Fix clearcoat IBL

1 files changed, 18 insertions, 8 deletions

diff --git a/brdf.cginc b/brdf.cginc
index da3fcd6..254adc3 100755
--- a/brdf.cginc
+++ b/brdf.cginc
@@ -70,10 +70,6 @@ float4 brdf(Pbr pbr, LightData data) {
   float3 specular = 0;
   float3 diffuse = 0;
 
-  // TODO parameterize
-  float f0 = 0.04f;
-  const float f90 = 1.0f;
-
 //#define FURNACE_TEST_DIRECT
 #if defined(FURNACE_TEST_DIRECT)
   // Create the conditions for the standard BRDF furnace test.
@@ -86,6 +82,9 @@ float4 brdf(Pbr pbr, LightData data) {
   data.direct.LoH = 1;
 #endif
 
+  // TODO parameterize
+  float f0 = 0.04f;
+  const float f90 = 1.0f;
   float2 dfg_uv = float2(data.common.NoV, pbr.roughness_perceptual);
   float3 dfg;
   [branch]
@@ -107,8 +106,8 @@ float4 brdf(Pbr pbr, LightData data) {
   } else {
     cc_dfg = float3(1, 1, 1);
   }
-  float cc_Ess = max(cc_dfg.y, 1e-4f);
-  float cc_energy_comp = 1.0f + cc_f0 * (1.0f / cc_dfg.xxx - 1.0f);
+  float3 cc_f0_color = lerp(cc_f0, pbr.albedo.xyz, pbr.metallic);
+  float3 cc_energy_comp = 1.0f + cc_f0_color * (1.0f / (cc_dfg.xxx + cc_dfg.yyy) - 1.0f);
 #endif
 
   // Direct
@@ -153,14 +152,23 @@ float4 brdf(Pbr pbr, LightData data) {
   // Indirect
 #if !defined(FURNACE_TEST_DIRECT) && (defined(FORWARD_BASE_PASS) || defined(OUTLINES_PASS))
   {
+    float3 remainder = 1.0f;
+#if defined(_CLEARCOAT)
+    float3 cc_specular_dfg = cc_dfg.xxx * cc_f0_color + cc_dfg.yyy;  // filament 5.3.4.6
+    float3 cc_indirect_specular = data.indirect.specular_cc * cc_specular_dfg;
+    cc_indirect_specular *= cc_energy_comp;
+    specular += cc_indirect_specular;
+    remainder -= cc_specular_dfg;
+#endif
+
     float3 specular_dfg = dfg.xxx * f0_color + dfg.yyy;  // filament 5.3.4.6
     float3 indirect_specular = data.indirect.specular * specular_dfg;
 
     indirect_specular *= energy_comp;
-    specular += indirect_specular;
+    specular += indirect_specular * remainder;
 
     float3 indirect_diffuse = pbr.albedo.xyz * data.indirect.diffuse * (1.0 - pbr.metallic);
-    diffuse  += indirect_diffuse;
+    diffuse  += indirect_diffuse * remainder;
   }
 #endif
 
@@ -175,7 +183,9 @@ float4 brdf(Pbr pbr, LightData data) {
   }
 #endif
 
+  diffuse  *= data.common.ao;
   specular *= data.common.spec_ao;
+
 #if defined(_EMISSIONS) && defined(FORWARD_BASE_PASS)
   float3 emission = pbr.emission;
 #else