Use material property block to set decal normal to world instanced matrix array instead of calculating it in the shader

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Decal/DecalSystem.cs

                     if (instanceCount == kDrawIndexedBatchSize)
                     {
                         m_PropertyBlock.SetMatrixArray(m_NormalToWorldID, m_InstanceNormalToWorld);
-//                        cmd.SetGlobalMatrixArray(m_NormalToWorldID, m_InstanceNormalToWorld);
                         cmd.DrawMeshInstanced(m_DecalMesh, 0, m_Decals[0].m_Material, 0, m_InstanceMatrices, kDrawIndexedBatchSize, m_PropertyBlock);
                         instanceCount = 0;
                     }
                     m_PropertyBlock.SetMatrixArray(m_NormalToWorldID, m_InstanceNormalToWorld);
-                    cmd.DrawMeshInstanced(m_DecalMesh, 0, m_Decals[0].m_Material, 0, m_InstanceMatrices, instanceCount, m_PropertyBlock);
-                    cmd.SetGlobalMatrixArray(m_NormalToWorldID, m_InstanceNormalToWorld);
+                    cmd.DrawMeshInstanced(m_DecalMesh, 0, m_Decals[0].m_Material, 0, m_InstanceMatrices, instanceCount, m_PropertyBlock);                    
                 }
             }
 

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

 #error Undefine_SHADERPASS
 #endif
 
-// need 3 x float3 interpolators...
-#define VARYINGS_NEED_POSITION_WS
-#define VARYINGS_NEED_TANGENT_TO_WORLD
-
 // This include will define the various Attributes/Varyings structure
 #include "../../ShaderPass/VaryingMesh.hlsl"

ScriptableRenderPipeline/HDRenderPipeline/HDRP/ShaderPass/ShaderPassDBuffer.hlsl

 
 #include "VertMesh.hlsl"
 
-float3 RemoveScale(float3 val)
-{
-	return normalize(val / length(val));
-}
-
-VaryingsMeshType Transform(AttributesMesh input)
-{
-    VaryingsMeshType output;
-
-	UNITY_SETUP_INSTANCE_ID(input)
-	UNITY_TRANSFER_INSTANCE_ID(input, output);
-
-    float3 positionWS = TransformObjectToWorld(input.positionOS);
-	positionWS = GetCameraRelativePositionWS(positionWS);
-	output.positionCS = TransformWorldToHClip(positionWS);
-
-	float3x3 decalRotation;
-	decalRotation[0] = RemoveScale(float3(UNITY_MATRIX_M[0][0], UNITY_MATRIX_M[0][1], UNITY_MATRIX_M[0][2]));
-	decalRotation[2] = RemoveScale(float3(UNITY_MATRIX_M[1][0], UNITY_MATRIX_M[1][1], UNITY_MATRIX_M[1][2]));
-	decalRotation[1] = RemoveScale(float3(UNITY_MATRIX_M[2][0], UNITY_MATRIX_M[2][1], UNITY_MATRIX_M[2][2]));
-
-	decalRotation = transpose(decalRotation);
-
-	output.positionWS = decalRotation[0];
-    output.normalWS = decalRotation[1];
-    output.tangentWS = float4(decalRotation[2], 0.0);
-
-    return output;
-}
-    varyingsType.vmesh = Transform(inputMesh);
+    varyingsType.vmesh = VertMesh(inputMesh);
     return PackVaryingsType(varyingsType);
 }
 
 
     DecalSurfaceData surfaceData;
 	float3x3 decalToWorld = (float3x3)UNITY_ACCESS_INSTANCED_PROP(matrix, normalToWorld);
-	// using the interpolators directly, because UnpackVaryingsMeshToFragInputs does some tangent space manipulations
-//	decalToWorld[0] = packedInput.vmesh.interpolators0;
-//	decalToWorld[1] = packedInput.vmesh.interpolators1;
-//	decalToWorld[2] = packedInput.vmesh.interpolators2.xyz;
-
     GetSurfaceData(positionDS.xz, decalToWorld, surfaceData);
 
 	ENCODE_INTO_DBUFFER(surfaceData, outDBuffer);