目标是让substance效果和unity效果一致
分2步：
1.完成1个shader，效果和standard完全一致，抛去不需要的功能
2.使用新的shader，在substance里替代原有的渲染
# pbr shader
拷贝2份完全一致的工程，都使用standard，效果调到一致
standard最大麻烦是一堆keyword，需要知道走哪个分支
外部设置进来的keyword
在frag里
#if UNITY_SAMPLE_FULL_SH_PER_PIXEL
return fixed4(1.0, 1.0, 1.0, 1.0);
#else
return fixed4(0,0,0, 1.0);
#endif
通过替换UNITY_SAMPLE_FULL_SH_PER_PIXEL，来确定哪些不清楚的keyword
总结如下（不全）：
UNITY_PASS_META 0 烘焙用，不需要
DYNAMICLIGHTMAP_ON 0 不用lightmap
_TANGENT_TO_WORLD 1 用了法线贴图，所以这个开关打开了
UNITY_SHOULD_SAMPLE_SH 1 受probe影响
HANDLE_SHADOWS_BLENDING_IN_GI 0 不需要
_GLOSSYREFLECTIONS_OFF 不需要反射探头，但是支持下光照探头
经过一堆奋战，第1个版本
Shader "PBR" { Properties { _Color("Color", Color) = (1,1,1,1) _MainTex("Albedo", 2D) = "white" {} _Cutoff("Alpha Cutoff", Range(0.0, 1.0)) = 0.5 _Glossiness("Smoothness", Range(0.0, 1.0)) = 0.5 _GlossMapScale("Smoothness Scale", Range(0.0, 1.0)) = 1.0 [Enum(Metallic Alpha,0,Albedo Alpha,1)] _SmoothnessTextureChannel ("Smoothness texture channel", Float) = 0 [Gamma] _Metallic("Metallic", Range(0.0, 1.0)) = 0.0 _MetallicGlossMap("Metallic", 2D) = "white" {} [ToggleOff] _SpecularHighlights("Specular Highlights", Float) = 1.0 [ToggleOff] _GlossyReflections("Glossy Reflections", Float) = 1.0 _BumpScale("Scale", Float) = 1.0 _BumpMap("Normal Map", 2D) = "bump" {} _Parallax ("Height Scale", Range (0.005, 0.08)) = 0.02 _ParallaxMap ("Height Map", 2D) = "black" {} _OcclusionStrength("Strength", Range(0.0, 1.0)) = 1.0 _OcclusionMap("Occlusion", 2D) = "white" {} _EmissionColor("Color", Color) = (0,0,0) _EmissionMap("Emission", 2D) = "white" {} _DetailMask("Detail Mask", 2D) = "white" {} _DetailAlbedoMap("Detail Albedo x2", 2D) = "grey" {} _DetailNormalMapScale("Scale", Float) = 1.0 _DetailNormalMap("Normal Map", 2D) = "bump" {} [Enum(UV0,0,UV1,1)] _UVSec ("UV Set for secondary textures", Float) = 0 // Blending state [HideInInspector] _Mode ("__mode", Float) = 0.0 [HideInInspector] _SrcBlend ("__src", Float) = 1.0 [HideInInspector] _DstBlend ("__dst", Float) = 0.0 [HideInInspector] _ZWrite ("__zw", Float) = 1.0 } SubShader { Tags { "LightMode" = "ForwardBase" "RenderType"="Opaque" "PerformanceChecks"="False" } LOD 300 pass{ CGPROGRAM #pragma vertex vert #pragma fragment frag #include "UnityCG.cginc" #include "AutoLight.cginc" #include "UnityStandardInput.cginc" struct vertinput { float4 vertex : POSITION; half3 normal : NORMAL; float2 uv0 : TEXCOORD0; float2 uv1 : TEXCOORD1; half4 tangent : TANGENT; }; struct v2f { UNITY_POSITION(pos); float4 tex : TEXCOORD0; float3 eyeVec : TEXCOORD1; float4 tangentToWorldAndPackedData[3] : TEXCOORD2; // [3x3:tangentToWorld | 1x3:viewDirForParallax or worldPos] half4 ambientOrLightmapUV : TEXCOORD5; // SH or Lightmap UV UNITY_SHADOW_COORDS(6) UNITY_FOG_COORDS(7) // next ones would not fit into SM2.0 limits, but they are always for SM3.0+ #if UNITY_REQUIRE_FRAG_WORLDPOS && !UNITY_PACK_WORLDPOS_WITH_TANGENT float3 posWorld : TEXCOORD8; #endif }; inline half4 VertexGIForward(vertinput v, float3 posWorld, half3 normalWorld) { half4 ambientOrLightmapUV = 0; //ambientOrLightmapUV.rgb = ShadeSHPerVertex (normalWorld, ambientOrLightmapUV.rgb); ambientOrLightmapUV.rgb += SHEvalLinearL2 (half4(normalWorld, 1.0)); return ambientOrLightmapUV; } struct FragmentCommonData { half3 diffColor, specColor; // Note: smoothness & oneMinusReflectivity for optimization purposes, mostly for DX9 SM2.0 level. // Most of the math is being done on these (1-x) values, and that saves a few precious ALU slots. half oneMinusReflectivity, smoothness; float3 normalWorld; float3 eyeVec; half alpha; float3 posWorld; }; inline FragmentCommonData MetallicSetup (float4 i_tex) { half2 metallicGloss = tex2D(_MetallicGlossMap, i_tex.xy).ra; metallicGloss.g *= _GlossMapScale; half metallic = metallicGloss.x; half smoothness = metallicGloss.y; // this is 1 minus the square root of real roughness m. half oneMinusReflectivity; half3 specColor; half3 diffColor = DiffuseAndSpecularFromMetallic (Albedo(i_tex), metallic, /*out*/ specColor, /*out*/ oneMinusReflectivity); FragmentCommonData o = (FragmentCommonData)0; o.diffColor = diffColor; o.specColor = specColor; o.oneMinusReflectivity = oneMinusReflectivity; o.smoothness = smoothness; return o; } UnityLight MainLight () { UnityLight l; l.color = _LightColor0.rgb; l.dir = _WorldSpaceLightPos0.xyz; return l; } half3 NormalInTangentSpace(float4 texcoords) { half3 normalTangent = UnpackScaleNormal(tex2D (_BumpMap, texcoords.xy), _BumpScale); return normalTangent; } float3 PerPixelWorldNormal(float4 i_tex, float4 tangentToWorld[3]) { half3 tangent = tangentToWorld[0].xyz; half3 binormal = tangentToWorld[1].xyz; half3 normal = tangentToWorld[2].xyz; half3 normalTangent = NormalInTangentSpace(i_tex); float3 normalWorld = normalize(tangent * normalTangent.x + binormal * normalTangent.y + normal * normalTangent.z); // @TODO: see if we can squeeze this normalize on SM2.0 as well return normalWorld; } inline FragmentCommonData FragmentSetup (inout float4 i_tex, float3 i_eyeVec, half3 i_viewDirForParallax, float4 tangentToWorld[3], float3 i_posWorld) { i_tex = Parallax(i_tex, i_viewDirForParallax); half alpha = Alpha(i_tex.xy); FragmentCommonData o = MetallicSetup (i_tex); o.normalWorld = PerPixelWorldNormal(i_tex, tangentToWorld); o.eyeVec = normalize(i_eyeVec); o.posWorld = i_posWorld; // NOTE: shader relies on pre-multiply alpha-blend (_SrcBlend = One, _DstBlend = OneMinusSrcAlpha) o.diffColor = PreMultiplyAlpha (o.diffColor, alpha, o.oneMinusReflectivity, /*out*/ o.alpha); return o; } #ifdef _PARALLAXMAP #define IN_VIEWDIR4PARALLAX(i) NormalizePerPixelNormal(half3(i.tangentToWorldAndPackedData[0].w,i.tangentToWorldAndPackedData[1].w,i.tangentToWorldAndPackedData[2].w)) #define IN_VIEWDIR4PARALLAX_FWDADD(i) NormalizePerPixelNormal(i.viewDirForParallax.xyz) #else #define IN_VIEWDIR4PARALLAX(i) half3(0,0,0) #define IN_VIEWDIR4PARALLAX_FWDADD(i) half3(0,0,0) #endif #if UNITY_REQUIRE_FRAG_WORLDPOS #if UNITY_PACK_WORLDPOS_WITH_TANGENT #define IN_WORLDPOS(i) half3(i.tangentToWorldAndPackedData[0].w,i.tangentToWorldAndPackedData[1].w,i.tangentToWorldAndPackedData[2].w) #else #define IN_WORLDPOS(i) i.posWorld #endif #define IN_WORLDPOS_FWDADD(i) i.posWorld #else #define IN_WORLDPOS(i) half3(0,0,0) #define IN_WORLDPOS_FWDADD(i) half3(0,0,0) #endif #define FRAGMENT_SETUP(x) FragmentCommonData x = \ FragmentSetup(i.tex, i.eyeVec, IN_VIEWDIR4PARALLAX(i), i.tangentToWorldAndPackedData, IN_WORLDPOS(i)); inline UnityGI UnityGIBase(UnityGIInput data, half occlusion, half3 normalWorld) { UnityGI o_gi; ResetUnityGI(o_gi); o_gi.light = data.light; o_gi.light.color *= data.atten; half3 ambient_contrib = SHEvalLinearL0L1 (half4(normalWorld, 1.0)); o_gi.indirect.diffuse = max(half3(0, 0, 0), data.ambient+ambient_contrib); o_gi.indirect.diffuse *= occlusion; return o_gi; } inline UnityGI FragmentGI (FragmentCommonData s, half occlusion, half4 i_ambientOrLightmapUV, half atten, UnityLight light, bool reflections) { UnityGIInput d; d.light = light; d.worldPos = s.posWorld; d.worldViewDir = -s.eyeVec; d.atten = atten; d.ambient = i_ambientOrLightmapUV.rgb; d.lightmapUV = 0; d.probeHDR[0] = unity_SpecCube0_HDR; d.probeHDR[1] = unity_SpecCube1_HDR; #if defined(UNITY_SPECCUBE_BLENDING) || defined(UNITY_SPECCUBE_BOX_PROJECTION) d.boxMin[0] = unity_SpecCube0_BoxMin; // .w holds lerp value for blending #endif #ifdef UNITY_SPECCUBE_BOX_PROJECTION d.boxMax[0] = unity_SpecCube0_BoxMax; d.probePosition[0] = unity_SpecCube0_ProbePosition; d.boxMax[1] = unity_SpecCube1_BoxMax; d.boxMin[1] = unity_SpecCube1_BoxMin; d.probePosition[1] = unity_SpecCube1_ProbePosition; #endif Unity_GlossyEnvironmentData g = UnityGlossyEnvironmentSetup(s.smoothness, -s.eyeVec, s.normalWorld, s.specColor); UnityGI o_gi = UnityGIBase(d, occlusion, s.normalWorld); //o_gi.indirect.specular = UnityGI_IndirectSpecular(d, occlusion, g); o_gi.indirect.specular = unity_IndirectSpecColor.rgb*occlusion; return o_gi; } inline UnityGI FragmentGI (FragmentCommonData s, half occlusion, half4 i_ambientOrLightmapUV, half atten, UnityLight light) { return FragmentGI(s, occlusion, i_ambientOrLightmapUV, atten, light, true); } v2f vert (vertinput v) { v2f o; float4 posWorld = mul(unity_ObjectToWorld, v.vertex); o.tangentToWorldAndPackedData[0].w = posWorld.x; o.tangentToWorldAndPackedData[1].w = posWorld.y; o.tangentToWorldAndPackedData[2].w = posWorld.z; o.pos = UnityObjectToClipPos(v.vertex); o.tex.xy = TRANSFORM_TEX(v.uv0, _MainTex); o.eyeVec = posWorld.xyz - _WorldSpaceCameraPos; float3 normalWorld = UnityObjectToWorldNormal(v.normal); float4 tangentWorld = float4(UnityObjectToWorldDir(v.tangent.xyz), v.tangent.w); float3x3 tangentToWorld = CreateTangentToWorldPerVertex(normalWorld, tangentWorld.xyz, tangentWorld.w); o.tangentToWorldAndPackedData[0].xyz = tangentToWorld[0]; o.tangentToWorldAndPackedData[1].xyz = tangentToWorld[1]; o.tangentToWorldAndPackedData[2].xyz = tangentToWorld[2]; //We need this for shadow receving UNITY_TRANSFER_SHADOW(o, v.uv1); o.ambientOrLightmapUV = VertexGIForward(v, posWorld, normalWorld); UNITY_TRANSFER_FOG(o,o.pos); return o; } half4 BRDF (half3 diffColor, half3 specColor, half oneMinusReflectivity, half smoothness, float3 normal, float3 viewDir, UnityLight light, UnityIndirect gi) { float3 halfDir = Unity_SafeNormalize (float3(light.dir) + viewDir); half nl = saturate(dot(normal, light.dir)); float nh = saturate(dot(normal, halfDir)); half nv = saturate(dot(normal, viewDir)); float lh = saturate(dot(light.dir, halfDir)); // Specular term half perceptualRoughness = SmoothnessToPerceptualRoughness (smoothness); half roughness = PerceptualRoughnessToRoughness(perceptualRoughness); // GGX Distribution multiplied by combined approximation of Visibility and Fresnel // See "Optimizing PBR for Mobile" from Siggraph 2015 moving mobile graphics course // https://community.arm.com/events/1155 half a = roughness; float a2 = a*a; float d = nh * nh * (a2 - 1.f) + 1.00001f; float specularTerm = a2 / (max(0.1f, lh*lh) * (roughness + 0.5f) * (d * d) * 4); // on mobiles (where half actually means something) denominator have risk of overflow // clamp below was added specifically to "fix" that, but dx compiler (we convert bytecode to metal/gles) // sees that specularTerm have only non-negative terms, so it skips max(0,..) in clamp (leaving only min(100,...)) #if defined (SHADER_API_MOBILE) specularTerm = specularTerm - 1e-4f; #endif #if defined (SHADER_API_MOBILE) specularTerm = clamp(specularTerm, 0.0, 100.0); // Prevent FP16 overflow on mobiles #endif half surfaceReduction = (0.6-0.08*perceptualRoughness); surfaceReduction = 1.0 - roughness*perceptualRoughness*surfaceReduction; half grazingTerm = saturate(smoothness + (1-oneMinusReflectivity)); half3 color = (diffColor + specularTerm * specColor) * light.color * nl + gi.diffuse * diffColor + surfaceReduction * gi.specular * FresnelLerpFast (specColor, grazingTerm, nv); return half4(color, 1); } half4 frag ( v2f i):SV_Target { FRAGMENT_SETUP(s) UnityLight mainLight = MainLight (); UNITY_LIGHT_ATTENUATION(atten, i, s.posWorld); half occlusion = Occlusion(i.tex.xy); UnityGI gi = FragmentGI (s, occlusion, i.ambientOrLightmapUV, atten, mainLight); half4 c = BRDF (s.diffColor, s.specColor, s.oneMinusReflectivity, s.smoothness, s.normalWorld, -s.eyeVec, gi.light, gi.indirect); c.rgb += Emission(i.tex.xy); UNITY_APPLY_FOG(i.fogCoord, c.rgb); c.a = 1.0; return c; } ENDCG } } CustomEditor "StandardShaderGUI" }
效果图
效果完全一致，继续删减keyword