Merge pull request #1070 from aftersomemath:simulate-load-message

PiperOrigin-RevId: 568995214
Change-Id: Iac7644c4b35a916aa6a7d1bb158ba15a024b43ac

python/mujoco/simulate.cc

@@ -203,7 +203,11 @@ PYBIND11_MODULE(_simulate, pymodule) {
       }))
       .def("destroy", &SimulateWrapper::Destroy,
            py::call_guard<py::gil_scoped_release>())
+      .def("load_message", CallIfNotNull(&mujoco::Simulate::LoadMessage),
+           py::call_guard<py::gil_scoped_release>())
       .def("load", &SimulateWrapper::Load)
+      .def("load_message_clear", CallIfNotNull(&mujoco::Simulate::LoadMessageClear),
+           py::call_guard<py::gil_scoped_release>())
       .def("sync", CallIfNotNull(&mujoco::Simulate::Sync),
            py::call_guard<py::gil_scoped_release>())
 

python/mujoco/viewer.py

@@ -174,9 +174,11 @@ def _reload(
 ) -> Optional[Tuple[mujoco.MjModel, mujoco.MjData]]:
   """Internal function for reloading a model in the viewer."""
   try:
+    simulate.load_message('') # path is unknown at this point
     load_tuple = loader()
   except Exception as e:  # pylint: disable=broad-except
     simulate.load_error = str(e)
+    simulate.load_message_clear()
   else:
     m, d = load_tuple[:2]