EMSUSD-788 support relative cache to USD in anon layers

lib/mayaUsd/python/wrapUtil.cpp

@@ -52,6 +52,11 @@ std::string ensureUSDFileExtension(const std::string& fileToCheck)
     return ret;
 }
 
+void updatePostponedPaths(const PXR_NS::SdfLayerHandle& layer)
+{
+    UsdMayaUtilFileSystem::updatePostponedRelativePaths(layer);
+}
+
 } // namespace
 
 void wrapUtil()
@@ -69,6 +74,7 @@ void wrapUtil()
               .def(
                   "handleAssetPathThatMaybeRelativeToLayer",
                   UsdMayaUtilFileSystem::handleAssetPathThatMaybeRelativeToLayer)
+              .def("updatePostponedRelativePaths", updatePostponedPaths)
               .def("ensureUSDFileExtension", ensureUSDFileExtension)
               .staticmethod("getPathRelativeToMayaSceneFile");
 }

lib/mayaUsd/utils/mayaEditRouter.cpp

@@ -168,15 +168,22 @@ void cacheMayaReference(const PXR_NS::VtDictionary& context, PXR_NS::VtDictionar
     std::string relDistLayerPath = dstLayerPath;
     if (makePathRelative) {
         const std::string layerDirPath = MayaUsd::getTargetLayerFolder(stage);
-        const auto        relativePathAndSuccess
-            = PXR_NS::UsdMayaUtilFileSystem::makePathRelativeTo(dstLayerPath, layerDirPath);
-        if (relativePathAndSuccess.second) {
-            relDistLayerPath = relativePathAndSuccess.first;
+        if (layerDirPath.empty()) {
+            // Making the path relative is postponed until the containing layer is saved.
+            auto layer = getCurrentTargetLayer(stage);
+            UsdMayaUtilFileSystem::markPathAsPostponedRelative(layer, dstLayerPath);
         } else {
-            TF_WARN(
-                "File name (%s) cannot be resolved as relative to the current edit target layer, "
-                "using the absolute path.",
-                dstLayerPath.c_str());
+            const auto relativePathAndSuccess
+                = PXR_NS::UsdMayaUtilFileSystem::makePathRelativeTo(dstLayerPath, layerDirPath);
+            if (relativePathAndSuccess.second) {
+                relDistLayerPath = relativePathAndSuccess.first;
+            } else {
+                TF_WARN(
+                    "File name (%s) cannot be resolved as relative to the current edit target "
+                    "layer, "
+                    "using the absolute path.",
+                    dstLayerPath.c_str());
+            }
         }
     }
 

lib/mayaUsd/utils/utilFileSystem.cpp

@@ -439,6 +439,14 @@ void updatePostponedRelativePathsForPrim(
     }
 }
 
+void UsdMayaUtilFileSystem::updatePostponedRelativePaths(const PXR_NS::SdfLayerHandle& layer)
+{
+    if (!layer)
+        return;
+
+    updatePostponedRelativePaths(layer, layer->GetRealPath());
+}
+
 void UsdMayaUtilFileSystem::updatePostponedRelativePaths(
     const PXR_NS::SdfLayerHandle& layer,
     const std::string&            layerFileName)

lib/mayaUsd/utils/utilFileSystem.h

@@ -165,6 +165,11 @@ void updatePostponedRelativePaths(
     const PXR_NS::SdfLayerHandle& layer,
     const std::string&            layerFileName);
 
+/*! \brief Turns the file paths marked through the call 'markPathAsPostponedRelative' to relative.
+ */
+MAYAUSD_CORE_PUBLIC
+void updatePostponedRelativePaths(const PXR_NS::SdfLayerHandle& layer);
+
 /*! \brief returns the flag specifying whether USD file paths should be saved as relative to Maya
  * scene file
  */

test/lib/mayaUsd/fileio/testCacheToUsd.py

@@ -151,11 +151,13 @@ def setUp(self):
         import mayaUsd_createStageWithNewLayer
         self.proxyShapePathStr = mayaUsd_createStageWithNewLayer.createStageWithNewLayer()
         self.stage = mayaUsd.lib.GetPrim(self.proxyShapePathStr).GetStage()
-        self.stage.GetRootLayer().identifier = self.getRootLayerFileName()
 
     def tearDown(self):
         self.removeCacheFile()
 
+    def makeRootLayerNotAnonymous(self):
+        self.stage.GetRootLayer().identifier = self.getRootLayerFileName()
+
     def verifyCacheFileDefaultPrim(self, cacheFilename, defaultPrimName):
         layer = Sdf.Layer.FindOrOpen(cacheFilename)
         self.assertIsNotNone(layer)
@@ -309,27 +311,41 @@ def runTestCacheToUsd(self, createMayaRefPrimFn, checkCacheParentFn):
         #       - Due to the way layer caching works in OpenUSD, asking for
         #         the layer identifier returns the absolute path.
         if relativePath:
+            if self.stage.GetRootLayer().anonymous:
+                self.assertNotIn('payload = @testCacheToUsd.usda', self.stage.GetRootLayer().ExportToString())
+                self.assertRegexpMatches(self.stage.GetRootLayer().ExportToString(), 'payload = @.*testCacheToUsd.usda')
+                self.makeRootLayerNotAnonymous()
+                mayaUsd.lib.Util.updatePostponedRelativePaths(self.stage.GetRootLayer())
+
             self.assertIn('payload = @testCacheToUsd.usda', self.stage.GetRootLayer().ExportToString())
 
         self.verifyCacheFileDefaultPrim(cacheFile, cachePrimName)
 
     def testCacheToUsdSibling(self):
+        self.makeRootLayerNotAnonymous()
         self.runTestCacheToUsd(createMayaRefPrimSiblingCache, checkSiblingCacheParent)
 
     def testCacheToUsdSiblingWithRelativePath(self):
+        self.makeRootLayerNotAnonymous()
         self.runTestCacheToUsd(createMayaRefPrimSiblingCacheWithRelativePath, checkSiblingCacheParent)
 
     def testCacheToUsdVariant(self):
+        self.makeRootLayerNotAnonymous()
         self.runTestCacheToUsd(createMayaRefPrimVariantCache, checkVariantCacheParent)
 
     def testCacheToUsdVariantWithRelativePath(self):
+        self.makeRootLayerNotAnonymous()
+        self.runTestCacheToUsd(createMayaRefPrimVariantCacheWithRelativePath, checkVariantCacheParent)
+
+    def testCacheToUsdVariantWithRelativePathInAnonLayer(self):
         self.runTestCacheToUsd(createMayaRefPrimVariantCacheWithRelativePath, checkVariantCacheParent)
 
     def testAutoEditAndCache(self):
         '''Test editing then caching a Maya Reference.
 
         Add a Maya Reference using auto-edit, then cache the edits.
         '''
+        self.makeRootLayerNotAnonymous()
         kDefaultPrimName = mayaRefUtils.defaultMayaReferencePrimName()
 
         # Since this is a brand new prim, it should not have variant sets.
@@ -392,6 +408,7 @@ def testEditAndMergeRigMayaRef(self):
         In particular, the rig generates multiple translation xform on some
         prim, verify that we do get these multiple translations.
         '''
+        self.makeRootLayerNotAnonymous()
         kDefaultPrimName = mayaRefUtils.defaultMayaReferencePrimName()
 
         # Since this is a brand new prim, it should not have variant sets.
@@ -484,6 +501,7 @@ def runTestMayaRefPrimTransform(self, createMayaRefPrimFn, checkCacheParentFn):
 
         # Create a Maya reference prim using the defaults, under a
         # newly-created parent.
+        self.makeRootLayerNotAnonymous()
         cacheParent = self.stage.DefinePrim('/CacheParent', 'Xform')
         cacheParentPathStr = self.proxyShapePathStr + ',/CacheParent'
         self.assertFalse(cacheParent.HasVariantSets())
@@ -578,10 +596,12 @@ def runTestMayaRefPrimTransform(self, createMayaRefPrimFn, checkCacheParentFn):
 
     def testMayaRefPrimTransform(self):
         '''Test transforming the Maya Reference prim, editing it in Maya, then merging back the result.'''
+        self.makeRootLayerNotAnonymous()
         self.runTestMayaRefPrimTransform(createMayaRefPrimSiblingCache, checkSiblingCacheParent)
 
     def testMayaRefPrimTransformToVariant(self):
         '''Test transforming the Maya Reference prim, editing it in Maya, then merging back the result.'''
+        self.makeRootLayerNotAnonymous()
         self.runTestMayaRefPrimTransform(createMayaRefPrimVariantCache, checkVariantCacheParent)
 
 if __name__ == '__main__':