Decouples physics backends from SimulationContext via PhysicsManager (#4564)

# Description

Refactors SimulationContext to use a PhysicsManager abstraction layer,
enabling cleaner separation between simulation orchestration and physics
backend implementation. Introduces backward-compatible deprecation for
configuration fields that moved to PhysxCfg.

## Type of change

- New feature (non-breaking change which adds functionality)
- Breaking change (existing functionality will not work without user
modification)
- Documentation update

## Checklist

- [x] I have read and understood the [contribution
guidelines](https://isaac-sim.github.io/IsaacLab/main/source/refs/contributing.html)
- [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 <[email protected]>
Co-authored-by: Kelly Guo <[email protected]>

Author: ooctipus

apps/isaaclab.python.kit

@@ -17,7 +17,6 @@ keywords = ["experience", "app", "usd"]
 "isaacsim.core.api" = {}
 "isaacsim.core.cloner" = {}
 "isaacsim.core.nodes" = {}
-"isaacsim.core.simulation_manager" = {}
 "isaacsim.core.throttling" = {}
 "isaacsim.core.utils" = {}
 "isaacsim.core.version" = {}

apps/isaacsim_5/isaaclab.python.kit

@@ -17,7 +17,6 @@ keywords = ["experience", "app", "usd"]
 "isaacsim.core.api" = {}
 "isaacsim.core.cloner" = {}
 "isaacsim.core.nodes" = {}
-"isaacsim.core.simulation_manager" = {}
 "isaacsim.core.throttling" = {}
 "isaacsim.core.utils" = {}
 "isaacsim.core.version" = {}

docs/source/how-to/optimize_stage_creation.rst

@@ -60,8 +60,7 @@ be called after the stage is created.
     sim = SimulationContext(cfg=SimulationCfg(create_stage_in_memory=True))
 
     # grab stage in memory and set stage context
-    stage_in_memory = sim.get_initial_stage()
-    with stage_utils.use_stage(stage_in_memory):
+    with stage_utils.use_stage(sim.stage):
         # create cartpole scene
         scene_cfg = CartpoleSceneCfg(num_envs=1024)
         scene = InteractiveScene(scene_cfg)

scripts/benchmarks/benchmark_view_comparison.py

@@ -70,8 +70,6 @@
 
 import torch
 
-from isaacsim.core.simulation_manager import SimulationManager
-
 import isaaclab.sim as sim_utils
 from isaaclab.sim.views import XformPrimView
 
@@ -138,7 +136,7 @@ def benchmark_view(view_type: str, num_iterations: int) -> tuple[dict[str, float
         num_prims = view.count
         view_name = "XformPrimView (Fabric)"
     else:  # physx
-        physics_sim_view = SimulationManager.get_physics_sim_view()
+        physics_sim_view = sim.physics_manager.get_physics_sim_view()
         view = physics_sim_view.create_rigid_body_view(pattern)
         num_prims = view.count
         view_name = "PhysX RigidBodyView"
@@ -196,8 +194,6 @@ def benchmark_view(view_type: str, num_iterations: int) -> tuple[dict[str, float
     computed_results["world_orientations_after_set"] = orientations_after_set.clone()
 
     # close simulation
-    sim.clear()
-    sim.clear_all_callbacks()
     sim.clear_instance()
 
     return timing_results, computed_results

scripts/benchmarks/benchmark_xform_prim_view.py

@@ -274,8 +274,6 @@ def benchmark_xform_prim_view(  # noqa: C901
     timing_results["interleaved_world_set_get"] = (time.perf_counter() - start_time) / num_iterations
 
     # close simulation
-    sim.clear()
-    sim.clear_all_callbacks()
     sim.clear_instance()
 
     return timing_results, computed_results

scripts/tutorials/04_sensors/run_usd_camera.py

@@ -196,7 +196,7 @@ def run_simulator(sim: sim_utils.SimulationContext, scene_entities: dict):
     camera_index = args_cli.camera_id
 
     # Create the markers for the --draw option outside of is_running() loop
-    if sim.has_gui() and args_cli.draw:
+    if sim.get_setting("/isaaclab/has_gui") and args_cli.draw:
         cfg = RAY_CASTER_MARKER_CFG.replace(prim_path="/Visuals/CameraPointCloud")
         cfg.markers["hit"].radius = 0.002
         pc_markers = VisualizationMarkers(cfg)
@@ -248,7 +248,11 @@ def run_simulator(sim: sim_utils.SimulationContext, scene_entities: dict):
             rep_writer.write(rep_output)
 
         # Draw pointcloud if there is a GUI and --draw has been passed
-        if sim.has_gui() and args_cli.draw and "distance_to_image_plane" in camera.data.output.keys():
+        if (
+            sim.get_setting("/isaaclab/has_gui")
+            and args_cli.draw
+            and "distance_to_image_plane" in camera.data.output.keys()
+        ):
             # Derive pointcloud from camera at camera_index
             pointcloud = create_pointcloud_from_depth(
                 intrinsic_matrix=camera.data.intrinsic_matrices[camera_index],

source/isaaclab/config/extension.toml

@@ -1,7 +1,7 @@
 [package]
 
 # Note: Semantic Versioning is used: https://semver.org/
-version = "3.1.0"
+version = "3.2.0"
 
 # Description
 title = "Isaac Lab framework for Robot Learning"

source/isaaclab/docs/CHANGELOG.rst

@@ -1,6 +1,17 @@
 Changelog
 ---------
 
+
+3.2.0 (2026-02-06)
+~~~~~~~~~~~~~~~~~~
+
+Changed
+^^^^^^^
+
+* Refactored :class:`~isaaclab.sim.SimulationContext` to use :class:`~isaaclab.physics.PhysicsManager`
+  abstraction layer for cleaner separation between simulation orchestration and physics backend.
+
+
 3.1.0 (2026-02-05)
 ~~~~~~~~~~~~~~~~~~
 

source/isaaclab/isaaclab/actuators/actuator_base_cfg.py

@@ -3,6 +3,8 @@
 #
 # SPDX-License-Identifier: BSD-3-Clause
 
+from __future__ import annotations
+
 from dataclasses import MISSING
 
 from isaaclab.utils import configclass

source/isaaclab/isaaclab/app/app_launcher.py

@@ -12,6 +12,8 @@
 :attr:`AppLauncher.app` property.
 """
 
+from __future__ import annotations
+
 import argparse
 import contextlib
 import logging