Updated additional settings

ScriptableRenderPipeline/HDRenderPipeline/Editor/Lighting/HDReflectionProbeEditor.Data.cs

             internal SerializedProperty farClip;
 
             internal SerializedProperty influenceShape;
-            internal SerializedProperty influenceSphereRadius; 
+            internal SerializedProperty influenceSphereRadius;
+            internal SerializedProperty dimmer;
 
             public SerializedReflectionProbe(SerializedObject so, SerializedObject addso)
             {
                 boxReprojectionVolumeSize = addso.Find((HDAdditionalReflectionData d) => d.m_BoxReprojectionVolumeSize);
                 boxReprojectionVolumeCenter = addso.Find((HDAdditionalReflectionData d) => d.m_BoxReprojectionVolumeCenter);
                 sphereReprojectionVolumeRadius = addso.Find((HDAdditionalReflectionData d) => d.m_SphereReprojectionVolumeRadius);
+                dimmer = addso.Find((HDAdditionalReflectionData d) => d.m_Dimmer);
             }
         }
 

ScriptableRenderPipeline/HDRenderPipeline/Editor/Lighting/HDReflectionProbeEditor.Drawers.cs

             true,
             CED.Action(Drawer_CaptureSettings)
         );
+
+        static readonly CED.IDrawer k_AdditionalSection = CED.FoldoutGroup(
+            "Additional settings",
+            (s, p, o) => p.dimmer,
+            true,
+            CED.Action(Drawer_AdditionalSettings)
+        );
         #endregion
 
         static void Drawer_CaptureSettings(UIState s, SerializedReflectionProbe p, Editor owner)
             EditorGUILayout.PropertyField(p.useOcclusionCulling);
             EditorGUILayout.PropertyField(p.nearClip);
             EditorGUILayout.PropertyField(p.farClip);
+        }
+
+        static void Drawer_AdditionalSettings(UIState s, SerializedReflectionProbe p, Editor owner)
+        {
+            EditorGUILayout.PropertyField(p.dimmer);
+
+            if (p.so.targetObjects.Length == 1)
+            {
+                var probe = (ReflectionProbe)p.so.targetObject;
+                if (probe.mode == ReflectionProbeMode.Custom && probe.customBakedTexture != null)
+                {
+                    var cubemap = probe.customBakedTexture as Cubemap;
+                    if (cubemap && cubemap.mipmapCount == 1)
+                        EditorGUILayout.HelpBox("No mipmaps in the cubemap, Smoothness value in Standard shader will be ignored.", MessageType.Warning);
+                }
+            }
         }
 
         #region Influence Volume

ScriptableRenderPipeline/HDRenderPipeline/Editor/Lighting/HDReflectionProbeEditor.cs

             k_InfluenceVolumeSection.Draw(s, p, this);
             k_SeparateProjectionVolumeSection.Draw(s, p, this);
             k_CaptureSection.Draw(s, p, this);
+            k_AdditionalSection.Draw(s, p, this);
 
             PerformOperations(s, p, this);