Move world to decal calculation to shaders, remove the need to set property block in c#

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Decal/DecalProjectorComponent.cs

         private static readonly int m_DecalToWorldR = Shader.PropertyToID("_DecalToWorldR");
 
         public Material m_Material;
-        private MaterialPropertyBlock m_PropertyBlock;
-
-        // normal space  __x  to decal space __x 
-        //              |\                  |\      
-        //              y z                 z y        
-        //                                    
-        private static Matrix4x4 m_NormalToDecal = Matrix4x4.Scale(new Vector3(1.0f, 1.0f, -1.0f)) * Matrix4x4.Rotate(Quaternion.AngleAxis(-90.0f, new Vector3(1, 0, 0))); 
 
         public int CullIndex
         {
 
         public void Start()
         {
-            m_PropertyBlock = new MaterialPropertyBlock();
             DecalSystem.instance.AddDecal(this);
         }
 
             DrawGizmo(true);
             // if this object is selected there is a chance the transform was changed so update culling info
             DecalSystem.instance.UpdateBoundingSphere(this);
-        }
-
-		public void UpdatePropertyBlock(Vector3 cameraPos)
-        {
-            Matrix4x4 CRWStoAWS = new Matrix4x4();
-            if (ShaderConfig.s_CameraRelativeRendering == 1)
-            {
-				CRWStoAWS = Matrix4x4.Translate(cameraPos);
-            }
-            else
-            {
-                CRWStoAWS = Matrix4x4.identity;
-            }
-
-            Matrix4x4 final = transform.localToWorldMatrix;
-            Matrix4x4 decalToWorldR = Matrix4x4.Rotate(transform.rotation) * m_NormalToDecal;
-            Matrix4x4 worldToDecal = Matrix4x4.Translate(new Vector3(0.5f, 0.0f, 0.5f)) * Matrix4x4.Scale(new Vector3(1.0f, -1.0f, 1.0f)) * final.inverse;
-            if (m_PropertyBlock == null)
-            {
-                m_PropertyBlock = new MaterialPropertyBlock();
-            }
-            m_PropertyBlock.SetMatrix(m_DecalToWorldR, decalToWorldR);
-            m_PropertyBlock.SetMatrix(m_WorldToDecal, worldToDecal * CRWStoAWS);
-        }
-
-        public MaterialPropertyBlock GetPropertyBlock()
-        {
-            return m_PropertyBlock;
         }
     }
 }

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Decal/DecalSystem.cs

                     !m_Decals[decalIndex].m_Material.GetTexture("_MaskMap"))
                     continue;
 
-                m_Decals[decalIndex].UpdatePropertyBlock(camera.cameraPos);
-                cmd.DrawMesh(m_DecalMesh, m_Decals[decalIndex].transform.localToWorldMatrix, m_Decals[decalIndex].m_Material, 0, 0,
-                    m_Decals[decalIndex].GetPropertyBlock());
+                cmd.DrawMesh(m_DecalMesh, m_Decals[decalIndex].transform.localToWorldMatrix, m_Decals[decalIndex].m_Material, 0, 0);
             }
         }
 

ScriptableRenderPipeline/HDRenderPipeline/HDRP/ShaderPass/ShaderPassDBuffer.hlsl

 	float d = LOAD_TEXTURE2D(_MainDepthTexture, posInput.positionSS).x;
 	UpdatePositionInput(d, UNITY_MATRIX_I_VP, UNITY_MATRIX_VP, posInput);
 
-	float3 positionWS = posInput.positionWS;
-	float3 positionDS = mul(_WorldToDecal, float4(positionWS, 1.0f)).xyz;
+	float3 positionWS = GetAbsolutePositionWS(posInput.positionWS);
+	float3 positionDS = mul(UNITY_MATRIX_I_M, float4(positionWS, 1.0f)).xyz;
+	positionDS = positionDS * float3(1.0f, -1.0f, 1.0f) + float3(0.5f, 0.0f, 0.5f);
 	clip(positionDS < 0 ? -1 : 1);
 	clip(positionDS > 1 ? -1 : 1);