Create a material ID swap utility

Assets/ScriptableRenderPipeline/HDRenderPipeline/Editor/HDRenderPipelineMenuItems.cs

             }
         }
 
+        [MenuItem("HDRenderPipeline/Swap standard and SSS material IDs")]
+        static void SwapStandardAndSssMaterialIds()
+        {
+            try
+            {
+                Object[] materials = Resources.FindObjectsOfTypeAll<Material>();
+                for (int i = 0, length = materials.Length; i < length; i++)
+                {
+                    Material mat = materials[i] as Material;
+
+                    EditorUtility.DisplayProgressBar(
+                        "Updating materials...",
+                        string.Format("{0} / {1}", i, length),
+                        i / (float)(length - 1));
+
+                    if (mat.shader.name == "HDRenderPipeline/Lit" || mat.shader.name == "HDRenderPipeline/LitTessellation")
+                    {
+                        int matID = (int)mat.GetFloat("_MaterialID");
+
+                        if (matID == 0)
+                        {
+                            matID = 1;
+                            mat.SetInt("_MaterialID", matID);
+                            EditorUtility.SetDirty(mat);
+                        }
+                        else if (matID == 1)
+                        {
+                            matID = 0;
+                            mat.SetInt("_MaterialID", matID);
+                            EditorUtility.SetDirty(mat);
+                        }
+                    }
+                }
+            }
+            finally
+            {
+                EditorUtility.ClearProgressBar();
+            }
+        }
+
         [MenuItem("HDRenderPipeline/Debug/Remove tessellation materials (not reversible)")]
         static void RemoveTessellationMaterials()
         {

Assets/ScriptableRenderPipeline/HDRenderPipeline/Material/Lit/Editor/BaseLitUI.cs

             bool depthOffsetEnable = material.GetFloat(kDepthOffsetEnable) > 0.0f;
             SetKeyword(material, "_DEPTHOFFSET_ON", depthOffsetEnable);
 
-            // Temp. material ID upgrade workaround: determine the material ID from the stencil reference value.
-            // Select the menu item [HDRenderPipeline -> Reset all material keywords] to proceed.
-            // Remove after upgrading all projects!
-            if (material.HasProperty(kMaterialID))
-            {
-                int sr = (int)material.GetFloat(kStencilRef);
-                Debug.Assert(sr > 0, "The stencil reference value must be greater than 0. This material will have an incorrect ID assigned to it.");
-
-                material.SetInt(kMaterialID, sr - 1);
-            }
-
             // Set the reference value for the stencil test.
             int stencilRef = (int)UnityEngine.Experimental.Rendering.HDPipeline.StencilBits.Standard;
             if (material.HasProperty(kMaterialID))