using HTile mask to determine what decal properties affect drawable geometry

ScriptableRenderPipeline/HDRenderPipeline/HDRP/HDRenderPipeline.cs

 		    CoreUtils.SetRenderTarget(cmd, m_HTileRT, ClearFlag.Color, CoreUtils.clearColorAllBlack);
 		}
 
-        public void SetHTile(CommandBuffer cmd)
+        public void SetHTile(int bindSlot, CommandBuffer cmd)
-            cmd.SetRandomWriteTarget(3, m_HTile);
+            cmd.SetRandomWriteTarget(bindSlot, m_HTile);
         }
 
         public void PushGlobalParams(CommandBuffer cmd)
             {
                 // setup GBuffer for rendering
                 CoreUtils.SetRenderTarget(cmd, m_GbufferManager.GetGBuffers(), m_CameraDepthStencilBufferRT);
+                if (m_FrameSettings.enableDBuffer)
+                {
+                    m_DbufferManager.SetHTile(m_GbufferManager.gbufferCount, cmd); 
+                }
 
                 // Render opaque objects into GBuffer
                 if (m_CurrentDebugDisplaySettings.IsDebugDisplayEnabled())
 				m_DbufferManager.ClearNormalTargetAndHTile(clearColorNormal, cmd);
 
 				CoreUtils.SetRenderTarget(cmd, m_DbufferManager.GetDBuffers(), m_CameraDepthStencilBufferRT); // do not clear anymore
-                m_DbufferManager.SetHTile(cmd);
+                m_DbufferManager.SetHTile(m_DbufferManager.dbufferCount, cmd);
                 DecalSystem.instance.Render(renderContext, camera, cmd);
                 cmd.ClearRandomWriteTargets();
             }

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Decal/Decal.hlsl

 	UNITY_DEFINE_INSTANCED_PROP(float4x4, normalToWorld)
 UNITY_INSTANCING_BUFFER_END(matrix)       
 
+RW_TEXTURE2D(float, _DecalHTile); // DXGI_FORMAT_R8_UINT is not supported by Unity
 
 // Must be in sync with RT declared in HDRenderPipeline.cs ::Rebuild
 void EncodeIntoDBuffer( DecalSurfaceData surfaceData,

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Decal/DecalProperties.hlsl

 
 float _DecalBlend;
 
-RW_TEXTURE2D(float, _DecalHTile); // DXGI_FORMAT_R8_UINT is not supported by Unity
-
 #endif 

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Decal/DecalUtilities.hlsl

 		FETCH_DBUFFER(DBuffer, _DBufferTexture, unPositionSS);
 		DecalSurfaceData decalSurfaceData;
 		DECODE_FROM_DBUFFER(DBuffer, decalSurfaceData);
+		uint mask = UnpackByte(_DecalHTile[unPositionSS / 8]); 
+		// using alpha compositing https://developer.nvidia.com/gpugems/GPUGems3/gpugems3_ch23.html
-		// using alpha compositing https://developer.nvidia.com/gpugems/GPUGems3/gpugems3_ch23.html
-		surfaceData.baseColor.xyz = surfaceData.baseColor.xyz * decalSurfaceData.baseColor.w + decalSurfaceData.baseColor.xyz;
-		surfaceData.normalWS.xyz = normalize(surfaceData.normalWS.xyz * decalSurfaceData.normalWS.w + decalSurfaceData.normalWS.xyz);
-		surfaceData.metallic = surfaceData.metallic * decalSurfaceData.mask.w + decalSurfaceData.mask.x;
-		surfaceData.ambientOcclusion = surfaceData.ambientOcclusion * decalSurfaceData.mask.w + decalSurfaceData.mask.y;
-		surfaceData.perceptualSmoothness = surfaceData.perceptualSmoothness * decalSurfaceData.mask.w + decalSurfaceData.mask.z;
+		if(mask & 1)
+		{
+			surfaceData.baseColor.xyz = surfaceData.baseColor.xyz * decalSurfaceData.baseColor.w + decalSurfaceData.baseColor.xyz;
+		}
+		if(mask & 2)
+		{
+			surfaceData.normalWS.xyz = normalize(surfaceData.normalWS.xyz * decalSurfaceData.normalWS.w + decalSurfaceData.normalWS.xyz);
+		}
+		if(mask & 4)
+		{
+			surfaceData.metallic = surfaceData.metallic * decalSurfaceData.mask.w + decalSurfaceData.mask.x;
+			surfaceData.ambientOcclusion = surfaceData.ambientOcclusion * decalSurfaceData.mask.w + decalSurfaceData.mask.y;
+			surfaceData.perceptualSmoothness = surfaceData.perceptualSmoothness * decalSurfaceData.mask.w + decalSurfaceData.mask.z;
+		}
 	}
 }