#include "UnityShaderVariables.cginc"#define UNITY_PASS_FORWARDADD#include "UnityCG.cginc"#include "Lighting.cginc"#include "AutoLight.cginc"#define INTERNAL_DATA#define WorldReflectionVector(data,normal) data.worldRefl#define WorldNormalVector(data,normal) normal// Original surface shader snippet:#line 18 ""#ifdef DUMMY_PREPROCESSOR_TO_WORK_AROUND_HLSL_COMPILER_LINE_HANDLING#endif //#pragma surface surf Lambert float4 _MainTint; sampler2D _MainTex; sampler2D _NormalMap; samplerCUBE _Cubemap; float _ReflAmount; struct Input { float2 uv_MainTex; float2 uv_NormalMap; float3 worldRefl; INTERNAL_DATA }; void surf (Input IN, inout SurfaceOutput o) { half4 c = tex2D (_MainTex, IN.uv_MainTex); //从法线贴图中提取法线信息，UnpackNormal这个函数在 CGInclude 文件夹中的Lighting中。 float3 normals=UnpackNormal(tex2D(_NormalMap,IN.uv_NormalMap)); o.Normal=normals; //上面使用法线贴图中的法线数据 替代了 原来的法线数据。 //法线被修改了，就不能 直接用原来的 内置属性 worldRefl 这个反射向量，而是要通过 WorldReflectionVector(IN,o.Normal)来获取。 //使用WorldReflectionVector 获得 基于法线贴图中的反射向量的 世界反射向量 o.Emission = texCUBE(_Cubemap,WorldReflectionVector(IN,o.Normal)).rgb * _ReflAmount; o.Albedo = c.rgb * _MainTint; o.Alpha = c.a; } // vertex-to-fragment interpolation datastruct v2f_surf { float4 pos : SV_POSITION; float4 pack0 : TEXCOORD0; half3 lightDir : TEXCOORD1; LIGHTING_COORDS(2,3)};float4 _MainTex_ST;float4 _NormalMap_ST;// vertex shaderv2f_surf vert_surf (appdata_full v) { v2f_surf o; o.pos = mul (UNITY_MATRIX_MVP, v.vertex); o.pack0.xy = TRANSFORM_TEX(v.texcoord, _MainTex); o.pack0.zw = TRANSFORM_TEX(v.texcoord, _NormalMap); TANGENT_SPACE_ROTATION; float3 lightDir = mul (rotation, ObjSpaceLightDir(v.vertex)); o.lightDir = lightDir; // pass lighting information to pixel shader TRANSFER_VERTEX_TO_FRAGMENT(o); return o;}// fragment shaderfixed4 frag_surf (v2f_surf IN) : SV_Target { // prepare and unpack data #ifdef UNITY_COMPILER_HLSL Input surfIN = (Input)0; #else Input surfIN; #endif surfIN.uv_MainTex = IN.pack0.xy; surfIN.uv_NormalMap = IN.pack0.zw; #ifdef UNITY_COMPILER_HLSL SurfaceOutput o = (SurfaceOutput)0; #else SurfaceOutput o; #endif o.Albedo = 0.0; o.Emission = 0.0; o.Specular = 0.0; o.Alpha = 0.0; o.Gloss = 0.0; // call surface function surf (surfIN, o); #ifndef USING_DIRECTIONAL_LIGHT fixed3 lightDir = normalize(IN.lightDir); #else fixed3 lightDir = IN.lightDir; #endif fixed4 c = LightingLambert (o, lightDir, LIGHT_ATTENUATION(IN)); c.a = 0.0; return c;}ENDCG} // ---- deferred lighting base geometry pass: Pass { Name "PREPASS" Tags { "LightMode" = "PrePassBase" } Fog {Mode Off}CGPROGRAM// compile directives#pragma vertex vert_surf#pragma fragment frag_surf#pragma exclude_renderers flash#include "HLSLSupport.cginc"#include "UnityShaderVariables.cginc"#define UNITY_PASS_PREPASSBASE#include "UnityCG.cginc"#include "Lighting.cginc"#define INTERNAL_DATA#define WorldReflectionVector(data,normal) data.worldRefl#define WorldNormalVector(data,normal) normal// Original surface shader snippet:#line 18 ""#ifdef DUMMY_PREPROCESSOR_TO_WORK_AROUND_HLSL_COMPILER_LINE_HANDLING#endif //#pragma surface surf Lambert float4 _MainTint; sampler2D _MainTex; sampler2D _NormalMap; samplerCUBE _Cubemap; float _ReflAmount; struct Input { float2 uv_MainTex; float2 uv_NormalMap; float3 worldRefl; INTERNAL_DATA }; void surf (Input IN, inout SurfaceOutput o) { half4 c = tex2D (_MainTex, IN.uv_MainTex); //从法线贴图中提取法线信息，UnpackNormal这个函数在 CGInclude 文件夹中的Lighting中。 float3 normals=UnpackNormal(tex2D(_NormalMap,IN.uv_NormalMap)); o.Normal=normals; //上面使用法线贴图中的法线数据 替代了 原来的法线数据。 //法线被修改了，就不能 直接用原来的 内置属性 worldRefl 这个反射向量，而是要通过 WorldReflectionVector(IN,o.Normal)来获取。 //使用WorldReflectionVector 获得 基于法线贴图中的反射向量的 世界反射向量 o.Emission = texCUBE(_Cubemap,WorldReflectionVector(IN,o.Normal)).rgb * _ReflAmount; o.Albedo = c.rgb * _MainTint; o.Alpha = c.a; } // vertex-to-fragment interpolation datastruct v2f_surf { float4 pos : SV_POSITION; float2 pack0 : TEXCOORD0; float3 TtoW0 : TEXCOORD1; float3 TtoW1 : TEXCOORD2; float3 TtoW2 : TEXCOORD3;};float4 _NormalMap_ST;// vertex shaderv2f_surf vert_surf (appdata_full v) { v2f_surf o; o.pos = mul (UNITY_MATRIX_MVP, v.vertex); o.pack0.xy = TRANSFORM_TEX(v.texcoord, _NormalMap); TANGENT_SPACE_ROTATION; o.TtoW0 = mul(rotation, ((float3x3)_Object2World)[0].xyz)*unity_Scale.w; o.TtoW1 = mul(rotation, ((float3x3)_Object2World)[1].xyz)*unity_Scale.w; o.TtoW2 = mul(rotation, ((float3x3)_Object2World)[2].xyz)*unity_Scale.w; return o;}// fragment shaderfixed4 frag_surf (v2f_surf IN) : SV_Target { // prepare and unpack data #ifdef UNITY_COMPILER_HLSL Input surfIN = (Input)0; #else Input surfIN; #endif surfIN.uv_NormalMap = IN.pack0.xy; #ifdef UNITY_COMPILER_HLSL SurfaceOutput o = (SurfaceOutput)0; #else SurfaceOutput o; #endif o.Albedo = 0.0; o.Emission = 0.0; o.Specular = 0.0; o.Alpha = 0.0; o.Gloss = 0.0; // call surface function surf (surfIN, o); fixed3 worldN; worldN.x = dot(IN.TtoW0, o.Normal); worldN.y = dot(IN.TtoW1, o.Normal); worldN.z = dot(IN.TtoW2, o.Normal); o.Normal = worldN; // output normal and specular fixed4 res; res.rgb = o.Normal * 0.5 + 0.5; res.a = o.Specular; return res;}ENDCG} // ---- deferred lighting final pass: Pass { Name "PREPASS" Tags { "LightMode" = "PrePassFinal" } ZWrite OffCGPROGRAM// compile directives#pragma vertex vert_surf#pragma fragment frag_surf#pragma multi_compile_prepassfinal#pragma exclude_renderers flash#include "HLSLSupport.cginc"#include "UnityShaderVariables.cginc"#define UNITY_PASS_PREPASSFINAL#include "UnityCG.cginc"#include "Lighting.cginc"#define INTERNAL_DATA half3 TtoW0; half3 TtoW1; half3 TtoW2;#define WorldReflectionVector(data,normal) reflect (data.worldRefl, half3(dot(data.TtoW0,normal), dot(data.TtoW1,normal), dot(data.TtoW2,normal)))#define WorldNormalVector(data,normal) fixed3(dot(data.TtoW0,normal), dot(data.TtoW1,normal), dot(data.TtoW2,normal))// Original surface shader snippet:#line 18 ""#ifdef DUMMY_PREPROCESSOR_TO_WORK_AROUND_HLSL_COMPILER_LINE_HANDLING#endif //#pragma surface surf Lambert float4 _MainTint; sampler2D _MainTex; sampler2D _NormalMap; samplerCUBE _Cubemap; float _ReflAmount; struct Input { float2 uv_MainTex; float2 uv_NormalMap; float3 worldRefl; INTERNAL_DATA }; void surf (Input IN, inout SurfaceOutput o) { half4 c = tex2D (_MainTex, IN.uv_MainTex); //从法线贴图中提取法线信息，UnpackNormal这个函数在 CGInclude 文件夹中的Lighting中。 float3 normals=UnpackNormal(tex2D(_NormalMap,IN.uv_NormalMap)); o.Normal=normals; //上面使用法线贴图中的法线数据 替代了 原来的法线数据。 //法线被修改了，就不能 直接用原来的 内置属性 worldRefl 这个反射向量，而是要通过 WorldReflectionVector(IN,o.Normal)来获取。 //使用WorldReflectionVector 获得 基于法线贴图中的反射向量的 世界反射向量 o.Emission = texCUBE(_Cubemap,WorldReflectionVector(IN,o.Normal)).rgb * _ReflAmount; o.Albedo = c.rgb * _MainTint; o.Alpha = c.a; } // vertex-to-fragment interpolation datastruct v2f_surf { float4 pos : SV_POSITION; float4 pack0 : TEXCOORD0; float4 screen : TEXCOORD1; fixed4 TtoW0 : TEXCOORD2; fixed4 TtoW1 : TEXCOORD3; fixed4 TtoW2 : TEXCOORD4;#ifdef LIGHTMAP_OFF float3 vlight : TEXCOORD5;#else float2 lmap : TEXCOORD5;#ifdef DIRLIGHTMAP_OFF float4 lmapFadePos : TEXCOORD6;#endif#endif};#ifndef LIGHTMAP_OFFfloat4 unity_LightmapST;#endiffloat4 _MainTex_ST;float4 _NormalMap_ST;// vertex shaderv2f_surf vert_surf (appdata_full v) { v2f_surf o; o.pos = mul (UNITY_MATRIX_MVP, v.vertex); o.pack0.xy = TRANSFORM_TEX(v.texcoord, _MainTex); o.pack0.zw = TRANSFORM_TEX(v.texcoord, _NormalMap); float3 viewDir = -ObjSpaceViewDir(v.vertex); float3 worldRefl = mul ((float3x3)_Object2World, viewDir); TANGENT_SPACE_ROTATION; o.TtoW0 = float4(mul(rotation, _Object2World[0].xyz), worldRefl.x)*unity_Scale.w; o.TtoW1 = float4(mul(rotation, _Object2World[1].xyz), worldRefl.y)*unity_Scale.w; o.TtoW2 = float4(mul(rotation, _Object2World[2].xyz), worldRefl.z)*unity_Scale.w; o.screen = ComputeScreenPos (o.pos);#ifndef LIGHTMAP_OFF o.lmap.xy = v.texcoord1.xy * unity_LightmapST.xy + unity_LightmapST.zw; #ifdef DIRLIGHTMAP_OFF o.lmapFadePos.xyz = (mul(_Object2World, v.vertex).xyz - unity_ShadowFadeCenterAndType.xyz) * unity_ShadowFadeCenterAndType.w; o.lmapFadePos.w = (-mul(UNITY_MATRIX_MV, v.vertex).z) * (1.0 - unity_ShadowFadeCenterAndType.w); #endif#else float3 worldN = mul((float3x3)_Object2World, SCALED_NORMAL); o.vlight = ShadeSH9 (float4(worldN,1.0));#endif return o;}sampler2D _LightBuffer;#if defined (SHADER_API_XBOX360) && defined (HDR_LIGHT_PREPASS_ON)sampler2D _LightSpecBuffer;#endif#ifndef LIGHTMAP_OFFsampler2D unity_Lightmap;sampler2D unity_LightmapInd;float4 unity_LightmapFade;#endiffixed4 unity_Ambient;// fragment shaderfixed4 frag_surf (v2f_surf IN) : SV_Target { // prepare and unpack data #ifdef UNITY_COMPILER_HLSL Input surfIN = (Input)0; #else Input surfIN; #endif surfIN.uv_MainTex = IN.pack0.xy; surfIN.uv_NormalMap = IN.pack0.zw; surfIN.worldRefl = float3(IN.TtoW0.w, IN.TtoW1.w, IN.TtoW2.w); surfIN.TtoW0 = IN.TtoW0.xyz; surfIN.TtoW1 = IN.TtoW1.xyz; surfIN.TtoW2 = IN.TtoW2.xyz; #ifdef UNITY_COMPILER_HLSL SurfaceOutput o = (SurfaceOutput)0; #else SurfaceOutput o; #endif o.Albedo = 0.0; o.Emission = 0.0; o.Specular = 0.0; o.Alpha = 0.0; o.Gloss = 0.0; // call surface function surf (surfIN, o); half4 light = tex2Dproj (_LightBuffer, UNITY_PROJ_COORD(IN.screen));#if defined (SHADER_API_MOBILE) light = max(light, half4(0.001));#endif#ifndef HDR_LIGHT_PREPASS_ON light = -log2(light);#endif#if defined (SHADER_API_XBOX360) && defined (HDR_LIGHT_PREPASS_ON) light.w = tex2Dproj (_LightSpecBuffer, UNITY_PROJ_COORD(IN.screen)).r;#endif // add lighting from lightmaps / vertex / ambient: #ifndef LIGHTMAP_OFF #ifdef DIRLIGHTMAP_OFF // dual lightmaps fixed4 lmtex = tex2D(unity_Lightmap, IN.lmap.xy); fixed4 lmtex2 = tex2D(unity_LightmapInd, IN.lmap.xy); half lmFade = length (IN.lmapFadePos) * unity_LightmapFade.z + unity_LightmapFade.w; half3 lmFull = DecodeLightmap (lmtex); half3 lmIndirect = DecodeLightmap (lmtex2); half3 lm = lerp (lmIndirect, lmFull, saturate(lmFade)); light.rgb += lm; #else // directional lightmaps fixed4 lmtex = tex2D(unity_Lightmap, IN.lmap.xy); fixed4 lmIndTex = tex2D(unity_LightmapInd, IN.lmap.xy); half4 lm = LightingLambert_DirLightmap(o, lmtex, lmIndTex, 1); light += lm; #endif #else light.rgb += IN.vlight; #endif half4 c = LightingLambert_PrePass (o, light); c.rgb += o.Emission; return c;}ENDCG} // ---- end of surface shader generated code#LINE 64 } FallBack "Diffuse"}果然，原来 INTERNAL_DATA 就是一个宏……
而且会发现在生成的代码中不止一个 INTERNAL_DATA。这是因为生成的代码中有多个PASS
forward rendering additive lights pass:deferred lighting base geometry pass:deferred lighting final pass:forward rendering base pass:每个PASS 都有一个，所以有好几个。
那么，不使用 INTERNAL_DATA，而是直接使用 具体的内容，可以吗？来试一下。
首先，从Shader 中删掉 INTERNAL_DATA。
Unity 报了以下错误
Shader error in 'CookBookShaders/Chapt4-4/Cubemap_NormalMap': invalid subscript 'TtoW0' at line 59是这一行的错
o.Emission = texCUBE(_Cubemap,WorldReflectionVector(IN,o.Normal)).rgb * _ReflAmount;因为从上面 Shader 编译后的代码看到，WorldReflectionVector 也是一个宏
#define WorldReflectionVector(data,normal) reflect (data.worldRefl, half3(dot(data.TtoW0,normal), dot(data.TtoW1,normal), dot(data.TtoW2,normal)))其实就是说，在WorldReflectionVector 这个函数里找不到 TtoW0 这个参数了。
然后，在 Input 结构体中添加 INTERNAL_DATA 的具体内容看看
struct Input { float2 uv_MainTex; float2 uv_NormalMap; float3 worldRefl; half3 TtoW0; half3 TtoW1; half3 TtoW2; };法线 Shader 已经正常工作啦
B：在Input 中 添加 float3 worldRefl 和 INTERNAL_DATA ，给o.Normal 赋值的话，就可以 用 WorldReflectionVector(IN,o.Normal) 获取到 法线贴图 计算后的 反射向量。
原文是这样写的
在Input 结构体中还有更多的内置函数，其中一部分如下：
float3 viewDir ：Will contain view direction, for computing Parallax effects, rimlighting, and so on.float4 COLOR ：Will contain interpolated per-vertex color.float4 screenPos：Will contain screen-space position for reflection effects. Used by WetStreet shader in Dark Unity, for example.float3 worldPos ：Will contain world space position.float3 worldRefl ：Will contain world reflection vector if Surface Shader does not write to o.Normal. See Reflect-Diffuse shader for example.float3 worldNormal ：Will contain world normal vector if Surface Shader does not write to o.Normal.float3 worldRef;INTERNAL_DATA：Will contain world reflection vector if Surface Shader writes to o.Normal. To get the reflection vector based on per-pixel normal map, use WorldReflectionVector (IN,o.Normal). See Reflect-Bumped shader for example.float3 worldNormal;INTERNAL_DATA：Will contain world normal vector if Surface Shader writes to o.Normal. To get the normal vector based on per-pixel normal map, use WorldNormalVector (IN, o.Normal).3、在 surf 函数中 添加了 读取 法线贴图的代码
//从法线贴图中提取法线信息，UnpackNormal这个函数在 CGInclude 文件夹中的Lighting中。 float3 normals=UnpackNormal(tex2D(_NormalMap,IN.uv_NormalMap));4、上一节中直接使用 Input 中的 worldRefl 这个反射向量来获取立方图 采样。这一次需要使用上面说的 WorldReflectionVector 来计算世界反射向量。
//使用WorldReflectionVector 获得 基于法线贴图中的反射向量的 世界反射向量o.Emission = texCUBE(_Cubemap,WorldReflectionVector(IN,o.Normal)).rgb * _ReflAmount;示例项目打包下载：
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