[HDRP] Improve decal performances when they use different material and the same draw order.

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

@@ -72,6 +72,16 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Fixed the point distribution for the diffuse denoiser sometimes not being properly intialized.
 - Fixed the bad blending between the sun and the clouds (case 1373282).
 - Fixed and optimize distance shadowmask fade.
+- Fixed compilation errors when using Elipse, Rectangle, Polygon, Checkerboard, RoundedPolygon, RoundedRectangle in a ray tracing shader graph (case 1377610).
+- Fixed outdated documentation about supported GPUs for ray tracing (case 1375895).
+- Fixed outdated documentation about recursie ray tracing effects support (case 1374904).
+- Fixed Shadow Matte not appearing in ray tracing effects (case 1364005).
+- Fixed Crash issue when adding an area light on its own.
+- Fixed rendertarget ColorMask in Forward with virtual texturing and transparent motion vectors.
+- Fixed light unit conversion after changing mid gray value.
+- Fixed Focus distance in path traced depth of field now takes into account the focus mode setting (volume vs camera).
+- Fixed stencil buffer resolve when MSAA is enabled so that OR operator is used instead of picking the last sample.
+- Fixed HDRP Decals performances when they use different materials (~5x improvement in the decal update loop code).
 
 ### Changed
 - Use RayTracingAccelerationStructure.CullInstances to filter Renderers and populate the acceleration structure with ray tracing instances for improved CPU performance on the main thread.
@@ -85,6 +95,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Modified HDRP to use common FSR logic from SRP core.
 - Optimized FSR by merging the RCAS logic into the FinalPass shader.
 - Integrate a help box to inform users of the potential dependency to directional lights when baking.
+- The rendering order of decals that have a similar draw order value was modified. The new order should be the reverse of the previous order.
 
 ## [13.1.0] - 2021-09-24
 

com.unity.render-pipelines.high-definition/Runtime/Material/Decal/DecalSystem.cs

@@ -492,9 +492,23 @@ public void UpdateCachedData(DecalHandle handle, DecalProjector decalProjector)
                 m_CachedFadeFactor[index] = data.fadeFactor;
                 m_CachedDecalLayerMask[index] = data.decalLayerMask;
 
+                UpdateCachedDrawOrder();
+
                 UpdateJobArrays(index, decalProjector);
             }
 
+            public void UpdateCachedDrawOrder()
+            {
+                if (this.m_Material.HasProperty(HDShaderIDs._DrawOrder))
+                {
+                    m_CachedDrawOrder = this.m_Material.GetInt(HDShaderIDs._DrawOrder);
+                }
+                else
+                {
+                    m_CachedDrawOrder = 0;
+                }
+            }
+
             // Update memory allocation and assign decal handle, then update cached data
             public DecalHandle AddDecal(int materialID, DecalProjector decalProjector)
             {
@@ -821,20 +835,7 @@ public int Count
                 }
             }
 
-            public int DrawOrder
-            {
-                get
-                {
-                    if (this.m_Material.HasProperty(HDShaderIDs._DrawOrder))
-                    {
-                        return this.m_Material.GetInt(HDShaderIDs._DrawOrder);
-                    }
-                    else
-                    {
-                        return 0;
-                    }
-                }
-            }
+            public int DrawOrder => m_CachedDrawOrder;
 
             private List<Matrix4x4[]> m_DecalToWorld = new List<Matrix4x4[]>();
             private List<Matrix4x4[]> m_NormalToWorld = new List<Matrix4x4[]>();
@@ -845,6 +846,7 @@ public int DrawOrder
             private int m_NumResults = 0;
             private int m_InstanceCount = 0;
             private int m_DecalsCount = 0;
+            private int m_CachedDrawOrder = 0;
             private Vector2[] m_CachedDrawDistances = new Vector2[kDecalBlockSize]; // x - draw distance, y - fade scale
             private Vector2[] m_CachedAngleFade = new Vector2[kDecalBlockSize]; // x - scale fade, y - bias fade
             private Vector4[] m_CachedUVScaleBias = new Vector4[kDecalBlockSize]; // xy - scale, zw bias
@@ -1100,10 +1102,12 @@ public void CreateDrawData()
             m_DecalSetsRenderList.Clear();
             foreach (var pair in m_DecalSets)
             {
+                pair.Value.UpdateCachedDrawOrder();
+
                 if (pair.Value.IsDrawn())
                 {
                     int insertIndex = 0;
-                    while ((insertIndex < m_DecalSetsRenderList.Count) && (pair.Value.DrawOrder >= m_DecalSetsRenderList[insertIndex].DrawOrder))
+                    while ((insertIndex < m_DecalSetsRenderList.Count) && (pair.Value.DrawOrder > m_DecalSetsRenderList[insertIndex].DrawOrder))
                     {
                         insertIndex++;
                     }