Change parametrization of procedural metering mask

com.unity.render-pipelines.high-definition/Documentation~/Override-Exposure.md

@@ -90,7 +90,7 @@ To configure **Automatic Mode**, select the **Metering Mode**. This tells the Ca
   | **Center Around Exposure target** | Whether the procedural mask will be centered around the GameObject set as Exposure Target in the [Camera](HDRP-Camera.html). |
   | **Center**                        | Sets the center of the procedural metering mask ([0,0] being bottom left of the screen and [1,1] top right of the screen). Available only when **Center Around Exposure target**  is disabled. |
   | **Offset**                        | Sets an offset to where mask is centered . Available only when **Center Around Exposure target**  is enabled. |
-  | **Radii**                         | Sets the radii (horizontal and vertical) of the procedural mask, in terms of fraction of the screen (i.e. 0.5 means a radius that stretches half of the screen). |
+  | **Radii**                         | Sets the radii (horizontal and vertical) of the procedural mask, in terms of fraction of half the screen (i.e. 0.5 means a mask that stretch half of the screen in both directions). |
   | **Softness**                      | Sets the softness of the mask, the higher the value the less influence is given to pixels at the edge of the mask. |
   | **Mask Min Intensity**            | All pixels below this threshold (in EV100 units) will be assigned a weight of 0 in the metering mask. |
   | **Mask Max Intensity**            | All pixels above this threshold (in EV100 units) will be assigned a weight of 0 in the metering mask. |

com.unity.render-pipelines.high-definition/Runtime/PostProcessing/Components/Exposure.cs

@@ -137,9 +137,9 @@ public sealed class Exposure : VolumeComponent, IPostProcessComponent
         /// </summary>
         public NoInterpVector2Parameter proceduralCenter = new NoInterpVector2Parameter(new Vector2(0.5f, 0.5f));
         /// <summary>
-        /// Sets the radii of the procedural mask, in terms of fraction of the screen (i.e. 0.5 means a radius that stretch half of the screen).
+        /// Sets the radii of the procedural mask, in terms of fraction of half the screen (i.e. 0.5 means a mask that stretch half of the screen in both directions).
         /// </summary>
-        public NoInterpVector2Parameter proceduralRadii  = new NoInterpVector2Parameter(new Vector2(0.15f, 0.15f));
+        public NoInterpVector2Parameter proceduralRadii  = new NoInterpVector2Parameter(new Vector2(0.3f, 0.3f));
         /// <summary>
         /// All pixels below this threshold (in EV100 units) will be assigned a weight of 0 in the metering mask. 
         /// </summary>

com.unity.render-pipelines.high-definition/Runtime/PostProcessing/PostProcessSystem.cs

@@ -1150,8 +1150,8 @@ internal void ComputeProceduralMeteringParams(HDCamera camera, out Vector4 proce
             float screenDiagonal = 0.5f * (camera.actualHeight + camera.actualWidth);
 
             proceduralParams1 = new Vector4(proceduralCenter.x, proceduralCenter.y,
-                m_Exposure.proceduralRadii.value.x * screenDiagonal,
-                m_Exposure.proceduralRadii.value.y * screenDiagonal);
+                m_Exposure.proceduralRadii.value.x * camera.actualWidth,
+                m_Exposure.proceduralRadii.value.y * camera.actualHeight);
 
             proceduralParams2 = new Vector4(1.0f / m_Exposure.proceduralSoftness.value, LightUtils.ConvertEvToLuminance(m_Exposure.maskMinIntensity.value), LightUtils.ConvertEvToLuminance(m_Exposure.maskMaxIntensity.value), 0.0f);
         }