diff --git a/VulkanHppGenerator.cpp b/VulkanHppGenerator.cpp
index bf4ae8e..a1ba5ce 100644
--- a/VulkanHppGenerator.cpp
+++ b/VulkanHppGenerator.cpp
@@ -10657,11 +10657,16 @@ std::string VulkanHppGenerator::generateStructConstructorArgument( bool listedAr
       {
         str += generateEnumInitializer( memberData.type, memberData.arraySizes, enumIt->second.values, enumIt->second.isBitmask );
       }
+      else if ( memberData.defaultValue.empty() )
+      {
+        // if there's no default value, it can be initialized with just {}
+        str += "{}";
+      }
       else
       {
-        assert( memberData.value.empty() );
-        // all the rest can be initialized with just {}
-        str += "{}";
+        assert( memberData.defaultValue.starts_with( "VK_" ) );
+        std::string tag = findTag( memberData.defaultValue );
+        str += "VULKAN_HPP_NAMESPACE::" + toCamelCase( stripPostfix( stripPrefix( memberData.defaultValue, "VK_" ), tag ) ) + tag;
       }
     }
   }
@@ -11129,8 +11134,7 @@ std::tuple<std::string, std::string, std::string, std::string>
     }
     else
     {
-      // as we don't have any meaningful default initialization values, everything can be initialized by just '{}'
-      // !
+      // when we don't have any default initialization value, everything can be initialized by just '{}'
       assert( member.arraySizes.empty() || member.bitCount.empty() );
       if ( !member.bitCount.empty() )
       {
@@ -11145,10 +11149,16 @@ std::tuple<std::string, std::string, std::string, std::string>
         {
           members += generateEnumInitializer( member.type, member.arraySizes, enumIt->second.values, enumIt->second.isBitmask );
         }
-        else
+        else if ( member.defaultValue.empty() )
         {
           members += "{}";
         }
+        else
+        {
+          assert( member.defaultValue.starts_with( "VK_" ) );
+          std::string tag = findTag( member.defaultValue );
+          members += "VULKAN_HPP_NAMESPACE::" + toCamelCase( stripPostfix( stripPrefix( member.defaultValue, "VK_" ), tag ) ) + tag;
+        }
       }
     }
     members += ";\n";
@@ -14703,6 +14713,20 @@ void VulkanHppGenerator::readTypeStruct( tinyxml2::XMLElement const * element, b
     }
     it->second.subStruct = determineSubStruct( *it );
 
+    // add some default values for some structures here!
+    if ( ( it->first == "VkRayTracingShaderGroupCreateInfoNV" ) || ( it->first == "VkRayTracingShaderGroupCreateInfoKHR" ) )
+    {
+      assert( ( ( it->first != "VkRayTracingShaderGroupCreateInfoNV" ) || ( it->second.members.size() == 7 ) ) &&
+              ( ( it->first != "VkRayTracingShaderGroupCreateInfoKHR" ) || ( it->second.members.size() == 8 ) ) );
+      assert( ( it->second.members[3].name == "generalShader" ) && ( it->second.members[4].name == "closestHitShader" ) &&
+              ( it->second.members[5].name == "anyHitShader" ) && ( it->second.members[6].name == "intersectionShader" ) );
+      bool isKHR = ( it->first == "VkRayTracingShaderGroupCreateInfoKHR" );
+      for ( size_t i : { 3, 4, 5, 6 } )
+      {
+        it->second.members[i].defaultValue = isKHR ? "VK_SHADER_UNUSED_KHR" : "VK_SHADER_UNUSED_NV";
+      }
+    }
+
     // check if multiple structure members use the very same (not empty) len attribute
     // Note: even though the arrays are not marked as optional, they still might be mutually exclusive (like in
     // VkWriteDescriptorSet)! That is, there's not enough information available in vk.xml to decide on that, so we
diff --git a/VulkanHppGenerator.hpp b/VulkanHppGenerator.hpp
index 729bab7..5348211 100644
--- a/VulkanHppGenerator.hpp
+++ b/VulkanHppGenerator.hpp
@@ -312,6 +312,7 @@ private:
 
   struct MemberData
   {
+    std::string                                 defaultValue   = {};
     TypeInfo                                    type           = {};
     std::string                                 name           = {};
     std::vector<std::string>                    arraySizes     = {};
diff --git a/vulkan/vulkan_structs.hpp b/vulkan/vulkan_structs.hpp
index 5bc552b..5f5d65a 100644
--- a/vulkan/vulkan_structs.hpp
+++ b/vulkan/vulkan_structs.hpp
@@ -93338,10 +93338,10 @@ namespace VULKAN_HPP_NAMESPACE
 #if !defined( VULKAN_HPP_NO_STRUCT_CONSTRUCTORS )
     VULKAN_HPP_CONSTEXPR RayTracingShaderGroupCreateInfoKHR(
       VULKAN_HPP_NAMESPACE::RayTracingShaderGroupTypeKHR type_                            = VULKAN_HPP_NAMESPACE::RayTracingShaderGroupTypeKHR::eGeneral,
-      uint32_t                                           generalShader_                   = {},
-      uint32_t                                           closestHitShader_                = {},
-      uint32_t                                           anyHitShader_                    = {},
-      uint32_t                                           intersectionShader_              = {},
+      uint32_t                                           generalShader_                   = VULKAN_HPP_NAMESPACE::ShaderUnusedKHR,
+      uint32_t                                           closestHitShader_                = VULKAN_HPP_NAMESPACE::ShaderUnusedKHR,
+      uint32_t                                           anyHitShader_                    = VULKAN_HPP_NAMESPACE::ShaderUnusedKHR,
+      uint32_t                                           intersectionShader_              = VULKAN_HPP_NAMESPACE::ShaderUnusedKHR,
       const void *                                       pShaderGroupCaptureReplayHandle_ = {},
       const void *                                       pNext_                           = nullptr ) VULKAN_HPP_NOEXCEPT
       : pNext( pNext_ )
@@ -93468,10 +93468,10 @@ namespace VULKAN_HPP_NAMESPACE
     VULKAN_HPP_NAMESPACE::StructureType                sType                           = StructureType::eRayTracingShaderGroupCreateInfoKHR;
     const void *                                       pNext                           = {};
     VULKAN_HPP_NAMESPACE::RayTracingShaderGroupTypeKHR type                            = VULKAN_HPP_NAMESPACE::RayTracingShaderGroupTypeKHR::eGeneral;
-    uint32_t                                           generalShader                   = {};
-    uint32_t                                           closestHitShader                = {};
-    uint32_t                                           anyHitShader                    = {};
-    uint32_t                                           intersectionShader              = {};
+    uint32_t                                           generalShader                   = VULKAN_HPP_NAMESPACE::ShaderUnusedKHR;
+    uint32_t                                           closestHitShader                = VULKAN_HPP_NAMESPACE::ShaderUnusedKHR;
+    uint32_t                                           anyHitShader                    = VULKAN_HPP_NAMESPACE::ShaderUnusedKHR;
+    uint32_t                                           intersectionShader              = VULKAN_HPP_NAMESPACE::ShaderUnusedKHR;
     const void *                                       pShaderGroupCaptureReplayHandle = {};
   };
 
@@ -93879,10 +93879,10 @@ namespace VULKAN_HPP_NAMESPACE
 #if !defined( VULKAN_HPP_NO_STRUCT_CONSTRUCTORS )
     VULKAN_HPP_CONSTEXPR RayTracingShaderGroupCreateInfoNV(
       VULKAN_HPP_NAMESPACE::RayTracingShaderGroupTypeKHR type_               = VULKAN_HPP_NAMESPACE::RayTracingShaderGroupTypeKHR::eGeneral,
-      uint32_t                                           generalShader_      = {},
-      uint32_t                                           closestHitShader_   = {},
-      uint32_t                                           anyHitShader_       = {},
-      uint32_t                                           intersectionShader_ = {},
+      uint32_t                                           generalShader_      = VULKAN_HPP_NAMESPACE::ShaderUnusedNV,
+      uint32_t                                           closestHitShader_   = VULKAN_HPP_NAMESPACE::ShaderUnusedNV,
+      uint32_t                                           anyHitShader_       = VULKAN_HPP_NAMESPACE::ShaderUnusedNV,
+      uint32_t                                           intersectionShader_ = VULKAN_HPP_NAMESPACE::ShaderUnusedNV,
       const void *                                       pNext_              = nullptr ) VULKAN_HPP_NOEXCEPT
       : pNext( pNext_ )
       , type( type_ )
@@ -93998,10 +93998,10 @@ namespace VULKAN_HPP_NAMESPACE
     VULKAN_HPP_NAMESPACE::StructureType                sType              = StructureType::eRayTracingShaderGroupCreateInfoNV;
     const void *                                       pNext              = {};
     VULKAN_HPP_NAMESPACE::RayTracingShaderGroupTypeKHR type               = VULKAN_HPP_NAMESPACE::RayTracingShaderGroupTypeKHR::eGeneral;
-    uint32_t                                           generalShader      = {};
-    uint32_t                                           closestHitShader   = {};
-    uint32_t                                           anyHitShader       = {};
-    uint32_t                                           intersectionShader = {};
+    uint32_t                                           generalShader      = VULKAN_HPP_NAMESPACE::ShaderUnusedNV;
+    uint32_t                                           closestHitShader   = VULKAN_HPP_NAMESPACE::ShaderUnusedNV;
+    uint32_t                                           anyHitShader       = VULKAN_HPP_NAMESPACE::ShaderUnusedNV;
+    uint32_t                                           intersectionShader = VULKAN_HPP_NAMESPACE::ShaderUnusedNV;
   };
 
   template <>