From a4acfc8261ba5c0485e96c0fe772749a8a213412 Mon Sep 17 00:00:00 2001
From: dmcdiar <dmcdiar@amazon.com>
Date: Tue, 20 Apr 2021 03:28:42 -0700
Subject: [PATCH] Changed the clearcloat enable Lua functor to set the
 forwardPassIBL shader option. Changed MeshFeatureProcessor to look for this
 shader option to determine if the material requires forward pass IBL
 specular.

---
 .../StandardPBR_ClearCoatEnableFeature.lua    |  1 +
 .../Code/Source/Mesh/MeshFeatureProcessor.cpp | 21 ++++++++++++++++---
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/Gems/Atom/Feature/Common/Assets/Materials/Types/StandardPBR_ClearCoatEnableFeature.lua b/Gems/Atom/Feature/Common/Assets/Materials/Types/StandardPBR_ClearCoatEnableFeature.lua
index c132e3d927..1c520c6274 100644
--- a/Gems/Atom/Feature/Common/Assets/Materials/Types/StandardPBR_ClearCoatEnableFeature.lua
+++ b/Gems/Atom/Feature/Common/Assets/Materials/Types/StandardPBR_ClearCoatEnableFeature.lua
@@ -26,4 +26,5 @@ end
 function Process(context)
     local enable = context:GetMaterialPropertyValue_bool("clearCoat.enable")
     context:SetShaderOptionValue_bool("o_clearCoat_feature_enabled", enable)
+    context:SetShaderOptionValue_bool("o_materialUseForwardPassIBLSpecular", enable)
 end
diff --git a/Gems/Atom/Feature/Common/Code/Source/Mesh/MeshFeatureProcessor.cpp b/Gems/Atom/Feature/Common/Code/Source/Mesh/MeshFeatureProcessor.cpp
index f0dbaa2928..fba970713b 100644
--- a/Gems/Atom/Feature/Common/Code/Source/Mesh/MeshFeatureProcessor.cpp
+++ b/Gems/Atom/Feature/Common/Code/Source/Mesh/MeshFeatureProcessor.cpp
@@ -966,10 +966,25 @@ namespace AZ
 
         bool MeshDataInstance::MaterialRequiresForwardPassIblSpecular(Data::Instance<RPI::Material> material) const
         {
-            RPI::MaterialPropertyIndex propertyIndex = material->FindPropertyIndex(AZ::Name("general.forwardPassIBLSpecular"));
-            if (propertyIndex.IsValid())
+            // look for a shader that has the o_materialUseForwardPassIBLSpecular option set
+            // Note: this should be changed to have the material automatically set the forwardPassIBLSpecular
+            // property and look for that instead of the shader option.
+            // [GFX TODO][ATOM-5040] Address Property Metadata Feedback Loop
+            for (auto& shaderItem : material->GetShaderCollection())
             {
-               return material->GetPropertyValue<bool>(propertyIndex);
+                if (shaderItem.IsEnabled())
+                {
+                    RPI::ShaderOptionIndex index = shaderItem.GetShaderOptionGroup().GetShaderOptionLayout()->FindShaderOptionIndex(Name{ "o_materialUseForwardPassIBLSpecular" });
+                    if (index.IsValid())
+                    {
+                        RPI::ShaderOptionValue value = shaderItem.GetShaderOptionGroup().GetValue(Name{ "o_materialUseForwardPassIBLSpecular" });
+                        if (value.GetIndex() != 0)
+                        {
+                            return true;
+                        }
+                    }
+
+                }
             }
 
             return false;