Raises exceptions from initialization callbacks inside SimContext (#2166)

# Description


Handling exceptions when raised inside the initialization callbacks

Fixes #1025 

## Type of change

- Bug fix (non-breaking change which fixes an issue)


## Checklist

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./isaaclab.sh --format`
- [x] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] I have updated the changelog and the corresponding version in the
extension's `config/extension.toml` file
- [x] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there

---------
Signed-off-by: Kelly Guo <kellyguo123@hotmail.com>
Co-authored-by: Kelly Guo <kellyg@nvidia.com>

source/isaaclab/config/extension.toml

 [package]
 
 # Note: Semantic Versioning is used: https://semver.org/
-version = "0.39.6"
+version = "0.39.7"
 
 # Description
 title = "Isaac Lab framework for Robot Learning"

source/isaaclab/docs/CHANGELOG.rst

 Changelog
 ---------
 
+0.39.7 (2025-05-19)
+~~~~~~~~~~~~~~~~~~~
+
+Fixed
+^^^^^^
+
+* Raising exceptions in step, render and reset if they occurred inside the initialization callbacks
+  of assets and sensors.used from the experience files and the double definition is removed.
+
+
 0.39.6 (2025-01-30)
 ~~~~~~~~~~~~~~~~~~~
 

source/isaaclab/isaaclab/assets/asset_base.py

@@ -5,6 +5,7 @@
 
 from __future__ import annotations
 
+import builtins
 import inspect
 import re
 import torch
@@ -16,7 +17,7 @@ from typing import TYPE_CHECKING, Any
 import isaacsim.core.utils.prims as prim_utils
 import omni.kit.app
 import omni.timeline
-from isaacsim.core.simulation_manager import SimulationManager
+from isaacsim.core.simulation_manager import IsaacEvents, SimulationManager
 
 import isaaclab.sim as sim_utils
 
@@ -102,6 +103,9 @@ class AssetBase(ABC):
             lambda event, obj=weakref.proxy(self): obj._invalidate_initialize_callback(event),
             order=10,
         )
+        self._prim_deletion_callback_id = SimulationManager.register_callback(
+            self._on_prim_deletion, event=IsaacEvents.PRIM_DELETION
+        )
         # add handle for debug visualization (this is set to a valid handle inside set_debug_vis)
         self._debug_vis_handle = None
         # set initial state of debug visualization
@@ -109,17 +113,8 @@ class AssetBase(ABC):
 
     def __del__(self):
         """Unsubscribe from the callbacks."""
-        # clear physics events handles
-        if self._initialize_handle:
-            self._initialize_handle.unsubscribe()
-            self._initialize_handle = None
-        if self._invalidate_initialize_handle:
-            self._invalidate_initialize_handle.unsubscribe()
-            self._invalidate_initialize_handle = None
-        # clear debug visualization
-        if self._debug_vis_handle:
-            self._debug_vis_handle.unsubscribe()
-            self._debug_vis_handle = None
+        # clear events handles
+        self._clear_callbacks()
 
     """
     Properties
@@ -288,10 +283,15 @@ class AssetBase(ABC):
             called whenever the simulator "plays" from a "stop" state.
         """
         if not self._is_initialized:
+            # obtain simulation related information
             self._backend = SimulationManager.get_backend()
             self._device = SimulationManager.get_physics_sim_device()
             # initialize the asset
-            self._initialize_impl()
+            try:
+                self._initialize_impl()
+            except Exception as e:
+                if builtins.ISAACLAB_CALLBACK_EXCEPTION is None:
+                    builtins.ISAACLAB_CALLBACK_EXCEPTION = e
             # set flag
             self._is_initialized = True
 
@@ -301,3 +301,37 @@ class AssetBase(ABC):
         if self._debug_vis_handle is not None:
             self._debug_vis_handle.unsubscribe()
             self._debug_vis_handle = None
+
+    def _on_prim_deletion(self, prim_path: str) -> None:
+        """Invalidates and deletes the callbacks when the prim is deleted.
+
+        Args:
+            prim_path: The path to the prim that is being deleted.
+
+        Note:
+            This function is called when the prim is deleted.
+        """
+        if prim_path == "/":
+            self._clear_callbacks()
+            return
+        result = re.match(
+            pattern="^" + "/".join(self.cfg.prim_path.split("/")[: prim_path.count("/") + 1]) + "$", string=prim_path
+        )
+        if result:
+            self._clear_callbacks()
+
+    def _clear_callbacks(self) -> None:
+        """Clears the callbacks."""
+        if self._prim_deletion_callback_id:
+            SimulationManager.deregister_callback(self._prim_deletion_callback_id)
+            self._prim_deletion_callback_id = None
+        if self._initialize_handle:
+            self._initialize_handle.unsubscribe()
+            self._initialize_handle = None
+        if self._invalidate_initialize_handle:
+            self._invalidate_initialize_handle.unsubscribe()
+            self._invalidate_initialize_handle = None
+        # clear debug visualization
+        if self._debug_vis_handle:
+            self._debug_vis_handle.unsubscribe()
+            self._debug_vis_handle = None

source/isaaclab/isaaclab/assets/rigid_object_collection/rigid_object_collection.py

@@ -15,7 +15,7 @@ import omni.kit.app
 import omni.log
 import omni.physics.tensors.impl.api as physx
 import omni.timeline
-from isaacsim.core.simulation_manager import SimulationManager
+from isaacsim.core.simulation_manager import IsaacEvents, SimulationManager
 from pxr import UsdPhysics
 
 import isaaclab.sim as sim_utils
@@ -67,7 +67,7 @@ class RigidObjectCollection(AssetBase):
         self.cfg = cfg.copy()
         # flag for whether the asset is initialized
         self._is_initialized = False
-
+        self._prim_paths = []
         # spawn the rigid objects
         for rigid_object_cfg in self.cfg.rigid_objects.values():
             # check if the rigid object path is valid
@@ -88,7 +88,7 @@ class RigidObjectCollection(AssetBase):
             matching_prims = sim_utils.find_matching_prims(rigid_object_cfg.prim_path)
             if len(matching_prims) == 0:
                 raise RuntimeError(f"Could not find prim with path {rigid_object_cfg.prim_path}.")
-
+            self._prim_paths.append(rigid_object_cfg.prim_path)
         # stores object names
         self._object_names_list = []
 
@@ -106,7 +106,9 @@ class RigidObjectCollection(AssetBase):
             lambda event, obj=weakref.proxy(self): obj._invalidate_initialize_callback(event),
             order=10,
         )
-
+        self._prim_deletion_callback_id = SimulationManager.register_callback(
+            self._on_prim_deletion, event=IsaacEvents.PRIM_DELETION
+        )
         self._debug_vis_handle = None
 
     """
@@ -688,3 +690,23 @@ class RigidObjectCollection(AssetBase):
         super()._invalidate_initialize_callback(event)
         # set all existing views to None to invalidate them
         self._root_physx_view = None
+
+    def _on_prim_deletion(self, prim_path: str) -> None:
+        """Invalidates and deletes the callbacks when the prim is deleted.
+
+        Args:
+            prim_path: The path to the prim that is being deleted.
+
+        Note:
+            This function is called when the prim is deleted.
+        """
+        if prim_path == "/":
+            self._clear_callbacks()
+            return
+        for prim_path_expr in self._prim_paths:
+            result = re.match(
+                pattern="^" + "/".join(prim_path_expr.split("/")[: prim_path.count("/") + 1]) + "$", string=prim_path
+            )
+            if result:
+                self._clear_callbacks()
+                return

source/isaaclab/isaaclab/sensors/sensor_base.py

@@ -11,7 +11,9 @@ Each sensor class should inherit from this class and implement the abstract meth
 
 from __future__ import annotations
 
+import builtins
 import inspect
+import re
 import torch
 import weakref
 from abc import ABC, abstractmethod
@@ -20,6 +22,7 @@ from typing import TYPE_CHECKING, Any
 
 import omni.kit.app
 import omni.timeline
+from isaacsim.core.simulation_manager import IsaacEvents, SimulationManager
 
 import isaaclab.sim as sim_utils
 
@@ -71,6 +74,9 @@ class SensorBase(ABC):
             lambda event, obj=weakref.proxy(self): obj._invalidate_initialize_callback(event),
             order=10,
         )
+        self._prim_deletion_callback_id = SimulationManager.register_callback(
+            self._on_prim_deletion, event=IsaacEvents.PRIM_DELETION
+        )
         # add handle for debug visualization (this is set to a valid handle inside set_debug_vis)
         self._debug_vis_handle = None
         # set initial state of debug visualization
@@ -79,16 +85,7 @@ class SensorBase(ABC):
     def __del__(self):
         """Unsubscribe from the callbacks."""
         # clear physics events handles
-        if self._initialize_handle:
-            self._initialize_handle.unsubscribe()
-            self._initialize_handle = None
-        if self._invalidate_initialize_handle:
-            self._invalidate_initialize_handle.unsubscribe()
-            self._invalidate_initialize_handle = None
-        # clear debug visualization
-        if self._debug_vis_handle:
-            self._debug_vis_handle.unsubscribe()
-            self._debug_vis_handle = None
+        self._clear_callbacks()
 
     """
     Properties
@@ -270,7 +267,11 @@ class SensorBase(ABC):
             called whenever the simulator "plays" from a "stop" state.
         """
         if not self._is_initialized:
-            self._initialize_impl()
+            try:
+                self._initialize_impl()
+            except Exception as e:
+                if builtins.ISAACLAB_CALLBACK_EXCEPTION is None:
+                    builtins.ISAACLAB_CALLBACK_EXCEPTION = e
             self._is_initialized = True
 
     def _invalidate_initialize_callback(self, event):
@@ -280,6 +281,40 @@ class SensorBase(ABC):
             self._debug_vis_handle.unsubscribe()
             self._debug_vis_handle = None
 
+    def _on_prim_deletion(self, prim_path: str) -> None:
+        """Invalidates and deletes the callbacks when the prim is deleted.
+
+        Args:
+            prim_path: The path to the prim that is being deleted.
+
+        Note:
+            This function is called when the prim is deleted.
+        """
+        if prim_path == "/":
+            self._clear_callbacks()
+            return
+        result = re.match(
+            pattern="^" + "/".join(self.cfg.prim_path.split("/")[: prim_path.count("/") + 1]) + "$", string=prim_path
+        )
+        if result:
+            self._clear_callbacks()
+
+    def _clear_callbacks(self) -> None:
+        """Clears the callbacks."""
+        if self._prim_deletion_callback_id:
+            SimulationManager.deregister_callback(self._prim_deletion_callback_id)
+            self._prim_deletion_callback_id = None
+        if self._initialize_handle:
+            self._initialize_handle.unsubscribe()
+            self._initialize_handle = None
+        if self._invalidate_initialize_handle:
+            self._invalidate_initialize_handle.unsubscribe()
+            self._invalidate_initialize_handle = None
+        # clear debug visualization
+        if self._debug_vis_handle:
+            self._debug_vis_handle.unsubscribe()
+            self._debug_vis_handle = None
+
     """
     Helper functions.
     """

source/isaaclab/isaaclab/sim/simulation_context.py

@@ -211,7 +211,11 @@ class SimulationContext(_SimulationContext):
         #   you can reproduce the issue by commenting out this line and running the test `test_articulation.py`.
         self._gravity_tensor = torch.tensor(self.cfg.gravity, dtype=torch.float32, device=self.cfg.device)
 
-        # add a callback to keep rendering when a stop is triggered through different GUI commands like (save as)
+        # define a global variable to store the exceptions raised in the callback stack
+        builtins.ISAACLAB_CALLBACK_EXCEPTION = None
+
+        # add callback to deal the simulation app when simulation is stopped.
+        # this is needed because physics views go invalid once we stop the simulation
         if not builtins.ISAAC_LAUNCHED_FROM_TERMINAL:
             timeline_event_stream = omni.timeline.get_timeline_interface().get_timeline_event_stream()
             self._app_control_on_stop_handle = timeline_event_stream.create_subscription_to_pop_by_type(
@@ -513,6 +517,11 @@ class SimulationContext(_SimulationContext):
 
     def reset(self, soft: bool = False):
         self._disable_app_control_on_stop_handle = True
+        # check if we need to raise an exception that was raised in a callback
+        if builtins.ISAACLAB_CALLBACK_EXCEPTION is not None:
+            exception_to_raise = builtins.ISAACLAB_CALLBACK_EXCEPTION
+            builtins.ISAACLAB_CALLBACK_EXCEPTION = None
+            raise exception_to_raise
         super().reset(soft=soft)
         # app.update() may be changing the cuda device in reset, so we force it back to our desired device here
         if "cuda" in self.device:
@@ -537,6 +546,11 @@ class SimulationContext(_SimulationContext):
             render: Whether to render the scene after stepping the physics simulation.
                     If set to False, the scene is not rendered and only the physics simulation is stepped.
         """
+        # check if we need to raise an exception that was raised in a callback
+        if builtins.ISAACLAB_CALLBACK_EXCEPTION is not None:
+            exception_to_raise = builtins.ISAACLAB_CALLBACK_EXCEPTION
+            builtins.ISAACLAB_CALLBACK_EXCEPTION = None
+            raise exception_to_raise
         # check if the simulation timeline is paused. in that case keep stepping until it is playing
         if not self.is_playing():
             # step the simulator (but not the physics) to have UI still active
@@ -570,6 +584,11 @@ class SimulationContext(_SimulationContext):
         Args:
             mode: The rendering mode. Defaults to None, in which case the current rendering mode is used.
         """
+        # check if we need to raise an exception that was raised in a callback
+        if builtins.ISAACLAB_CALLBACK_EXCEPTION is not None:
+            exception_to_raise = builtins.ISAACLAB_CALLBACK_EXCEPTION
+            builtins.ISAACLAB_CALLBACK_EXCEPTION = None
+            raise exception_to_raise
         # check if we need to change the render mode
         if mode is not None:
             self.set_render_mode(mode)
@@ -840,3 +859,8 @@ def build_simulation_context(
         # Clear the stage
         sim.clear_all_callbacks()
         sim.clear_instance()
+        # check if we need to raise an exception that was raised in a callback
+        if builtins.ISAACLAB_CALLBACK_EXCEPTION is not None:
+            exception_to_raise = builtins.ISAACLAB_CALLBACK_EXCEPTION
+            builtins.ISAACLAB_CALLBACK_EXCEPTION = None
+            raise exception_to_raise

source/isaaclab/test/assets/test_articulation.py

@@ -609,9 +609,8 @@ def test_out_of_range_default_joint_pos(sim, num_articulations, device, add_grou
     assert ctypes.c_long.from_address(id(articulation)).value == 1
 
     # Play sim
-    sim.reset()
-    # Check if articulation is initialized
-    assert not articulation.is_initialized
+    with pytest.raises(ValueError):
+        sim.reset()
 
 
 @pytest.mark.parametrize("device", ["cuda:0", "cpu"])
@@ -633,9 +632,8 @@ def test_out_of_range_default_joint_vel(sim, device):
     assert ctypes.c_long.from_address(id(articulation)).value == 1
 
     # Play sim
-    sim.reset()
-    # Check if articulation is initialized
-    assert not articulation.is_initialized
+    with pytest.raises(ValueError):
+        sim.reset()
 
 
 @pytest.mark.parametrize("num_articulations", [1, 2])
@@ -1062,14 +1060,11 @@ def test_setting_velocity_limit_implicit(sim, num_articulations, device, vel_lim
         device=device,
     )
     # Play sim
-    sim.reset()
-
     if vel_limit_sim is not None and vel_limit is not None:
-        # Case 1: during initialization, the actuator will raise a ValueError and fail to
-        #  initialize when both these attributes are set.
-        # note: The Exception is not caught with self.assertRaises or try-except
-        assert len(articulation.actuators) == 0
+        with pytest.raises(ValueError):
+            sim.reset()
         return
+    sim.reset()
 
     # read the values set into the simulation
     physx_vel_limit = articulation.root_physx_view.get_dof_max_velocities().to(device)
@@ -1170,12 +1165,11 @@ def test_setting_effort_limit_implicit(sim, num_articulations, device, effort_li
         device=device,
     )
     # Play sim
-    sim.reset()
-
     if effort_limit_sim is not None and effort_limit is not None:
-        # during initialization, the actuator will raise a ValueError and fail to initialize
-        assert len(articulation.actuators) == 0
+        with pytest.raises(ValueError):
+            sim.reset()
         return
+    sim.reset()
 
     # obtain the physx effort limits
     physx_effort_limit = articulation.root_physx_view.get_dof_max_forces().to(device=device)
@@ -1610,9 +1604,8 @@ def test_body_incoming_joint_wrench_b_single_joint(sim, num_articulations, devic
             self.assertEqual(ctypes.c_long.from_address(id(articulation)).value, 1)
 
             # Play sim
-            sim.reset()
-            # Check if articulation is initialized
-            self.assertFalse(articulation._is_initialized)
+            with pytest.raises(RuntimeError):
+                sim.reset()
 
 
 if __name__ == "__main__":

source/isaaclab/test/assets/test_deformable_object.py

@@ -173,10 +173,8 @@ def test_initialization_on_device_cpu():
         assert ctypes.c_long.from_address(id(cube_object)).value == 1
 
         # Play sim
-        sim.reset()
-
-        # Check if object is initialized
-        assert not cube_object.is_initialized
+        with pytest.raises(RuntimeError):
+            sim.reset()
 
 
 @pytest.mark.parametrize("num_cubes", [1, 2])
@@ -214,10 +212,8 @@ def test_initialization_with_no_deformable_body(sim, num_cubes):
     assert ctypes.c_long.from_address(id(cube_object)).value == 1
 
     # Play sim
-    sim.reset()
-
-    # Check if object is initialized
-    assert not cube_object.is_initialized
+    with pytest.raises(RuntimeError):
+        sim.reset()
 
 
 @pytest.mark.parametrize("num_cubes", [1, 2])

source/isaaclab/test/assets/test_rigid_object.py

@@ -168,10 +168,8 @@ def test_initialization_with_no_rigid_body(num_cubes, device):
         assert ctypes.c_long.from_address(id(cube_object)).value == 1
 
         # Play sim
-        sim.reset()
-
-        # Check if object is initialized
-        assert not cube_object.is_initialized
+        with pytest.raises(RuntimeError):
+            sim.reset()
 
 
 @pytest.mark.parametrize("num_cubes", [1, 2])
@@ -187,10 +185,8 @@ def test_initialization_with_articulation_root(num_cubes, device):
         assert ctypes.c_long.from_address(id(cube_object)).value == 1
 
         # Play sim
-        sim.reset()
-
-        # Check if object is initialized
-        assert not cube_object.is_initialized
+        with pytest.raises(RuntimeError):
+            sim.reset()
 
 
 @pytest.mark.parametrize("device", ["cuda:0", "cpu"])

source/isaaclab/test/assets/test_rigid_object_collection.py

@@ -203,10 +203,8 @@ def test_initialization_with_no_rigid_body(sim, num_cubes, device):
     assert ctypes.c_long.from_address(id(object_collection)).value == 1
 
     # Play sim
-    sim.reset()
-
-    # Check if object is initialized
-    assert not object_collection.is_initialized
+    with pytest.raises(RuntimeError):
+        sim.reset()
 
 
 @pytest.mark.parametrize("device", ["cuda:0", "cpu"])

source/isaaclab_tasks/isaaclab_tasks/manager_based/manipulation/lift/config/franka/ik_abs_env_cfg.py

@@ -80,7 +80,7 @@ class FrankaTeddyBearLiftEnvCfg(FrankaCubeLiftEnvCfg):
         )
 
         # Make the end effector less stiff to not hurt the poor teddy bear
-        self.scene.robot.actuators["panda_hand"].effort_limit = 50.0
+        self.scene.robot.actuators["panda_hand"].effort_limit_sim = 50.0
         self.scene.robot.actuators["panda_hand"].stiffness = 40.0
         self.scene.robot.actuators["panda_hand"].damping = 10.0