Avoid errors if user define null params in volume component

com.unity.render-pipelines.core/Runtime/Volume/VolumeComponent.cs

@@ -96,7 +96,12 @@ protected virtual void OnEnable()
                 .AsReadOnly();
 
             foreach (var parameter in parameters)
-                parameter.OnEnable();
+            {
+                if(parameter != null)
+                    parameter.OnEnable();
+                else
+                    Debug.LogWarning("Volume Component " + GetType().Name + " contains a null parameter; please make sure all parameters are initialized to a default value. Until this is fixed the null parameters will not be considered by the system.");
+            }
         }
 
         /// <summary>
@@ -108,7 +113,10 @@ protected virtual void OnDisable()
                 return;
 
             foreach (var parameter in parameters)
-                parameter.OnDisable();
+            {
+                if (parameter != null)
+                    parameter.OnDisable();
+            }
         }
         /// <summary>
         /// Interpolates a <see cref="VolumeComponent"/> with this component by an interpolation
@@ -222,7 +230,10 @@ public override int GetHashCode()
         public void Release()
         {
             for (int i = 0; i < parameters.Count; i++)
-                parameters[i].Release();
+            {
+                if(parameters[i] != null)
+                    parameters[i].Release();
+            }
         }
     }
 }

com.unity.render-pipelines.core/Runtime/Volume/VolumeManager.cs

@@ -227,8 +227,11 @@ void ReplaceData(VolumeStack stack, List<VolumeComponent> components)
 
                 for (int i = 0; i < count; i++)
                 {
-                    target.parameters[i].overrideState = false;
-                    target.parameters[i].SetValue(component.parameters[i]);
+                    if(target.parameters[i] != null)
+                    {
+                        target.parameters[i].overrideState = false;
+                        target.parameters[i].SetValue(component.parameters[i]);
+                    }
                 }
             }
         }

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

@@ -1,4 +1,4 @@
-# Changelog
+# Changelog
 All notable changes to this package will be documented in this file.
 
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
@@ -48,6 +48,7 @@ The version number for this package has increased due to a version update of a r
 - Fixed the ray tracing shadow UI being displayed while it shouldn't (case 1286391).
 - Fixed issues with physically-based DoF, improved speed and robustness 
 - Fixed a warning happening when putting the range of lights to 0.
+- Fixed issue when null parameters in a volume component would spam null reference errors. Produce a warning instead.
 
 ### Changed
 - Combined occlusion meshes into one to reduce draw calls and state changes with XR single-pass.