From 880a9a8de6be02eb726609b93f0981693d188f07 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Patrick=20H=C3=A4rtl?= <haertl@ux3d.io>
Date: Mon, 27 May 2024 16:26:38 +0200
Subject: [PATCH 01/18] Add helper comments

---
 source/Renderer/shaders/brdf.glsl          | 10 +++++-----
 source/Renderer/shaders/material_info.glsl |  2 ++
 source/Renderer/shaders/pbr.frag           |  1 +
 3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/source/Renderer/shaders/brdf.glsl b/source/Renderer/shaders/brdf.glsl
index dcb55ce5..558f3ae0 100644
--- a/source/Renderer/shaders/brdf.glsl
+++ b/source/Renderer/shaders/brdf.glsl
@@ -8,9 +8,9 @@
 
 // The following equation models the Fresnel reflectance term of the spec equation (aka F())
 // Implementation of fresnel from [4], Equation 15
-vec3 F_Schlick(vec3 f0, vec3 f90, float VdotH)
+vec3 F_Schlick(vec3 f0, vec3 f90, float VdotH) 
 {
-    return f0 + (f90 - f0) * pow(clamp(1.0 - VdotH, 0.0, 1.0), 5.0);
+    return f0 + (f90 - f0) * pow(clamp(1.0 - VdotH, 0.0, 1.0), 5.0); // dialectric_fresnel
 }
 
 float F_Schlick(float f0, float f90, float VdotH)
@@ -152,7 +152,7 @@ float D_Charlie(float sheenRoughness, float NdotH)
 vec3 BRDF_lambertian(vec3 f0, vec3 f90, vec3 diffuseColor, float specularWeight, float VdotH)
 {
     // see https://seblagarde.wordpress.com/2012/01/08/pi-or-not-to-pi-in-game-lighting-equation/
-    return (1.0 - specularWeight * F_Schlick(f0, f90, VdotH)) * (diffuseColor / M_PI);
+    return (1.0 - specularWeight * F_Schlick(f0, f90, VdotH)) * (diffuseColor / M_PI); // 1.0 - specularWeight * => mix dielectric_fresnel * diffuse_bdrf
 }
 
 
@@ -182,7 +182,7 @@ vec3 BRDF_specularGGX(vec3 f0, vec3 f90, float alphaRoughness, float specularWei
     float Vis = V_GGX(NdotL, NdotV, alphaRoughness);
     float D = D_GGX(NdotH, alphaRoughness);
 
-    return specularWeight * F * Vis * D;
+    return specularWeight * F * Vis * D; // Vis * D => specular_brdf
 }
 
 
@@ -193,7 +193,7 @@ vec3 BRDF_specularGGXIridescence(vec3 f0, vec3 f90, vec3 iridescenceFresnel, flo
     float Vis = V_GGX(NdotL, NdotV, alphaRoughness);
     float D = D_GGX(NdotH, alphaRoughness);
 
-    return specularWeight * F * Vis * D;
+    return specularWeight * F * Vis * D; // Vis * D => specular_brdf
 }
 #endif
 
diff --git a/source/Renderer/shaders/material_info.glsl b/source/Renderer/shaders/material_info.glsl
index d0f761a0..aefe9c85 100644
--- a/source/Renderer/shaders/material_info.glsl
+++ b/source/Renderer/shaders/material_info.glsl
@@ -69,6 +69,8 @@ struct MaterialInfo
     float alphaRoughness;           // roughness mapped to a more linear change in the roughness (proposed by [2])
     vec3 c_diff;
 
+    float fresnel_w;
+
     vec3 f90;                       // reflectance color at grazing angle
     float metallic;
 
diff --git a/source/Renderer/shaders/pbr.frag b/source/Renderer/shaders/pbr.frag
index f229a428..643a22d7 100644
--- a/source/Renderer/shaders/pbr.frag
+++ b/source/Renderer/shaders/pbr.frag
@@ -58,6 +58,7 @@ void main()
     materialInfo.ior = 1.5;
     materialInfo.f0 = vec3(0.04);
     materialInfo.specularWeight = 1.0;
+    materialInfo.fresnel_w = pow(1 - abs(VdotH), 5);
 
     // If the MR debug output is selected, we have to enforce evaluation of the non-iridescence BRDF functions.
 #if DEBUG == DEBUG_METALLIC_ROUGHNESS

From b69adea2d18f9021c79dc4b87c719b320daf7803 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Patrick=20H=C3=A4rtl?= <haertl@ux3d.io>
Date: Tue, 25 Jun 2024 17:48:48 +0200
Subject: [PATCH 02/18] WIP Refactor shader

---
 source/Renderer/shaders/brdf.glsl          |  48 +----
 source/Renderer/shaders/functions.glsl     |   7 +
 source/Renderer/shaders/ibl.glsl           | 119 +++--------
 source/Renderer/shaders/material_info.glsl |   6 +-
 source/Renderer/shaders/pbr.frag           | 218 ++++++++++++---------
 source/Renderer/shaders/punctual.glsl      |   2 +-
 6 files changed, 164 insertions(+), 236 deletions(-)

diff --git a/source/Renderer/shaders/brdf.glsl b/source/Renderer/shaders/brdf.glsl
index 558f3ae0..8718ceea 100644
--- a/source/Renderer/shaders/brdf.glsl
+++ b/source/Renderer/shaders/brdf.glsl
@@ -10,7 +10,7 @@
 // Implementation of fresnel from [4], Equation 15
 vec3 F_Schlick(vec3 f0, vec3 f90, float VdotH) 
 {
-    return f0 + (f90 - f0) * pow(clamp(1.0 - VdotH, 0.0, 1.0), 5.0); // dialectric_fresnel
+    return f0 + (f90 - f0) * pow(clamp(1.0 - VdotH, 0.0, 1.0), 5.0);
 }
 
 float F_Schlick(float f0, float f90, float VdotH)
@@ -149,54 +149,22 @@ float D_Charlie(float sheenRoughness, float NdotH)
 
 
 //https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#acknowledgments AppendixB
-vec3 BRDF_lambertian(vec3 f0, vec3 f90, vec3 diffuseColor, float specularWeight, float VdotH)
+vec3 BRDF_lambertian(vec3 diffuseColor)
 {
     // see https://seblagarde.wordpress.com/2012/01/08/pi-or-not-to-pi-in-game-lighting-equation/
-    return (1.0 - specularWeight * F_Schlick(f0, f90, VdotH)) * (diffuseColor / M_PI); // 1.0 - specularWeight * => mix dielectric_fresnel * diffuse_bdrf
+    return (diffuseColor / M_PI); // 1.0 - specularWeight * => mix dielectric_fresnel * diffuse_bdrf
 }
 
-
-#ifdef MATERIAL_IRIDESCENCE
-//https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#acknowledgments AppendixB
-vec3 BRDF_lambertianIridescence(vec3 f0, vec3 f90, vec3 iridescenceFresnel, float iridescenceFactor, vec3 diffuseColor, float specularWeight, float VdotH)
-{
-    // Use the maximum component of the iridescence Fresnel color
-    // Maximum is used instead of the RGB value to not get inverse colors for the diffuse BRDF
-    vec3 iridescenceFresnelMax = vec3(max(max(iridescenceFresnel.r, iridescenceFresnel.g), iridescenceFresnel.b));
-
-    vec3 schlickFresnel = F_Schlick(f0, f90, VdotH);
-
-    // Blend default specular Fresnel with iridescence Fresnel
-    vec3 F = mix(schlickFresnel, iridescenceFresnelMax, iridescenceFactor);
-
-    // see https://seblagarde.wordpress.com/2012/01/08/pi-or-not-to-pi-in-game-lighting-equation/
-    return (1.0 - specularWeight * F) * (diffuseColor / M_PI);
-}
-#endif
-
-
 //  https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#acknowledgments AppendixB
-vec3 BRDF_specularGGX(vec3 f0, vec3 f90, float alphaRoughness, float specularWeight, float VdotH, float NdotL, float NdotV, float NdotH)
+vec3 BRDF_specularGGX(float alphaRoughness, float NdotL, float NdotV, float NdotH)
 {
-    vec3 F = F_Schlick(f0, f90, VdotH);
     float Vis = V_GGX(NdotL, NdotV, alphaRoughness);
     float D = D_GGX(NdotH, alphaRoughness);
 
-    return specularWeight * F * Vis * D; // Vis * D => specular_brdf
+    return vec3(Vis * D);
 }
 
 
-#ifdef MATERIAL_IRIDESCENCE
-vec3 BRDF_specularGGXIridescence(vec3 f0, vec3 f90, vec3 iridescenceFresnel, float alphaRoughness, float iridescenceFactor, float specularWeight, float VdotH, float NdotL, float NdotV, float NdotH)
-{
-    vec3 F = mix(F_Schlick(f0, f90, VdotH), iridescenceFresnel, iridescenceFactor);
-    float Vis = V_GGX(NdotL, NdotV, alphaRoughness);
-    float D = D_GGX(NdotH, alphaRoughness);
-
-    return specularWeight * F * Vis * D; // Vis * D => specular_brdf
-}
-#endif
-
 #ifdef MATERIAL_ANISOTROPY
 // GGX Distribution Anisotropic (Same as Babylon.js)
 // https://blog.selfshadow.com/publications/s2012-shading-course/burley/s2012_pbs_disney_brdf_notes_v3.pdf Addenda
@@ -218,7 +186,7 @@ float V_GGX_anisotropic(float NdotL, float NdotV, float BdotV, float TdotV, floa
     return clamp(v, 0.0, 1.0);
 }
 
-vec3 BRDF_specularGGXAnisotropy(vec3 f0, vec3 f90, float alphaRoughness, float anisotropy, vec3 n, vec3 v, vec3 l, vec3 h, vec3 t, vec3 b)
+vec3 BRDF_specularGGXAnisotropy(float alphaRoughness, float anisotropy, vec3 n, vec3 v, vec3 l, vec3 h, vec3 t, vec3 b)
 {
     // Roughness along the anisotropy bitangent is the material roughness, while the tangent roughness increases with anisotropy.
     float at = mix(alphaRoughness, 1.0, anisotropy * anisotropy);
@@ -227,13 +195,11 @@ vec3 BRDF_specularGGXAnisotropy(vec3 f0, vec3 f90, float alphaRoughness, float a
     float NdotL = clamp(dot(n, l), 0.0, 1.0);
     float NdotH = clamp(dot(n, h), 0.001, 1.0);
     float NdotV = dot(n, v);
-    float VdotH = clamp(dot(v, h), 0.0, 1.0);
 
     float V = V_GGX_anisotropic(NdotL, NdotV, dot(b, v), dot(t, v), dot(t, l), dot(b, l), at, ab);
     float D = D_GGX_anisotropic(NdotH, dot(t, h), dot(b, h), anisotropy, at, ab);
 
-    vec3 F = F_Schlick(f0, f90, VdotH);
-    return F * V * D;
+    return vec3(V * D);
 }
 #endif
 
diff --git a/source/Renderer/shaders/functions.glsl b/source/Renderer/shaders/functions.glsl
index 1c7db9f0..b9179a0f 100644
--- a/source/Renderer/shaders/functions.glsl
+++ b/source/Renderer/shaders/functions.glsl
@@ -84,3 +84,10 @@ float applyIorToRoughness(float roughness, float ior)
     // an IOR of 1.5 results in the default amount of microfacet refraction.
     return roughness * clamp(ior * 2.0 - 2.0, 0.0, 1.0);
 }
+
+vec3 rgb_mix(vec3 base, vec3 layer, vec3 rgb_alpha)
+{
+    float rgb_alpha_max = max(rgb_alpha.r, max(rgb_alpha.g, rgb_alpha.b));
+    return (1.0 - rgb_alpha_max) * base + rgb_alpha * layer;
+}
+
diff --git a/source/Renderer/shaders/ibl.glsl b/source/Renderer/shaders/ibl.glsl
index a2d2ff77..0e01b819 100644
--- a/source/Renderer/shaders/ibl.glsl
+++ b/source/Renderer/shaders/ibl.glsl
@@ -17,51 +17,48 @@ vec4 getSheenSample(vec3 reflection, float lod)
     return textureLod(u_CharlieEnvSampler, u_EnvRotation * reflection, lod) * u_EnvIntensity;
 }
 
-
-vec3 getIBLRadianceGGX(vec3 n, vec3 v, float roughness, vec3 F0, float specularWeight)
+vec3 getIBLGGXFresnel(vec3 n, vec3 v, vec3 F0, float roughness, float specularWeight)
 {
+    // see https://bruop.github.io/ibl/#single_scattering_results at Single Scattering Results
+    // Roughness dependent fresnel, from Fdez-Aguera
     float NdotV = clampedDot(n, v);
-    float lod = roughness * float(u_MipCount - 1);
-    vec3 reflection = normalize(reflect(-v, n));
-
     vec2 brdfSamplePoint = clamp(vec2(NdotV, roughness), vec2(0.0, 0.0), vec2(1.0, 1.0));
     vec2 f_ab = texture(u_GGXLUT, brdfSamplePoint).rg;
-    vec4 specularSample = getSpecularSample(reflection, lod);
-
-    vec3 specularLight = specularSample.rgb;
+    vec3 Fr = max(vec3(1.0 - roughness), F0) - F0;
+    vec3 k_S = F0 + Fr * pow(1.0 - NdotV, 5.0);
+    vec3 FssEss = specularWeight * k_S * f_ab.x + f_ab.y;
+    return FssEss;
+}
 
-    // see https://bruop.github.io/ibl/#single_scattering_results at Single Scattering Results
-    // Roughness dependent fresnel, from Fdez-Aguera
+vec3 getIBLLambertianFresnel(vec3 n, vec3 v, float roughness, vec3 diffuseColor, vec3 F0, float specularWeight) 
+{
+    float NdotV = clampedDot(n, v);
+    vec2 brdfSamplePoint = clamp(vec2(NdotV, roughness), vec2(0.0, 0.0), vec2(1.0, 1.0));
+    vec2 f_ab = texture(u_GGXLUT, brdfSamplePoint).rg;
     vec3 Fr = max(vec3(1.0 - roughness), F0) - F0;
     vec3 k_S = F0 + Fr * pow(1.0 - NdotV, 5.0);
-    vec3 FssEss = k_S * f_ab.x + f_ab.y;
+    vec3 FssEss = specularWeight * k_S * f_ab.x + f_ab.y; // <--- GGX / specular light contribution (scale it down if the specularWeight is low)
 
-    return specularWeight * specularLight * FssEss;
+    // Multiple scattering, from Fdez-Aguera
+    float Ems = (1.0 - (f_ab.x + f_ab.y));
+    vec3 F_avg = specularWeight * (F0 + (1.0 - F0) / 21.0);
+    vec3 FmsEms = Ems * FssEss * F_avg / (1.0 - F_avg * Ems);
+    vec3 k_D = diffuseColor * (1.0 - FssEss + FmsEms); // we use +FmsEms as indicated by the formula in the blog post (might be a typo in the implementation)
+    return (FmsEms + k_D);
 }
 
 
-#ifdef MATERIAL_IRIDESCENCE
-vec3 getIBLRadianceGGXIridescence(vec3 n, vec3 v, float roughness, vec3 F0, vec3 iridescenceFresnel, float iridescenceFactor, float specularWeight)
+vec3 getIBLRadianceGGX(vec3 n, vec3 v, float roughness)
 {
     float NdotV = clampedDot(n, v);
     float lod = roughness * float(u_MipCount - 1);
     vec3 reflection = normalize(reflect(-v, n));
-
-    vec2 brdfSamplePoint = clamp(vec2(NdotV, roughness), vec2(0.0, 0.0), vec2(1.0, 1.0));
-    vec2 f_ab = texture(u_GGXLUT, brdfSamplePoint).rg;
     vec4 specularSample = getSpecularSample(reflection, lod);
 
     vec3 specularLight = specularSample.rgb;
 
-    // see https://bruop.github.io/ibl/#single_scattering_results at Single Scattering Results
-    // Roughness dependent fresnel, from Fdez-Aguera
-    vec3 Fr = max(vec3(1.0 - roughness), F0) - F0;
-    vec3 k_S = mix(F0 + Fr * pow(1.0 - NdotV, 5.0), iridescenceFresnel, iridescenceFactor);
-    vec3 FssEss = k_S * f_ab.x + f_ab.y;
-
-    return specularWeight * specularLight * FssEss;
+    return specularLight;
 }
-#endif
 
 
 #ifdef MATERIAL_TRANSMISSION
@@ -130,68 +127,8 @@ vec3 getIBLVolumeRefraction(vec3 n, vec3 v, float perceptualRoughness, vec3 base
 #endif
 
 
-// specularWeight is introduced with KHR_materials_specular
-vec3 getIBLRadianceLambertian(vec3 n, vec3 v, float roughness, vec3 diffuseColor, vec3 F0, float specularWeight)
-{
-    float NdotV = clampedDot(n, v);
-    vec2 brdfSamplePoint = clamp(vec2(NdotV, roughness), vec2(0.0, 0.0), vec2(1.0, 1.0));
-    vec2 f_ab = texture(u_GGXLUT, brdfSamplePoint).rg;
-
-    vec3 irradiance = getDiffuseLight(n);
-
-    // see https://bruop.github.io/ibl/#single_scattering_results at Single Scattering Results
-    // Roughness dependent fresnel, from Fdez-Aguera
-
-    vec3 Fr = max(vec3(1.0 - roughness), F0) - F0;
-    vec3 k_S = F0 + Fr * pow(1.0 - NdotV, 5.0);
-    vec3 FssEss = specularWeight * k_S * f_ab.x + f_ab.y; // <--- GGX / specular light contribution (scale it down if the specularWeight is low)
-
-    // Multiple scattering, from Fdez-Aguera
-    float Ems = (1.0 - (f_ab.x + f_ab.y));
-    vec3 F_avg = specularWeight * (F0 + (1.0 - F0) / 21.0);
-    vec3 FmsEms = Ems * FssEss * F_avg / (1.0 - F_avg * Ems);
-    vec3 k_D = diffuseColor * (1.0 - FssEss + FmsEms); // we use +FmsEms as indicated by the formula in the blog post (might be a typo in the implementation)
-
-    return (FmsEms + k_D) * irradiance;
-}
-
-
-#ifdef MATERIAL_IRIDESCENCE
-// specularWeight is introduced with KHR_materials_specular
-vec3 getIBLRadianceLambertianIridescence(vec3 n, vec3 v, float roughness, vec3 diffuseColor, vec3 F0, vec3 iridescenceF0, float iridescenceFactor, float specularWeight)
-{
-    float NdotV = clampedDot(n, v);
-    vec2 brdfSamplePoint = clamp(vec2(NdotV, roughness), vec2(0.0, 0.0), vec2(1.0, 1.0));
-    vec2 f_ab = texture(u_GGXLUT, brdfSamplePoint).rg;
-
-    vec3 irradiance = getDiffuseLight(n);
-
-    // Use the maximum component of the iridescence Fresnel color
-    // Maximum is used instead of the RGB value to not get inverse colors for the diffuse BRDF
-    vec3 iridescenceF0Max = vec3(max(max(iridescenceF0.r, iridescenceF0.g), iridescenceF0.b));
-
-    // Blend between base F0 and iridescence F0
-    vec3 mixedF0 = mix(F0, iridescenceF0Max, iridescenceFactor);
-
-    // see https://bruop.github.io/ibl/#single_scattering_results at Single Scattering Results
-    // Roughness dependent fresnel, from Fdez-Aguera
-
-    vec3 Fr = max(vec3(1.0 - roughness), mixedF0) - mixedF0;
-    vec3 k_S = mixedF0 + Fr * pow(1.0 - NdotV, 5.0);
-    vec3 FssEss = specularWeight * k_S * f_ab.x + f_ab.y; // <--- GGX / specular light contribution (scale it down if the specularWeight is low)
-
-    // Multiple scattering, from Fdez-Aguera
-    float Ems = (1.0 - (f_ab.x + f_ab.y));
-    vec3 F_avg = specularWeight * (mixedF0 + (1.0 - mixedF0) / 21.0);
-    vec3 FmsEms = Ems * FssEss * F_avg / (1.0 - F_avg * Ems);
-    vec3 k_D = diffuseColor * (1.0 - FssEss + FmsEms); // we use +FmsEms as indicated by the formula in the blog post (might be a typo in the implementation)
-
-    return (FmsEms + k_D) * irradiance;
-}
-#endif
-
 #ifdef MATERIAL_ANISOTROPY
-vec3 getIBLRadianceAnisotropy(vec3 n, vec3 v, float roughness, float anisotropy, vec3 anisotropyDirection, vec3 F0, float specularWeight)
+vec3 getIBLRadianceAnisotropy(vec3 n, vec3 v, float roughness, float anisotropy, vec3 anisotropyDirection)
 {
     float NdotV = clampedDot(n, v);
 
@@ -205,19 +142,11 @@ vec3 getIBLRadianceAnisotropy(vec3 n, vec3 v, float roughness, float anisotropy,
     float lod = roughness * float(u_MipCount - 1);
     vec3 reflection = normalize(reflect(-v, bentNormal));
 
-    vec2 brdfSamplePoint = clamp(vec2(NdotV, roughness), vec2(0.0, 0.0), vec2(1.0, 1.0));
-    vec2 f_ab = texture(u_GGXLUT, brdfSamplePoint).rg;
     vec4 specularSample = getSpecularSample(reflection, lod);
 
     vec3 specularLight = specularSample.rgb;
 
-    // see https://bruop.github.io/ibl/#single_scattering_results at Single Scattering Results
-    // Roughness dependent fresnel, from Fdez-Aguera
-    vec3 Fr = max(vec3(1.0 - roughness), F0) - F0;
-    vec3 k_S = F0 + Fr * pow(1.0 - NdotV, 5.0);
-    vec3 FssEss = k_S * f_ab.x + f_ab.y;
-
-    return specularWeight * specularLight * FssEss;
+    return specularLight;
 }
 #endif
 
diff --git a/source/Renderer/shaders/material_info.glsl b/source/Renderer/shaders/material_info.glsl
index aefe9c85..a4dca937 100644
--- a/source/Renderer/shaders/material_info.glsl
+++ b/source/Renderer/shaders/material_info.glsl
@@ -65,6 +65,7 @@ struct MaterialInfo
     float ior;
     float perceptualRoughness;      // roughness value, as authored by the model creator (input to shader)
     vec3 f0;                        // full reflectance color (n incidence angle)
+    vec3 f0_dielectric;
 
     float alphaRoughness;           // roughness mapped to a more linear change in the roughness (proposed by [2])
     vec3 c_diff;
@@ -72,6 +73,7 @@ struct MaterialInfo
     float fresnel_w;
 
     vec3 f90;                       // reflectance color at grazing angle
+    vec3 f90_dielectric;
     float metallic;
 
     vec3 baseColor;
@@ -282,9 +284,9 @@ MaterialInfo getSpecularInfo(MaterialInfo info)
     specularTexture.rgb = texture(u_SpecularColorSampler, getSpecularColorUV()).rgb;
 #endif
 
-    vec3 dielectricSpecularF0 = min(info.f0 * u_KHR_materials_specular_specularColorFactor * specularTexture.rgb, vec3(1.0));
-    info.f0 = mix(dielectricSpecularF0, info.baseColor.rgb, info.metallic);
+    info.f0_dielectric = min(info.f0 * u_KHR_materials_specular_specularColorFactor * specularTexture.rgb, vec3(1.0));
     info.specularWeight = u_KHR_materials_specular_specularFactor * specularTexture.a;
+    info.f90_dielectric = info.specularWeight;
     info.c_diff = mix(info.baseColor.rgb, vec3(0), info.metallic);
     return info;
 }
diff --git a/source/Renderer/shaders/pbr.frag b/source/Renderer/shaders/pbr.frag
index 643a22d7..d7948e0c 100644
--- a/source/Renderer/shaders/pbr.frag
+++ b/source/Renderer/shaders/pbr.frag
@@ -40,6 +40,7 @@ void main()
 #if ALPHAMODE == ALPHAMODE_OPAQUE
     baseColor.a = 1.0;
 #endif
+    vec3 color = vec3(0);
 
     vec3 v = normalize(u_Camera - v_Position);
     NormalInfo normalInfo = getNormalInfo(v);
@@ -57,8 +58,12 @@ void main()
     // The default index of refraction of 1.5 yields a dielectric normal incidence reflectance of 0.04.
     materialInfo.ior = 1.5;
     materialInfo.f0 = vec3(0.04);
+    materialInfo.f0_dielectric = materialInfo.f0;
     materialInfo.specularWeight = 1.0;
-    materialInfo.fresnel_w = pow(1 - abs(VdotH), 5);
+
+    // Anything less than 2% is physically impossible and is instead considered to be shadowing. Compare to "Real-Time-Rendering" 4th editon on page 325.
+    materialInfo.f90 = vec3(1.0);
+    materialInfo.f90_dielectric = materialInfo.f90;
 
     // If the MR debug output is selected, we have to enforce evaluation of the non-iridescence BRDF functions.
 #if DEBUG == DEBUG_METALLIC_ROUGHNESS
@@ -115,17 +120,23 @@ void main()
     // Compute reflectance.
     float reflectance = max(max(materialInfo.f0.r, materialInfo.f0.g), materialInfo.f0.b);
 
-    // Anything less than 2% is physically impossible and is instead considered to be shadowing. Compare to "Real-Time-Rendering" 4th editon on page 325.
-    materialInfo.f90 = vec3(1.0);
-
     // LIGHTING
-    vec3 f_specular = vec3(0.0);
+    vec3 f_specular_dielectric = vec3(0.0);
+    vec3 f_specular_metal = vec3(0.0);
     vec3 f_diffuse = vec3(0.0);
+    vec3 f_dielectric_brdf_ibl = vec3(0.0);
+    vec3 f_metal_brdf_ibl = vec3(0.0);
+    vec3 f_specular_fresnel_ibl = vec3(0.0);
+    vec3 f_diffuse_fresnel_ibl = vec3(0.0);
+    vec3 f_metal_fresnel_ibl = vec3(0.0);
     vec3 f_emissive = vec3(0.0);
     vec3 f_clearcoat = vec3(0.0);
     vec3 f_sheen = vec3(0.0);
     vec3 f_transmission = vec3(0.0);
 
+    float clearcoatFactor = 0.0;
+    vec3 clearcoatFresnel = vec3(0);
+
     float albedoSheenScaling = 1.0;
 
 #ifdef MATERIAL_IRIDESCENCE
@@ -137,48 +148,82 @@ void main()
     }
 #endif
 
+#ifdef MATERIAL_CLEARCOAT
+    clearcoatFactor = materialInfo.clearcoatFactor;
+    clearcoatFresnel = F_Schlick(materialInfo.clearcoatF0, materialInfo.clearcoatF90, clampedDot(materialInfo.clearcoatNormal, v));
+#endif
+
     // Calculate lighting contribution from image based lighting source (IBL)
 #ifdef USE_IBL
-#ifdef MATERIAL_IRIDESCENCE
-    f_specular += getIBLRadianceGGXIridescence(n, v, materialInfo.perceptualRoughness, materialInfo.f0, iridescenceFresnel, materialInfo.iridescenceFactor, materialInfo.specularWeight);
-    f_diffuse += getIBLRadianceLambertianIridescence(n, v, materialInfo.perceptualRoughness, materialInfo.c_diff, materialInfo.f0, iridescenceF0, materialInfo.iridescenceFactor, materialInfo.specularWeight);
-#elif defined(MATERIAL_ANISOTROPY)
-    f_specular += getIBLRadianceAnisotropy(n, v, materialInfo.perceptualRoughness, materialInfo.anisotropyStrength, materialInfo.anisotropicB, materialInfo.f0, materialInfo.specularWeight);
-    f_diffuse += getIBLRadianceLambertian(n, v, materialInfo.perceptualRoughness, materialInfo.c_diff, materialInfo.f0, materialInfo.specularWeight);
+    // Calculate fresnel mix for IBL
+    f_specular_fresnel_ibl = getIBLGGXFresnel(n, v, materialInfo.f0_dielectric, materialInfo.perceptualRoughness, materialInfo.specularWeight);
+    f_diffuse_fresnel_ibl = getIBLLambertianFresnel(n, v, materialInfo.perceptualRoughness, materialInfo.c_diff, materialInfo.f0, materialInfo.specularWeight);
+    f_metal_fresnel_ibl = getIBLGGXFresnel(n, v, baseColor.rgb, materialInfo.perceptualRoughness, 1.0);
+    f_diffuse = getDiffuseLight(n);
+
+#if defined(MATERIAL_TRANSMISSION) && defined(USE_IBL)
+    f_transmission = getIBLVolumeRefraction(
+        n, v,
+        materialInfo.perceptualRoughness,
+        materialInfo.c_diff, materialInfo.f0, materialInfo.f90,
+        v_Position, u_ModelMatrix, u_ViewMatrix, u_ProjectionMatrix,
+        materialInfo.ior, materialInfo.thickness, materialInfo.attenuationColor, materialInfo.attenuationDistance, materialInfo.dispersion);
+    f_diffuse = mix(f_diffuse, f_transmission, materialInfo.transmissionFactor);
+#endif
+
+#ifdef MATERIAL_ANISOTROPY
+    f_specular_metal = getIBLRadianceAnisotropy(n, v, materialInfo.perceptualRoughness, materialInfo.anisotropyStrength, materialInfo.anisotropicB);
+    f_specular_dielectric = f_specular_metal;
 #else
-    f_specular += getIBLRadianceGGX(n, v, materialInfo.perceptualRoughness, materialInfo.f0, materialInfo.specularWeight);
-    f_diffuse += getIBLRadianceLambertian(n, v, materialInfo.perceptualRoughness, materialInfo.c_diff, materialInfo.f0, materialInfo.specularWeight);
+    f_specular_metal = getIBLRadianceGGX(n, v, materialInfo.perceptualRoughness);
+    f_specular_dielectric = f_specular_metal;
 #endif
 
+    f_metal_brdf_ibl = f_metal_fresnel_ibl * f_specular_metal;
+    f_dielectric_brdf_ibl = f_diffuse_fresnel_ibl * f_diffuse + f_specular_fresnel_ibl * f_specular_dielectric;
+
+#ifdef MATERIAL_IRIDESCENCE
+    f_metal_brdf_ibl = mix(f_metal_brdf_ibl, f_specular_metal * iridescenceFresnel, materialInfo.iridescenceFactor);
+    f_dielectric_brdf_ibl = mix(f_dielectric_brdf_ibl, rgb_mix(f_diffuse, f_specular_dielectric, iridescenceFresnel), materialInfo.iridescenceFactor);
+#endif
+
+
 #ifdef MATERIAL_CLEARCOAT
-    f_clearcoat += getIBLRadianceGGX(materialInfo.clearcoatNormal, v, materialInfo.clearcoatRoughness, materialInfo.clearcoatF0, 1.0);
+    f_clearcoat = getIBLRadianceGGX(materialInfo.clearcoatNormal, v, materialInfo.clearcoatRoughness);
 #endif
 
 #ifdef MATERIAL_SHEEN
-    f_sheen += getIBLRadianceCharlie(n, v, materialInfo.sheenRoughnessFactor, materialInfo.sheenColorFactor);
+    f_sheen = getIBLRadianceCharlie(n, v, materialInfo.sheenRoughnessFactor, materialInfo.sheenColorFactor);
     albedoSheenScaling = 1.0 - max3(materialInfo.sheenColorFactor) * albedoSheenScalingLUT(NdotV, materialInfo.sheenRoughnessFactor);
 #endif
+
+    color = mix(f_dielectric_brdf_ibl, f_metal_brdf_ibl, materialInfo.metallic);
+    color = f_sheen + color * albedoSheenScaling;
+    color = color * (1.0 - clearcoatFactor * clearcoatFresnel) + f_clearcoat;
+
+#ifdef HAS_OCCLUSION_MAP
+    float ao = 1.0;
+    ao = texture(u_OcclusionSampler,  getOcclusionUV()).r;
+    color = color * (1.0 + u_OcclusionStrength * (ao - 1.0)); 
 #endif
 
-#if defined(MATERIAL_TRANSMISSION) && defined(USE_IBL)
-    f_transmission += getIBLVolumeRefraction(
-        n, v,
-        materialInfo.perceptualRoughness,
-        materialInfo.c_diff, materialInfo.f0, materialInfo.f90,
-        v_Position, u_ModelMatrix, u_ViewMatrix, u_ProjectionMatrix,
-        materialInfo.ior, materialInfo.thickness, materialInfo.attenuationColor, materialInfo.attenuationDistance, materialInfo.dispersion);
 #endif
 
-    vec3 f_diffuse_ibl = f_diffuse;
-    vec3 f_specular_ibl = f_specular;
+    
     vec3 f_sheen_ibl = f_sheen;
     vec3 f_clearcoat_ibl = f_clearcoat;
     f_diffuse = vec3(0.0);
-    f_specular = vec3(0.0);
+    f_specular_dielectric = vec3(0.0);
+    f_specular_metal = vec3(0.0);
+    vec3 f_dielectric_brdf = vec3(0.0);
+    vec3 f_metal_brdf = vec3(0.0);
     f_sheen = vec3(0.0);
     f_clearcoat = vec3(0.0);
 
-#ifdef USE_PUNCTUAL
+#ifdef USE_PUNCTUAL2
+    //vec3 dielectric_brdf = mix(diffuse, specular_dielectric, dielectric_fresnel);
+    //vec3 metal_brdf = metal_fresnel * specular_metal;
+
     for (int i = 0; i < LIGHT_COUNT; ++i)
     {
         Light light = u_Lights[i];
@@ -201,39 +246,18 @@ void main()
         float NdotH = clampedDot(n, h);
         float LdotH = clampedDot(l, h);
         float VdotH = clampedDot(v, h);
-        if (NdotL > 0.0 || NdotV > 0.0)
-        {
-            // Calculation of analytical light
-            // https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#acknowledgments AppendixB
-            vec3 intensity = getLighIntensity(light, pointToLight);
-            vec3 l_diffuse = vec3(0.0);
-            vec3 l_specular = vec3(0.0);
-#ifdef MATERIAL_IRIDESCENCE
-            l_diffuse += intensity * NdotL *  BRDF_lambertianIridescence(materialInfo.f0, materialInfo.f90, iridescenceFresnel, materialInfo.iridescenceFactor, materialInfo.c_diff, materialInfo.specularWeight, VdotH);
-            l_specular += intensity * NdotL * BRDF_specularGGXIridescence(materialInfo.f0, materialInfo.f90, iridescenceFresnel, materialInfo.alphaRoughness, materialInfo.iridescenceFactor, materialInfo.specularWeight, VdotH, NdotL, NdotV, NdotH);
-#elif defined(MATERIAL_ANISOTROPY)
-            l_diffuse += intensity * NdotL *  BRDF_lambertian(materialInfo.f0, materialInfo.f90, materialInfo.c_diff, materialInfo.specularWeight, VdotH);
-            l_specular += intensity * NdotL * BRDF_specularGGXAnisotropy(materialInfo.f0, materialInfo.f90, materialInfo.alphaRoughness, materialInfo.anisotropyStrength, n, v, l, h, materialInfo.anisotropicT, materialInfo.anisotropicB);
-#else
-            l_diffuse += intensity * NdotL *  BRDF_lambertian(materialInfo.f0, materialInfo.f90, materialInfo.c_diff, materialInfo.specularWeight, VdotH);
-            l_specular += intensity * NdotL * BRDF_specularGGX(materialInfo.f0, materialInfo.f90, materialInfo.alphaRoughness, materialInfo.specularWeight, VdotH, NdotL, NdotV, NdotH);
-#endif
 
-#ifdef MATERIAL_SHEEN
-            f_sheen += intensity * getPunctualRadianceSheen(materialInfo.sheenColorFactor, materialInfo.sheenRoughnessFactor, NdotL, NdotV, NdotH);
-            float l_albedoSheenScaling = min(1.0 - max3(materialInfo.sheenColorFactor) * albedoSheenScalingLUT(NdotV, materialInfo.sheenRoughnessFactor),
-                1.0 - max3(materialInfo.sheenColorFactor) * albedoSheenScalingLUT(NdotL, materialInfo.sheenRoughnessFactor));
-            l_diffuse *= l_albedoSheenScaling;
-            l_specular *= l_albedoSheenScaling;
-#endif
-            f_diffuse += l_diffuse;
-            f_specular += l_specular;
-
-#ifdef MATERIAL_CLEARCOAT
-            f_clearcoat += intensity * getPunctualRadianceClearCoat(materialInfo.clearcoatNormal, v, l, h, VdotH,
-                materialInfo.clearcoatF0, materialInfo.clearcoatF90, materialInfo.clearcoatRoughness);
-#endif
-        }
+        vec3 dielectric_fresnel = F_Schlick(materialInfo.f0_dielectric * materialInfo.specularWeight, materialInfo.f90_dielectric, NdotV);
+        vec3 metal_fresnel = baseColor.rgb + (vec3(1.0) - baseColor.rgb) * pow(1 - abs(VdotH), 5);
+        
+        vec3 l_diffuse = BRDF_lambertian(baseColor.rgb);
+        vec3 l_specular_dielectric = vec3(0.0);
+        vec3 l_specular_metal = vec3(0.0);
+        vec3 l_dielectric_brdf = vec3(0.0);
+        vec3 l_metal_brdf = vec3(0.0);
+        vec3 l_clearcoat = vec3(0.0);
+        vec3 l_sheen = vec3(0.0);
+        float l_albedoSheenScaling = 1.0;
 
         // BTDF (Bidirectional Transmittance Distribution Function)
 #ifdef MATERIAL_TRANSMISSION
@@ -249,9 +273,46 @@ void main()
 #ifdef MATERIAL_VOLUME
         transmittedLight = applyVolumeAttenuation(transmittedLight, length(transmissionRay), materialInfo.attenuationColor, materialInfo.attenuationDistance);
 #endif
+        l_diffuse = mix(l_diffuse, transmittedLight, materialInfo.transmissionFactor);
+#endif
+
+        if (NdotL > 0.0 || NdotV > 0.0)
+        {
+            // Calculation of analytical light
+            // https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#acknowledgments AppendixB
+            vec3 intensity = getLighIntensity(light, pointToLight);
+
+#ifdef MATERIAL_ANISOTROPY
+            l_specular_metal = intensity * NdotL * BRDF_specularGGXAnisotropy(materialInfo.alphaRoughness, materialInfo.anisotropyStrength, n, v, l, h, materialInfo.anisotropicT, materialInfo.anisotropicB);
+            l_specular_dielectric = l_specular_metal;
+#else
+            l_specular_metal = intensity * NdotL * BRDF_specularGGX(materialInfo.alphaRoughness, NdotL, NdotV, NdotH);
+            l_specular_dielectric = l_specular_metal;
+#endif
+
+            l_metal_brdf = metal_fresnel * l_specular_metal;
+            l_dielectric_brdf = mix(l_diffuse, l_specular_dielectric, dielectric_fresnel); // Do we need to handle vec3 fresnel here?
+
+#ifdef MATERIAL_IRIDESCENCE
+            l_metal_brdf = mix(l_metal_brdf, l_specular_metal * iridescenceFresnel, materialInfo.iridescenceFactor);
+            l_dielectric_brdf = mix(l_dielectric_brdf, rgb_mix(l_diffuse, l_specular_dielectric, iridescenceFresnel), materialInfo.iridescenceFactor);
+#endif
 
-        f_transmission += transmittedLight;
+#ifdef MATERIAL_CLEARCOAT
+            l_clearcoat = intensity * getPunctualRadianceClearCoat(materialInfo.clearcoatNormal, v, l, h, VdotH,
+                materialInfo.clearcoatF0, materialInfo.clearcoatF90, materialInfo.clearcoatRoughness);
 #endif
+
+#ifdef MATERIAL_SHEEN
+            l_sheen = intensity * getPunctualRadianceSheen(materialInfo.sheenColorFactor, materialInfo.sheenRoughnessFactor, NdotL, NdotV, NdotH);
+            l_albedoSheenScaling = min(1.0 - max3(materialInfo.sheenColorFactor) * albedoSheenScalingLUT(NdotV, materialInfo.sheenRoughnessFactor),
+                1.0 - max3(materialInfo.sheenColorFactor) * albedoSheenScalingLUT(NdotL, materialInfo.sheenRoughnessFactor));
+#endif
+        }
+        vec3 l_color = mix(l_dielectric_brdf, l_metal_brdf, materialInfo.metallic);
+        l_color = l_sheen + l_color * l_albedoSheenScaling;
+        l_color = l_color * (1.0 - clearcoatFactor * clearcoatFresnel) + l_clearcoat;
+        color += l_color;
     }
 #endif
 
@@ -263,48 +324,11 @@ void main()
     f_emissive *= texture(u_EmissiveSampler, getEmissiveUV()).rgb;
 #endif
 
-    // Layer blending
 
-    float clearcoatFactor = 0.0;
-    vec3 clearcoatFresnel = vec3(0);
-    vec3 diffuse;
-    vec3 specular;
-    vec3 sheen;
-    vec3 clearcoat;
-
-    float ao = 1.0;
-    // Apply optional PBR terms for additional (optional) shading
-#ifdef HAS_OCCLUSION_MAP
-    ao = texture(u_OcclusionSampler,  getOcclusionUV()).r;
-    diffuse = f_diffuse + mix(f_diffuse_ibl, f_diffuse_ibl * ao, u_OcclusionStrength) * albedoSheenScaling;
-    // apply ambient occlusion to all lighting that is not punctual
-    specular = f_specular + mix(f_specular_ibl, f_specular_ibl * ao, u_OcclusionStrength) * albedoSheenScaling;
-    sheen = f_sheen + mix(f_sheen_ibl, f_sheen_ibl * ao, u_OcclusionStrength);
-    clearcoat = f_clearcoat + mix(f_clearcoat_ibl, f_clearcoat_ibl * ao, u_OcclusionStrength);
-#else
-    diffuse = f_diffuse_ibl * albedoSheenScaling + f_diffuse;
-    specular = f_specular_ibl * albedoSheenScaling + f_specular;
-    sheen = f_sheen_ibl + f_sheen;
-    clearcoat = f_clearcoat_ibl + f_clearcoat;
-#endif
-
-#ifdef MATERIAL_CLEARCOAT
-    clearcoatFactor = materialInfo.clearcoatFactor;
-    clearcoatFresnel = F_Schlick(materialInfo.clearcoatF0, materialInfo.clearcoatF90, clampedDot(materialInfo.clearcoatNormal, v));
-    clearcoat *= clearcoatFactor;
-#endif
-
-#ifdef MATERIAL_TRANSMISSION
-    diffuse = mix(diffuse, f_transmission, materialInfo.transmissionFactor);
-#endif
-
-    vec3 color = vec3(0);
 #ifdef MATERIAL_UNLIT
     color = baseColor.rgb;
 #else
-    color = f_emissive + diffuse + specular;
-    color = sheen + color;
-    color = color * (1.0 - clearcoatFactor * clearcoatFresnel) + clearcoat;
+    color = f_emissive + color;
 #endif
 
 #if DEBUG == DEBUG_NONE
diff --git a/source/Renderer/shaders/punctual.glsl b/source/Renderer/shaders/punctual.glsl
index 1e7af287..be6d91a2 100644
--- a/source/Renderer/shaders/punctual.glsl
+++ b/source/Renderer/shaders/punctual.glsl
@@ -98,7 +98,7 @@ vec3 getPunctualRadianceClearCoat(vec3 clearcoatNormal, vec3 v, vec3 l, vec3 h,
     float NdotL = clampedDot(clearcoatNormal, l);
     float NdotV = clampedDot(clearcoatNormal, v);
     float NdotH = clampedDot(clearcoatNormal, h);
-    return NdotL * BRDF_specularGGX(f0, f90, clearcoatRoughness * clearcoatRoughness, 1.0, VdotH, NdotL, NdotV, NdotH);
+    return NdotL * BRDF_specularGGX(clearcoatRoughness * clearcoatRoughness, NdotL, NdotV, NdotH);
 }
 
 

From 1e974990a5f2d8f7ad9d569a094b0e771191ef8d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Patrick=20H=C3=A4rtl?= <haertl@ux3d.io>
Date: Thu, 11 Jul 2024 16:14:43 +0200
Subject: [PATCH 03/18] Fix shader error

---
 source/Renderer/shaders/material_info.glsl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/source/Renderer/shaders/material_info.glsl b/source/Renderer/shaders/material_info.glsl
index a4dca937..e5462696 100644
--- a/source/Renderer/shaders/material_info.glsl
+++ b/source/Renderer/shaders/material_info.glsl
@@ -286,7 +286,7 @@ MaterialInfo getSpecularInfo(MaterialInfo info)
 
     info.f0_dielectric = min(info.f0 * u_KHR_materials_specular_specularColorFactor * specularTexture.rgb, vec3(1.0));
     info.specularWeight = u_KHR_materials_specular_specularFactor * specularTexture.a;
-    info.f90_dielectric = info.specularWeight;
+    info.f90_dielectric = vec3(info.specularWeight);
     info.c_diff = mix(info.baseColor.rgb, vec3(0), info.metallic);
     return info;
 }

From afed40287063dfd8951170258a942e1cffcf410e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Patrick=20H=C3=A4rtl?= <haertl@ux3d.io>
Date: Thu, 11 Jul 2024 17:35:40 +0200
Subject: [PATCH 04/18] Fix clearcoat

---
 source/Renderer/shaders/pbr.frag | 19 +++++++------------
 1 file changed, 7 insertions(+), 12 deletions(-)

diff --git a/source/Renderer/shaders/pbr.frag b/source/Renderer/shaders/pbr.frag
index d7948e0c..cc391cf9 100644
--- a/source/Renderer/shaders/pbr.frag
+++ b/source/Renderer/shaders/pbr.frag
@@ -130,7 +130,7 @@ void main()
     vec3 f_diffuse_fresnel_ibl = vec3(0.0);
     vec3 f_metal_fresnel_ibl = vec3(0.0);
     vec3 f_emissive = vec3(0.0);
-    vec3 f_clearcoat = vec3(0.0);
+    vec3 clearcoat_brdf = vec3(0.0);
     vec3 f_sheen = vec3(0.0);
     vec3 f_transmission = vec3(0.0);
 
@@ -189,7 +189,7 @@ void main()
 
 
 #ifdef MATERIAL_CLEARCOAT
-    f_clearcoat = getIBLRadianceGGX(materialInfo.clearcoatNormal, v, materialInfo.clearcoatRoughness);
+    clearcoat_brdf = getIBLRadianceGGX(materialInfo.clearcoatNormal, v, materialInfo.clearcoatRoughness);
 #endif
 
 #ifdef MATERIAL_SHEEN
@@ -199,7 +199,7 @@ void main()
 
     color = mix(f_dielectric_brdf_ibl, f_metal_brdf_ibl, materialInfo.metallic);
     color = f_sheen + color * albedoSheenScaling;
-    color = color * (1.0 - clearcoatFactor * clearcoatFresnel) + f_clearcoat;
+    color = mix(color, clearcoat_brdf, clearcoatFactor * clearcoatFresnel);
 
 #ifdef HAS_OCCLUSION_MAP
     float ao = 1.0;
@@ -209,16 +209,11 @@ void main()
 
 #endif
 
-    
-    vec3 f_sheen_ibl = f_sheen;
-    vec3 f_clearcoat_ibl = f_clearcoat;
     f_diffuse = vec3(0.0);
     f_specular_dielectric = vec3(0.0);
     f_specular_metal = vec3(0.0);
     vec3 f_dielectric_brdf = vec3(0.0);
     vec3 f_metal_brdf = vec3(0.0);
-    f_sheen = vec3(0.0);
-    f_clearcoat = vec3(0.0);
 
 #ifdef USE_PUNCTUAL2
     //vec3 dielectric_brdf = mix(diffuse, specular_dielectric, dielectric_fresnel);
@@ -255,7 +250,7 @@ void main()
         vec3 l_specular_metal = vec3(0.0);
         vec3 l_dielectric_brdf = vec3(0.0);
         vec3 l_metal_brdf = vec3(0.0);
-        vec3 l_clearcoat = vec3(0.0);
+        vec3 l_clearcoat_brdf = vec3(0.0);
         vec3 l_sheen = vec3(0.0);
         float l_albedoSheenScaling = 1.0;
 
@@ -299,7 +294,7 @@ void main()
 #endif
 
 #ifdef MATERIAL_CLEARCOAT
-            l_clearcoat = intensity * getPunctualRadianceClearCoat(materialInfo.clearcoatNormal, v, l, h, VdotH,
+            l_clearcoat_brdf = intensity * getPunctualRadianceClearCoat(materialInfo.clearcoatNormal, v, l, h, VdotH,
                 materialInfo.clearcoatF0, materialInfo.clearcoatF90, materialInfo.clearcoatRoughness);
 #endif
 
@@ -311,7 +306,7 @@ void main()
         }
         vec3 l_color = mix(l_dielectric_brdf, l_metal_brdf, materialInfo.metallic);
         l_color = l_sheen + l_color * l_albedoSheenScaling;
-        l_color = l_color * (1.0 - clearcoatFactor * clearcoatFresnel) + l_clearcoat;
+        color = mix(l_color, l_clearcoat_brdf, clearcoatFactor * clearcoatFresnel);
         color += l_color;
     }
 #endif
@@ -328,7 +323,7 @@ void main()
 #ifdef MATERIAL_UNLIT
     color = baseColor.rgb;
 #else
-    color = f_emissive + color;
+    color = f_emissive * (1.0 - clearcoatFactor * clearcoatFresnel) + color;
 #endif
 
 #if DEBUG == DEBUG_NONE

From 56abd6c637d98c85d60e4f15954b08d717daaf16 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Patrick=20H=C3=A4rtl?= <haertl@ux3d.io>
Date: Thu, 11 Jul 2024 17:51:47 +0200
Subject: [PATCH 05/18] Fix specularWeight in IBL

---
 source/Renderer/shaders/ibl.glsl | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/source/Renderer/shaders/ibl.glsl b/source/Renderer/shaders/ibl.glsl
index 0e01b819..ceab900a 100644
--- a/source/Renderer/shaders/ibl.glsl
+++ b/source/Renderer/shaders/ibl.glsl
@@ -26,7 +26,7 @@ vec3 getIBLGGXFresnel(vec3 n, vec3 v, vec3 F0, float roughness, float specularWe
     vec2 f_ab = texture(u_GGXLUT, brdfSamplePoint).rg;
     vec3 Fr = max(vec3(1.0 - roughness), F0) - F0;
     vec3 k_S = F0 + Fr * pow(1.0 - NdotV, 5.0);
-    vec3 FssEss = specularWeight * k_S * f_ab.x + f_ab.y;
+    vec3 FssEss = specularWeight * (k_S * f_ab.x + f_ab.y);
     return FssEss;
 }
 
@@ -37,7 +37,7 @@ vec3 getIBLLambertianFresnel(vec3 n, vec3 v, float roughness, vec3 diffuseColor,
     vec2 f_ab = texture(u_GGXLUT, brdfSamplePoint).rg;
     vec3 Fr = max(vec3(1.0 - roughness), F0) - F0;
     vec3 k_S = F0 + Fr * pow(1.0 - NdotV, 5.0);
-    vec3 FssEss = specularWeight * k_S * f_ab.x + f_ab.y; // <--- GGX / specular light contribution (scale it down if the specularWeight is low)
+    vec3 FssEss = specularWeight * (k_S * f_ab.x + f_ab.y); // <--- GGX / specular light contribution (scale it down if the specularWeight is low)
 
     // Multiple scattering, from Fdez-Aguera
     float Ems = (1.0 - (f_ab.x + f_ab.y));

From 781e518043043bb7bf06e7d65c59b6408aec7ae3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Patrick=20H=C3=A4rtl?= <haertl@ux3d.io>
Date: Thu, 11 Jul 2024 18:29:36 +0200
Subject: [PATCH 06/18] Fix specular glossiness

---
 source/Renderer/shaders/material_info.glsl | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/source/Renderer/shaders/material_info.glsl b/source/Renderer/shaders/material_info.glsl
index e5462696..0870e2d5 100644
--- a/source/Renderer/shaders/material_info.glsl
+++ b/source/Renderer/shaders/material_info.glsl
@@ -224,6 +224,8 @@ MaterialInfo getSpecularGlossinessInfo(MaterialInfo info)
     info.f0 *= sgSample.rgb; // specular
 #endif // ! HAS_SPECULAR_GLOSSINESS_MAP
 
+    info.f0_dielectric = info.f0;
+
     info.perceptualRoughness = 1.0 - info.perceptualRoughness; // 1 - glossiness
     info.c_diff = info.baseColor.rgb * (1.0 - max(max(info.f0.r, info.f0.g), info.f0.b));
     return info;

From dce179ef6a12d292355f2c65c233fe780d303cd1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Patrick=20H=C3=A4rtl?= <haertl@ux3d.io>
Date: Fri, 12 Jul 2024 12:26:14 +0200
Subject: [PATCH 07/18] First fix for puctual lights

---
 source/Renderer/shaders/pbr.frag | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/source/Renderer/shaders/pbr.frag b/source/Renderer/shaders/pbr.frag
index cc391cf9..366967b5 100644
--- a/source/Renderer/shaders/pbr.frag
+++ b/source/Renderer/shaders/pbr.frag
@@ -215,7 +215,7 @@ void main()
     vec3 f_dielectric_brdf = vec3(0.0);
     vec3 f_metal_brdf = vec3(0.0);
 
-#ifdef USE_PUNCTUAL2
+#ifdef USE_PUNCTUAL
     //vec3 dielectric_brdf = mix(diffuse, specular_dielectric, dielectric_fresnel);
     //vec3 metal_brdf = metal_fresnel * specular_metal;
 
@@ -242,8 +242,8 @@ void main()
         float LdotH = clampedDot(l, h);
         float VdotH = clampedDot(v, h);
 
-        vec3 dielectric_fresnel = F_Schlick(materialInfo.f0_dielectric * materialInfo.specularWeight, materialInfo.f90_dielectric, NdotV);
-        vec3 metal_fresnel = baseColor.rgb + (vec3(1.0) - baseColor.rgb) * pow(1 - abs(VdotH), 5);
+        vec3 dielectric_fresnel = F_Schlick(materialInfo.f0_dielectric * materialInfo.specularWeight, materialInfo.f90_dielectric, abs(VdotH));
+        vec3 metal_fresnel = F_Schlick(baseColor.rgb, vec3(1.0), abs(VdotH));
         
         vec3 l_diffuse = BRDF_lambertian(baseColor.rgb);
         vec3 l_specular_dielectric = vec3(0.0);
@@ -271,8 +271,6 @@ void main()
         l_diffuse = mix(l_diffuse, transmittedLight, materialInfo.transmissionFactor);
 #endif
 
-        if (NdotL > 0.0 || NdotV > 0.0)
-        {
             // Calculation of analytical light
             // https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#acknowledgments AppendixB
             vec3 intensity = getLighIntensity(light, pointToLight);
@@ -286,7 +284,7 @@ void main()
 #endif
 
             l_metal_brdf = metal_fresnel * l_specular_metal;
-            l_dielectric_brdf = mix(l_diffuse, l_specular_dielectric, dielectric_fresnel); // Do we need to handle vec3 fresnel here?
+            l_dielectric_brdf = mix(intensity * l_diffuse, l_specular_dielectric, dielectric_fresnel); // Do we need to handle vec3 fresnel here?
 
 #ifdef MATERIAL_IRIDESCENCE
             l_metal_brdf = mix(l_metal_brdf, l_specular_metal * iridescenceFresnel, materialInfo.iridescenceFactor);
@@ -303,10 +301,9 @@ void main()
             l_albedoSheenScaling = min(1.0 - max3(materialInfo.sheenColorFactor) * albedoSheenScalingLUT(NdotV, materialInfo.sheenRoughnessFactor),
                 1.0 - max3(materialInfo.sheenColorFactor) * albedoSheenScalingLUT(NdotL, materialInfo.sheenRoughnessFactor));
 #endif
-        }
         vec3 l_color = mix(l_dielectric_brdf, l_metal_brdf, materialInfo.metallic);
         l_color = l_sheen + l_color * l_albedoSheenScaling;
-        color = mix(l_color, l_clearcoat_brdf, clearcoatFactor * clearcoatFresnel);
+        l_color = mix(l_color, l_clearcoat_brdf, clearcoatFactor * clearcoatFresnel);
         color += l_color;
     }
 #endif

From c7111498d1510f6e6151e1c44d5b392b531a03a3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Patrick=20H=C3=A4rtl?= <haertl@ux3d.io>
Date: Fri, 12 Jul 2024 12:57:55 +0200
Subject: [PATCH 08/18] Multiply diffuse with ndotl

---
 source/Renderer/shaders/pbr.frag | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/source/Renderer/shaders/pbr.frag b/source/Renderer/shaders/pbr.frag
index 366967b5..3bf59c4c 100644
--- a/source/Renderer/shaders/pbr.frag
+++ b/source/Renderer/shaders/pbr.frag
@@ -270,7 +270,8 @@ void main()
 #endif
         l_diffuse = mix(l_diffuse, transmittedLight, materialInfo.transmissionFactor);
 #endif
-
+        if (NdotL > 0.0 || NdotV > 0.0)
+        {
             // Calculation of analytical light
             // https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#acknowledgments AppendixB
             vec3 intensity = getLighIntensity(light, pointToLight);
@@ -282,9 +283,10 @@ void main()
             l_specular_metal = intensity * NdotL * BRDF_specularGGX(materialInfo.alphaRoughness, NdotL, NdotV, NdotH);
             l_specular_dielectric = l_specular_metal;
 #endif
+            l_diffuse = intensity * NdotL * l_diffuse;
 
             l_metal_brdf = metal_fresnel * l_specular_metal;
-            l_dielectric_brdf = mix(intensity * l_diffuse, l_specular_dielectric, dielectric_fresnel); // Do we need to handle vec3 fresnel here?
+            l_dielectric_brdf = mix(l_diffuse, l_specular_dielectric, dielectric_fresnel); // Do we need to handle vec3 fresnel here?
 
 #ifdef MATERIAL_IRIDESCENCE
             l_metal_brdf = mix(l_metal_brdf, l_specular_metal * iridescenceFresnel, materialInfo.iridescenceFactor);
@@ -301,6 +303,7 @@ void main()
             l_albedoSheenScaling = min(1.0 - max3(materialInfo.sheenColorFactor) * albedoSheenScalingLUT(NdotV, materialInfo.sheenRoughnessFactor),
                 1.0 - max3(materialInfo.sheenColorFactor) * albedoSheenScalingLUT(NdotL, materialInfo.sheenRoughnessFactor));
 #endif
+        }
         vec3 l_color = mix(l_dielectric_brdf, l_metal_brdf, materialInfo.metallic);
         l_color = l_sheen + l_color * l_albedoSheenScaling;
         l_color = mix(l_color, l_clearcoat_brdf, clearcoatFactor * clearcoatFresnel);

From d0b428c8946052cb640c4cf772686eb6c3abf3c2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Patrick=20H=C3=A4rtl?= <haertl@ux3d.io>
Date: Fri, 12 Jul 2024 15:55:06 +0200
Subject: [PATCH 09/18] Remove dead comments

---
 source/Renderer/shaders/brdf.glsl | 2 +-
 source/Renderer/shaders/pbr.frag  | 3 ---
 2 files changed, 1 insertion(+), 4 deletions(-)

diff --git a/source/Renderer/shaders/brdf.glsl b/source/Renderer/shaders/brdf.glsl
index 8718ceea..da16c3d3 100644
--- a/source/Renderer/shaders/brdf.glsl
+++ b/source/Renderer/shaders/brdf.glsl
@@ -152,7 +152,7 @@ float D_Charlie(float sheenRoughness, float NdotH)
 vec3 BRDF_lambertian(vec3 diffuseColor)
 {
     // see https://seblagarde.wordpress.com/2012/01/08/pi-or-not-to-pi-in-game-lighting-equation/
-    return (diffuseColor / M_PI); // 1.0 - specularWeight * => mix dielectric_fresnel * diffuse_bdrf
+    return (diffuseColor / M_PI);
 }
 
 //  https://github.com/KhronosGroup/glTF/tree/master/specification/2.0#acknowledgments AppendixB
diff --git a/source/Renderer/shaders/pbr.frag b/source/Renderer/shaders/pbr.frag
index 3bf59c4c..1c344c15 100644
--- a/source/Renderer/shaders/pbr.frag
+++ b/source/Renderer/shaders/pbr.frag
@@ -216,9 +216,6 @@ void main()
     vec3 f_metal_brdf = vec3(0.0);
 
 #ifdef USE_PUNCTUAL
-    //vec3 dielectric_brdf = mix(diffuse, specular_dielectric, dielectric_fresnel);
-    //vec3 metal_brdf = metal_fresnel * specular_metal;
-
     for (int i = 0; i < LIGHT_COUNT; ++i)
     {
         Light light = u_Lights[i];

From 5aa9b6abb683d80a55a2fad995d713c02e4e380a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Patrick=20H=C3=A4rtl?= <haertl@ux3d.io>
Date: Tue, 16 Jul 2024 11:04:04 +0200
Subject: [PATCH 10/18] Remove mix for f0

---
 source/Renderer/shaders/material_info.glsl | 1 -
 1 file changed, 1 deletion(-)

diff --git a/source/Renderer/shaders/material_info.glsl b/source/Renderer/shaders/material_info.glsl
index 0870e2d5..39cd3451 100644
--- a/source/Renderer/shaders/material_info.glsl
+++ b/source/Renderer/shaders/material_info.glsl
@@ -249,7 +249,6 @@ MaterialInfo getMetallicRoughnessInfo(MaterialInfo info)
 
     // Achromatic f0 based on IOR.
     info.c_diff = mix(info.baseColor.rgb,  vec3(0), info.metallic);
-    info.f0 = mix(info.f0, info.baseColor.rgb, info.metallic);
     return info;
 }
 #endif

From 4c68aea0c6eea95b724ab4d1100bd9aded8c4379 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Patrick=20H=C3=A4rtl?= <haertl@ux3d.io>
Date: Tue, 16 Jul 2024 11:55:52 +0200
Subject: [PATCH 11/18] Do not use c_diff in transmission

---
 source/Renderer/shaders/pbr.frag | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/source/Renderer/shaders/pbr.frag b/source/Renderer/shaders/pbr.frag
index 1c344c15..0913d2eb 100644
--- a/source/Renderer/shaders/pbr.frag
+++ b/source/Renderer/shaders/pbr.frag
@@ -165,7 +165,7 @@ void main()
     f_transmission = getIBLVolumeRefraction(
         n, v,
         materialInfo.perceptualRoughness,
-        materialInfo.c_diff, materialInfo.f0, materialInfo.f90,
+        baseColor.rgb, materialInfo.f0, materialInfo.f90,
         v_Position, u_ModelMatrix, u_ViewMatrix, u_ProjectionMatrix,
         materialInfo.ior, materialInfo.thickness, materialInfo.attenuationColor, materialInfo.attenuationDistance, materialInfo.dispersion);
     f_diffuse = mix(f_diffuse, f_transmission, materialInfo.transmissionFactor);
@@ -260,7 +260,7 @@ void main()
         l = normalize(pointToLight);
 
         vec3 intensity = getLighIntensity(light, pointToLight);
-        vec3 transmittedLight = intensity * getPunctualRadianceTransmission(n, v, l, materialInfo.alphaRoughness, materialInfo.f0, materialInfo.f90, materialInfo.c_diff, materialInfo.ior);
+        vec3 transmittedLight = intensity * getPunctualRadianceTransmission(n, v, l, materialInfo.alphaRoughness, materialInfo.f0, materialInfo.f90, baseColor.rgb, materialInfo.ior);
 
 #ifdef MATERIAL_VOLUME
         transmittedLight = applyVolumeAttenuation(transmittedLight, length(transmissionRay), materialInfo.attenuationColor, materialInfo.attenuationDistance);

From e558bb17ef82a3d6f212189096dbd6ebc5b556c8 Mon Sep 17 00:00:00 2001
From: Mathias Kanzler <kanzler@ux3d.io>
Date: Thu, 18 Jul 2024 11:23:51 +0200
Subject: [PATCH 12/18] Move FmsEms to getIBLGGXFresnel as mentioned in change
 request and use basecolor instead of c_diff

---
 source/Renderer/shaders/ibl.glsl | 18 ++++++++++++++----
 source/Renderer/shaders/pbr.frag |  4 ++--
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/source/Renderer/shaders/ibl.glsl b/source/Renderer/shaders/ibl.glsl
index ceab900a..012a8f5c 100644
--- a/source/Renderer/shaders/ibl.glsl
+++ b/source/Renderer/shaders/ibl.glsl
@@ -27,11 +27,19 @@ vec3 getIBLGGXFresnel(vec3 n, vec3 v, vec3 F0, float roughness, float specularWe
     vec3 Fr = max(vec3(1.0 - roughness), F0) - F0;
     vec3 k_S = F0 + Fr * pow(1.0 - NdotV, 5.0);
     vec3 FssEss = specularWeight * (k_S * f_ab.x + f_ab.y);
-    return FssEss;
+
+    // Multiple scattering, from Fdez-Aguera
+    float Ems = (1.0 - (f_ab.x + f_ab.y));
+    vec3 F_avg = specularWeight * (F0 + (1.0 - F0) / 21.0);
+    vec3 FmsEms = Ems * FssEss * F_avg / (1.0 - F_avg * Ems);
+
+    return FssEss + FmsEms;
 }
 
-vec3 getIBLLambertianFresnel(vec3 n, vec3 v, float roughness, vec3 diffuseColor, vec3 F0, float specularWeight) 
+vec3 getIBLLambertianFresnel(vec3 n, vec3 v, float roughness, vec3 F0, float specularWeight) 
 {
+    // see https://bruop.github.io/ibl/#single_scattering_results at Single Scattering Results
+    // Roughness dependent fresnel, from Fdez-Aguera
     float NdotV = clampedDot(n, v);
     vec2 brdfSamplePoint = clamp(vec2(NdotV, roughness), vec2(0.0, 0.0), vec2(1.0, 1.0));
     vec2 f_ab = texture(u_GGXLUT, brdfSamplePoint).rg;
@@ -43,8 +51,10 @@ vec3 getIBLLambertianFresnel(vec3 n, vec3 v, float roughness, vec3 diffuseColor,
     float Ems = (1.0 - (f_ab.x + f_ab.y));
     vec3 F_avg = specularWeight * (F0 + (1.0 - F0) / 21.0);
     vec3 FmsEms = Ems * FssEss * F_avg / (1.0 - F_avg * Ems);
-    vec3 k_D = diffuseColor * (1.0 - FssEss + FmsEms); // we use +FmsEms as indicated by the formula in the blog post (might be a typo in the implementation)
-    return (FmsEms + k_D);
+
+
+    vec3 k_D =  (1.0 - (FssEss + FmsEms)); // we use (1.0 - (FssEss + FmsEms)) instead of (1.0 - FssEss + FmsEms) as indicated by the formula in the blog post (might be a typo in the implementation)
+    return k_D; 
 }
 
 
diff --git a/source/Renderer/shaders/pbr.frag b/source/Renderer/shaders/pbr.frag
index 0913d2eb..c3e71a82 100644
--- a/source/Renderer/shaders/pbr.frag
+++ b/source/Renderer/shaders/pbr.frag
@@ -157,9 +157,9 @@ void main()
 #ifdef USE_IBL
     // Calculate fresnel mix for IBL
     f_specular_fresnel_ibl = getIBLGGXFresnel(n, v, materialInfo.f0_dielectric, materialInfo.perceptualRoughness, materialInfo.specularWeight);
-    f_diffuse_fresnel_ibl = getIBLLambertianFresnel(n, v, materialInfo.perceptualRoughness, materialInfo.c_diff, materialInfo.f0, materialInfo.specularWeight);
+    f_diffuse_fresnel_ibl = getIBLLambertianFresnel(n, v, materialInfo.perceptualRoughness, materialInfo.f0, materialInfo.specularWeight);
     f_metal_fresnel_ibl = getIBLGGXFresnel(n, v, baseColor.rgb, materialInfo.perceptualRoughness, 1.0);
-    f_diffuse = getDiffuseLight(n);
+    f_diffuse = getDiffuseLight(n) * baseColor.rgb ;
 
 #if defined(MATERIAL_TRANSMISSION) && defined(USE_IBL)
     f_transmission = getIBLVolumeRefraction(

From 422f054976fa63571f05141293c4033e05d12bff Mon Sep 17 00:00:00 2001
From: Mathias Kanzler <kanzler@ux3d.io>
Date: Thu, 18 Jul 2024 12:26:06 +0200
Subject: [PATCH 13/18] Simplify code

---
 source/Renderer/shaders/ibl.glsl | 24 +-----------------------
 source/Renderer/shaders/pbr.frag | 18 ++++++++----------
 2 files changed, 9 insertions(+), 33 deletions(-)

diff --git a/source/Renderer/shaders/ibl.glsl b/source/Renderer/shaders/ibl.glsl
index 012a8f5c..875fbed7 100644
--- a/source/Renderer/shaders/ibl.glsl
+++ b/source/Renderer/shaders/ibl.glsl
@@ -17,7 +17,7 @@ vec4 getSheenSample(vec3 reflection, float lod)
     return textureLod(u_CharlieEnvSampler, u_EnvRotation * reflection, lod) * u_EnvIntensity;
 }
 
-vec3 getIBLGGXFresnel(vec3 n, vec3 v, vec3 F0, float roughness, float specularWeight)
+vec3 getIBLGGXFresnel(vec3 n, vec3 v, float roughness, vec3 F0, float specularWeight)
 {
     // see https://bruop.github.io/ibl/#single_scattering_results at Single Scattering Results
     // Roughness dependent fresnel, from Fdez-Aguera
@@ -36,28 +36,6 @@ vec3 getIBLGGXFresnel(vec3 n, vec3 v, vec3 F0, float roughness, float specularWe
     return FssEss + FmsEms;
 }
 
-vec3 getIBLLambertianFresnel(vec3 n, vec3 v, float roughness, vec3 F0, float specularWeight) 
-{
-    // see https://bruop.github.io/ibl/#single_scattering_results at Single Scattering Results
-    // Roughness dependent fresnel, from Fdez-Aguera
-    float NdotV = clampedDot(n, v);
-    vec2 brdfSamplePoint = clamp(vec2(NdotV, roughness), vec2(0.0, 0.0), vec2(1.0, 1.0));
-    vec2 f_ab = texture(u_GGXLUT, brdfSamplePoint).rg;
-    vec3 Fr = max(vec3(1.0 - roughness), F0) - F0;
-    vec3 k_S = F0 + Fr * pow(1.0 - NdotV, 5.0);
-    vec3 FssEss = specularWeight * (k_S * f_ab.x + f_ab.y); // <--- GGX / specular light contribution (scale it down if the specularWeight is low)
-
-    // Multiple scattering, from Fdez-Aguera
-    float Ems = (1.0 - (f_ab.x + f_ab.y));
-    vec3 F_avg = specularWeight * (F0 + (1.0 - F0) / 21.0);
-    vec3 FmsEms = Ems * FssEss * F_avg / (1.0 - F_avg * Ems);
-
-
-    vec3 k_D =  (1.0 - (FssEss + FmsEms)); // we use (1.0 - (FssEss + FmsEms)) instead of (1.0 - FssEss + FmsEms) as indicated by the formula in the blog post (might be a typo in the implementation)
-    return k_D; 
-}
-
-
 vec3 getIBLRadianceGGX(vec3 n, vec3 v, float roughness)
 {
     float NdotV = clampedDot(n, v);
diff --git a/source/Renderer/shaders/pbr.frag b/source/Renderer/shaders/pbr.frag
index c3e71a82..7863e225 100644
--- a/source/Renderer/shaders/pbr.frag
+++ b/source/Renderer/shaders/pbr.frag
@@ -126,9 +126,6 @@ void main()
     vec3 f_diffuse = vec3(0.0);
     vec3 f_dielectric_brdf_ibl = vec3(0.0);
     vec3 f_metal_brdf_ibl = vec3(0.0);
-    vec3 f_specular_fresnel_ibl = vec3(0.0);
-    vec3 f_diffuse_fresnel_ibl = vec3(0.0);
-    vec3 f_metal_fresnel_ibl = vec3(0.0);
     vec3 f_emissive = vec3(0.0);
     vec3 clearcoat_brdf = vec3(0.0);
     vec3 f_sheen = vec3(0.0);
@@ -155,11 +152,6 @@ void main()
 
     // Calculate lighting contribution from image based lighting source (IBL)
 #ifdef USE_IBL
-    // Calculate fresnel mix for IBL
-    f_specular_fresnel_ibl = getIBLGGXFresnel(n, v, materialInfo.f0_dielectric, materialInfo.perceptualRoughness, materialInfo.specularWeight);
-    f_diffuse_fresnel_ibl = getIBLLambertianFresnel(n, v, materialInfo.perceptualRoughness, materialInfo.f0, materialInfo.specularWeight);
-    f_metal_fresnel_ibl = getIBLGGXFresnel(n, v, baseColor.rgb, materialInfo.perceptualRoughness, 1.0);
-    f_diffuse = getDiffuseLight(n) * baseColor.rgb ;
 
 #if defined(MATERIAL_TRANSMISSION) && defined(USE_IBL)
     f_transmission = getIBLVolumeRefraction(
@@ -179,8 +171,14 @@ void main()
     f_specular_dielectric = f_specular_metal;
 #endif
 
+    // Calculate fresnel mix for IBL  
+
+    vec3 f_metal_fresnel_ibl = getIBLGGXFresnel(n, v, materialInfo.perceptualRoughness, baseColor.rgb, 1.0);
     f_metal_brdf_ibl = f_metal_fresnel_ibl * f_specular_metal;
-    f_dielectric_brdf_ibl = f_diffuse_fresnel_ibl * f_diffuse + f_specular_fresnel_ibl * f_specular_dielectric;
+ 
+    vec3 f_dielectric_fresnel_ibl = getIBLGGXFresnel(n, v, materialInfo.perceptualRoughness, materialInfo.f0, materialInfo.specularWeight);
+    f_diffuse = getDiffuseLight(n) * baseColor.rgb ;
+    f_dielectric_brdf_ibl = mix(f_diffuse, f_specular_dielectric,  f_dielectric_fresnel_ibl);
 
 #ifdef MATERIAL_IRIDESCENCE
     f_metal_brdf_ibl = mix(f_metal_brdf_ibl, f_specular_metal * iridescenceFresnel, materialInfo.iridescenceFactor);
@@ -207,7 +205,7 @@ void main()
     color = color * (1.0 + u_OcclusionStrength * (ao - 1.0)); 
 #endif
 
-#endif
+#endif //end USE_IBL
 
     f_diffuse = vec3(0.0);
     f_specular_dielectric = vec3(0.0);

From e58869e858d916e1f0aaa4e1a104e0d7d75032a8 Mon Sep 17 00:00:00 2001
From: Mathias Kanzler <kanzler@ux3d.io>
Date: Thu, 18 Jul 2024 14:26:22 +0200
Subject: [PATCH 14/18] Remove c_diff

---
 source/Renderer/shaders/material_info.glsl | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/source/Renderer/shaders/material_info.glsl b/source/Renderer/shaders/material_info.glsl
index 39cd3451..dccd8ef6 100644
--- a/source/Renderer/shaders/material_info.glsl
+++ b/source/Renderer/shaders/material_info.glsl
@@ -68,7 +68,6 @@ struct MaterialInfo
     vec3 f0_dielectric;
 
     float alphaRoughness;           // roughness mapped to a more linear change in the roughness (proposed by [2])
-    vec3 c_diff;
 
     float fresnel_w;
 
@@ -227,7 +226,6 @@ MaterialInfo getSpecularGlossinessInfo(MaterialInfo info)
     info.f0_dielectric = info.f0;
 
     info.perceptualRoughness = 1.0 - info.perceptualRoughness; // 1 - glossiness
-    info.c_diff = info.baseColor.rgb * (1.0 - max(max(info.f0.r, info.f0.g), info.f0.b));
     return info;
 }
 #endif
@@ -247,8 +245,6 @@ MaterialInfo getMetallicRoughnessInfo(MaterialInfo info)
     info.metallic *= mrSample.b;
 #endif
 
-    // Achromatic f0 based on IOR.
-    info.c_diff = mix(info.baseColor.rgb,  vec3(0), info.metallic);
     return info;
 }
 #endif
@@ -288,7 +284,6 @@ MaterialInfo getSpecularInfo(MaterialInfo info)
     info.f0_dielectric = min(info.f0 * u_KHR_materials_specular_specularColorFactor * specularTexture.rgb, vec3(1.0));
     info.specularWeight = u_KHR_materials_specular_specularFactor * specularTexture.a;
     info.f90_dielectric = vec3(info.specularWeight);
-    info.c_diff = mix(info.baseColor.rgb, vec3(0), info.metallic);
     return info;
 }
 #endif

From 1292c8b7fbe52497a5f6ae216da46b83d85a35d3 Mon Sep 17 00:00:00 2001
From: Mathias Kanzler <kanzler@ux3d.io>
Date: Thu, 18 Jul 2024 14:32:47 +0200
Subject: [PATCH 15/18] Fix transmission

---
 source/Renderer/shaders/pbr.frag | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/source/Renderer/shaders/pbr.frag b/source/Renderer/shaders/pbr.frag
index 7863e225..0f23bda9 100644
--- a/source/Renderer/shaders/pbr.frag
+++ b/source/Renderer/shaders/pbr.frag
@@ -153,6 +153,8 @@ void main()
     // Calculate lighting contribution from image based lighting source (IBL)
 #ifdef USE_IBL
 
+    f_diffuse = getDiffuseLight(n) * baseColor.rgb ;
+
 #if defined(MATERIAL_TRANSMISSION) && defined(USE_IBL)
     f_transmission = getIBLVolumeRefraction(
         n, v,
@@ -177,7 +179,6 @@ void main()
     f_metal_brdf_ibl = f_metal_fresnel_ibl * f_specular_metal;
  
     vec3 f_dielectric_fresnel_ibl = getIBLGGXFresnel(n, v, materialInfo.perceptualRoughness, materialInfo.f0, materialInfo.specularWeight);
-    f_diffuse = getDiffuseLight(n) * baseColor.rgb ;
     f_dielectric_brdf_ibl = mix(f_diffuse, f_specular_dielectric,  f_dielectric_fresnel_ibl);
 
 #ifdef MATERIAL_IRIDESCENCE

From 6ac6e802a16799b6b95210d2e02a9f7d2e50cc82 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Patrick=20H=C3=A4rtl?= <haertl@ux3d.io>
Date: Thu, 18 Jul 2024 17:45:36 +0200
Subject: [PATCH 16/18] Fix iridesence

---
 source/Renderer/shaders/material_info.glsl | 11 ++++------
 source/Renderer/shaders/pbr.frag           | 25 ++++++++++------------
 2 files changed, 15 insertions(+), 21 deletions(-)

diff --git a/source/Renderer/shaders/material_info.glsl b/source/Renderer/shaders/material_info.glsl
index 2a7a1849..380c6689 100644
--- a/source/Renderer/shaders/material_info.glsl
+++ b/source/Renderer/shaders/material_info.glsl
@@ -68,7 +68,6 @@ struct MaterialInfo
 {
     float ior;
     float perceptualRoughness;      // roughness value, as authored by the model creator (input to shader)
-    vec3 f0;                        // full reflectance color (n incidence angle)
     vec3 f0_dielectric;
 
     float alphaRoughness;           // roughness mapped to a more linear change in the roughness (proposed by [2])
@@ -221,17 +220,15 @@ vec4 getBaseColor()
 #ifdef MATERIAL_SPECULARGLOSSINESS
 MaterialInfo getSpecularGlossinessInfo(MaterialInfo info)
 {
-    info.f0 = u_SpecularFactor;
+    info.f0_dielectric = u_SpecularFactor;
     info.perceptualRoughness = u_GlossinessFactor;
 
 #ifdef HAS_SPECULAR_GLOSSINESS_MAP
     vec4 sgSample = texture(u_SpecularGlossinessSampler, getSpecularGlossinessUV());
     info.perceptualRoughness *= sgSample.a ; // glossiness to roughness
-    info.f0 *= sgSample.rgb; // specular
+    info.f0_dielectric *= sgSample.rgb; // specular
 #endif // ! HAS_SPECULAR_GLOSSINESS_MAP
 
-    info.f0_dielectric = info.f0;
-
     info.perceptualRoughness = 1.0 - info.perceptualRoughness; // 1 - glossiness
     return info;
 }
@@ -288,7 +285,7 @@ MaterialInfo getSpecularInfo(MaterialInfo info)
     specularTexture.rgb = texture(u_SpecularColorSampler, getSpecularColorUV()).rgb;
 #endif
 
-    info.f0_dielectric = min(info.f0 * u_KHR_materials_specular_specularColorFactor * specularTexture.rgb, vec3(1.0));
+    info.f0_dielectric = min(info.f0_dielectric * u_KHR_materials_specular_specularColorFactor * specularTexture.rgb, vec3(1.0));
     info.specularWeight = u_KHR_materials_specular_specularFactor * specularTexture.a;
     info.f90_dielectric = vec3(info.specularWeight);
     return info;
@@ -400,7 +397,7 @@ MaterialInfo getClearCoatInfo(MaterialInfo info, NormalInfo normalInfo)
 #ifdef MATERIAL_IOR
 MaterialInfo getIorInfo(MaterialInfo info)
 {
-    info.f0 = vec3(pow(( u_Ior - 1.0) /  (u_Ior + 1.0), 2.0));
+    info.f0_dielectric = vec3(pow(( u_Ior - 1.0) /  (u_Ior + 1.0), 2.0));
     info.ior = u_Ior;
     return info;
 }
diff --git a/source/Renderer/shaders/pbr.frag b/source/Renderer/shaders/pbr.frag
index 447e8ee2..e86c919f 100644
--- a/source/Renderer/shaders/pbr.frag
+++ b/source/Renderer/shaders/pbr.frag
@@ -57,8 +57,7 @@ void main()
     
     // The default index of refraction of 1.5 yields a dielectric normal incidence reflectance of 0.04.
     materialInfo.ior = 1.5;
-    materialInfo.f0 = vec3(0.04);
-    materialInfo.f0_dielectric = materialInfo.f0;
+    materialInfo.f0_dielectric = vec3(0.04);
     materialInfo.specularWeight = 1.0;
 
     // Anything less than 2% is physically impossible and is instead considered to be shadowing. Compare to "Real-Time-Rendering" 4th editon on page 325.
@@ -121,8 +120,6 @@ void main()
     // convert to material roughness by squaring the perceptual roughness.
     materialInfo.alphaRoughness = materialInfo.perceptualRoughness * materialInfo.perceptualRoughness;
 
-    // Compute reflectance.
-    float reflectance = max(max(materialInfo.f0.r, materialInfo.f0.g), materialInfo.f0.b);
 
     // LIGHTING
     vec3 f_specular_dielectric = vec3(0.0);
@@ -143,8 +140,8 @@ void main()
     float diffuseTransmissionThickness = 1.0;
 
 #ifdef MATERIAL_IRIDESCENCE
-    vec3 iridescenceFresnel = evalIridescence(1.0, materialInfo.iridescenceIor, NdotV, materialInfo.iridescenceThickness, materialInfo.f0);
-    vec3 iridescenceF0 = Schlick_to_F0(iridescenceFresnel, NdotV);
+    vec3 iridescenceFresnel_dielectric = evalIridescence(1.0, materialInfo.iridescenceIor, NdotV, materialInfo.iridescenceThickness, materialInfo.f0_dielectric);
+    vec3 iridescenceFresnel_metallic = evalIridescence(1.0, materialInfo.iridescenceIor, NdotV, materialInfo.iridescenceThickness, baseColor.rgb);
 
     if (materialInfo.iridescenceThickness == 0.0) {
         materialInfo.iridescenceFactor = 0.0;
@@ -182,7 +179,7 @@ void main()
     f_specular_transmission = getIBLVolumeRefraction(
         n, v,
         materialInfo.perceptualRoughness,
-        baseColor.rgb, materialInfo.f0, materialInfo.f90,
+        baseColor.rgb, materialInfo.f0_dielectric, materialInfo.f90,
         v_Position, u_ModelMatrix, u_ViewMatrix, u_ProjectionMatrix,
         materialInfo.ior, materialInfo.thickness, materialInfo.attenuationColor, materialInfo.attenuationDistance, materialInfo.dispersion);
     f_diffuse = mix(f_diffuse, f_specular_transmission, materialInfo.transmissionFactor);
@@ -201,12 +198,12 @@ void main()
     vec3 f_metal_fresnel_ibl = getIBLGGXFresnel(n, v, materialInfo.perceptualRoughness, baseColor.rgb, 1.0);
     f_metal_brdf_ibl = f_metal_fresnel_ibl * f_specular_metal;
  
-    vec3 f_dielectric_fresnel_ibl = getIBLGGXFresnel(n, v, materialInfo.perceptualRoughness, materialInfo.f0, materialInfo.specularWeight);
+    vec3 f_dielectric_fresnel_ibl = getIBLGGXFresnel(n, v, materialInfo.perceptualRoughness, materialInfo.f0_dielectric, materialInfo.specularWeight);
     f_dielectric_brdf_ibl = mix(f_diffuse, f_specular_dielectric,  f_dielectric_fresnel_ibl);
 
 #ifdef MATERIAL_IRIDESCENCE
-    f_metal_brdf_ibl = mix(f_metal_brdf_ibl, f_specular_metal * iridescenceFresnel, materialInfo.iridescenceFactor);
-    f_dielectric_brdf_ibl = mix(f_dielectric_brdf_ibl, rgb_mix(f_diffuse, f_specular_dielectric, iridescenceFresnel), materialInfo.iridescenceFactor);
+    f_metal_brdf_ibl = mix(f_metal_brdf_ibl, f_specular_metal * iridescenceFresnel_metallic, materialInfo.iridescenceFactor);
+    f_dielectric_brdf_ibl = mix(f_dielectric_brdf_ibl, rgb_mix(f_diffuse, f_specular_dielectric, iridescenceFresnel_dielectric), materialInfo.iridescenceFactor);
 #endif
 
 
@@ -296,7 +293,7 @@ void main()
         pointToLight -= transmissionRay;
         l = normalize(pointToLight);
 
-        vec3 transmittedLight = lightIntensity * getPunctualRadianceTransmission(n, v, l, materialInfo.alphaRoughness, materialInfo.f0, materialInfo.f90, baseColor.rgb, materialInfo.ior);
+        vec3 transmittedLight = lightIntensity * getPunctualRadianceTransmission(n, v, l, materialInfo.alphaRoughness, materialInfo.f0_dielectric, materialInfo.f90, baseColor.rgb, materialInfo.ior);
 
 #ifdef MATERIAL_VOLUME
         transmittedLight = applyVolumeAttenuation(transmittedLight, length(transmissionRay), materialInfo.attenuationColor, materialInfo.attenuationDistance);
@@ -320,8 +317,8 @@ void main()
         l_dielectric_brdf = mix(l_diffuse, l_specular_dielectric, dielectric_fresnel); // Do we need to handle vec3 fresnel here?
 
 #ifdef MATERIAL_IRIDESCENCE
-        l_metal_brdf = mix(l_metal_brdf, l_specular_metal * iridescenceFresnel, materialInfo.iridescenceFactor);
-        l_dielectric_brdf = mix(l_dielectric_brdf, rgb_mix(l_diffuse, l_specular_dielectric, iridescenceFresnel), materialInfo.iridescenceFactor);
+        l_metal_brdf = mix(l_metal_brdf, l_specular_metal * iridescenceFresnel_metallic, materialInfo.iridescenceFactor);
+        l_dielectric_brdf = mix(l_dielectric_brdf, rgb_mix(l_diffuse, l_specular_dielectric, iridescenceFresnel_dielectric), materialInfo.iridescenceFactor);
 #endif
 
 #ifdef MATERIAL_CLEARCOAT
@@ -502,7 +499,7 @@ vec3 specularTexture = vec3(1.0);
     // Iridescence:
 #ifdef MATERIAL_IRIDESCENCE
 #if DEBUG == DEBUG_IRIDESCENCE
-    g_finalColor.rgb = iridescenceFresnel * materialInfo.iridescenceFactor;
+    g_finalColor.rgb = mix(iridescenceFresnel_dielectric, iridescenceFresnel_metallic, materialInfo.metallic) * materialInfo.iridescenceFactor;
 #endif
 #if DEBUG == DEBUG_IRIDESCENCE_FACTOR
     g_finalColor.rgb = vec3(materialInfo.iridescenceFactor);

From cd8edf72f447deb7720e65c24119f74fcae6bb41 Mon Sep 17 00:00:00 2001
From: Mathias Kanzler <kanzler@ux3d.io>
Date: Tue, 23 Jul 2024 11:45:49 +0200
Subject: [PATCH 17/18] Remove unsupported debug channels and give debug views
 more descriptive names

---
 source/GltfState/gltf_state.js   | 52 ++++++++++++--------------------
 source/Renderer/shaders/pbr.frag | 21 -------------
 2 files changed, 19 insertions(+), 54 deletions(-)

diff --git a/source/GltfState/gltf_state.js b/source/GltfState/gltf_state.js
index ecea059c..ab1e6f4e 100644
--- a/source/GltfState/gltf_state.js
+++ b/source/GltfState/gltf_state.js
@@ -149,10 +149,8 @@ GltfState.DebugOutput = {
         EMISSIVE: "Emissive",
     },
 
-    /** output metallic roughness */
+    /** metallic roughness */
     mr: {
-        /** output the combined metallic roughness */
-        METALLIC_ROUGHNESS: "Metallic Roughness",
         /** output the base color value */
         BASECOLOR: "Base Color",
         /** output the metallic value from pbr metallic roughness */
@@ -161,69 +159,57 @@ GltfState.DebugOutput = {
         ROUGHNESS: "Roughness",
     },
 
-    /** output clearcoat lighting */
+    /** KHR_materials_clearcoat */
     clearcoat: {
-        /** output the combined clear coat */
-        CLEARCOAT: "ClearCoat",
-        /** output the clear coat factor */
-        CLEARCOAT_FACTOR: "ClearCoat Factor",
+        /** output the clear coat strength */
+        CLEARCOAT_FACTOR: "ClearCoat Strength",
         /** output the clear coat roughness */
         CLEARCOAT_ROUGHNESS: "ClearCoat Roughness",
         /** output the clear coat normal */
         CLEARCOAT_NORMAL: "ClearCoat Normal",
     },
 
-    /** output sheen lighting */
+    /** KHR_materials_sheen */
     sheen: {
-        /** output the combined sheen */
-        SHEEN: "Sheen",
         /** output the sheen color*/
         SHEEN_COLOR: "Sheen Color",
         /** output the sheen roughness*/
         SHEEN_ROUGHNESS: "Sheen Roughness",
     },
 
-    /** output specular lighting */
+    /** KHR_materials_specular */
     specular: {
-        /** output the combined specular */
-        SPECULAR: "Specular",
-        /** output the specular factor*/
-        SPECULAR_FACTOR: "Specular Factor",
+        /** output the specular strength*/
+        SPECULAR_FACTOR: "Specular Strength",
         /** output the specular color*/
         SPECULAR_COLOR: "Specular Color",
     },
 
-    /** output tranmission lighting */
+    /** KHR_materials_transmission */
     transmission: {
-        /** output the combined transmission/volume */
-        TRANSMISSION_VOLUME: "Transmission/Volume",
-        /** output the transmission factor*/
-        TRANSMISSION_FACTOR: "Transmission Factor",
+        /** output the transmission strength*/
+        TRANSMISSION_FACTOR: "Transmission Strength",
         /** output the volume thickness*/
         VOLUME_THICKNESS: "Volume Thickness",
     },
 
-    /** output diffuse tranmission lighting */
+    /** KHR_materials_diffuse_tranmission */
     diffuseTransmission: {
-        /** output the combined diffuse tranmission */
-        DIFFUSE_TRANSMISSION: "Diffuse Transmission",
-        /** output the diffuse tranmission factor */
-        DIFFUSE_TRANSMISSION_FACTOR: "Diffuse Transmission Factor",
+        /** output the diffuse tranmission strength */
+        DIFFUSE_TRANSMISSION_FACTOR: "Diffuse Transmission Strength",
         /** output the diffuse tranmission color factor */
-        DIFFUSE_TRANSMISSION_COLOR_FACTOR: "Diffuse Transmission Color Factor",
+        DIFFUSE_TRANSMISSION_COLOR_FACTOR: "Diffuse Transmission Color",
     },
 
-    /** output iridescence */
+    /** KHR_materials_iridescence */
     iridescence: {
-        /** output the combined iridescence */
-        IRIDESCENCE: "Iridescence",
-        /** output the iridescence factor*/
-        IRIDESCENCE_FACTOR: "Iridescence Factor",
+        /** output the iridescence strength*/
+        IRIDESCENCE_FACTOR: "Iridescence Strength",
         /** output the iridescence thickness*/
         IRIDESCENCE_THICKNESS: "Iridescence Thickness",
     },
 
-    /** output anisotropy */
+    /** KHR_materials_anisotropy */
     anisotropy: {
         /** output the anisotropic strength*/
         ANISOTROPIC_STRENGTH: "Anisotropic Strength",
diff --git a/source/Renderer/shaders/pbr.frag b/source/Renderer/shaders/pbr.frag
index e86c919f..ae901f83 100644
--- a/source/Renderer/shaders/pbr.frag
+++ b/source/Renderer/shaders/pbr.frag
@@ -420,9 +420,6 @@ void main()
 
     // MR:
 #ifdef MATERIAL_METALLICROUGHNESS
-#if DEBUG == DEBUG_METALLIC_ROUGHNESS
-    g_finalColor.rgb = linearTosRGB(diffuse + specular);
-#endif
 #if DEBUG == DEBUG_METALLIC
     g_finalColor.rgb = vec3(materialInfo.metallic);
 #endif
@@ -436,9 +433,6 @@ void main()
 
     // Clearcoat:
 #ifdef MATERIAL_CLEARCOAT
-#if DEBUG == DEBUG_CLEARCOAT
-    g_finalColor.rgb = linearTosRGB(clearcoat);
-#endif
 #if DEBUG == DEBUG_CLEARCOAT_FACTOR
     g_finalColor.rgb = vec3(materialInfo.clearcoatFactor);
 #endif
@@ -452,9 +446,6 @@ void main()
 
     // Sheen:
 #ifdef MATERIAL_SHEEN
-#if DEBUG == DEBUG_SHEEN
-    g_finalColor.rgb = linearTosRGB(sheen);
-#endif
 #if DEBUG == DEBUG_SHEEN_COLOR
     g_finalColor.rgb = materialInfo.sheenColorFactor;
 #endif
@@ -465,9 +456,6 @@ void main()
 
     // Specular:
 #ifdef MATERIAL_SPECULAR
-#if DEBUG == DEBUG_SPECULAR
-    g_finalColor.rgb = linearTosRGB(specular);
-#endif
 #if DEBUG == DEBUG_SPECULAR_FACTOR
     g_finalColor.rgb = vec3(materialInfo.specularWeight);
 #endif
@@ -483,9 +471,6 @@ vec3 specularTexture = vec3(1.0);
 
     // Transmission, Volume:
 #ifdef MATERIAL_TRANSMISSION
-#if DEBUG == DEBUG_TRANSMISSION_VOLUME
-    g_finalColor.rgb = linearTosRGB(f_specular_transmission * materialInfo.transmissionFactor);
-#endif
 #if DEBUG == DEBUG_TRANSMISSION_FACTOR
     g_finalColor.rgb = vec3(materialInfo.transmissionFactor);
 #endif
@@ -498,9 +483,6 @@ vec3 specularTexture = vec3(1.0);
 
     // Iridescence:
 #ifdef MATERIAL_IRIDESCENCE
-#if DEBUG == DEBUG_IRIDESCENCE
-    g_finalColor.rgb = mix(iridescenceFresnel_dielectric, iridescenceFresnel_metallic, materialInfo.metallic) * materialInfo.iridescenceFactor;
-#endif
 #if DEBUG == DEBUG_IRIDESCENCE_FACTOR
     g_finalColor.rgb = vec3(materialInfo.iridescenceFactor);
 #endif
@@ -530,9 +512,6 @@ vec3 specularTexture = vec3(1.0);
 
     // Diffuse Transmission:
 #ifdef MATERIAL_DIFFUSE_TRANSMISSION
-#if DEBUG == DEBUG_DIFFUSE_TRANSMISSION
-    g_finalColor.rgb = linearTosRGB(f_diffuse_transmission * vec3(materialInfo.diffuseTransmissionFactor));
-#endif
 #if DEBUG == DEBUG_DIFFUSE_TRANSMISSION_FACTOR
     g_finalColor.rgb = linearTosRGB(vec3(materialInfo.diffuseTransmissionFactor));
 #endif

From c22a47af7aac63cecb86c1ab4418d8ccbcdc9f04 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Patrick=20H=C3=A4rtl?= <haertl@ux3d.io>
Date: Tue, 23 Jul 2024 14:53:11 +0200
Subject: [PATCH 18/18] Remove unused variable

---
 source/Renderer/shaders/pbr.frag | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/source/Renderer/shaders/pbr.frag b/source/Renderer/shaders/pbr.frag
index ae901f83..b285bf4b 100644
--- a/source/Renderer/shaders/pbr.frag
+++ b/source/Renderer/shaders/pbr.frag
@@ -170,8 +170,7 @@ void main()
 #ifdef MATERIAL_VOLUME
         diffuseTransmissionIBL = applyVolumeAttenuation(diffuseTransmissionIBL, diffuseTransmissionThickness, materialInfo.attenuationColor, materialInfo.attenuationDistance);
 #endif
-    f_diffuse_transmission += diffuseTransmissionIBL;
-    f_diffuse = mix(f_diffuse, f_diffuse_transmission, materialInfo.diffuseTransmissionFactor);
+    f_diffuse = mix(f_diffuse, diffuseTransmissionIBL, materialInfo.diffuseTransmissionFactor);
 #endif
 
 
@@ -282,7 +281,6 @@ void main()
         diffuse_btdf = applyVolumeAttenuation(diffuse_btdf, diffuseTransmissionThickness, materialInfo.attenuationColor, materialInfo.attenuationDistance);
 #endif
         l_diffuse = mix(l_diffuse, diffuse_btdf, materialInfo.diffuseTransmissionFactor);
-        f_diffuse_transmission += diffuse_btdf;
 #endif // MATERIAL_DIFFUSE_TRANSMISSION
 
         // BTDF (Bidirectional Transmittance Distribution Function)