MAYA-114695 Properly detect animated compound plug

lib/mayaUsd/fileio/utils/writeUtil.cpp

@@ -615,6 +615,24 @@ VtValue UsdMayaWriteUtil::GetVtValue(
     return VtValue();
 }
 
+namespace {
+bool _IsAnimated(const MPlug& p)
+{
+    if (p.isDestination()) {
+        return true;
+    }
+    if (p.isCompound()) {
+        const unsigned int numChildren = p.numChildren();
+        for (unsigned int i = 0; i < numChildren; ++i) {
+            if (_IsAnimated(p.child(i))) {
+                return true;
+            }
+        }
+    }
+    return false;
+}
+} // namespace
+
 bool UsdMayaWriteUtil::SetUsdAttr(
     const MPlug&               attrPlug,
     const UsdAttribute&        usdAttr,
@@ -625,8 +643,7 @@ bool UsdMayaWriteUtil::SetUsdAttr(
         return false;
     }
 
-    bool isAnimated = attrPlug.isDestination();
-    if (usdTime.IsDefault() == isAnimated) {
+    if (!(usdTime.IsDefault() || _IsAnimated(attrPlug))) {
         return true;
     }
 

test/lib/usd/translators/testUsdExportAnimation.py

@@ -62,4 +62,46 @@ def testExportStaticSingleSampleOn(self):
             prim = stage.GetPrimAtPath("/root")
             attr = prim.GetAttribute("xformOp:translate")
             num_samples = attr.GetNumTimeSamples()
-            self.assertEqual(num_samples, int(not state))
+            self.assertEqual(num_samples, int(not state))
+
+    def testExportAnimatedCompundValue(self):
+        """MayaUSD Issue #1712: Test that animated custom compound attributes
+           on a mesh are exported."""
+        cmds.file(new=True, force=True)
+        cubeShape = "MyCubeShape"
+        cmds.polyCube(name="MyCube")
+        cmds.addAttr(cubeShape, sn="tf2", ln="TestFloatTwo", at="float2")
+        cmds.addAttr(cubeShape, sn="tf2u", ln="TestFloatTwoU", at="float", p="TestFloatTwo")
+        cmds.addAttr(cubeShape, sn="tf2v", ln="TestFloatTwoV", at="float", p="TestFloatTwo")
+        cmds.setAttr(cubeShape + ".TestFloatTwoU", e=True, keyable=True)
+        cmds.setAttr(cubeShape + ".TestFloatTwoV", e=True, keyable=True)
+        cmds.setKeyframe(cubeShape, attribute="tf2")
+        cmds.currentTime(10)
+        cmds.setAttr(cubeShape + ".TestFloatTwoU", 20.0)
+        cmds.setAttr(cubeShape + ".TestFloatTwoV", 40.0)
+        cmds.setKeyframe(cubeShape, attribute="tf2")
+        cmds.addAttr(cubeShape, ci=True, sn="USD_UserExportedAttributesJson", ln="USD_UserExportedAttributesJson", dt="string")
+        cmds.setAttr(cubeShape + ".USD_UserExportedAttributesJson", '{"TestFloatTwo": {}}', type="string")
+
+        # Exporting with a time range results in time samples:
+        path = os.path.join(self.temp_dir, "animatedCompoundValue.usda")
+        cmds.mayaUSDExport(f=path, exportSkels="auto", frameRange=(1, 10), sss=True)
+
+        stage = Usd.Stage.Open(path)
+
+        prim = stage.GetPrimAtPath("/MyCube")
+        attr = prim.GetAttribute("userProperties:TestFloatTwo")
+        self.assertGreater(attr.GetNumTimeSamples(), 1)
+
+        # Exporting without time range results in a single authored value:
+        path = os.path.join(self.temp_dir, "animatedCompoundValueStatic.usda")
+        cmds.mayaUSDExport(f=path)
+
+        stage = Usd.Stage.Open(path)
+
+        prim = stage.GetPrimAtPath("/MyCube")
+        attr = prim.GetAttribute("userProperties:TestFloatTwo")
+        self.assertEqual(attr.GetNumTimeSamples(), 0)
+        # Make sure value is there because previous code did not write any:
+        self.assertEqual(attr.Get(), [20.0, 40.0])
+