Implement custom drawer for layer mask parameters

com.unity.render-pipelines.core/Editor/Volume/Drawers/IntParameterDrawer.cs

@@ -1,5 +1,6 @@
 using UnityEngine;
 using UnityEngine.Rendering;
+using UnityEditorInternal;
 
 namespace UnityEditor.Rendering
 {
@@ -104,4 +105,19 @@ public override bool OnGUI(SerializedDataParameter parameter, GUIContent title)
             return true;
         }
     }
+
+    [VolumeParameterDrawer(typeof(LayerMaskParameter))]
+    sealed class LayerMaskParameterDrawer : VolumeParameterDrawer
+    {
+        public override bool OnGUI(SerializedDataParameter parameter, GUIContent title)
+        {
+            var value = parameter.value;
+
+            if (value.propertyType != SerializedPropertyType.LayerMask)
+                return false;
+
+            value.intValue = EditorGUILayout.MaskField(title, value.intValue, InternalEditorUtility.layers);
+            return true;
+        }
+    }
 }

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

@@ -41,6 +41,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Fixed decal draw order for ShaderGraph decal materials.
 - Fixed StackLit ShaderGraph surface option property block to only display energy conserving specular color option for the specular parametrization (case 1257050)
 - Fixed missing BeginCameraRendering call for custom render mode of a Camera.
+- Fixed LayerMask editor for volume parameters.
 
 ### Changed
 - Removed the material pass probe volumes evaluation mode.