Allowing a new prim spec to be written in edit target layers

lib/mayaUsd/ufe/Utils.cpp

@@ -82,7 +82,7 @@ uint32_t findLayerIndex(const UsdPrim& prim, const SdfLayerHandle& layer)
 {
     uint32_t position { 0 };
 
-    const PcpPrimIndex& primIndex = prim.GetPrimIndex();
+    const PcpPrimIndex& primIndex = prim.ComputeExpandedPrimIndex();
 
     // iterate through the expanded primIndex
     for (PcpNodeRef node : primIndex.GetNodeRange()) {

test/lib/ufe/testAttributeBlock.py

@@ -20,8 +20,9 @@
 import mayaUtils
 import ufeUtils
 import usdUtils
+import testUtils
 
-from pxr import UsdGeom, Vt, Gf
+from pxr import UsdGeom, Vt, Gf, Usd
 
 from maya import cmds
 from maya import standalone
@@ -348,5 +349,45 @@ def testAttributeBlocking3dMatrixOps(self):
         # authoring new transformation edit is allowed.
         self.assertTrue(mayaUsdUfe.isAttributeEditAllowed(transformAttr))
 
+    def testIsAttributeEditAllowed(self):
+        '''
+        Verify a edit target layer from a referenced prim can be allowed to edit if it's a stronger layer.
+        '''
+        rootLaerPath = testUtils.getTestScene("attributeBlock", "root.usda")
+        stage = Usd.Stage.Open(rootLaerPath)
+
+        primA = stage.GetPrimAtPath("/root/a")
+        self.assertTrue(primA.IsValid())
+        fooattrA = primA.GetAttribute("foo")
+        self.assertTrue(fooattrA.IsValid())
+
+        root = stage.GetPrimAtPath('/root')
+        targetLayer = None 
+
+        for layer in stage.GetUsedLayers():
+            if 'subBRef' in layer.identifier:
+                targetLayer = layer 
+                break 
+
+        self.assertIsNotNone(targetLayer)
+
+        editTarget = _getEditTarget(targetLayer, root)
+        self.assertIsNotNone(editTarget)
+        stage.SetEditTarget(editTarget)
+
+        self.assertEqual(fooattrA.Get(), 0.0)
+        self.assertTrue(mayaUsdUfe.isAttributeEditAllowed(fooattrA))
+        fooattrA.Set(10.0)
+        primspecA = targetLayer.GetObjectAtPath('/root/a.foo')
+        self.assertTrue(bool(primspecA))
+
+
+def _getEditTarget(layer, prim):
+    query = Usd.PrimCompositionQuery(prim)
+    for arc in query.GetCompositionArcs():
+        if (arc.GetTargetNode().layerStack.identifier.rootLayer == layer
+            and not arc.GetTargetNode().path.ContainsPrimVariantSelection()):
+            return Usd.EditTarget(layer, arc.GetTargetNode())
+
 if __name__ == '__main__':
     unittest.main(verbosity=2)

test/testSamples/attributeBlock/root.usda

@@ -0,0 +1,12 @@
+#usda 1.0
+(
+    defaultPrim = "root"
+    subLayers = [
+        @subB.usda@,
+        @subC.usda@,
+    ]
+)
+
+def "root"
+{
+}

test/testSamples/attributeBlock/subB.usda

@@ -0,0 +1,15 @@
+#usda 1.0
+(
+    defaultPrim = "root"
+    subLayers = [
+        @sublayerOfSubB.usda@,
+    ]
+
+)
+
+def "root" (
+    prepend references = @subBRef.usda@
+)
+{
+
+}

test/testSamples/attributeBlock/subBRef.usda

@@ -0,0 +1,12 @@
+#usda 1.0
+(
+    defaultPrim = "root"
+)
+def "root"
+{
+    over "b" 
+    {
+        float foo = 10.0
+    }
+
+}

test/testSamples/attributeBlock/subC.usda

@@ -0,0 +1,9 @@
+#usda 1.0
+(
+    defaultPrim = "root"
+)
+def "root" (
+    prepend references = @subCRef.usda@
+)
+{
+}

test/testSamples/attributeBlock/subCRef.usda

@@ -0,0 +1,16 @@
+#usda 1.0
+(
+    defaultPrim = "root"
+)
+def "root"
+{
+    def "a" 
+    {
+        float foo = 0.0
+    }
+
+    def "b" 
+    {
+        float foo = 0.0
+    }
+}

test/testSamples/attributeBlock/sublayerOfSubB.usda

@@ -0,0 +1,9 @@
+#usda 1.0
+(
+    defaultPrim = "root"
+)
+def "root"
+{
+
+
+}