Merge pull request #1844 from Autodesk/t_gamaj/MAYA-114374/no_parenting_to_instances

MAYA-114374 Prevent parenting under an instance

Author: Krystian Ligenza

lib/mayaUsd/ufe/UsdUndoInsertChildCommand.cpp

@@ -76,6 +76,15 @@ UsdUndoInsertChildCommand::UsdUndoInsertChildCommand(
         throw std::runtime_error(err.c_str());
     }
 
+    // Reparenting directly under an instance prim is disallowed
+    if (parentPrim.IsInstance()) {
+        std::string err = TfStringPrintf(
+            "Parenting geometric prim [%s] under instance prim [%s] is not allowed.",
+            childPrim.GetName().GetString().c_str(),
+            parentPrim.GetName().GetString().c_str());
+        throw std::runtime_error(err.c_str());
+    }
+
     // Apply restriction rules
     ufe::applyCommandRestriction(childPrim, "reparent");
     ufe::applyCommandRestriction(parentPrim, "reparent");
@@ -115,6 +124,7 @@ UsdUndoInsertChildCommand::Ptr UsdUndoInsertChildCommand::create(
     if (parent->path().startsWith(child->path())) {
         return nullptr;
     }
+
     return std::make_shared<MakeSharedEnabler<UsdUndoInsertChildCommand>>(parent, child, pos);
 }
 

test/lib/ufe/testParentCmd.py

@@ -939,6 +939,15 @@ def testAlreadyChild(self):
             self.assertIn("pSphere1", childrenNames(children))
             self.assertIn("pCylinderShape1", childrenNames(children))
 
+    def testIllegalInstance(self):
+        '''Parenting an object to an instance must report an error.'''
+
+        with OpenFileCtx("simpleHierarchy.ma"):
+            with self.assertRaises(RuntimeError):
+                cmds.parent(
+                    "|mayaUsdProxy1|mayaUsdProxyShape1,/hierarchy_instance2",
+                    "|mayaUsdProxy1|mayaUsdProxyShape1,/hierarchy_instance1")
+
     def testUnparentUSD(self):
         '''Unparent USD node.'''
 

test/testSamples/parentCmd/simpleHierarchy.usda

@@ -109,3 +109,23 @@ def Xform "pCylinder1" (
     }
 }
 
+def "hierarchy_instance1" (
+    instanceable = true
+    kind = "component"
+    prepend references = </pCylinder1>
+)
+{
+    double3 xformOp:translate = (9.056107292292669, -3, 0)
+    uniform token[] xformOpOrder = ["xformOp:translate"]
+}
+
+def "hierarchy_instance2" (
+    instanceable = true
+    kind = "component"
+    prepend references = </pCylinder1>
+)
+{
+    double3 xformOp:translate = (9.056107292292669, -6, 0)
+    uniform token[] xformOpOrder = ["xformOp:translate"]
+}
+