Merge pull request #6 from Unity-Technologies/ReflectionArchiTest

Reflectionarchitest

Assets/ScriptableRenderLoop/HDRenderLoop/HDRenderLoop.cs

                 float blendDistance = Mathf.Min(maxBlendDist, probe.blendDistance);
                 l.innerDistance = probe.bounds.extents - new Vector3(blendDistance, blendDistance, blendDistance);
 
-                l.sliceIndex = m_cubeReflTexArray.FetchSlice(probe.texture);
+                l.envIndex = m_cubeReflTexArray.FetchSlice(probe.texture);
 
                 l.offsetLS = probe.center; // center is misnamed, it is the offset (in local space) from center of the bounding box to the cubemap capture point
                 l.blendDistance = blendDistance;

Assets/ScriptableRenderLoop/HDRenderLoop/Shaders/Lighting/Deferred.shader

             #pragma vertex VertDeferred
             #pragma fragment FragDeferred
 
+            #include "Common.hlsl"
             // Chose supported lighting architecture in case of deferred rendering
             #pragma multi_compile SINGLE_PASS
 

Assets/ScriptableRenderLoop/HDRenderLoop/Shaders/Lighting/LightDefinition.cs

         public EnvShapeType envShapeType;
 
         public Vector3 forward;
-        public float unused2;
+        public float envIndex;
-        public int sliceIndex;
+        public int unused0;
-        public float unused0;
+        public float unused1;
-        public float unused1;
+        public float unused2;
     };
 
 } // namespace UnityEngine.Experimental.ScriptableRenderLoop

Assets/ScriptableRenderLoop/HDRenderLoop/Shaders/Lighting/LightDefinition.cs.hlsl

 	float3 positionWS;
 	int envShapeType;
 	float3 forward;
-	float unused2;
+	float envIndex;
-	int sliceIndex;
+	int unused0;
-	float unused0;
-	float3 offsetLS;
+	float3 offsetLS;
+	float unused2;
 };
 
 //
 {
 	return value.forward;
 }
-float GetUnused2(EnvLightData value)
+float GetEnvIndex(EnvLightData value)
-	return value.unused2;
+	return value.envIndex;
 }
 float3 GetUp(EnvLightData value)
 {
 {
 	return value.right;
 }
-int GetSliceIndex(EnvLightData value)
+int GetUnused0(EnvLightData value)
-	return value.sliceIndex;
+	return value.unused0;
-float GetUnused0(EnvLightData value)
+float GetUnused1(EnvLightData value)
-	return value.unused0;
+	return value.unused1;
-float GetUnused1(EnvLightData value)
+float GetUnused2(EnvLightData value)
-	return value.unused1;
+	return value.unused2;
 }
 
 

Assets/ScriptableRenderLoop/HDRenderLoop/Shaders/Lighting/Lighting.hlsl

 // It is also in charge to define the sampling function for shadowmap, ies, cookie and reflection 
 // as only the lighting architecture is aware of the usage of texture atlas, array and format (latlong, 2D, cube)
 
+#define LIGHTING // This define is used to know that we have include lighting when compiling material, else it will generate "default" function that are neutral to use Material.hlsl alone.
+
 #ifdef SINGLE_PASS 
 #include "Assets/ScriptableRenderLoop/HDRenderLoop/Shaders/Lighting/SinglePass/SinglePass.hlsl"
 //#elif ...

Assets/ScriptableRenderLoop/HDRenderLoop/Shaders/Lighting/SinglePass/SinglePass.hlsl

 // It use  maxed list of lights of the scene - use just as proof of concept - do not used in regular game
 //-----------------------------------------------------------------------------
 
+// Use texture array for reflection
+UNITY_DECLARE_TEXCUBEARRAY(_EnvTextures);
+UNITY_DECLARE_TEXCUBE(_SkyTexture);
+
+#define SINGLE_PASS_CONTEXT_SAMPLE_REFLECTION_PROBES 0
+#define SINGLE_PASS_CONTEXT_SAMPLE_SKY 1
+
+// Note: envIndex is whatever the lighting architecture want, it can contain information like in which texture to sample (in case we have a compressed BC6H texture and an uncompressed for real time reflection ?)
+// EnvIndex can also be use to fetch in another array of struct (to  atlas information etc...).
+float4 SampleEnv(int lightLoopContext, int envIndex, float3 dirWS, float lod)
+{
+    // This code will be inlined as lightLoopContext is hardcoded in the light loop
+    if (lightLoopContext == SINGLE_PASS_CONTEXT_SAMPLE_REFLECTION_PROBES)
+    {
+        return UNITY_SAMPLE_TEXCUBEARRAY_LOD(_EnvTextures, float4(dirWS, envIndex), lod);
+    }
+    else // SINGLE_PASS_SAMPLE_SKY
+    {
+        return UNITY_SAMPLE_TEXCUBE_LOD(_SkyTexture, dirWS, lod);
+    }    
+}
 
 /*
 float SampleShadow(int shadowIndex)
 	shadowData
 	return UNITY_SAMPLE_SHADOW(_ShadowMapAtlas, ...);
 }
-*/
+*/

Assets/ScriptableRenderLoop/HDRenderLoop/Shaders/Lighting/SinglePass/SinglePassLoop.hlsl

 StructuredBuffer<EnvLightData> _EnvLightList;
 int _EnvLightCount;
 
-// Use texture array for reflection
-UNITY_DECLARE_TEXCUBEARRAY(_EnvTextures);
+EnvLightData _EnvLightSky;
 
 /*
 // Use texture atlas for shadow map
     {
         float4 localDiffuseLighting;
         float4 localSpecularLighting;
-        EvaluateBSDF_Env(V, positionWS, prelightData, _EnvLightList[j], bsdfData, UNITY_PASS_TEXCUBEARRAY(_EnvTextures), localDiffuseLighting, localSpecularLighting);
+        EvaluateBSDF_Env(SINGLE_PASS_CONTEXT_SAMPLE_REFLECTION_PROBES, V, positionWS, prelightData, _EnvLightList[j], bsdfData, localDiffuseLighting, localSpecularLighting);
+        iblDiffuseLighting.rgb = lerp(iblDiffuseLighting.rgb, localDiffuseLighting.rgb, localDiffuseLighting.a); // Should be remove by the compiler if it is smart as all is constant 0
+        iblSpecularLighting.rgb = lerp(iblSpecularLighting.rgb, localSpecularLighting.rgb, localSpecularLighting.a);
+    }
+
+    /*
+    // Sky Ibl
+    {
+        float4 localDiffuseLighting;
+        float4 localSpecularLighting;
+        EvaluateBSDF_Env(SINGLE_PASS_CONTEXT_SAMPLE_SKY, V, positionWS, prelightData, _EnvLightSky, bsdfData, localDiffuseLighting, localSpecularLighting);
+    */
+    specularLighting += iblSpecularLighting;
+
-
-    specularLighting += iblSpecularLighting;
-}
+}

Assets/ScriptableRenderLoop/HDRenderLoop/Shaders/Material/Lit/Lit.hlsl

 }
 
 //-----------------------------------------------------------------------------
+// EvaluateBSDF_Env - Reference
+// ----------------------------------------------------------------------------
+
+// Ref: Moving Frostbite to PBR (Appendix A)
+float3 IntegrateLambertIBLRef(  int lightLoopContext, 
+                                EnvLightData lightData, BSDFData bsdfData,
+                                uint sampleCount = 2048)
+{
+    float3 N        = bsdfData.normalWS;
+    float3 acc      = float3(0.0, 0.0, 0.0);
+    // Add some jittering on Hammersley2d
+    float2 randNum  = InitRandom(N.xy * 0.5 + 0.5);
+
+    float3 tangentX, tangentY;
+    GetLocalFrame(N, tangentX, tangentY);
+
+    for (uint i = 0; i < sampleCount; ++i)
+    {
+        float2 u    = Hammersley2d(i, sampleCount);
+        u           = frac(u + randNum + 0.5);
+
+        float3 L;
+        float NdotL;
+        float weightOverPdf;
+        ImportanceSampleLambert(u, N, tangentX, tangentY, L, NdotL, weightOverPdf);
+
+        if (NdotL > 0.0)
+        {
+            float4 val = SampleEnv(lightLoopContext, lightData.envIndex, L, 0);
+
+            // diffuse Albedo is apply here as describe in ImportanceSampleLambert function
+            acc += bsdfData.diffuseColor * Lambert() * weightOverPdf * val.rgb;
+        }
+    }
+
+    return acc / sampleCount;
+}
+
+float3 IntegrateDisneyDiffuseIBLRef(int lightLoopContext,
+                                    float3 V, EnvLightData lightData, BSDFData bsdfData,
+                                    uint sampleCount = 2048)
+{
+    float3 N = bsdfData.normalWS;
+    float NdotV = dot(N, V);
+    float3 acc  = float3(0.0, 0.0, 0.0);
+    // Add some jittering on Hammersley2d
+    float2 randNum  = InitRandom(N.xy * 0.5 + 0.5);
+
+    float3 tangentX, tangentY;
+    GetLocalFrame(N, tangentX, tangentY);
+
+    for (uint i = 0; i < sampleCount; ++i)
+    {
+        float2 u    = Hammersley2d(i, sampleCount);
+        u           = frac(u + randNum + 0.5);
+
+        float3 L;
+        float NdotL;
+        float weightOverPdf;
+        // for Disney we still use a Cosine importance sampling, true Disney importance sampling imply a look up table
+        ImportanceSampleLambert(u, N, tangentX, tangentY, L, NdotL, weightOverPdf);
+
+        if (NdotL > 0.0)
+        {            
+            float3 H = normalize(L + V);
+            float LdotH = dot(L, H);
+            // Note: we call DisneyDiffuse that require to multiply by Albedo / PI. Divide by PI is already taken into account
+            // in weightOverPdf of ImportanceSampleLambert call.
+            float disneyDiffuse = DisneyDiffuse(NdotV, NdotL, LdotH, bsdfData.perceptualRoughness);
+
+            // diffuse Albedo is apply here as describe in ImportanceSampleLambert function
+            float4 val = SampleEnv(lightLoopContext, lightData.envIndex, L, 0);
+            acc += bsdfData.diffuseColor * disneyDiffuse * weightOverPdf * val.rgb;
+        }
+    }
+
+    return acc / sampleCount;
+}
+
+// Ref: Moving Frostbite to PBR (Appendix A)
+float3 IntegrateSpecularGGXIBLRef(  int lightLoopContext,
+                                    float3 V, EnvLightData lightData, BSDFData bsdfData,
+                                    uint sampleCount = 2048)
+{
+    float3 N        = bsdfData.normalWS;
+    float NdotV     = saturate(dot(N, V));
+    float3 acc      = float3(0.0, 0.0, 0.0);
+
+    // Add some jittering on Hammersley2d
+    float2 randNum  = InitRandom(V.xy * 0.5 + 0.5);
+
+    float3 tangentX, tangentY;
+    GetLocalFrame(N, tangentX, tangentY);
+
+    for (uint i = 0; i < sampleCount; ++i)
+    {
+        float2 u    = Hammersley2d(i, sampleCount);
+        u           = frac(u + randNum + 0.5);
+
+        float VdotH;
+        float NdotL;
+        float3 L;
+        float weightOverPdf;
+
+        // GGX BRDF
+        ImportanceSampleGGX(u, V, N, tangentX, tangentY, bsdfData.roughness, NdotV,
+                            L, VdotH, NdotL, weightOverPdf);
+
+        if (NdotL > 0.0)
+        {
+            // Fresnel component is apply here as describe in ImportanceSampleGGX function
+            float3 FweightOverPdf = F_Schlick(bsdfData.fresnel0, VdotH) * weightOverPdf;
+
+            float4 val = SampleEnv(lightLoopContext, lightData.envIndex, L, 0);
+
+            acc += FweightOverPdf * val.rgb;
+        }
+    }
+
+    return acc / sampleCount;
+}
+
+//-----------------------------------------------------------------------------
-// We must implement EvaluateBSDF_Env for various environment map case. For now just cube array and cube (but could add latlong later).
-// As a loop can call several version inside the same lighting architecture (think about sky and reflection probes, one isolated uncompressed, the others compressed BC6H in a textures array)
-// we need to implemnt various version here. To factor code we play with macro to generate the various varient.
-#define UNITY_ARGS_ENV(tex) UNITY_ARGS_TEXCUBEARRAY(tex)
-#define UNITY_SAMPLE_ENV_LOD(tex, coord, lightData, lod) UNITY_SAMPLE_TEXCUBEARRAY_LOD(tex, float4(coord, lightData.sliceIndex), lod)
-#include "LitEnvTemplate.hlsl"
-#undef UNITY_ARGS_ENV
-#undef UNITY_SAMPLE_ENV_LOD
+// _preIntegratedFGD and _CubemapLD are unique for each BRDF
+void EvaluateBSDF_Env(  int lightLoopContext,
+                        float3 V, float3 positionWS, PreLightData prelightData, EnvLightData lightData, BSDFData bsdfData,
+                        out float4 diffuseLighting,
+                        out float4 specularLighting)
+{
+#ifdef LIT_DISPLAY_REFERENCE
+
+    specularLighting.rgb = IntegrateSpecularGGXIBLRef(V, lightData, bsdfData);
+    specularLighting.a = 1.0;
+
+/*
+    #ifdef DIFFUSE_LAMBERT_BRDF
+    diffuseLighting.rgb = IntegrateLambertIBLRef(lightData, bsdfData);
+    #else
+    diffuseLighting.rgb = IntegrateDisneyDiffuseIBLRef(V, lightData, bsdfData);
+    #endif
+    diffuseLighting.a = 1.0;
+*/
+    diffuseLighting = float4(0.0, 0.0, 0.0, 0.0);
+
+#else
+    // TODO: factor this code in common, so other material authoring don't require to rewrite everything, 
+    // also think about how such a loop can handle 2 cubemap at the same time as old unity. Macro can allow to do that
+    // but we need to have UNITY_SAMPLE_ENV_LOD replace by a true function instead that is define by the lighting arcitecture.
+    // Also not sure how to deal with 2 intersection....
+    // Box and sphere are related to light property (but we have also distance based roughness etc...)
+
+    // TODO: test the strech from Tomasz
+    // float shrinkedRoughness = AnisotropicStrechAtGrazingAngle(bsdfData.roughness, bsdfData.perceptualRoughness, NdotV);
+    
+    // Note: As explain in GetPreLightData we use normalWS and not iblNormalWS here (in case of anisotropy)
+    float3 rayWS = GetSpecularDominantDir(bsdfData.normalWS, prelightData.iblR, bsdfData.roughness);
-#define UNITY_ARGS_ENV(tex) UNITY_ARGS_TEXCUBE(tex)
-#define UNITY_SAMPLE_ENV_LOD(tex, coord, lightData, lod) UNITY_SAMPLE_TEXCUBE_LOD(tex, float3(coord), lod)
-#include "LitEnvTemplate.hlsl"
-#undef UNITY_ARGS_ENV
-#undef UNITY_SAMPLE_ENV_LOD
+    float3 R = rayWS;
+    float weight = 1.0;
+
+    // In this code we redefine a bit the behavior of the reflcetion proble. We separate the projection volume (the proxy of the scene) form the influence volume (what pixel on the screen is affected)
+
+    // 1. First determine the projection volume
+    
+    // In Unity the cubemaps are capture with the localToWorld transform of the component. 
+    // This mean that location and oritention matter. So after intersection of proxy volume we need to convert back to world.
+    
+    // CAUTION: localToWorld is the transform use to convert the cubemap capture point to world space (mean it include the offset)
+    // the center of the bounding box is thus in locals space: positionLS - offsetLS
+    // We use this formulation as it is the one of legacy unity that was using only AABB box.
+
+    float3x3 worldToLocal = transpose(float3x3(lightData.right, lightData.up, lightData.forward)); // worldToLocal assume no scaling
+    float3 positionLS = positionWS - lightData.positionWS;
+    positionLS = mul(positionLS, worldToLocal).xyz - lightData.offsetLS; // We want to calculate the intersection from the center of the bounding box.
+
+    if (lightData.envShapeType == ENVSHAPETYPE_BOX)
+    {
+        float3 rayLS = mul(rayWS, worldToLocal);
+        float3 boxOuterDistance = lightData.innerDistance + float3(lightData.blendDistance, lightData.blendDistance, lightData.blendDistance);
+        float dist = BoxRayIntersectSimple(positionLS, rayLS, -boxOuterDistance, boxOuterDistance);
+
+        // No need to normalize for fetching cubemap
+        // We can reuse dist calculate in LS directly in WS as there is no scaling. Also the offset is already include in lightData.positionWS
+        R = (positionWS + dist * rayWS) - lightData.positionWS;
+        
+        // TODO: add distance based roughness
+    } 
+    else if (lightData.envShapeType == ENVSHAPETYPE_SPHERE)
+    {
+        float3 rayLS = mul(rayWS, worldToLocal);
+        float sphereOuterDistance = lightData.innerDistance.x + lightData.blendDistance;
+        float dist = SphereRayIntersectSimple(positionLS, rayLS, sphereOuterDistance);
+
+        R = (positionWS + dist * rayWS) - lightData.positionWS;
+    }
+
+    // 2. Apply the influence volume (Box volume is used for culling whatever the influence shape)
+    // TODO: In the future we could have an influence volume inside the projection volume (so with a different transform, in this case we will need another transform)
+    if (lightData.envShapeType == ENVSHAPETYPE_SPHERE)
+    {
+        float distFade = max(length(positionLS) - lightData.innerDistance.x, 0.0);
+        weight = saturate(1.0 - distFade / max(lightData.blendDistance, 0.0001)); // avoid divide by zero
+    }
+    else // ENVSHAPETYPE_BOX or ENVSHAPETYPE_NONE 
+    {
+        // Calculate falloff value, so reflections on the edges of the volume would gradually blend to previous reflection.
+        float distFade = DistancePointBox(positionLS, -lightData.innerDistance, lightData.innerDistance);
+        weight = saturate(1.0 - distFade / max(lightData.blendDistance, 0.0001)); // avoid divide by zero
+    }
+
+    // Smooth weighting
+    weight = smoothstep01(weight);
+
+    // TODO: we must always perform a weight calculation as due to tiled rendering we need to smooth out cubemap at boundaries.
+    // So goal is to split into two category and have an option to say if we parallax correct or not.
+
+    // TODO: compare current Morten version: offline cubemap with a particular remap + the bias in perceptualRoughnessToMipmapLevel
+    // to classic remap like unreal/Frobiste. The function GetSpecularDominantDir can result in a better matching in this case
+    // We let GetSpecularDominantDir currently as it still an improvement but not as good as it could be
+    float mip = perceptualRoughnessToMipmapLevel(bsdfData.perceptualRoughness);
+    float4 preLD = SampleEnv(lightLoopContext, lightData.envIndex, R, mip);
+    specularLighting.rgb = preLD.rgb * prelightData.specularFGD;
+
+    // Apply specular occlusion on it
+    specularLighting.rgb *= bsdfData.specularOcclusion;
+    specularLighting.a = weight;
+
+    diffuseLighting = float4(0.0, 0.0, 0.0, 0.0);
+
+#endif    
+}
+
+

Assets/ScriptableRenderLoop/HDRenderLoop/Shaders/Material/Material.hlsl

 #include "Builtin/BuiltinData.hlsl"
 
 //-----------------------------------------------------------------------------
-// SurfaceData
+// Material definition
+
+// In case lighting.hlsl is not include before including material.hlsl, define some neutral function, so it doesn't complain
+#ifndef LIGHTING
+float4 SampleEnv(int lightLoopContext, int envIndex, float3 dirWS, float lod)
+{
+    return float4(0.0, 0.0, 0.0, 0.0);
+}
+#endif
 
 // Here we include all the different lighting model supported by the renderloop based on define done in .shader
 #ifdef UNITY_MATERIAL_LIT

Assets/ScriptableRenderLoop/fptl/lightlistbuild-clustered.compute

 	const int N = (const int) LimitPow2AndClamp((unsigned int) length, MAX_NR_COARSE_ENTRIES);			// N is 1 when length is zero but will still not enter first for-loop
 
 	// bitonic sort can only handle arrays with a power of two length. Fill remaining entries with greater than possible index.
-	for(int t=length+localThreadID; t<N; t+=NR_THREADS) { coarseList[t]=MAX_NR_COARSE_ENTRIES; }		// impossible index
+	for(int t=length+localThreadID; t<N; t+=NR_THREADS) { coarseList[t]=0xffffffff; }		// impossible index
 	GroupMemoryBarrierWithGroupSync();
 
 	for(int k=2; k<=N; k=2*k)

Assets/ScriptableRenderLoop/fptl/lightlistbuild.compute

 	const int N = (const int) LimitPow2AndClamp((unsigned int) length, MAX_NR_COARSE_ENTRIES);			// N is 1 when length is zero but will still not enter first for-loop
 
 	// bitonic sort can only handle arrays with a power of two length. Fill remaining entries with greater than possible index.
-	for(int t=length+localThreadID; t<N; t+=NR_THREADS) { prunedList[t]=MAX_NR_COARSE_ENTRIES; }		// impossible index
+	for(int t=length+localThreadID; t<N; t+=NR_THREADS) { prunedList[t]=0xffffffff; }		// impossible index
 	GroupMemoryBarrierWithGroupSync();
 
 	for(int k=2; k<=N; k=2*k)

Assets/ScriptableRenderLoop/HDRenderLoop/Shaders/Material/Lit/LitEnvTemplate.hlsl.meta

-fileFormatVersion: 2
-guid: 22c20a34a48ade04daa95ffdc51ac052
-timeCreated: 1476997917
-licenseType: Pro
-ShaderImporter:
-  defaultTextures: []
-  userData: 
-  assetBundleName: 
-  assetBundleVariant: 

Assets/ScriptableRenderLoop/HDRenderLoop/Shaders/Material/Lit/LitEnvTemplate.hlsl

-//-----------------------------------------------------------------------------
-// EvaluateBSDF_Env - Reference
-// ----------------------------------------------------------------------------
-
-// Ref: Moving Frostbite to PBR (Appendix A)
-float3 IntegrateLambertIBLRef(  EnvLightData lightData, BSDFData bsdfData,
-                                UNITY_ARGS_ENV(_EnvTextures),
-                                uint sampleCount = 2048)
-{
-    float3 N        = bsdfData.normalWS;
-    float3 acc      = float3(0.0, 0.0, 0.0);
-    // Add some jittering on Hammersley2d
-    float2 randNum  = InitRandom(N.xy * 0.5 + 0.5);
-
-    float3 tangentX, tangentY;
-    GetLocalFrame(N, tangentX, tangentY);
-
-    for (uint i = 0; i < sampleCount; ++i)
-    {
-        float2 u    = Hammersley2d(i, sampleCount);
-        u           = frac(u + randNum + 0.5);
-
-        float3 L;
-        float NdotL;
-        float weightOverPdf;
-        ImportanceSampleLambert(u, N, tangentX, tangentY, L, NdotL, weightOverPdf);
-
-        if (NdotL > 0.0)
-        {
-            float4 val = UNITY_SAMPLE_ENV_LOD(_EnvTextures, L, lightData, 0);
-
-            // diffuse Albedo is apply here as describe in ImportanceSampleLambert function
-            acc += bsdfData.diffuseColor * Lambert() * weightOverPdf * val.rgb;
-        }
-    }
-
-    return acc / sampleCount;
-}
-
-float3 IntegrateDisneyDiffuseIBLRef(float3 V, EnvLightData lightData, BSDFData bsdfData,
-                                    UNITY_ARGS_ENV(_EnvTextures),
-                                    uint sampleCount = 2048)
-{
-    float3 N = bsdfData.normalWS;
-    float NdotV = dot(N, V);
-    float3 acc  = float3(0.0, 0.0, 0.0);
-    // Add some jittering on Hammersley2d
-    float2 randNum  = InitRandom(N.xy * 0.5 + 0.5);
-
-    float3 tangentX, tangentY;
-    GetLocalFrame(N, tangentX, tangentY);
-
-    for (uint i = 0; i < sampleCount; ++i)
-    {
-        float2 u    = Hammersley2d(i, sampleCount);
-        u           = frac(u + randNum + 0.5);
-
-        float3 L;
-        float NdotL;
-        float weightOverPdf;
-        // for Disney we still use a Cosine importance sampling, true Disney importance sampling imply a look up table
-        ImportanceSampleLambert(u, N, tangentX, tangentY, L, NdotL, weightOverPdf);
-
-        if (NdotL > 0.0)
-        {            
-            float3 H = normalize(L + V);
-            float LdotH = dot(L, H);
-            // Note: we call DisneyDiffuse that require to multiply by Albedo / PI. Divide by PI is already taken into account
-            // in weightOverPdf of ImportanceSampleLambert call.
-            float disneyDiffuse = DisneyDiffuse(NdotV, NdotL, LdotH, bsdfData.perceptualRoughness);
-
-            // diffuse Albedo is apply here as describe in ImportanceSampleLambert function
-            float4 val = UNITY_SAMPLE_ENV_LOD(_EnvTextures, L, lightData, 0);
-            acc += bsdfData.diffuseColor * disneyDiffuse * weightOverPdf * val.rgb;
-        }
-    }
-
-    return acc / sampleCount;
-}
-
-// Ref: Moving Frostbite to PBR (Appendix A)
-float3 IntegrateSpecularGGXIBLRef(  float3 V, EnvLightData lightData, BSDFData bsdfData,
-                                    UNITY_ARGS_ENV(_EnvTextures),
-                                    uint sampleCount = 2048)
-{
-    float3 N        = bsdfData.normalWS;
-    float NdotV     = saturate(dot(N, V));
-    float3 acc      = float3(0.0, 0.0, 0.0);
-
-    // Add some jittering on Hammersley2d
-    float2 randNum  = InitRandom(V.xy * 0.5 + 0.5);
-
-    float3 tangentX, tangentY;
-    GetLocalFrame(N, tangentX, tangentY);
-
-    for (uint i = 0; i < sampleCount; ++i)
-    {
-        float2 u    = Hammersley2d(i, sampleCount);
-        u           = frac(u + randNum + 0.5);
-
-        float VdotH;
-        float NdotL;
-        float3 L;
-        float weightOverPdf;
-
-        // GGX BRDF
-        ImportanceSampleGGX(u, V, N, tangentX, tangentY, bsdfData.roughness, NdotV,
-                            L, VdotH, NdotL, weightOverPdf);
-
-        if (NdotL > 0.0)
-        {
-            // Fresnel component is apply here as describe in ImportanceSampleGGX function
-            float3 FweightOverPdf = F_Schlick(bsdfData.fresnel0, VdotH) * weightOverPdf;
-
-            float4 val = UNITY_SAMPLE_ENV_LOD(_EnvTextures, L, lightData, 0);
-
-            acc += FweightOverPdf * val.rgb;
-        }
-    }
-
-    return acc / sampleCount;
-}
-
-//-----------------------------------------------------------------------------
-// EvaluateBSDF_Env
-// ----------------------------------------------------------------------------
-
-// _preIntegratedFGD and _CubemapLD are unique for each BRDF
-void EvaluateBSDF_Env(  float3 V, float3 positionWS, PreLightData prelightData, EnvLightData lightData, BSDFData bsdfData,
-                        UNITY_ARGS_ENV(_EnvTextures),
-                        out float4 diffuseLighting,
-                        out float4 specularLighting)
-{
-#ifdef LIT_DISPLAY_REFERENCE
-
-    specularLighting.rgb = IntegrateSpecularGGXIBLRef(V, lightData, bsdfData, UNITY_PASS_ENV(_EnvTextures));
-    specularLighting.a = 1.0;
-
-/*
-    #ifdef DIFFUSE_LAMBERT_BRDF
-    diffuseLighting.rgb = IntegrateLambertIBLRef(lightData, bsdfData, UNITY_PASS_ENV(_EnvTextures));
-    #else
-    diffuseLighting.rgb = IntegrateDisneyDiffuseIBLRef(V, lightData, bsdfData, UNITY_PASS_ENV(_EnvTextures));
-    #endif
-    diffuseLighting.a = 1.0;
-*/
-    diffuseLighting = float4(0.0, 0.0, 0.0, 0.0);
-
-#else
-    // TODO: factor this code in common, so other material authoring don't require to rewrite everything, 
-    // also think about how such a loop can handle 2 cubemap at the same time as old unity. Macro can allow to do that
-    // but we need to have UNITY_SAMPLE_ENV_LOD replace by a true function instead that is define by the lighting arcitecture.
-    // Also not sure how to deal with 2 intersection....
-    // Box and sphere are related to light property (but we have also distance based roughness etc...)
-
-    // TODO: test the strech from Tomasz
-    // float shrinkedRoughness = AnisotropicStrechAtGrazingAngle(bsdfData.roughness, bsdfData.perceptualRoughness, NdotV);
-    
-    // Note: As explain in GetPreLightData we use normalWS and not iblNormalWS here (in case of anisotropy)
-    float3 rayWS = GetSpecularDominantDir(bsdfData.normalWS, prelightData.iblR, bsdfData.roughness);
-
-    float3 R = rayWS;
-    float weight = 1.0;
-
-    // In this code we redefine a bit the behavior of the reflcetion proble. We separate the projection volume (the proxy of the scene) form the influence volume (what pixel on the screen is affected)
-
-    // 1. First determine the projection volume
-    
-    // In Unity the cubemaps are capture with the localToWorld transform of the component. 
-    // This mean that location and oritention matter. So after intersection of proxy volume we need to convert back to world.
-    
-    // CAUTION: localToWorld is the transform use to convert the cubemap capture point to world space (mean it include the offset)
-    // the center of the bounding box is thus in locals space: positionLS - offsetLS
-    // We use this formulation as it is the one of legacy unity that was using only AABB box.
-
-    float3x3 worldToLocal = transpose(float3x3(lightData.right, lightData.up, lightData.forward)); // worldToLocal assume no scaling
-    float3 positionLS = positionWS - lightData.positionWS;
-    positionLS = mul(positionLS, worldToLocal).xyz - lightData.offsetLS; // We want to calculate the intersection from the center of the bounding box.
-
-    if (lightData.envShapeType == ENVSHAPETYPE_BOX)
-    {
-        float3 rayLS = mul(rayWS, worldToLocal);
-        float3 boxOuterDistance = lightData.innerDistance + float3(lightData.blendDistance, lightData.blendDistance, lightData.blendDistance);
-        float dist = BoxRayIntersectSimple(positionLS, rayLS, -boxOuterDistance, boxOuterDistance);
-
-        // No need to normalize for fetching cubemap
-        // We can reuse dist calculate in LS directly in WS as there is no scaling. Also the offset is already include in lightData.positionWS
-        R = (positionWS + dist * rayWS) - lightData.positionWS;
-        
-        // TODO: add distance based roughness
-    } 
-    else if (lightData.envShapeType == ENVSHAPETYPE_SPHERE)
-    {
-        float3 rayLS = mul(rayWS, worldToLocal);
-        float sphereOuterDistance = lightData.innerDistance.x + lightData.blendDistance;
-        float dist = SphereRayIntersectSimple(positionLS, rayLS, sphereOuterDistance);
-
-        R = (positionWS + dist * rayWS) - lightData.positionWS;
-    }
-
-    // 2. Apply the influence volume (Box volume is used for culling whatever the influence shape)
-    // TODO: In the future we could have an influence volume inside the projection volume (so with a different transform, in this case we will need another transform)
-    if (lightData.envShapeType == ENVSHAPETYPE_SPHERE)
-    {
-        float distFade = max(length(positionLS) - lightData.innerDistance.x, 0.0);
-        weight = saturate(1.0 - distFade / max(lightData.blendDistance, 0.0001)); // avoid divide by zero
-    }
-    else // ENVSHAPETYPE_BOX or ENVSHAPETYPE_NONE 
-    {
-        // Calculate falloff value, so reflections on the edges of the volume would gradually blend to previous reflection.
-        float distFade = DistancePointBox(positionLS, -lightData.innerDistance, lightData.innerDistance);
-        weight = saturate(1.0 - distFade / max(lightData.blendDistance, 0.0001)); // avoid divide by zero
-    }
-
-    // Smooth weighting
-    weight = smoothstep01(weight);
-
-    // TODO: we must always perform a weight calculation as due to tiled rendering we need to smooth out cubemap at boundaries.
-    // So goal is to split into two category and have an option to say if we parallax correct or not.
-
-    // TODO: compare current Morten version: offline cubemap with a particular remap + the bias in perceptualRoughnessToMipmapLevel
-    // to classic remap like unreal/Frobiste. The function GetSpecularDominantDir can result in a better matching in this case
-    // We let GetSpecularDominantDir currently as it still an improvement but not as good as it could be
-    float mip = perceptualRoughnessToMipmapLevel(bsdfData.perceptualRoughness);
-    float4 preLD = UNITY_SAMPLE_ENV_LOD(_EnvTextures, R, lightData, mip);
-    specularLighting.rgb = preLD.rgb * prelightData.specularFGD;
-
-    // Apply specular occlusion on it
-    specularLighting.rgb *= bsdfData.specularOcclusion;
-    specularLighting.a = weight;
-
-    diffuseLighting = float4(0.0, 0.0, 0.0, 0.0);
-
-#endif    
-}
-