Fix color curves changes not applying immediately in editor (#6322)

* Always recompute LUT hash when colro curves are overridden

* Changelog

* Missing tiny part of comment

Co-authored-by: sebastienlagarde <[email protected]>

Author: FrancescoC-unity

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

@@ -299,6 +299,19 @@ public override int GetHashCode()
             }
         }
 
+        /// <summary>
+        /// Returns true if any of the volume properites has been overridden.
+        /// </summary>
+        /// <returns>True if any of the volume properites has been overridden.</returns>
+        public bool AnyPropertiesIsOverridden()
+        {
+            for (int i = 0; i < parameters.Count; ++i)
+            {
+                if (parameters[i].overrideState) return true;
+            }
+            return false;
+        }
+
         /// <summary>
         /// Unity calls this method before the object is destroyed.
         /// </summary>

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

@@ -56,6 +56,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Fixed camera bridge action in release build (case 1367866).
 - Fixed contact shadow disappearing when shadowmask is used and no non-static object is available.
 - Fixed atmospheric scattering being incorrectly enabled when scene lighting is disabled.
+- Fixed for changes of color curves not being applied immediately.
 
 ### Changed
 - Optimizations for the physically based depth of field.

com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/HDRenderPipeline.PostProcess.cs

@@ -4306,7 +4306,8 @@ TextureHandle ColorGradingPass(RenderGraph renderGraph)
             var currentGradingHash = ComputeLUTHash();
 
             // The lut we have already is ok.
-            if (currentGradingHash == m_LutHash)
+            if (currentGradingHash == m_LutHash &&
+                !m_Curves.AnyPropertiesIsOverridden()) // Curves content are not hashed, to compute the hash of the curves would probably be more expensive than actually running the LUT pass. So we just check if the project is using anything but the default
                 return logLut;
 
             // Else we update the hash and we recompute the LUT.