Adds support for Stage in Memory (#375)

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Support using a stage in memory, rather the default stage attached to a
usd context, for faster operations during stage initialization and
cloning.

The feature requires a change on Isaac Sim which is tracked separately.

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- New feature (non-breaking change which adds functionality)

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- [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
- [ ] 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

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---------
Signed-off-by: Kelly Guo <kellyguo123@hotmail.com>
Signed-off-by: rwiltz <165190220+rwiltz@users.noreply.github.com>
Signed-off-by: Ashwin Varghese Kuruttukulam <123109010+ashwinvkNV@users.noreply.github.com>
Signed-off-by: Kelly Guo <kellyg@nvidia.com>
Signed-off-by: Michael Gussert <michael@gussert.com>
Co-authored-by: peterd-NV <peterd@nvidia.com>
Co-authored-by: Kelly Guo <kellyg@nvidia.com>
Co-authored-by: cosmith-nvidia <141183495+cosmith-nvidia@users.noreply.github.com>
Co-authored-by: jaczhangnv <jaczhang@nvidia.com>
Co-authored-by: rwiltz <165190220+rwiltz@users.noreply.github.com>
Co-authored-by: Yanzi Zhu <yanziz@nvidia.com>
Co-authored-by: nv-mhaselton <mhaselton@nvidia.com>
Co-authored-by: CY Chen <cyc@nvidia.com>
Co-authored-by: oahmednv <oahmed@Nvidia.com>
Co-authored-by: Ashwin Varghese Kuruttukulam <123109010+ashwinvkNV@users.noreply.github.com>
Co-authored-by: Rafael Wiltz <rwiltz@nvidia.com>
Co-authored-by: Michael Gussert <michael@gussert.com>
Co-authored-by: Kelly Guo <kellyguo123@hotmail.com>
Co-authored-by: chengronglai <chengrongl@nvidia.com>
Co-authored-by: pulkitg01 <pulkitg@nvidia.com>
Co-authored-by: Connor Smith <cosmith@nvidia.com>
Co-authored-by: Ashwin Varghese Kuruttukulam <ashwinvk@nvidia.com>
Co-authored-by: lotusl-code <lotusl@nvidia.com>

scripts/demos/h1_locomotion.py

@@ -45,6 +45,7 @@ import torch
 
 import carb
 import omni
+from isaacsim.core.utils.stage import get_current_stage
 from omni.kit.viewport.utility import get_viewport_from_window_name
 from omni.kit.viewport.utility.camera_state import ViewportCameraState
 from pxr import Gf, Sdf
@@ -110,7 +111,7 @@ class H1RoughDemo:
 
     def create_camera(self):
         """Creates a camera to be used for third-person view."""
-        stage = omni.usd.get_context().get_stage()
+        stage = get_current_stage()
         self.viewport = get_viewport_from_window_name("Viewport")
         # Create camera
         self.camera_path = "/World/Camera"

scripts/demos/multi_asset.py

@@ -19,6 +19,8 @@ from __future__ import annotations
 
 import argparse
 
+from isaacsim.core.utils.stage import get_current_stage
+
 from isaaclab.app import AppLauncher
 
 # add argparse arguments
@@ -37,7 +39,6 @@ simulation_app = app_launcher.app
 
 import random
 
-import omni.usd
 from pxr import Gf, Sdf
 
 import isaaclab.sim as sim_utils
@@ -69,8 +70,8 @@ from isaaclab_assets.robots.anymal import ANYDRIVE_3_LSTM_ACTUATOR_CFG  # isort:
 
 def randomize_shape_color(prim_path_expr: str):
     """Randomize the color of the geometry."""
-    # acquire stage
-    stage = omni.usd.get_context().get_stage()
+    # get stage handle
+    stage = get_current_stage()
     # resolve prim paths for spawning and cloning
     prim_paths = sim_utils.find_matching_prim_paths(prim_path_expr)
     # manually clone prims if the source prim path is a regex expression

scripts/imitation_learning/robomimic/robust_eval.py

+# Copyright (c) 2022-2025, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
 # Copyright (c) 2022-2025, The Isaac Lab Project Developers.
 # All rights reserved.
 #

scripts/tools/check_instanceable.py

@@ -68,6 +68,7 @@ import isaacsim.core.utils.prims as prim_utils
 from isaacsim.core.api.simulation_context import SimulationContext
 from isaacsim.core.cloner import GridCloner
 from isaacsim.core.utils.carb import set_carb_setting
+from isaacsim.core.utils.stage import get_current_stage
 
 from isaaclab.utils import Timer
 from isaaclab.utils.assets import check_file_path
@@ -82,6 +83,10 @@ def main():
     sim = SimulationContext(
         stage_units_in_meters=1.0, physics_dt=0.01, rendering_dt=0.01, backend="torch", device="cuda:0"
     )
+
+    # get stage handle
+    stage = get_current_stage()
+
     # enable fabric which avoids passing data over to USD structure
     # this speeds up the read-write operation of GPU buffers
     if sim.get_physics_context().use_gpu_pipeline:
@@ -94,7 +99,7 @@ def main():
     set_carb_setting(sim._settings, "/persistent/omnihydra/useSceneGraphInstancing", True)
 
     # Create interface to clone the scene
-    cloner = GridCloner(spacing=args_cli.spacing)
+    cloner = GridCloner(spacing=args_cli.spacing, stage=stage)
     cloner.define_base_env("/World/envs")
     prim_utils.define_prim("/World/envs/env_0")
     # Spawn things into stage

scripts/tools/cosmos/cosmos_prompt_gen.py

+# Copyright (c) 2022-2025, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
 # Copyright (c) 2024-2025, The Isaac Lab Project Developers.
 # All rights reserved.
 #

scripts/tools/hdf5_to_mp4.py

+# Copyright (c) 2022-2025, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
 # Copyright (c) 2024-2025, The Isaac Lab Project Developers.
 # All rights reserved.
 #

scripts/tools/mp4_to_hdf5.py

+# Copyright (c) 2022-2025, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
 # Copyright (c) 2024-2025, The Isaac Lab Project Developers.
 # All rights reserved.
 #

scripts/tools/test/test_cosmos_prompt_gen.py

+# Copyright (c) 2022-2025, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
 # Copyright (c) 2024-2025, The Isaac Lab Project Developers.
 # All rights reserved.
 #

scripts/tools/test/test_hdf5_to_mp4.py

+# Copyright (c) 2022-2025, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
 # Copyright (c) 2024-2025, The Isaac Lab Project Developers.
 # All rights reserved.
 #

scripts/tools/test/test_mp4_to_hdf5.py

+# Copyright (c) 2022-2025, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
 # Copyright (c) 2024-2025, The Isaac Lab Project Developers.
 # All rights reserved.
 #

scripts/tutorials/01_assets/add_new_robot.py

@@ -24,11 +24,14 @@ simulation_app = app_launcher.app
 import numpy as np
 import torch
 
+import isaacsim.core.utils.stage as stage_utils
+
 import isaaclab.sim as sim_utils
 from isaaclab.actuators import ImplicitActuatorCfg
 from isaaclab.assets import AssetBaseCfg
 from isaaclab.assets.articulation import ArticulationCfg
 from isaaclab.scene import InteractiveScene, InteractiveSceneCfg
+from isaaclab.sim.utils import attach_stage_to_usd_context
 from isaaclab.utils.assets import ISAAC_NUCLEUS_DIR
 
 JETBOT_CONFIG = ArticulationCfg(
@@ -160,13 +163,16 @@ def run_simulator(sim: sim_utils.SimulationContext, scene: InteractiveScene):
 def main():
     """Main function."""
     # Initialize the simulation context
-    sim_cfg = sim_utils.SimulationCfg(device=args_cli.device)
+    sim_cfg = sim_utils.SimulationCfg(device=args_cli.device, create_stage_in_memory=True)
     sim = sim_utils.SimulationContext(sim_cfg)
 
     sim.set_camera_view([3.5, 0.0, 3.2], [0.0, 0.0, 0.5])
-    # design scene
+    # Design scene
     scene_cfg = NewRobotsSceneCfg(args_cli.num_envs, env_spacing=2.0)
-    scene = InteractiveScene(scene_cfg)
+    # Create scene with stage in memory and then attach to USD context
+    with stage_utils.use_stage(sim.get_initial_stage()):
+        scene = InteractiveScene(scene_cfg)
+        attach_stage_to_usd_context()
     # Play the simulator
     sim.reset()
     # Now we are ready!

scripts/tutorials/01_assets/run_articulation.py

@@ -35,10 +35,12 @@ simulation_app = app_launcher.app
 import torch
 
 import isaacsim.core.utils.prims as prim_utils
+import isaacsim.core.utils.stage as stage_utils
 
 import isaaclab.sim as sim_utils
 from isaaclab.assets import Articulation
 from isaaclab.sim import SimulationContext
+from isaaclab.sim.utils import attach_stage_to_usd_context
 
 ##
 # Pre-defined configs
@@ -121,12 +123,14 @@ def run_simulator(sim: sim_utils.SimulationContext, entities: dict[str, Articula
 def main():
     """Main function."""
     # Load kit helper
-    sim_cfg = sim_utils.SimulationCfg(device=args_cli.device)
+    sim_cfg = sim_utils.SimulationCfg(device=args_cli.device, create_stage_in_memory=True)
     sim = SimulationContext(sim_cfg)
     # Set main camera
     sim.set_camera_view([2.5, 0.0, 4.0], [0.0, 0.0, 2.0])
-    # Design scene
-    scene_entities, scene_origins = design_scene()
+    # Create scene with stage in memory and then attach to USD context
+    with stage_utils.use_stage(sim.get_initial_stage()):
+        scene_entities, scene_origins = design_scene()
+        attach_stage_to_usd_context()
     scene_origins = torch.tensor(scene_origins, device=sim.device)
     # Play the simulator
     sim.reset()

scripts/tutorials/01_assets/run_deformable_object.py

@@ -36,11 +36,13 @@ simulation_app = app_launcher.app
 import torch
 
 import isaacsim.core.utils.prims as prim_utils
+import isaacsim.core.utils.stage as stage_utils
 
 import isaaclab.sim as sim_utils
 import isaaclab.utils.math as math_utils
 from isaaclab.assets import DeformableObject, DeformableObjectCfg
 from isaaclab.sim import SimulationContext
+from isaaclab.sim.utils import attach_stage_to_usd_context
 
 
 def design_scene():
@@ -146,12 +148,14 @@ def run_simulator(sim: sim_utils.SimulationContext, entities: dict[str, Deformab
 def main():
     """Main function."""
     # Load kit helper
-    sim_cfg = sim_utils.SimulationCfg(device=args_cli.device)
+    sim_cfg = sim_utils.SimulationCfg(device=args_cli.device, create_stage_in_memory=True)
     sim = SimulationContext(sim_cfg)
     # Set main camera
     sim.set_camera_view(eye=[3.0, 0.0, 1.0], target=[0.0, 0.0, 0.5])
-    # Design scene
-    scene_entities, scene_origins = design_scene()
+    # Create scene with stage in memory and then attach to USD context
+    with stage_utils.use_stage(sim.get_initial_stage()):
+        scene_entities, scene_origins = design_scene()
+        attach_stage_to_usd_context()
     scene_origins = torch.tensor(scene_origins, device=sim.device)
     # Play the simulator
     sim.reset()

scripts/tutorials/01_assets/run_rigid_object.py

@@ -36,11 +36,13 @@ simulation_app = app_launcher.app
 import torch
 
 import isaacsim.core.utils.prims as prim_utils
+import isaacsim.core.utils.stage as stage_utils
 
 import isaaclab.sim as sim_utils
 import isaaclab.utils.math as math_utils
 from isaaclab.assets import RigidObject, RigidObjectCfg
 from isaaclab.sim import SimulationContext
+from isaaclab.sim.utils import attach_stage_to_usd_context
 
 
 def design_scene():
@@ -126,12 +128,14 @@ def run_simulator(sim: sim_utils.SimulationContext, entities: dict[str, RigidObj
 def main():
     """Main function."""
     # Load kit helper
-    sim_cfg = sim_utils.SimulationCfg(device=args_cli.device)
+    sim_cfg = sim_utils.SimulationCfg(device=args_cli.device, create_stage_in_memory=True)
     sim = SimulationContext(sim_cfg)
     # Set main camera
     sim.set_camera_view(eye=[1.5, 0.0, 1.0], target=[0.0, 0.0, 0.0])
-    # Design scene
-    scene_entities, scene_origins = design_scene()
+    # Create scene with stage in memory and then attach to USD context
+    with stage_utils.use_stage(sim.get_initial_stage()):
+        scene_entities, scene_origins = design_scene()
+        attach_stage_to_usd_context()
     scene_origins = torch.tensor(scene_origins, device=sim.device)
     # Play the simulator
     sim.reset()

scripts/tutorials/02_scene/create_scene.py

@@ -35,10 +35,13 @@ simulation_app = app_launcher.app
 
 import torch
 
+import isaacsim.core.utils.stage as stage_utils
+
 import isaaclab.sim as sim_utils
 from isaaclab.assets import ArticulationCfg, AssetBaseCfg
 from isaaclab.scene import InteractiveScene, InteractiveSceneCfg
 from isaaclab.sim import SimulationContext
+from isaaclab.sim.utils import attach_stage_to_usd_context
 from isaaclab.utils import configclass
 
 ##
@@ -110,13 +113,16 @@ def run_simulator(sim: sim_utils.SimulationContext, scene: InteractiveScene):
 def main():
     """Main function."""
     # Load kit helper
-    sim_cfg = sim_utils.SimulationCfg(device=args_cli.device)
+    sim_cfg = sim_utils.SimulationCfg(device=args_cli.device, create_stage_in_memory=True)
     sim = SimulationContext(sim_cfg)
     # Set main camera
     sim.set_camera_view([2.5, 0.0, 4.0], [0.0, 0.0, 2.0])
     # Design scene
     scene_cfg = CartpoleSceneCfg(num_envs=args_cli.num_envs, env_spacing=2.0)
-    scene = InteractiveScene(scene_cfg)
+    # Create scene with stage in memory and then attach to USD context
+    with stage_utils.use_stage(sim.get_initial_stage()):
+        scene = InteractiveScene(scene_cfg)
+        attach_stage_to_usd_context()
     # Play the simulator
     sim.reset()
     # Now we are ready!

scripts/tutorials/03_envs/create_cartpole_base_env.py

@@ -141,6 +141,7 @@ def main():
     env_cfg = CartpoleEnvCfg()
     env_cfg.scene.num_envs = args_cli.num_envs
     env_cfg.sim.device = args_cli.device
+    env_cfg.sim.create_stage_in_memory = True
     # setup base environment
     env = ManagerBasedEnv(cfg=env_cfg)
 

scripts/tutorials/03_envs/create_cube_base_env.py

@@ -314,7 +314,9 @@ def main():
     """Main function."""
 
     # setup base environment
-    env = ManagerBasedEnv(cfg=CubeEnvCfg())
+    env_cfg = CubeEnvCfg()
+    env_cfg.sim.create_stage_in_memory = True
+    env = ManagerBasedEnv(cfg=env_cfg)
 
     # setup target position commands
     target_position = torch.rand(env.num_envs, 3, device=env.device) * 2

scripts/tutorials/03_envs/create_quadruped_base_env.py

@@ -205,6 +205,7 @@ def main():
     """Main function."""
     # setup base environment
     env_cfg = QuadrupedEnvCfg()
+    env_cfg.sim.create_stage_in_memory = True
     env = ManagerBasedEnv(cfg=env_cfg)
 
     # load level policy

scripts/tutorials/03_envs/policy_inference_in_usd.py

@@ -70,6 +70,7 @@ def main():
     env_cfg.sim.device = args_cli.device
     if args_cli.device == "cpu":
         env_cfg.sim.use_fabric = False
+    env_cfg.sim.create_stage_in_memory = True
 
     # create environment
     env = ManagerBasedRLEnv(cfg=env_cfg)

scripts/tutorials/03_envs/run_cartpole_rl_env.py

@@ -46,6 +46,7 @@ def main():
     env_cfg = CartpoleEnvCfg()
     env_cfg.scene.num_envs = args_cli.num_envs
     env_cfg.sim.device = args_cli.device
+    env_cfg.sim.create_stage_in_memory = True
     # setup RL environment
     env = ManagerBasedRLEnv(cfg=env_cfg)
 

scripts/tutorials/04_sensors/add_sensors_on_robot.py

@@ -41,10 +41,13 @@ simulation_app = app_launcher.app
 
 import torch
 
+import isaacsim.core.utils.stage as stage_utils
+
 import isaaclab.sim as sim_utils
 from isaaclab.assets import ArticulationCfg, AssetBaseCfg
 from isaaclab.scene import InteractiveScene, InteractiveSceneCfg
 from isaaclab.sensors import CameraCfg, ContactSensorCfg, RayCasterCfg, patterns
+from isaaclab.sim.utils import attach_stage_to_usd_context
 from isaaclab.utils import configclass
 
 ##
@@ -157,13 +160,16 @@ def main():
     """Main function."""
 
     # Initialize the simulation context
-    sim_cfg = sim_utils.SimulationCfg(dt=0.005, device=args_cli.device)
+    sim_cfg = sim_utils.SimulationCfg(dt=0.005, device=args_cli.device, create_stage_in_memory=True)
     sim = sim_utils.SimulationContext(sim_cfg)
     # Set main camera
     sim.set_camera_view(eye=[3.5, 3.5, 3.5], target=[0.0, 0.0, 0.0])
-    # design scene
+    # Design scene
     scene_cfg = SensorsSceneCfg(num_envs=args_cli.num_envs, env_spacing=2.0)
-    scene = InteractiveScene(scene_cfg)
+    # Create scene with stage in memory and then attach to USD context
+    with stage_utils.use_stage(sim.get_initial_stage()):
+        scene = InteractiveScene(scene_cfg)
+        attach_stage_to_usd_context()
     # Play the simulator
     sim.reset()
     # Now we are ready!

scripts/tutorials/04_sensors/run_frame_transformer.py

@@ -35,6 +35,7 @@ simulation_app = app_launcher.app
 import math
 import torch
 
+import isaacsim.core.utils.stage as stage_utils
 import isaacsim.util.debug_draw._debug_draw as omni_debug_draw
 
 import isaaclab.sim as sim_utils
@@ -44,6 +45,7 @@ from isaaclab.markers import VisualizationMarkers
 from isaaclab.markers.config import FRAME_MARKER_CFG
 from isaaclab.sensors import FrameTransformer, FrameTransformerCfg, OffsetCfg
 from isaaclab.sim import SimulationContext
+from isaaclab.sim.utils import attach_stage_to_usd_context
 
 ##
 # Pre-defined configs
@@ -164,12 +166,14 @@ def run_simulator(sim: sim_utils.SimulationContext, scene_entities: dict):
 def main():
     """Main function."""
     # Load kit helper
-    sim_cfg = sim_utils.SimulationCfg(dt=0.005, device=args_cli.device)
+    sim_cfg = sim_utils.SimulationCfg(dt=0.005, device=args_cli.device, create_stage_in_memory=True)
     sim = SimulationContext(sim_cfg)
     # Set main camera
     sim.set_camera_view(eye=[2.5, 2.5, 2.5], target=[0.0, 0.0, 0.0])
-    # Design the scene
-    scene_entities = design_scene()
+    # Create scene with stage in memory and then attach to USD context
+    with stage_utils.use_stage(sim.get_initial_stage()):
+        scene_entities = design_scene()
+        attach_stage_to_usd_context()
     # Play the simulator
     sim.reset()
     # Now we are ready!

scripts/tutorials/04_sensors/run_ray_caster.py

@@ -34,10 +34,12 @@ simulation_app = app_launcher.app
 import torch
 
 import isaacsim.core.utils.prims as prim_utils
+import isaacsim.core.utils.stage as stage_utils
 
 import isaaclab.sim as sim_utils
 from isaaclab.assets import RigidObject, RigidObjectCfg
 from isaaclab.sensors.ray_caster import RayCaster, RayCasterCfg, patterns
+from isaaclab.sim.utils import attach_stage_to_usd_context
 from isaaclab.utils.assets import ISAAC_NUCLEUS_DIR
 from isaaclab.utils.timer import Timer
 
@@ -130,12 +132,14 @@ def run_simulator(sim: sim_utils.SimulationContext, scene_entities: dict):
 def main():
     """Main function."""
     # Load simulation context
-    sim_cfg = sim_utils.SimulationCfg(device=args_cli.device)
+    sim_cfg = sim_utils.SimulationCfg(device=args_cli.device, create_stage_in_memory=True)
     sim = sim_utils.SimulationContext(sim_cfg)
     # Set main camera
     sim.set_camera_view([0.0, 15.0, 15.0], [0.0, 0.0, -2.5])
-    # Design the scene
-    scene_entities = design_scene()
+    # Create scene with stage in memory and then attach to USD context
+    with stage_utils.use_stage(sim.get_initial_stage()):
+        scene_entities = design_scene()
+        attach_stage_to_usd_context()
     # Play simulator
     sim.reset()
     # Now we are ready!

scripts/tutorials/04_sensors/run_ray_caster_camera.py

@@ -39,10 +39,12 @@ import os
 import torch
 
 import isaacsim.core.utils.prims as prim_utils
+import isaacsim.core.utils.stage as stage_utils
 import omni.replicator.core as rep
 
 import isaaclab.sim as sim_utils
 from isaaclab.sensors.ray_caster import RayCasterCamera, RayCasterCameraCfg, patterns
+from isaaclab.sim.utils import attach_stage_to_usd_context
 from isaaclab.utils import convert_dict_to_backend
 from isaaclab.utils.assets import ISAAC_NUCLEUS_DIR
 from isaaclab.utils.math import project_points, unproject_depth
@@ -163,11 +165,14 @@ def run_simulator(sim: sim_utils.SimulationContext, scene_entities: dict):
 def main():
     """Main function."""
     # Load kit helper
-    sim = sim_utils.SimulationContext()
+    sim_cfg = sim_utils.SimulationCfg(create_stage_in_memory=True)
+    sim = sim_utils.SimulationContext(sim_cfg)
     # Set main camera
     sim.set_camera_view([2.5, 2.5, 3.5], [0.0, 0.0, 0.0])
-    # design the scene
-    scene_entities = design_scene()
+    # Create scene with stage in memory and then attach to USD context
+    with stage_utils.use_stage(sim.get_initial_stage()):
+        scene_entities = design_scene()
+        attach_stage_to_usd_context()
     # Play simulator
     sim.reset()
     # Now we are ready!

scripts/tutorials/04_sensors/run_usd_camera.py

@@ -66,6 +66,7 @@ import random
 import torch
 
 import isaacsim.core.utils.prims as prim_utils
+import isaacsim.core.utils.stage as stage_utils
 import omni.replicator.core as rep
 
 import isaaclab.sim as sim_utils
@@ -74,6 +75,7 @@ from isaaclab.markers import VisualizationMarkers
 from isaaclab.markers.config import RAY_CASTER_MARKER_CFG
 from isaaclab.sensors.camera import Camera, CameraCfg
 from isaaclab.sensors.camera.utils import create_pointcloud_from_depth
+from isaaclab.sim.utils import attach_stage_to_usd_context
 from isaaclab.utils import convert_dict_to_backend
 
 
@@ -268,12 +270,14 @@ def run_simulator(sim: sim_utils.SimulationContext, scene_entities: dict):
 def main():
     """Main function."""
     # Load simulation context
-    sim_cfg = sim_utils.SimulationCfg(device=args_cli.device)
+    sim_cfg = sim_utils.SimulationCfg(device=args_cli.device, create_stage_in_memory=True)
     sim = sim_utils.SimulationContext(sim_cfg)
     # Set main camera
     sim.set_camera_view([2.5, 2.5, 2.5], [0.0, 0.0, 0.0])
-    # design the scene
-    scene_entities = design_scene()
+    # Create scene with stage in memory and then attach to USD context
+    with stage_utils.use_stage(sim.get_initial_stage()):
+        scene_entities = design_scene()
+        attach_stage_to_usd_context()
     # Play simulator
     sim.reset()
     # Now we are ready!

scripts/tutorials/05_controllers/run_diff_ik.py

@@ -39,6 +39,8 @@ simulation_app = app_launcher.app
 
 import torch
 
+import isaacsim.core.utils.stage as stage_utils
+
 import isaaclab.sim as sim_utils
 from isaaclab.assets import AssetBaseCfg
 from isaaclab.controllers import DifferentialIKController, DifferentialIKControllerCfg
@@ -46,6 +48,7 @@ from isaaclab.managers import SceneEntityCfg
 from isaaclab.markers import VisualizationMarkers
 from isaaclab.markers.config import FRAME_MARKER_CFG
 from isaaclab.scene import InteractiveScene, InteractiveSceneCfg
+from isaaclab.sim.utils import attach_stage_to_usd_context
 from isaaclab.utils import configclass
 from isaaclab.utils.assets import ISAAC_NUCLEUS_DIR
 from isaaclab.utils.math import subtract_frame_transforms
@@ -190,13 +193,16 @@ def run_simulator(sim: sim_utils.SimulationContext, scene: InteractiveScene):
 def main():
     """Main function."""
     # Load kit helper
-    sim_cfg = sim_utils.SimulationCfg(dt=0.01, device=args_cli.device)
+    sim_cfg = sim_utils.SimulationCfg(dt=0.01, device=args_cli.device, create_stage_in_memory=True)
     sim = sim_utils.SimulationContext(sim_cfg)
     # Set main camera
     sim.set_camera_view([2.5, 2.5, 2.5], [0.0, 0.0, 0.0])
     # Design scene
     scene_cfg = TableTopSceneCfg(num_envs=args_cli.num_envs, env_spacing=2.0)
-    scene = InteractiveScene(scene_cfg)
+    # Create scene with stage in memory and then attach to USD context
+    with stage_utils.use_stage(sim.get_initial_stage()):
+        scene = InteractiveScene(scene_cfg)
+        attach_stage_to_usd_context()
     # Play the simulator
     sim.reset()
     # Now we are ready!

scripts/tutorials/05_controllers/run_osc.py

@@ -38,6 +38,8 @@ simulation_app = app_launcher.app
 
 import torch
 
+import isaacsim.core.utils.stage as stage_utils
+
 import isaaclab.sim as sim_utils
 from isaaclab.assets import Articulation, AssetBaseCfg
 from isaaclab.controllers import OperationalSpaceController, OperationalSpaceControllerCfg
@@ -45,6 +47,7 @@ from isaaclab.markers import VisualizationMarkers
 from isaaclab.markers.config import FRAME_MARKER_CFG
 from isaaclab.scene import InteractiveScene, InteractiveSceneCfg
 from isaaclab.sensors import ContactSensorCfg
+from isaaclab.sim.utils import attach_stage_to_usd_context
 from isaaclab.utils import configclass
 from isaaclab.utils.math import (
     combine_frame_transforms,
@@ -462,13 +465,16 @@ def convert_to_task_frame(osc: OperationalSpaceController, command: torch.tensor
 def main():
     """Main function."""
     # Load kit helper
-    sim_cfg = sim_utils.SimulationCfg(dt=0.01, device=args_cli.device)
+    sim_cfg = sim_utils.SimulationCfg(dt=0.01, device=args_cli.device, create_stage_in_memory=True)
     sim = sim_utils.SimulationContext(sim_cfg)
     # Set main camera
     sim.set_camera_view([2.5, 2.5, 2.5], [0.0, 0.0, 0.0])
     # Design scene
     scene_cfg = SceneCfg(num_envs=args_cli.num_envs, env_spacing=2.0)
-    scene = InteractiveScene(scene_cfg)
+    # Create scene with stage in memory and then attach to USD context
+    with stage_utils.use_stage(sim.get_initial_stage()):
+        scene = InteractiveScene(scene_cfg)
+        attach_stage_to_usd_context()
     # Play the simulator
     sim.reset()
     # Now we are ready!

source/isaaclab/config/extension.toml

 [package]
 
 # Note: Semantic Versioning is used: https://semver.org/
-version = "0.41.21"
+version = "0.42.21"
 
 # Description
 title = "Isaac Lab framework for Robot Learning"

source/isaaclab/docs/CHANGELOG.rst

 Changelog
 ---------
 
-0.41.21 (2025-06-25)
+0.42.21 (2025-06-25)
 ~~~~~~~~~~~~~~~~~~~~
 
 Added
@@ -12,7 +12,7 @@ Added
   env instance
 
 
-0.41.20 (2025-07-11)
+0.42.20 (2025-07-11)
 ~~~~~~~~~~~~~~~~~~~~
 
 Fixed
@@ -22,7 +22,7 @@ Fixed
 restricting the resetting joint indices be that user defined joint indices.
 
 
-0.41.19 (2025-07-11)
+0.42.19 (2025-07-11)
 ~~~~~~~~~~~~~~~~~~~~
 
 Fixed
@@ -32,7 +32,7 @@ Fixed
   env_ids are passed.
 
 
-0.41.18 (2025-07-09)
+0.42.18 (2025-07-09)
 ~~~~~~~~~~~~~~~~~~~~
 
 Added
@@ -49,7 +49,7 @@ Fixed
   buffer on recording.
 
 
-0.41.17 (2025-07-10)
+0.42.17 (2025-07-10)
 ~~~~~~~~~~~~~~~~~~~~
 
 Added
@@ -80,7 +80,7 @@ Changed
 * Changed the implementation of :func:`~isaaclab.utils.math.copysign` to better reflect the documented functionality.
 
 
-0.41.16 (2025-07-08)
+0.42.16 (2025-07-08)
 ~~~~~~~~~~~~~~~~~~~~
 
 Fixed
@@ -90,7 +90,7 @@ Fixed
   :class:`~isaaclab.assets.articulation.RigidObjectCollectionData`
 
 
-0.41.15 (2025-07-08)
+0.42.15 (2025-07-08)
 ~~~~~~~~~~~~~~~~~~~~
 
 Added
@@ -99,7 +99,7 @@ Added
 * Added ability to set platform height independent of object height for trimesh terrains.
 
 
-0.41.14 (2025-07-01)
+0.42.14 (2025-07-01)
 ~~~~~~~~~~~~~~~~~~~~
 
 Added
@@ -110,7 +110,7 @@ Added
 * Added deprecation warnings to the existing :attr:`max_height_noise` but still functions.
 
 
-0.41.13 (2025-07-03)
+0.42.13 (2025-07-03)
 ~~~~~~~~~~~~~~~~~~~~
 
 Fixed
@@ -119,7 +119,7 @@ Fixed
 * Fixed unittest tests that are floating inside pytests for articulation and rendering
 
 
-0.41.12 (2025-07-03)
+0.42.12 (2025-07-03)
 ~~~~~~~~~~~~~~~~~~~~
 
 Changed
@@ -129,7 +129,7 @@ Changed
   videos with the ``--video`` flag.
 
 
-0.41.11 (2025-06-27)
+0.42.11 (2025-06-27)
 ~~~~~~~~~~~~~~~~~~~~
 
 Added
@@ -144,7 +144,7 @@ Fixed
 * Fixed the implementation mistake in :func:`~isaaclab.utils.math.quat_inv`.
 
 
-0.41.10 (2025-06-25)
+0.42.10 (2025-06-25)
 ~~~~~~~~~~~~~~~~~~~~
 
 Fixed
@@ -153,7 +153,7 @@ Fixed
 * Fixed :func:`~isaaclab.utils.dict.update_class_from_dict` preventing setting flat Iterables with different lengths.
 
 
-0.41.9 (2025-06-25)
+0.42.9 (2025-06-25)
 ~~~~~~~~~~~~~~~~~~~
 
 Added
@@ -163,7 +163,7 @@ Added
   sampling, which is now the default behavior. If set to False, the previous behavior of sharing the same bias value across all components is retained.
 
 
-0.41.8 (2025-06-18)
+0.42.8 (2025-06-18)
 ~~~~~~~~~~~~~~~~~~~
 
 Fixed
@@ -175,7 +175,7 @@ Fixed
 * added pytest that check against these data consistencies
 
 
-0.41.7 (2025-06-24)
+0.42.7 (2025-06-24)
 ~~~~~~~~~~~~~~~~~~~
 
 Added
@@ -189,12 +189,16 @@ Changed
 * Renamed :func:`~isaaclab.utils.noise.NoiseModel.apply` method to :func:`~isaaclab.utils.noise.NoiseModel.__call__`.
 
 
+<<<<<<< HEAD
 <<<<<<< HEAD
 
 0.40.6 (2025-06-12)
 =======
 0.41.6 (2025-06-12)
 >>>>>>> cf094c211f (Updates to Isaac Sim 5.0 (#379))
+=======
+0.42.6 (2025-06-12)
+>>>>>>> b048c33739 (Adds support for Stage in Memory (#375))
 ~~~~~~~~~~~~~~~~~~~
 
 Fixed
@@ -203,7 +207,7 @@ Fixed
 * Fixed potential issues in :func:`~isaaclab.envs.mdp.events.randomize_visual_texture_material` related to handling visual prims during texture randomization.
 
 
-0.41.5 (2025-05-22)
+0.42.5 (2025-05-22)
 ~~~~~~~~~~~~~~~~~~~
 
 Fixed
@@ -213,7 +217,7 @@ Fixed
   currently has limitations for CPU simulation. Collision filtering needs to be manually enabled when using CPU simulation.
 
 
-0.41.4 (2025-06-03)
+0.42.4 (2025-06-03)
 ~~~~~~~~~~~~~~~~~~~
 
 Changed
@@ -224,7 +228,7 @@ Changed
   passed in the ``TerrainGeneratorCfg``.
 
 
-0.41.3 (2025-03-20)
+0.42.3 (2025-03-20)
 ~~~~~~~~~~~~~~~~~~~
 
 Changed
@@ -239,7 +243,7 @@ Changed
   more readable.
 
 
-0.41.2 (2025-05-10)
+0.42.2 (2025-05-31)
 ~~~~~~~~~~~~~~~~~~~
 
 Added
@@ -249,7 +253,7 @@ Added
 * Added support for specifying module:task_name as task name to avoid module import for ``gym.make``
 
 
-0.41.1 (2025-06-02)
+0.42.1 (2025-06-02)
 ~~~~~~~~~~~~~~~~~~~
 
 Added
@@ -265,6 +269,16 @@ Changed
   to make it available for mdp functions.
 
 
+0.42.0 (2025-06-02)
+~~~~~~~~~~~~~~~~~~~
+
+Added
+^^^^^
+
+* Added support for stage in memory and cloning in fabric. This will help improve performance for scene setup and lower
+  overall startup time.
+
+
 0.41.0 (2025-05-19)
 ~~~~~~~~~~~~~~~~~~~
 

source/isaaclab/isaaclab/assets/articulation/articulation.py

@@ -13,7 +13,6 @@ from collections.abc import Sequence
 from prettytable import PrettyTable
 from typing import TYPE_CHECKING
 
-import isaacsim.core.utils.stage as stage_utils
 import omni.log
 import omni.physics.tensors.impl.api as physx
 from isaacsim.core.simulation_manager import SimulationManager
@@ -1578,14 +1577,13 @@ class Articulation(AssetBase):
         self._spatial_tendon_names = list()
         # parse fixed tendons properties if they exist
         if self.num_fixed_tendons > 0 or self.num_spatial_tendons > 0:
-            stage = stage_utils.get_current_stage()
             joint_paths = self.root_physx_view.dof_paths[0]
 
             # iterate over all joints to find tendons attached to them
             for j in range(self.num_joints):
                 usd_joint_path = joint_paths[j]
                 # check whether joint has tendons - tendon name follows the joint name it is attached to
-                joint = UsdPhysics.Joint.Get(stage, usd_joint_path)
+                joint = UsdPhysics.Joint.Get(self.stage, usd_joint_path)
                 if joint.GetPrim().HasAPI(PhysxSchema.PhysxTendonAxisRootAPI):
                     joint_name = usd_joint_path.split("/")[-1]
                     self._fixed_tendon_names.append(joint_name)

source/isaaclab/isaaclab/assets/asset_base.py

@@ -18,6 +18,7 @@ import isaacsim.core.utils.prims as prim_utils
 import omni.kit.app
 import omni.timeline
 from isaacsim.core.simulation_manager import IsaacEvents, SimulationManager
+from isaacsim.core.utils.stage import get_current_stage
 
 import isaaclab.sim as sim_utils
 
@@ -69,6 +70,8 @@ class AssetBase(ABC):
         self.cfg = cfg.copy()
         # flag for whether the asset is initialized
         self._is_initialized = False
+        # get stage handle
+        self.stage = get_current_stage()
 
         # check if base asset path is valid
         # note: currently the spawner does not work if there is a regex pattern in the leaf

source/isaaclab/isaaclab/assets/rigid_object/rigid_object_data.py

@@ -7,6 +7,7 @@ import torch
 import weakref
 
 import omni.physics.tensors.impl.api as physx
+from isaacsim.core.utils.stage import get_current_stage_id
 
 import isaaclab.utils.math as math_utils
 from isaaclab.utils.buffers import TimestampedBuffer
@@ -51,7 +52,8 @@ class RigidObjectData:
         self._sim_timestamp = 0.0
 
         # Obtain global physics sim view
-        physics_sim_view = physx.create_simulation_view("torch")
+        stage_id = get_current_stage_id()
+        physics_sim_view = physx.create_simulation_view("torch", stage_id)
         physics_sim_view.set_subspace_roots("/")
         gravity = physics_sim_view.get_gravity()
         # Convert to direction vector

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

@@ -7,6 +7,7 @@ import torch
 import weakref
 
 import omni.physics.tensors.impl.api as physx
+from isaacsim.core.utils.stage import get_current_stage_id
 
 import isaaclab.utils.math as math_utils
 from isaaclab.utils.buffers import TimestampedBuffer
@@ -54,7 +55,8 @@ class RigidObjectCollectionData:
         self._sim_timestamp = 0.0
 
         # Obtain global physics sim view
-        physics_sim_view = physx.create_simulation_view("torch")
+        stage_id = get_current_stage_id()
+        physics_sim_view = physx.create_simulation_view("torch", stage_id)
         physics_sim_view.set_subspace_roots("/")
         gravity = physics_sim_view.get_gravity()
         # Convert to direction vector

source/isaaclab/isaaclab/devices/teleop_device_factory.py

+# Copyright (c) 2022-2025, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
 # Copyright (c) 2022-2025, The Isaac Lab Project Developers.
 # All rights reserved.
 #

source/isaaclab/isaaclab/envs/direct_marl_env.py

@@ -17,6 +17,7 @@ from collections.abc import Sequence
 from dataclasses import MISSING
 from typing import Any, ClassVar
 
+import isaacsim.core.utils.stage as stage_utils
 import isaacsim.core.utils.torch as torch_utils
 import omni.kit.app
 import omni.log
@@ -25,6 +26,7 @@ from isaacsim.core.version import get_version
 from isaaclab.managers import EventManager
 from isaaclab.scene import InteractiveScene
 from isaaclab.sim import SimulationContext
+from isaaclab.sim.utils import attach_stage_to_usd_context
 from isaaclab.utils.noise import NoiseModel
 from isaaclab.utils.timer import Timer
 
@@ -117,8 +119,10 @@ class DirectMARLEnv(gym.Env):
 
         # generate scene
         with Timer("[INFO]: Time taken for scene creation", "scene_creation"):
-            self.scene = InteractiveScene(self.cfg.scene)
-            self._setup_scene()
+            with stage_utils.use_stage(self.sim.get_initial_stage()):
+                self.scene = InteractiveScene(self.cfg.scene)
+                self._setup_scene()
+                attach_stage_to_usd_context()
         print("[INFO]: Scene manager: ", self.scene)
 
         # set up camera viewport controller

source/isaaclab/isaaclab/envs/direct_rl_env.py

@@ -17,6 +17,7 @@ from collections.abc import Sequence
 from dataclasses import MISSING
 from typing import Any, ClassVar
 
+import isaacsim.core.utils.stage as stage_utils
 import isaacsim.core.utils.torch as torch_utils
 import omni.kit.app
 import omni.log
@@ -26,6 +27,7 @@ from isaacsim.core.version import get_version
 from isaaclab.managers import EventManager
 from isaaclab.scene import InteractiveScene
 from isaaclab.sim import SimulationContext
+from isaaclab.sim.utils import attach_stage_to_usd_context
 from isaaclab.utils.noise import NoiseModel
 from isaaclab.utils.timer import Timer
 
@@ -123,8 +125,10 @@ class DirectRLEnv(gym.Env):
 
         # generate scene
         with Timer("[INFO]: Time taken for scene creation", "scene_creation"):
-            self.scene = InteractiveScene(self.cfg.scene)
-            self._setup_scene()
+            with stage_utils.use_stage(self.sim.get_initial_stage()):
+                self.scene = InteractiveScene(self.cfg.scene)
+                self._setup_scene()
+                attach_stage_to_usd_context()
         print("[INFO]: Scene manager: ", self.scene)
 
         # set up camera viewport controller

source/isaaclab/isaaclab/envs/manager_based_env.py

@@ -8,6 +8,7 @@ import torch
 from collections.abc import Sequence
 from typing import Any
 
+import isaacsim.core.utils.stage as stage_utils
 import isaacsim.core.utils.torch as torch_utils
 import omni.log
 from isaacsim.core.simulation_manager import SimulationManager
@@ -15,6 +16,7 @@ from isaacsim.core.simulation_manager import SimulationManager
 from isaaclab.managers import ActionManager, EventManager, ObservationManager, RecorderManager
 from isaaclab.scene import InteractiveScene
 from isaaclab.sim import SimulationContext
+from isaaclab.sim.utils import attach_stage_to_usd_context
 from isaaclab.ui.widgets import ManagerLiveVisualizer
 from isaaclab.utils.timer import Timer
 
@@ -127,7 +129,10 @@ class ManagerBasedEnv:
 
         # generate scene
         with Timer("[INFO]: Time taken for scene creation", "scene_creation"):
-            self.scene = InteractiveScene(self.cfg.scene)
+            # get stage handle and set stage context
+            with stage_utils.use_stage(self.sim.get_initial_stage()):
+                self.scene = InteractiveScene(self.cfg.scene)
+                attach_stage_to_usd_context()
         print("[INFO]: Scene manager: ", self.scene)
 
         # set up camera viewport controller

source/isaaclab/isaaclab/envs/mdp/events.py

@@ -20,8 +20,8 @@ from typing import TYPE_CHECKING, Literal
 
 import carb
 import omni.physics.tensors.impl.api as physx
-import omni.usd
 from isaacsim.core.utils.extensions import enable_extension
+from isaacsim.core.utils.stage import get_current_stage
 from pxr import Gf, Sdf, UsdGeom, Vt
 
 import isaaclab.sim as sim_utils
@@ -92,7 +92,7 @@ def randomize_rigid_body_scale(
         env_ids = env_ids.cpu()
 
     # acquire stage
-    stage = omni.usd.get_context().get_stage()
+    stage = get_current_stage()
     # resolve prim paths for spawning and cloning
     prim_paths = sim_utils.find_matching_prim_paths(asset.cfg.prim_path)
 

source/isaaclab/isaaclab/envs/ui/base_env_window.py

@@ -15,6 +15,7 @@ import isaacsim
 import omni.kit.app
 import omni.kit.commands
 import omni.usd
+from isaacsim.core.utils.stage import get_current_stage
 from pxr import PhysxSchema, Sdf, Usd, UsdGeom, UsdPhysics
 
 from isaaclab.ui.widgets import ManagerLiveVisualizer
@@ -60,6 +61,9 @@ class BaseEnvWindow:
             *self.env.scene.articulations.keys(),
         ]
 
+        # get stage handle
+        self.stage = get_current_stage()
+
         # Listeners for environment selection changes
         self._ui_listeners: list[ManagerLiveVisualizer] = []
 
@@ -300,8 +304,7 @@ class BaseEnvWindow:
             # stop the recording
             _ = omni.kit.commands.execute("StopRecording")
             # save the current stage
-            stage = omni.usd.get_context().get_stage()
-            source_layer = stage.GetRootLayer()
+            source_layer = self.stage.GetRootLayer()
             # output the stage to a file
             stage_usd_path = os.path.join(self.animation_log_dir, "Stage.usd")
             source_prim_path = "/"
@@ -311,8 +314,8 @@ class BaseEnvWindow:
                 temp_layer = Sdf.Layer.CreateNew(stage_usd_path)
             temp_stage = Usd.Stage.Open(temp_layer)
             # update stage data
-            UsdGeom.SetStageUpAxis(temp_stage, UsdGeom.GetStageUpAxis(stage))
-            UsdGeom.SetStageMetersPerUnit(temp_stage, UsdGeom.GetStageMetersPerUnit(stage))
+            UsdGeom.SetStageUpAxis(temp_stage, UsdGeom.GetStageUpAxis(self.stage))
+            UsdGeom.SetStageMetersPerUnit(temp_stage, UsdGeom.GetStageMetersPerUnit(self.stage))
             # copy the prim
             Sdf.CreatePrimInLayer(temp_layer, source_prim_path)
             Sdf.CopySpec(source_layer, source_prim_path, temp_layer, source_prim_path)

source/isaaclab/isaaclab/markers/visualization_markers.py

@@ -25,11 +25,14 @@ from dataclasses import MISSING
 
 import isaacsim.core.utils.stage as stage_utils
 import omni.kit.commands
+import omni.log
 import omni.physx.scripts.utils as physx_utils
+from isaacsim.core.utils.stage import get_current_stage
 from pxr import Gf, PhysxSchema, Sdf, Usd, UsdGeom, UsdPhysics, Vt
 
 import isaaclab.sim as sim_utils
 from isaaclab.sim.spawners import SpawnerCfg
+from isaaclab.sim.utils import attach_stage_to_usd_context, is_current_stage_in_memory
 from isaaclab.utils.configclass import configclass
 from isaaclab.utils.math import convert_quat
 
@@ -145,8 +148,8 @@ class VisualizationMarkers:
         # get next free path for the prim
         prim_path = stage_utils.get_next_free_path(cfg.prim_path)
         # create a new prim
-        stage = stage_utils.get_current_stage()
-        self._instancer_manager = UsdGeom.PointInstancer.Define(stage, prim_path)
+        self.stage = get_current_stage()
+        self._instancer_manager = UsdGeom.PointInstancer.Define(self.stage, prim_path)
         # store inputs
         self.prim_path = prim_path
         self.cfg = cfg
@@ -395,6 +398,15 @@ class VisualizationMarkers:
                 child_prim.SetInstanceable(False)
             # check if prim is a mesh -> if so, make it invisible to secondary rays
             if child_prim.IsA(UsdGeom.Gprim):
+                # early attach stage to usd context if stage is in memory
+                # since stage in memory is not supported by the "ChangePropertyCommand" kit command
+                if is_current_stage_in_memory():
+                    omni.log.warn(
+                        "Attaching stage in memory to USD context early to support omni kit command during stage"
+                        " creation."
+                    )
+                    attach_stage_to_usd_context()
+
                 # invisible to secondary rays such as depth images
                 omni.kit.commands.execute(
                     "ChangePropertyCommand",

source/isaaclab/isaaclab/scene/interactive_scene.py

@@ -12,6 +12,7 @@ import omni.log
 import omni.usd
 from isaacsim.core.cloner import GridCloner
 from isaacsim.core.prims import XFormPrim
+from isaacsim.core.utils.stage import get_current_stage, get_current_stage_id
 from pxr import PhysxSchema
 
 import isaaclab.sim as sim_utils
@@ -27,6 +28,7 @@ from isaaclab.assets import (
     RigidObjectCollectionCfg,
 )
 from isaaclab.sensors import ContactSensorCfg, FrameTransformerCfg, SensorBase, SensorBaseCfg
+from isaaclab.sim import SimulationContext
 from isaaclab.terrains import TerrainImporter, TerrainImporterCfg
 
 from .interactive_scene_cfg import InteractiveSceneCfg
@@ -119,12 +121,14 @@ class InteractiveScene:
         self._rigid_object_collections = dict()
         self._sensors = dict()
         self._extras = dict()
-        # obtain the current stage
-        self.stage = omni.usd.get_context().get_stage()
+        # get stage handle
+        self.sim = SimulationContext.instance()
+        self.stage = get_current_stage()
+        self.stage_id = get_current_stage_id()
         # physics scene path
         self._physics_scene_path = None
         # prepare cloner for environment replication
-        self.cloner = GridCloner(spacing=self.cfg.env_spacing)
+        self.cloner = GridCloner(spacing=self.cfg.env_spacing, stage=self.stage)
         self.cloner.define_base_env(self.env_ns)
         self.env_prim_paths = self.cloner.generate_paths(f"{self.env_ns}/env", self.cfg.num_envs)
         # create source prim

source/isaaclab/isaaclab/sensors/camera/camera.py

@@ -154,9 +154,8 @@ class Camera(SensorBase):
                     " will be disabled in the current workflow and may lead to longer load times and increased memory"
                     " usage."
                 )
-                stage = omni.usd.get_context().get_stage()
                 with Sdf.ChangeBlock():
-                    for prim in stage.Traverse():
+                    for prim in self.stage.Traverse():
                         prim.SetInstanceable(False)
 
     def __del__(self):
@@ -421,12 +420,10 @@ class Camera(SensorBase):
         self._render_product_paths: list[str] = list()
         self._rep_registry: dict[str, list[rep.annotators.Annotator]] = {name: list() for name in self.cfg.data_types}
 
-        # Obtain current stage
-        stage = omni.usd.get_context().get_stage()
         # Convert all encapsulated prims to Camera
         for cam_prim_path in self._view.prim_paths:
             # Get camera prim
-            cam_prim = stage.GetPrimAtPath(cam_prim_path)
+            cam_prim = self.stage.GetPrimAtPath(cam_prim_path)
             # Check if prim is a camera
             if not cam_prim.IsA(UsdGeom.Camera):
                 raise RuntimeError(f"Prim at path '{cam_prim_path}' is not a Camera.")

source/isaaclab/isaaclab/sensors/camera/tiled_camera.py

@@ -13,7 +13,6 @@ from collections.abc import Sequence
 from typing import TYPE_CHECKING, Any
 
 import carb
-import omni.usd
 import warp as wp
 from isaacsim.core.prims import XFormPrim
 from isaacsim.core.version import get_version
@@ -173,12 +172,10 @@ class TiledCamera(Camera):
         # Create frame count buffer
         self._frame = torch.zeros(self._view.count, device=self._device, dtype=torch.long)
 
-        # Obtain current stage
-        stage = omni.usd.get_context().get_stage()
         # Convert all encapsulated prims to Camera
         for cam_prim_path in self._view.prim_paths:
             # Get camera prim
-            cam_prim = stage.GetPrimAtPath(cam_prim_path)
+            cam_prim = self.stage.GetPrimAtPath(cam_prim_path)
             # Check if prim is a camera
             if not cam_prim.IsA(UsdGeom.Camera):
                 raise RuntimeError(f"Prim at path '{cam_prim_path}' is not a Camera.")

source/isaaclab/isaaclab/sensors/sensor_base.py

@@ -23,6 +23,7 @@ from typing import TYPE_CHECKING, Any
 import omni.kit.app
 import omni.timeline
 from isaacsim.core.simulation_manager import IsaacEvents, SimulationManager
+from isaacsim.core.utils.stage import get_current_stage
 
 import isaaclab.sim as sim_utils
 
@@ -59,6 +60,8 @@ class SensorBase(ABC):
         self._is_initialized = False
         # flag for whether the sensor is in visualization mode
         self._is_visualizing = False
+        # get stage handle
+        self.stage = get_current_stage()
 
         # note: Use weakref on callbacks to ensure that this object can be deleted when its destructor is called.
         # add callbacks for stage play/stop

source/isaaclab/isaaclab/sim/schemas/schemas.py

@@ -8,9 +8,9 @@ from __future__ import annotations
 
 import math
 
-import isaacsim.core.utils.stage as stage_utils
 import omni.log
 import omni.physx.scripts.utils as physx_utils
+from isaacsim.core.utils.stage import get_current_stage
 from omni.physx.scripts import deformableUtils as deformable_utils
 from pxr import PhysxSchema, Usd, UsdPhysics
 
@@ -44,9 +44,10 @@ def define_articulation_root_properties(
         ValueError: When the prim path is not valid.
         TypeError: When the prim already has conflicting API schemas.
     """
-    # obtain stage
+    # get stage handle
     if stage is None:
-        stage = stage_utils.get_current_stage()
+        stage = get_current_stage()
+
     # get articulation USD prim
     prim = stage.GetPrimAtPath(prim_path)
     # check if prim path is valid
@@ -102,9 +103,10 @@ def modify_articulation_root_properties(
     Raises:
         NotImplementedError: When the root prim is not a rigid body and a fixed joint is to be created.
     """
-    # obtain stage
+    # get stage handle
     if stage is None:
-        stage = stage_utils.get_current_stage()
+        stage = get_current_stage()
+
     # get articulation USD prim
     articulation_prim = stage.GetPrimAtPath(prim_path)
     # check if prim has articulation applied on it
@@ -204,9 +206,10 @@ def define_rigid_body_properties(
         ValueError: When the prim path is not valid.
         TypeError: When the prim already has conflicting API schemas.
     """
-    # obtain stage
+    # get stage handle
     if stage is None:
-        stage = stage_utils.get_current_stage()
+        stage = get_current_stage()
+
     # get USD prim
     prim = stage.GetPrimAtPath(prim_path)
     # check if prim path is valid
@@ -250,9 +253,10 @@ def modify_rigid_body_properties(
     Returns:
         True if the properties were successfully set, False otherwise.
     """
-    # obtain stage
+    # get stage handle
     if stage is None:
-        stage = stage_utils.get_current_stage()
+        stage = get_current_stage()
+
     # get rigid-body USD prim
     rigid_body_prim = stage.GetPrimAtPath(prim_path)
     # check if prim has rigid-body applied on it
@@ -299,9 +303,10 @@ def define_collision_properties(
     Raises:
         ValueError: When the prim path is not valid.
     """
-    # obtain stage
+    # get stage handle
     if stage is None:
-        stage = stage_utils.get_current_stage()
+        stage = get_current_stage()
+
     # get USD prim
     prim = stage.GetPrimAtPath(prim_path)
     # check if prim path is valid
@@ -343,9 +348,10 @@ def modify_collision_properties(
     Returns:
         True if the properties were successfully set, False otherwise.
     """
-    # obtain stage
+    # get stage handle
     if stage is None:
-        stage = stage_utils.get_current_stage()
+        stage = get_current_stage()
+
     # get USD prim
     collider_prim = stage.GetPrimAtPath(prim_path)
     # check if prim has collision applied on it
@@ -390,9 +396,10 @@ def define_mass_properties(prim_path: str, cfg: schemas_cfg.MassPropertiesCfg, s
     Raises:
         ValueError: When the prim path is not valid.
     """
-    # obtain stage
+    # get stage handle
     if stage is None:
-        stage = stage_utils.get_current_stage()
+        stage = get_current_stage()
+
     # get USD prim
     prim = stage.GetPrimAtPath(prim_path)
     # check if prim path is valid
@@ -435,9 +442,10 @@ def modify_mass_properties(prim_path: str, cfg: schemas_cfg.MassPropertiesCfg, s
     Returns:
         True if the properties were successfully set, False otherwise.
     """
-    # obtain stage
+    # get stage handle
     if stage is None:
-        stage = stage_utils.get_current_stage()
+        stage = get_current_stage()
+
     # get USD prim
     rigid_prim = stage.GetPrimAtPath(prim_path)
     # check if prim has mass API applied on it
@@ -478,9 +486,10 @@ def activate_contact_sensors(prim_path: str, threshold: float = 0.0, stage: Usd.
         ValueError: If the input prim path is not valid.
         ValueError: If there are no rigid bodies under the prim path.
     """
-    # obtain stage
+    # get stage handle
     if stage is None:
-        stage = stage_utils.get_current_stage()
+        stage = get_current_stage()
+
     # get prim
     prim: Usd.Prim = stage.GetPrimAtPath(prim_path)
     # check if prim is valid
@@ -564,9 +573,10 @@ def modify_joint_drive_properties(
     Raises:
         ValueError: If the input prim path is not valid.
     """
-    # obtain stage
+    # get stage handle
     if stage is None:
-        stage = stage_utils.get_current_stage()
+        stage = get_current_stage()
+
     # get USD prim
     prim = stage.GetPrimAtPath(prim_path)
     # check if prim path is valid
@@ -666,9 +676,10 @@ def modify_fixed_tendon_properties(
     Raises:
         ValueError: If the input prim path is not valid.
     """
-    # obtain stage
+    # get stage handle
     if stage is None:
-        stage = stage_utils.get_current_stage()
+        stage = get_current_stage()
+
     # get USD prim
     tendon_prim = stage.GetPrimAtPath(prim_path)
     # check if prim has fixed tendon applied on it
@@ -734,7 +745,7 @@ def modify_spatial_tendon_properties(
     """
     # obtain stage
     if stage is None:
-        stage = stage_utils.get_current_stage()
+        stage = get_current_stage()
     # get USD prim
     tendon_prim = stage.GetPrimAtPath(prim_path)
     # check if prim has spatial tendon applied on it
@@ -792,9 +803,10 @@ def define_deformable_body_properties(
         ValueError: When the prim path is not valid.
         ValueError: When the prim has no mesh or multiple meshes.
     """
-    # obtain stage
+    # get stage handle
     if stage is None:
-        stage = stage_utils.get_current_stage()
+        stage = get_current_stage()
+
     # get USD prim
     prim = stage.GetPrimAtPath(prim_path)
     # check if prim path is valid
@@ -867,9 +879,9 @@ def modify_deformable_body_properties(
     Returns:
         True if the properties were successfully set, False otherwise.
     """
-    # obtain stage
+    # get stage handle
     if stage is None:
-        stage = stage_utils.get_current_stage()
+        stage = get_current_stage()
 
     # get deformable-body USD prim
     deformable_body_prim = stage.GetPrimAtPath(prim_path)

source/isaaclab/isaaclab/sim/simulation_cfg.py

@@ -339,3 +339,9 @@ class SimulationCfg:
 
     render: RenderCfg = RenderCfg()
     """Render settings. Default is RenderCfg()."""
+
+    create_stage_in_memory: bool = False
+    """If stage is first created in memory and then attached to usd context for simulation and rendering.
+
+    Creating the stage in memory can reduce start-up time.
+    """

source/isaaclab/isaaclab/sim/simulation_context.py

@@ -24,6 +24,7 @@ import flatdict
 import isaacsim.core.utils.stage as stage_utils
 import omni.log
 import omni.physx
+import omni.usd
 from isaacsim.core.api.simulation_context import SimulationContext as _SimulationContext
 from isaacsim.core.utils.carb import get_carb_setting, set_carb_setting
 from isaacsim.core.utils.viewports import set_camera_view
@@ -128,6 +129,12 @@ class SimulationContext(_SimulationContext):
         if stage_utils.get_current_stage() is None:
             raise RuntimeError("The stage has not been created. Did you run the simulator?")
 
+        # create stage in memory if requested
+        if self.cfg.create_stage_in_memory:
+            self._initial_stage = stage_utils.create_new_stage_in_memory()
+        else:
+            self._initial_stage = omni.usd.get_context().get_stage()
+
         # acquire settings interface
         self.carb_settings = carb.settings.get_settings()
 
@@ -257,6 +264,7 @@ class SimulationContext(_SimulationContext):
             sim_params=sim_params,
             physics_prim_path=self.cfg.physics_prim_path,
             device=self.cfg.device,
+            stage=self._initial_stage,
         )
 
     def _apply_physics_settings(self):
@@ -526,6 +534,14 @@ class SimulationContext(_SimulationContext):
                 self.physics_sim_view.update_articulations_kinematic()
             self._update_fabric(0.0, 0.0)
 
+    def get_initial_stage(self) -> Usd.Stage:
+        """Returns stage handle used during scene creation.
+
+        Returns:
+            The stage used during scene creation.
+        """
+        return self._initial_stage
+
     """
     Operations - Override (standalone)
     """
@@ -660,17 +676,18 @@ class SimulationContext(_SimulationContext):
 
     def _init_stage(self, *args, **kwargs) -> Usd.Stage:
         _ = super()._init_stage(*args, **kwargs)
-        # a stage update here is needed for the case when physics_dt != rendering_dt, otherwise the app crashes
-        # when in headless mode
-        self.set_setting("/app/player/playSimulations", False)
-        self._app.update()
-        self.set_setting("/app/player/playSimulations", True)
-        # set additional physx parameters and bind material
-        self._set_additional_physx_params()
-        # load flatcache/fabric interface
-        self._load_fabric_interface()
-        # return the stage
-        return self.stage
+        with stage_utils.use_stage(self.get_initial_stage()):
+            # a stage update here is needed for the case when physics_dt != rendering_dt, otherwise the app crashes
+            # when in headless mode
+            self.set_setting("/app/player/playSimulations", False)
+            self._app.update()
+            self.set_setting("/app/player/playSimulations", True)
+            # set additional physx parameters and bind material
+            self._set_additional_physx_params()
+            # load flatcache/fabric interface
+            self._load_fabric_interface()
+            # return the stage
+            return self.stage
 
     async def _initialize_stage_async(self, *args, **kwargs) -> Usd.Stage:
         await super()._initialize_stage_async(*args, **kwargs)

source/isaaclab/isaaclab/sim/spawners/from_files/from_files.py

@@ -8,7 +8,6 @@ from __future__ import annotations
 from typing import TYPE_CHECKING
 
 import isaacsim.core.utils.prims as prim_utils
-import isaacsim.core.utils.stage as stage_utils
 import omni.kit.commands
 import omni.log
 from pxr import Gf, Sdf, Usd
@@ -19,8 +18,16 @@ try:
 except ModuleNotFoundError:
     from pxr import Semantics
 
+from isaacsim.core.utils.stage import get_current_stage
+
 from isaaclab.sim import converters, schemas
-from isaaclab.sim.utils import bind_physics_material, bind_visual_material, clone, select_usd_variants
+from isaaclab.sim.utils import (
+    bind_physics_material,
+    bind_visual_material,
+    clone,
+    is_current_stage_in_memory,
+    select_usd_variants,
+)
 
 if TYPE_CHECKING:
     from . import from_files_cfg
@@ -166,18 +173,28 @@ def spawn_ground_plane(
     # Change the color of the plane
     # Warning: This is specific to the default grid plane asset.
     if cfg.color is not None:
-        prop_path = f"{prim_path}/Looks/theGrid/Shader.inputs:diffuse_tint"
-        # change the color
-        omni.kit.commands.execute(
-            "ChangePropertyCommand",
-            prop_path=Sdf.Path(prop_path),
-            value=Gf.Vec3f(*cfg.color),
-            prev=None,
-            type_to_create_if_not_exist=Sdf.ValueTypeNames.Color3f,
-        )
+        # avoiding this step if stage is in memory since the "ChangePropertyCommand" kit command
+        # is not supported in stage in memory
+        if is_current_stage_in_memory():
+            omni.log.warn(
+                "Ground plane color modification is not supported while the stage is in memory. Skipping operation."
+            )
+
+        else:
+            prop_path = f"{prim_path}/Looks/theGrid/Shader.inputs:diffuse_tint"
+
+            # change the color
+            omni.kit.commands.execute(
+                "ChangePropertyCommand",
+                prop_path=Sdf.Path(prop_path),
+                value=Gf.Vec3f(*cfg.color),
+                prev=None,
+                type_to_create_if_not_exist=Sdf.ValueTypeNames.Color3f,
+            )
     # Remove the light from the ground plane
     # It isn't bright enough and messes up with the user's lighting settings
-    omni.kit.commands.execute("ToggleVisibilitySelectedPrims", selected_paths=[f"{prim_path}/SphereLight"])
+    stage = get_current_stage()
+    omni.kit.commands.execute("ToggleVisibilitySelectedPrims", selected_paths=[f"{prim_path}/SphereLight"], stage=stage)
 
     prim = prim_utils.get_prim_at_path(prim_path)
     # Apply semantic tags
@@ -231,8 +248,10 @@ def _spawn_from_usd_file(
     Raises:
         FileNotFoundError: If the USD file does not exist at the given path.
     """
+    # get stage handle
+    stage = get_current_stage()
+
     # check file path exists
-    stage: Usd.Stage = stage_utils.get_current_stage()
     if not stage.ResolveIdentifierToEditTarget(usd_path):
         raise FileNotFoundError(f"USD file not found at path: '{usd_path}'.")
     # spawn asset if it doesn't exist.

source/isaaclab/isaaclab/sim/spawners/materials/physics_materials.py

@@ -8,7 +8,7 @@ from __future__ import annotations
 from typing import TYPE_CHECKING
 
 import isaacsim.core.utils.prims as prim_utils
-import isaacsim.core.utils.stage as stage_utils
+from isaacsim.core.utils.stage import get_current_stage
 from pxr import PhysxSchema, Usd, UsdPhysics, UsdShade
 
 from isaaclab.sim.utils import clone, safe_set_attribute_on_usd_schema
@@ -41,9 +41,12 @@ def spawn_rigid_body_material(prim_path: str, cfg: physics_materials_cfg.RigidBo
     Raises:
         ValueError:  When a prim already exists at the specified prim path and is not a material.
     """
+    # get stage handle
+    stage = get_current_stage()
+
     # create material prim if no prim exists
     if not prim_utils.is_prim_path_valid(prim_path):
-        _ = UsdShade.Material.Define(stage_utils.get_current_stage(), prim_path)
+        _ = UsdShade.Material.Define(stage, prim_path)
 
     # obtain prim
     prim = prim_utils.get_prim_at_path(prim_path)
@@ -99,9 +102,12 @@ def spawn_deformable_body_material(prim_path: str, cfg: physics_materials_cfg.De
 
     .. _PxFEMSoftBodyMaterial: https://nvidia-omniverse.github.io/PhysX/physx/5.4.1/_api_build/structPxFEMSoftBodyMaterialModel.html
     """
+    # get stage handle
+    stage = get_current_stage()
+
     # create material prim if no prim exists
     if not prim_utils.is_prim_path_valid(prim_path):
-        _ = UsdShade.Material.Define(stage_utils.get_current_stage(), prim_path)
+        _ = UsdShade.Material.Define(stage, prim_path)
 
     # obtain prim
     prim = prim_utils.get_prim_at_path(prim_path)

source/isaaclab/isaaclab/sim/spawners/materials/visual_materials.py

@@ -9,9 +9,15 @@ from typing import TYPE_CHECKING
 
 import isaacsim.core.utils.prims as prim_utils
 import omni.kit.commands
+import omni.log
 from pxr import Usd
 
-from isaaclab.sim.utils import clone, safe_set_attribute_on_usd_prim
+from isaaclab.sim.utils import (
+    attach_stage_to_usd_context,
+    clone,
+    is_current_stage_in_memory,
+    safe_set_attribute_on_usd_prim,
+)
 from isaaclab.utils.assets import NVIDIA_NUCLEUS_DIR
 
 if TYPE_CHECKING:
@@ -48,9 +54,19 @@ def spawn_preview_surface(prim_path: str, cfg: visual_materials_cfg.PreviewSurfa
     """
     # spawn material if it doesn't exist.
     if not prim_utils.is_prim_path_valid(prim_path):
+        # early attach stage to usd context if stage is in memory
+        # since stage in memory is not supported by the "CreatePreviewSurfaceMaterialPrim" kit command
+        if is_current_stage_in_memory():
+            omni.log.warn(
+                "Attaching stage in memory to USD context early to support an operation which doesn't support stage in"
+                " memory."
+            )
+            attach_stage_to_usd_context()
+
         omni.kit.commands.execute("CreatePreviewSurfaceMaterialPrim", mtl_path=prim_path, select_new_prim=False)
     else:
         raise ValueError(f"A prim already exists at path: '{prim_path}'.")
+
     # obtain prim
     prim = prim_utils.get_prim_at_path(f"{prim_path}/Shader")
     # apply properties
@@ -58,7 +74,7 @@ def spawn_preview_surface(prim_path: str, cfg: visual_materials_cfg.PreviewSurfa
     del cfg["func"]
     for attr_name, attr_value in cfg.items():
         safe_set_attribute_on_usd_prim(prim, f"inputs:{attr_name}", attr_value, camel_case=True)
-    # return prim
+
     return prim
 
 
@@ -93,6 +109,15 @@ def spawn_from_mdl_file(prim_path: str, cfg: visual_materials_cfg.MdlMaterialCfg
     """
     # spawn material if it doesn't exist.
     if not prim_utils.is_prim_path_valid(prim_path):
+        # early attach stage to usd context if stage is in memory
+        # since stage in memory is not supported by the "CreateMdlMaterialPrim" kit command
+        if is_current_stage_in_memory():
+            omni.log.warn(
+                "Attaching stage in memory to USD context early to support an operation which doesn't support stage in"
+                " memory."
+            )
+            attach_stage_to_usd_context()
+
         # extract material name from path
         material_name = cfg.mdl_path.split("/")[-1].split(".")[0]
         omni.kit.commands.execute(

source/isaaclab/isaaclab/sim/spawners/sensors/sensors.py

@@ -12,7 +12,7 @@ import omni.kit.commands
 import omni.log
 from pxr import Sdf, Usd
 
-from isaaclab.sim.utils import clone
+from isaaclab.sim.utils import attach_stage_to_usd_context, clone, is_current_stage_in_memory
 from isaaclab.utils import to_camel_case
 
 if TYPE_CHECKING:
@@ -88,6 +88,15 @@ def spawn_camera(
 
     # lock camera from viewport (this disables viewport movement for camera)
     if cfg.lock_camera:
+        # early attach stage to usd context if stage is in memory
+        # since stage in memory is not supported by the "ChangePropertyCommand" kit command
+        if is_current_stage_in_memory():
+            omni.log.warn(
+                "Attaching stage in memory to USD context early to support an operation which doesn't support stage in"
+                " memory."
+            )
+            attach_stage_to_usd_context()
+
         omni.kit.commands.execute(
             "ChangePropertyCommand",
             prop_path=Sdf.Path(f"{prim_path}.omni:kit:cameraLock"),

source/isaaclab/isaaclab/sim/spawners/wrappers/wrappers.py

@@ -12,6 +12,7 @@ from typing import TYPE_CHECKING
 import carb
 import isaacsim.core.utils.prims as prim_utils
 import isaacsim.core.utils.stage as stage_utils
+from isaacsim.core.utils.stage import get_current_stage
 from pxr import Sdf, Usd
 
 import isaaclab.sim as sim_utils
@@ -42,6 +43,9 @@ def spawn_multi_asset(
     Returns:
         The created prim at the first prim path.
     """
+    # get stage handle
+    stage = get_current_stage()
+
     # resolve: {SPAWN_NS}/AssetName
     # note: this assumes that the spawn namespace already exists in the stage
     root_path, asset_path = prim_path.rsplit("/", 1)
@@ -88,9 +92,6 @@ def spawn_multi_asset(
     # resolve prim paths for spawning and cloning
     prim_paths = [f"{source_prim_path}/{asset_path}" for source_prim_path in source_prim_paths]
 
-    # acquire stage
-    stage = stage_utils.get_current_stage()
-
     # manually clone prims if the source prim path is a regex expression
     # note: unlike in the cloner API from Isaac Sim, we do not "reset" xforms on the copied prims.
     #   This is because the "spawn" calls during the creation of the proto prims already handles this operation.

source/isaaclab/test/devices/test_device_constructors.py

+# Copyright (c) 2022-2025, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
 # Copyright (c) 2022-2025, The Isaac Lab Project Developers.
 # All rights reserved.
 #

source/isaaclab/test/sim/test_stage_in_memory.py

+# Copyright (c) 2022-2025, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+# Copyright (c) 2022-2025, The Isaac Lab Project Developers.
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+"""Launch Isaac Sim Simulator first."""
+
+from isaaclab.app import AppLauncher
+
+# launch omniverse app
+simulation_app = AppLauncher(headless=True, enable_cameras=True).app
+
+"""Rest everything follows."""
+
+import isaacsim.core.utils.prims as prim_utils
+import isaacsim.core.utils.stage as stage_utils
+import omni
+import omni.physx
+import omni.usd
+import pytest
+import usdrt
+from isaacsim.core.cloner import GridCloner
+
+import isaaclab.sim as sim_utils
+from isaaclab.sim.simulation_context import SimulationCfg, SimulationContext
+from isaaclab.utils.assets import ISAACLAB_NUCLEUS_DIR
+
+
+@pytest.fixture
+def sim():
+    """Create a simulation context."""
+    cfg = SimulationCfg(create_stage_in_memory=True)
+    sim = SimulationContext(cfg=cfg)
+    stage_utils.update_stage()
+    yield sim
+    omni.physx.get_physx_simulation_interface().detach_stage()
+    sim.stop()
+    sim.clear()
+    sim.clear_all_callbacks()
+    sim.clear_instance()
+
+
+"""
+Tests
+"""
+
+
+def test_stage_in_memory_with_shapes(sim):
+    """Test spawning of shapes with stage in memory."""
+
+    # define parameters
+    num_clones = 10
+
+    # grab stage in memory and set as current stage via the with statement
+    stage_in_memory = sim.get_initial_stage()
+    with stage_utils.use_stage(stage_in_memory):
+        # create cloned cone stage
+        for i in range(num_clones):
+            prim_utils.create_prim(f"/World/env_{i}", "Xform", translation=(i, i, 0))
+
+        cfg = sim_utils.MultiAssetSpawnerCfg(
+            assets_cfg=[
+                sim_utils.ConeCfg(
+                    radius=0.3,
+                    height=0.6,
+                ),
+                sim_utils.CuboidCfg(
+                    size=(0.3, 0.3, 0.3),
+                ),
+                sim_utils.SphereCfg(
+                    radius=0.3,
+                ),
+            ],
+            random_choice=True,
+            rigid_props=sim_utils.RigidBodyPropertiesCfg(
+                solver_position_iteration_count=4, solver_velocity_iteration_count=0
+            ),
+            mass_props=sim_utils.MassPropertiesCfg(mass=1.0),
+            collision_props=sim_utils.CollisionPropertiesCfg(),
+        )
+        prim_path_regex = "/World/env_.*/Cone"
+        cfg.func(prim_path_regex, cfg)
+
+        # verify stage is in memory
+        assert sim_utils.is_current_stage_in_memory()
+
+        # verify prims exist in stage in memory
+        prims = prim_utils.find_matching_prim_paths(prim_path_regex)
+        assert len(prims) == num_clones
+
+        # verify prims do not exist in context stage
+        context_stage = omni.usd.get_context().get_stage()
+        with stage_utils.use_stage(context_stage):
+            prims = prim_utils.find_matching_prim_paths(prim_path_regex)
+            assert len(prims) != num_clones
+
+        # attach stage to context
+        sim_utils.attach_stage_to_usd_context()
+
+    # verify stage is no longer in memory
+    assert not sim_utils.is_current_stage_in_memory()
+
+    # verify prims now exist in context stage
+    prims = prim_utils.find_matching_prim_paths(prim_path_regex)
+    assert len(prims) == num_clones
+
+
+def test_stage_in_memory_with_usds(sim):
+    """Test spawning of USDs with stage in memory."""
+
+    # define parameters
+    num_clones = 10
+    usd_paths = [
+        f"{ISAACLAB_NUCLEUS_DIR}/Robots/ANYbotics/ANYmal-C/anymal_c.usd",
+        f"{ISAACLAB_NUCLEUS_DIR}/Robots/ANYbotics/ANYmal-D/anymal_d.usd",
+    ]
+
+    # grab stage in memory and set as current stage via the with statement
+    stage_in_memory = sim.get_initial_stage()
+    with stage_utils.use_stage(stage_in_memory):
+        # create cloned robot stage
+        for i in range(num_clones):
+            prim_utils.create_prim(f"/World/env_{i}", "Xform", translation=(i, i, 0))
+
+        cfg = sim_utils.MultiUsdFileCfg(
+            usd_path=usd_paths,
+            random_choice=True,
+            rigid_props=sim_utils.RigidBodyPropertiesCfg(
+                disable_gravity=False,
+                retain_accelerations=False,
+                linear_damping=0.0,
+                angular_damping=0.0,
+                max_linear_velocity=1000.0,
+                max_angular_velocity=1000.0,
+                max_depenetration_velocity=1.0,
+            ),
+            articulation_props=sim_utils.ArticulationRootPropertiesCfg(
+                enabled_self_collisions=True, solver_position_iteration_count=4, solver_velocity_iteration_count=0
+            ),
+            activate_contact_sensors=True,
+        )
+        prim_path_regex = "/World/env_.*/Robot"
+        cfg.func(prim_path_regex, cfg)
+
+        # verify stage is in memory
+        assert sim_utils.is_current_stage_in_memory()
+
+        # verify prims exist in stage in memory
+        prims = prim_utils.find_matching_prim_paths(prim_path_regex)
+        assert len(prims) == num_clones
+
+        # verify prims do not exist in context stage
+        context_stage = omni.usd.get_context().get_stage()
+        with stage_utils.use_stage(context_stage):
+            prims = prim_utils.find_matching_prim_paths(prim_path_regex)
+            assert len(prims) != num_clones
+
+        # attach stage to context
+        sim_utils.attach_stage_to_usd_context()
+
+    # verify stage is no longer in memory
+    assert not sim_utils.is_current_stage_in_memory()
+
+    # verify prims now exist in context stage
+    prims = prim_utils.find_matching_prim_paths(prim_path_regex)
+    assert len(prims) == num_clones
+
+
+def test_stage_in_memory_with_clone_in_fabric(sim):
+    """Test cloning in fabric with stage in memory."""
+
+    # define parameters
+    usd_path = f"{ISAACLAB_NUCLEUS_DIR}/Robots/ANYbotics/ANYmal-C/anymal_c.usd"
+    num_clones = 100
+
+    # grab stage in memory and set as current stage via the with statement
+    stage_in_memory = sim.get_initial_stage()
+    with stage_utils.use_stage(stage_in_memory):
+        # set up paths
+        base_env_path = "/World/envs"
+        source_prim_path = f"{base_env_path}/env_0"
+
+        # create cloner
+        cloner = GridCloner(spacing=3, stage=stage_in_memory)
+        cloner.define_base_env(base_env_path)
+
+        # create source prim
+        prim_utils.create_prim(f"{source_prim_path}/Robot", "Xform", usd_path=usd_path)
+
+        # generate target paths
+        target_paths = cloner.generate_paths("/World/envs/env", num_clones)
+
+        # clone robots at target paths
+        cloner.clone(
+            source_prim_path=source_prim_path,
+            base_env_path=base_env_path,
+            prim_paths=target_paths,
+            replicate_physics=True,
+            clone_in_fabric=True,
+        )
+        prim_path_regex = "/World/envs/env_.*"
+
+        # verify prims do not exist in context stage
+        context_stage = omni.usd.get_context().get_stage()
+        with stage_utils.use_stage(context_stage):
+            prims = prim_utils.find_matching_prim_paths(prim_path_regex)
+            assert len(prims) != num_clones
+
+        # attach stage to context
+        sim_utils.attach_stage_to_usd_context()
+
+    # verify stage is no longer in memory
+    assert not sim_utils.is_current_stage_in_memory()
+
+    # verify prims now exist in fabric stage using usdrt apis
+    stage_id = stage_utils.get_current_stage_id()
+    usdrt_stage = usdrt.Usd.Stage.Attach(stage_id)
+    for i in range(num_clones):
+        prim = usdrt_stage.GetPrimAtPath(f"/World/envs/env_{i}/Robot")
+        assert prim.IsValid()

source/isaaclab/utils/assets.py

+# Copyright (c) 2022-2025, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+# Copyright (c) 2022-2025, The Isaac Lab Project Developers.
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause

source/isaaclab_mimic/isaaclab_mimic/envs/franka_stack_ik_rel_visuomotor_cosmos_mimic_env_cfg.py

+# Copyright (c) 2024-2025, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: Apache-2.0
+
 # Copyright (c) 2025, The Isaac Lab Project Developers.
 # All rights reserved.
 #

source/isaaclab_mimic/isaaclab_mimic/envs/pinocchio_envs/exhaustpipe_gr1t2_mimic_env_cfg.py

+# Copyright (c) 2024-2025, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: Apache-2.0
+
 # Copyright (c) 2025, The Isaac Lab Project Developers.
 # All rights reserved.
 #

source/isaaclab_mimic/isaaclab_mimic/envs/pinocchio_envs/nutpour_gr1t2_mimic_env_cfg.py

+# Copyright (c) 2024-2025, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: Apache-2.0
+
 # Copyright (c) 2025, The Isaac Lab Project Developers.
 # All rights reserved.
 #

source/isaaclab_tasks/isaaclab_tasks/direct/shadow_hand/shadow_hand_vision_env.py

@@ -8,14 +8,14 @@ from __future__ import annotations
 
 import torch
 
-import omni.usd
-
 # from Isaac Sim 4.2 onwards, pxr.Semantics is deprecated
 try:
     import Semantics
 except ModuleNotFoundError:
     from pxr import Semantics
 
+from isaacsim.core.utils.stage import get_current_stage
+
 import isaaclab.sim as sim_utils
 from isaaclab.assets import Articulation, RigidObject
 from isaaclab.scene import InteractiveSceneCfg
@@ -78,7 +78,7 @@ class ShadowHandVisionEnv(InHandManipulationEnv):
         self.object = RigidObject(self.cfg.object_cfg)
         self._tiled_camera = TiledCamera(self.cfg.tiled_camera)
         # get stage
-        stage = omni.usd.get_context().get_stage()
+        stage = get_current_stage()
         # add semantics for in-hand cube
         prim = stage.GetPrimAtPath("/World/envs/env_0/object")
         sem = Semantics.SemanticsAPI.Apply(prim, "Semantics")

source/isaaclab_tasks/isaaclab_tasks/manager_based/manipulation/pick_place/exhaustpipe_gr1t2_base_env_cfg.py

+# Copyright (c) 2022-2025, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
 # Copyright (c) 2025, The Isaac Lab Project Developers.
 # All rights reserved.
 #

source/isaaclab_tasks/isaaclab_tasks/manager_based/manipulation/pick_place/exhaustpipe_gr1t2_pink_ik_env_cfg.py

+# Copyright (c) 2022-2025, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
 # Copyright (c) 2025, The Isaac Lab Project Developers.
 # All rights reserved.
 #

source/isaaclab_tasks/isaaclab_tasks/manager_based/manipulation/pick_place/mdp/pick_place_events.py

+# Copyright (c) 2022-2025, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
 # Copyright (c) 2025, The Isaac Lab Project Developers.
 # All rights reserved.
 #

source/isaaclab_tasks/isaaclab_tasks/manager_based/manipulation/pick_place/nutpour_gr1t2_base_env_cfg.py

+# Copyright (c) 2022-2025, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
 # Copyright (c) 2025, The Isaac Lab Project Developers.
 # All rights reserved.
 #

source/isaaclab_tasks/isaaclab_tasks/manager_based/manipulation/pick_place/nutpour_gr1t2_pink_ik_env_cfg.py

+# Copyright (c) 2022-2025, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
 # Copyright (c) 2025, The Isaac Lab Project Developers.
 # All rights reserved.
 #

source/isaaclab_tasks/isaaclab_tasks/manager_based/manipulation/stack/config/franka/stack_ik_rel_visuomotor_cosmos_env_cfg.py

+# Copyright (c) 2022-2025, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
 # Copyright (c) 2025, The Isaac Lab Project Developers.
 # All rights reserved.
 #