[RPW]Fix Diffusion Profile Volume Component inspector when opened wit…

com.unity.render-pipelines.core/Editor/Volume/VolumeComponentEditor.cs

@@ -166,6 +166,11 @@ internal Editor inspector
             set => m_Inspector = value;
         }
 
+        /// <summary>
+        /// Obtains the <see cref="Volume"/> that is being edited from this volume component
+        /// </summary>
+        protected Volume volume => inspector?.target as Volume;
+
         List<(GUIContent displayName, int displayOrder, SerializedDataParameter param)> m_Parameters;
 
         static Dictionary<Type, VolumeParameterDrawer> s_ParameterDrawers;

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

@@ -120,6 +120,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Fixed HDRP build issues with DOTS_INSTANCING_ON shader variant.
 - Fixed default value of "Distortion Blur" from 1 to 0 according to the doc.
 - Fixed Transparent Depth Pre/Post pass by default for the built-in HDRP Hair shader graph.
+- Fixed NullReferenceException when opening a Volume Component with a Diffusion Profile with any inspector.
 
 ### Changed
 - Converted most TGA textures files to TIF to reduce the size of HDRP material samples.

com.unity.render-pipelines.high-definition/Editor/Lighting/DiffusionProfileOverrideEditor.cs

@@ -14,7 +14,6 @@ namespace UnityEditor.Rendering.HighDefinition
     sealed class DiffusionProfileOverrideEditor : VolumeComponentEditor
     {
         SerializedDataParameter m_DiffusionProfiles;
-        Volume m_Volume;
 
         DiffusionProfileSettingsListUI listUI = new DiffusionProfileSettingsListUI();
 
@@ -23,8 +22,6 @@ sealed class DiffusionProfileOverrideEditor : VolumeComponentEditor
         public override void OnEnable()
         {
             var o = new PropertyFetcher<DiffusionProfileOverride>(serializedObject);
-
-            m_Volume = (m_Inspector.target as Volume);
             m_DiffusionProfiles = Unpack(o.Find(x => x.diffusionProfiles));
         }
 
@@ -36,7 +33,7 @@ public override void OnInspectorGUI()
 
             // If the volume is null it means that we're editing the component from the asset
             // So we can't access the bounds of the volume to fill diffusion profiles used in the volume
-            if (m_Volume != null && !m_Volume.isGlobal)
+            if (volume != null && !volume.isGlobal)
             {
                 if (GUILayout.Button("Fill Profile List With Scene Materials"))
                     FillProfileListWithScene();
@@ -54,10 +51,10 @@ void DrawDiffusionProfileElement(SerializedProperty element, Rect rect, int inde
         void FillProfileListWithScene()
         {
             var profiles = new HashSet<DiffusionProfileSettings>();
-            if (m_Volume.isGlobal)
+            if (volume.isGlobal)
                 return;
 
-            var volumeCollider = m_Volume.GetComponent<Collider>();
+            var volumeCollider = volume.GetComponent<Collider>();
 
             // Get all mesh renderers that are within the current volume
             var diffusionProfiles = new List<DiffusionProfileSettings>();