Fixed the diffusion profile becoming invalid when hitting the reset button (case 1269462).

com.unity.render-pipelines.high-definition/CHANGELOG.md

@@ -83,6 +83,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Fixed SSGI compilation issues on PS4.
 - Fixed "Screen position out of view frustum" error when camera is on exactly the planar reflection probe plane.
 - Workaround issue that caused objects using eye shader to not be rendered on xbox.
+- Fixed the usage of GUIEnable for volume components (case 1280018).
+- Fixed the diffusion profile becoming invalid when hitting the reset (case 1269462).
 
 ### Changed
 - Preparation pass for RTSSShadows to be supported by render graph.

com.unity.render-pipelines.high-definition/Runtime/Material/DiffusionProfile/DiffusionProfileSettings.cs

@@ -1,4 +1,5 @@
 using System;
+using UnityEditor.Rendering.HighDefinition;
 
 namespace UnityEngine.Rendering.HighDefinition
 {
@@ -52,14 +53,19 @@ public enum TransmissionMode : uint
 
         // Here we need to have one parameter in the diffusion profile parameter because the deserialization call the default constructor
         public DiffusionProfile(bool dontUseDefaultConstructor)
+        {
+            ResetToDefault();
+        }
+
+        public void ResetToDefault()
         {
             scatteringDistance = Color.grey;
-            transmissionTint   = Color.white;
-            texturingMode      = TexturingMode.PreAndPostScatter;
-            transmissionMode   = TransmissionMode.ThinObject;
-            thicknessRemap     = new Vector2(0f, 5f);
-            worldScale         = 1f;
-            ior                = 1.4f; // Typical value for skin specular reflectance
+            transmissionTint = Color.white;
+            texturingMode = TexturingMode.PreAndPostScatter;
+            transmissionMode = TransmissionMode.ThinObject;
+            thicknessRemap = new Vector2(0f, 5f);
+            worldScale = 1f;
+            ior = 1.4f; // Typical value for skin specular reflectance
         }
 
         internal void Validate()
@@ -223,6 +229,15 @@ void OnEnable()
 #endif
         }
 
+        internal void Reset()
+        {
+            if (profile.hash == 0)
+            {
+                profile.ResetToDefault();
+                profile.hash = DiffusionProfileHashTable.GenerateUniqueHash(this);
+            }
+        }
+
         internal void UpdateCache()
         {
             worldScaleAndFilterRadiusAndThicknessRemap = new Vector4(profile.worldScale,

com.unity.render-pipelines.high-definition/Runtime/Utilities/DiffusionProfileHashTable.cs

@@ -32,7 +32,7 @@ static uint GetDiffusionProfileHash(DiffusionProfileSettings asset)
             return (exponent << 23) | mantissa;
         }
 
-        static uint GenerateUniqueHash(DiffusionProfileSettings asset)
+        static internal uint GenerateUniqueHash(DiffusionProfileSettings asset)
         {
             uint hash = GetDiffusionProfileHash(asset);