.. _migrating-to-isaaclab-3-0:

Migrating To 3.0
================

.. currentmodule:: isaaclab

Choose the path that matches the code you are starting from. The Isaac Lab 2.x path is organized in
the order most projects should migrate: install the new release, configure a backend, update task APIs,
then move training and visualization workflows.

**Choose your starting point:**

* :ref:`Migration from Isaac Lab 2.x to 3.0 <migrating-from-isaaclab-2-x>` -- update an existing
  Isaac Lab project for the new installation, APIs, and multi-backend architecture.
* :ref:`Migration from Isaac Gym and IsaacGymEnvs <migrating-from-isaacgymenvs>` -- port an Isaac Gym
  task, simulation configuration, or training workflow to Isaac Lab.
* :ref:`Migration of deformables <migrating-deformables>` -- move from the old soft-body API to
  surface and volume deformables.

.. contents:: On this page
   :local:
   :depth: 1
   :backlinks: top


.. _migrating-from-isaaclab-2-x:

.. rubric:: Migration from Isaac Lab 2.x to 3.0

Isaac Lab 3.0 separates backend-specific simulation code from the core API and introduces unified
commands for common workflows. Work through the following sections in order; skip a section only when
your project does not use that feature.

.. seealso::

   This part of the page is the source of truth for the ``isaaclab-migrating-2x-to-3x`` agent skill
   (`skills/user/migrate-2x-to-3x/ <../../../skills/user/migrate-2x-to-3x/SKILL.md>`__).
   When you change it, update the skill so agent guidance stays in sync. See
   :doc:`/source/developer-tools/agent_skills`.


Installation
------------

Start from a fresh Isaac Lab 3.0 checkout and Python 3.12 environment instead of upgrading the
packages inside an existing 2.x environment. The recommended workflow now uses ``uv`` to resolve the
project environment and optional integrations when a command runs. The ``isaaclab.sh`` installer is
still available for manually managed environments, but it is no longer the default path.

.. grid:: 2
   :gutter: 2

   .. grid-item-card:: Isaac Lab 2.x

      Create and activate an environment, install every extension, then launch a library-specific script.

      .. code-block:: bash

         conda create -n env_isaaclab python=3.11
         conda activate env_isaaclab
         ./isaaclab.sh --install rsl_rl
         ./isaaclab.sh -p scripts/reinforcement_learning/rsl_rl/train.py \
            --task Isaac-Cartpole

   .. grid-item-card:: Isaac Lab 3.0

      Install ``uv`` once; ``uv run`` creates or synchronizes the project environment and launches the
      unified command. Select optional runtimes with ``--extra`` before ``isaaclab``.

      .. code-block:: bash

         curl -LsSf https://astral.sh/uv/install.sh | sh
         uv run --extra isaacsim isaaclab train \
            --rl_library rsl_rl --task Isaac-Cartpole \
            physics=isaacsim_physx

Use ``uv run isaaclab ...`` for Newton-only workflows, ``--extra ovphysx`` for OV PhysX, and
``--extra isaacsim`` for full Isaac Sim support. See :ref:`installation-method-uv` for platform-specific
setup, the complete extras list, and manually managed environment options.


Multi-Backend Architecture and Presets
--------------------------------------

Understand the new package boundaries first, then make environment configuration backend-selectable.

.. grid:: 2
   :gutter: 2

   .. grid-item-card:: Isaac Lab 2.x

      Physics-specific configuration and implementations were exposed through the core package, and
      environments typically configured one PhysX backend directly.

      .. code-block:: python

         import isaaclab.sim as sim_utils

         self.sim.physics = sim_utils.PhysxCfg(...)

   .. grid-item-card:: Isaac Lab 3.0

      Core assets dispatch to the selected backend. Import backend-owned configuration explicitly and
      use a preset when an environment supports multiple backends.

      .. code-block:: python

         from isaaclab.utils import configclass
         from isaaclab_physx.physics import PhysxCfg
         from isaaclab_tasks.utils import PresetCfg

         @configclass
         class PhysicsPresets(PresetCfg):
             isaacsim_physx: PhysxCfg = PhysxCfg(...)
             default: PhysxCfg = isaacsim_physx

         self.sim.physics = PhysicsPresets()


.. rubric:: Multi-Backend Architecture

Isaac Lab 3.0 introduces a **factory-based multi-backend architecture** that allows asset classes
to be backed by different physics engines — currently **PhysX** and **Newton**.

When you instantiate an asset class from the ``isaaclab`` package (e.g., ``Articulation``,
``RigidObject``), a factory automatically resolves and loads the correct backend implementation:

.. code-block:: python

   from isaaclab.assets import Articulation, ArticulationCfg

   # The factory pattern creates the appropriate backend implementation.
   # No import changes are needed — the same isaaclab imports work regardless of backend.
   robot = Articulation(cfg=ArticulationCfg(...))

The factory works by convention: for a class defined in ``isaaclab.assets.articulation``, it
imports the matching class from the active backend package. The ``isaaclab_physx``,
``isaaclab_newton``, and ``isaaclab_ov`` packages mirror the ``isaaclab`` module structure.

The concrete default remains task-specific so launching without an override stays predictable.
Tasks can expose alternatives such as ``physics=physx``, ``physics=ovphysx``, or
``physics=newton_mjwarp`` without changing their asset import paths.

For a comprehensive overview of the factory pattern and backend selection,
see :doc:`/source/concepts/backend_architecture`. To add a new backend, see
:doc:`/source/developer-tools/add_physics_backend`.


.. rubric:: New ``isaaclab_physx`` and ``isaaclab_newton`` Extensions

Two new backend extensions have been introduced:

- **``isaaclab_physx``** — PhysX-specific implementations of asset and sensor classes.
- **``isaaclab_newton``** — Newton-specific implementations of supported asset classes, including
  articulations, rigid objects, and deformable objects.

The following classes have been moved to ``isaaclab_physx``:

.. list-table::
   :header-rows: 1
   :widths: 50 50

   * - Isaac Lab 2.x
     - Isaac Lab 3.0
   * - ``from isaaclab.assets import SurfaceGripper``
     - ``from isaaclab_physx.assets import SurfaceGripper``
   * - ``from isaaclab.assets import SurfaceGripperCfg``
     - ``from isaaclab_physx.assets import SurfaceGripperCfg``

.. note::

   Deformable object public APIs remain in the backend-neutral ``isaaclab``
   package. Continue importing :class:`~isaaclab.assets.DeformableObject`,
   :class:`~isaaclab.assets.DeformableObjectCfg`, and
   :class:`~isaaclab.assets.DeformableObjectData` from ``isaaclab.assets``.

.. note::

   The ``isaaclab_physx`` extension is installed automatically with Isaac Lab. No additional
   installation steps are required.


.. rubric:: Backend-Neutral Imports

The following asset classes remain in the ``isaaclab`` package and can still be imported as before:

- :class:`~isaaclab.assets.Articulation`, :class:`~isaaclab.assets.ArticulationCfg`, :class:`~isaaclab.assets.ArticulationData`
- :class:`~isaaclab.assets.RigidObject`, :class:`~isaaclab.assets.RigidObjectCfg`, :class:`~isaaclab.assets.RigidObjectData`
- :class:`~isaaclab.assets.RigidObjectCollection`, :class:`~isaaclab.assets.RigidObjectCollectionCfg`, :class:`~isaaclab.assets.RigidObjectCollectionData`

These classes now inherit from new abstract base classes but maintain full backward compatibility.

The following sensor classes also remain in the ``isaaclab`` package with unchanged imports:

- :class:`~isaaclab.sensors.ContactSensor`, :class:`~isaaclab.sensors.ContactSensorCfg`, :class:`~isaaclab.sensors.ContactSensorData`
- :class:`~isaaclab.sensors.Imu`, :class:`~isaaclab.sensors.ImuCfg`, :class:`~isaaclab.sensors.ImuData`
- :class:`~isaaclab.sensors.Pva`, :class:`~isaaclab.sensors.PvaCfg`, :class:`~isaaclab.sensors.PvaData`
- :class:`~isaaclab.sensors.FrameTransformer`, :class:`~isaaclab.sensors.FrameTransformerCfg`, :class:`~isaaclab.sensors.FrameTransformerData`
- :class:`~isaaclab.sensors.JointWrenchSensor`, :class:`~isaaclab.sensors.JointWrenchSensorCfg`,
  :class:`~isaaclab.sensors.JointWrenchSensorData`

These sensor classes now use factory patterns that automatically instantiate the appropriate backend
implementation (PhysX by default), maintaining full backward compatibility.

.. note::

   The ``Imu`` sensor in Isaac Lab 3.0 is **not** the same as the ``Imu`` sensor in 2.x.
   The old ``Imu`` (full state sensor) has been renamed to :class:`~isaaclab.sensors.Pva`.
   The new :class:`~isaaclab.sensors.Imu` is a lightweight sensor that only provides angular velocity
   and linear acceleration. See :ref:`imu-to-pva-migration` below for details.

If you need to import the PhysX sensor implementations directly (e.g., for type hints or subclassing),
you can import from ``isaaclab_physx.sensors``:

.. code-block:: python

   # Direct PhysX implementation imports
   from isaaclab_physx.sensors import ContactSensor, ContactSensorData
   from isaaclab_physx.sensors import Imu, ImuData
   from isaaclab_physx.sensors import Pva, PvaData
   from isaaclab_physx.sensors import FrameTransformer, FrameTransformerData
   from isaaclab_physx.sensors import JointWrenchSensor, JointWrenchSensorData


.. rubric:: Newton Backend Implementations

A new extension ``isaaclab_newton`` provides Newton physics backend implementations for:

- :class:`~isaaclab_newton.assets.Articulation` and :class:`~isaaclab_newton.assets.ArticulationData`
- :class:`~isaaclab_newton.assets.RigidObject` and :class:`~isaaclab_newton.assets.RigidObjectData`
- :class:`~isaaclab_newton.sensors.JointWrenchSensor` and
  :class:`~isaaclab_newton.sensors.JointWrenchSensorData`

These classes implement the same base interfaces as their PhysX counterparts
(:class:`~isaaclab.assets.BaseArticulation`, :class:`~isaaclab.assets.BaseRigidObject`),
ensuring a consistent API across backends. They use the same warp-based data conventions
(``wp.array`` with structured types, ``_index`` / ``_mask`` write methods).

.. note::

   The ``isaaclab_newton`` extension requires the ``newton`` package and its dependencies
   (``mujoco``, ``mujoco-warp``). These are installed automatically when installing the
   ``isaaclab_newton`` package.

If you need to import Newton implementations directly (e.g., for type hints or subclassing):

.. code-block:: python

   from isaaclab_newton.assets import Articulation as NewtonArticulation
   from isaaclab_newton.assets import RigidObject as NewtonRigidObject


.. _schemas-cfg-refactor:

.. rubric:: Schema Configuration Class Refactor

In Isaac Lab 3.0, the spawner schema cfg classes are split into solver-common
**base classes** (in ``isaaclab.sim.schemas``) and **backend-specific subclasses**
in ``isaaclab_physx.sim.schemas`` and ``isaaclab_newton.sim.schemas``. This makes
the same asset cfg portable across PhysX and Newton backends, and adds slots
for backend-specific asset-level knobs (e.g., MuJoCo gravity compensation).

For the full design, see :ref:`schema-cfgs`.

**Class moves and renames**

The following 2.x class names are kept as deprecated aliases. They forward to
the new location and will be removed in 4.0.

.. list-table::
   :header-rows: 1
   :widths: 40 60

   * - Isaac Lab 2.x
     - Isaac Lab 3.0
   * - ``RigidBodyPropertiesCfg``
     - :class:`~isaaclab.sim.schemas.RigidBodyBaseCfg` (solver-common fields) +
       :class:`~isaaclab_physx.sim.schemas.PhysxRigidBodyPropertiesCfg` (PhysX-specific)
   * - ``JointDrivePropertiesCfg``
     - :class:`~isaaclab.sim.schemas.JointDriveBaseCfg` +
       :class:`~isaaclab_physx.sim.schemas.PhysxJointDrivePropertiesCfg`
   * - ``CollisionPropertiesCfg``
     - :class:`~isaaclab.sim.schemas.CollisionBaseCfg` +
       :class:`~isaaclab_physx.sim.schemas.PhysxCollisionPropertiesCfg`
   * - ``ArticulationRootPropertiesCfg``
     - :class:`~isaaclab.sim.schemas.ArticulationRootBaseCfg` +
       :class:`~isaaclab_physx.sim.schemas.PhysxArticulationRootPropertiesCfg`
   * - ``RigidBodyMaterialCfg``
     - :class:`~isaaclab.sim.spawners.materials.RigidBodyMaterialBaseCfg` +
       :class:`~isaaclab_physx.sim.spawners.materials.PhysxRigidBodyMaterialCfg`
   * - ``MeshCollisionPropertiesCfg`` family (``ConvexHullPropertiesCfg``,
       ``ConvexDecompositionPropertiesCfg``, ``TriangleMeshPropertiesCfg``,
       ``TriangleMeshSimplificationPropertiesCfg``, ``SDFMeshPropertiesCfg``)
     - :class:`~isaaclab.sim.schemas.MeshCollisionBaseCfg` +
       ``Physx*PropertiesCfg`` family in :mod:`isaaclab_physx.sim.schemas`
   * - ``FixedTendonPropertiesCfg``, ``SpatialTendonPropertiesCfg``
     - :class:`~isaaclab_physx.sim.schemas.PhysxFixedTendonPropertiesCfg`,
       :class:`~isaaclab_physx.sim.schemas.PhysxSpatialTendonPropertiesCfg`

**Code migration**

Existing 2.x code continues to work via the deprecation aliases (with a
``DeprecationWarning``; removed in 4.0):

.. code-block:: python

   # Isaac Lab 2.x
   import isaaclab.sim as sim_utils
   rigid_props = sim_utils.RigidBodyPropertiesCfg(disable_gravity=True, linear_damping=0.1)

Recommended 3.0 pattern when targeting PhysX:

.. code-block:: python

   # Isaac Lab 3.0 — PhysX backend
   from isaaclab_physx.sim.schemas import PhysxRigidBodyPropertiesCfg
   rigid_props = PhysxRigidBodyPropertiesCfg(disable_gravity=True, linear_damping=0.1)

Backend-portable 3.0 pattern (universal-physics fields only):

.. code-block:: python

   # Isaac Lab 3.0 — backend-portable
   from isaaclab.sim.schemas import RigidBodyBaseCfg
   rigid_props = RigidBodyBaseCfg(rigid_body_enabled=True, disable_gravity=True)

**Field renames on** ``JointDriveBaseCfg``

Two cfg fields were renamed so their snake_case names map identity-style to the
USD camelCase attribute names. The old names remain as deprecated dataclass
fields on :class:`~isaaclab.sim.schemas.JointDriveBaseCfg` (so
``dataclasses.fields()`` still sees them) and are forwarded to the new fields
in ``__post_init__`` with a ``DeprecationWarning``. Setting **both** the old
and new field on the same instance is silent — the canonical (new) field
wins; the old field's value is discarded after the warning. Both aliases are
scheduled for removal in 4.0.

.. list-table::
   :header-rows: 1
   :widths: 35 35 30

   * - Isaac Lab 2.x
     - Isaac Lab 3.0
     - USD attribute (unchanged)
   * - :attr:`~isaaclab.sim.schemas.JointDriveBaseCfg.max_velocity`
     - :attr:`~isaaclab.sim.schemas.JointDriveBaseCfg.max_joint_velocity`
     - ``physxJoint:maxJointVelocity``
   * - :attr:`~isaaclab.sim.schemas.JointDriveBaseCfg.max_effort`
     - :attr:`~isaaclab.sim.schemas.JointDriveBaseCfg.max_force`
     - ``drive:<axis>:physics:maxForce``

Isaac Lab 2.x style still works (emits ``DeprecationWarning``; removed in 4.0):

.. code-block:: python

   import isaaclab.sim as sim_utils
   sim_utils.JointDrivePropertiesCfg(max_effort=80.0, max_velocity=5.0)

Recommended 3.0 pattern, backend-portable:

.. code-block:: python

   from isaaclab.sim.schemas import JointDriveBaseCfg
   JointDriveBaseCfg(max_force=80.0, max_joint_velocity=5.0)

Recommended 3.0 pattern, PhysX-targeted:

.. code-block:: python

   from isaaclab_physx.sim.schemas import PhysxJointDrivePropertiesCfg
   PhysxJointDrivePropertiesCfg(max_force=80.0, max_joint_velocity=5.0)

**New Newton and MuJoCo cfg classes**

For the Newton backend (and Newton's MuJoCo solver), new cfg classes are
available under :mod:`isaaclab_newton.sim.schemas`:

.. list-table::
   :header-rows: 1
   :widths: 50 50

   * - Class
     - Use case
   * - :class:`~isaaclab_newton.sim.schemas.NewtonCollisionPropertiesCfg`
     - ``newton:contactMargin`` / ``newton:contactGap`` via ``NewtonCollisionAPI``
   * - :class:`~isaaclab_newton.sim.schemas.NewtonMeshCollisionPropertiesCfg`
     - ``newton:maxHullVertices`` via ``NewtonMeshCollisionAPI``
   * - :class:`~isaaclab_newton.sim.schemas.NewtonMaterialPropertiesCfg`
     - ``newton:torsionalFriction`` / ``newton:rollingFriction`` via ``NewtonMaterialAPI``
   * - :class:`~isaaclab_newton.sim.schemas.NewtonArticulationRootPropertiesCfg`
     - ``newton:selfCollisionEnabled`` via ``NewtonArticulationRootAPI``
   * - :class:`~isaaclab_newton.sim.schemas.MujocoRigidBodyPropertiesCfg`
     - ``mjc:gravcomp`` (body-level gravity compensation, MuJoCo solver only)
   * - :class:`~isaaclab_newton.sim.schemas.MujocoJointDrivePropertiesCfg`
     - ``mjc:actuatorgravcomp`` via ``MjcJointAPI`` (joint-level routing)

The MuJoCo cfgs subclass their Newton parent because MuJoCo is one of Newton's
solver options.

.. note::

   Spawners auto-enable body-level gravity compensation when joint-level
   ``actuatorgravcomp=True`` is requested but no Mujoco rigid-body cfg is
   provided — without ``gravcomp`` on the bodies, ``actuatorgravcomp`` is a
   no-op (no forces to route). To override, pass an explicit
   ``MujocoRigidBodyPropertiesCfg`` in ``rigid_props``. See
   :ref:`schema-cfgs-gravcomp` for details.

For complete tables of which fields live on which class and where each lands in
USD, see :ref:`schema-cfgs`.


.. rubric:: Multi-Backend Support: PresetCfg Pattern

Isaac Lab 3.0 introduces a **PresetCfg pattern** for writing environment configurations
that work with both the PhysX and Newton backends. Instead of hard-coding a single
physics config, environments declare named configuration variants. The active variant
is selected at launch via a Hydra CLI override.

**What is PresetCfg?**

:class:`~isaaclab_tasks.utils.PresetCfg` is a base ``@configclass`` whose typed fields
represent named variants of a configuration section. The field named ``default`` is used
when no CLI override is given. Other fields are named presets selectable with
``presets=<name>`` on the command line:

.. code-block:: python

   from isaaclab.physics import PhysxAutoCfg
   from isaaclab.utils import configclass
   from isaaclab_ov.physics import OvPhysxCfg
   from isaaclab_tasks.utils import PresetCfg

   @configclass
   class MyPhysicsCfg(PresetCfg):
       isaacsim_physx: PhysxCfg = PhysxCfg(...)
       ovphysx: OvPhysxCfg = OvPhysxCfg()
       physx: PhysxAutoCfg = PhysxAutoCfg(isaacsim_physx=isaacsim_physx, ovphysx=ovphysx)
       default: PhysxCfg = isaacsim_physx  # used when no override is given
       newton_mjwarp:  NewtonCfg = NewtonCfg(...)  # selected by physics=newton_mjwarp

**Selecting a preset at launch**

Pass ``physics=newton_mjwarp`` on the CLI to swap the entire config section.
Use ``physics=physx`` to opt into automatic PhysX-family selection. The legacy
``presets=NAME`` form still works for the same values.

.. code-block:: bash

   # Run with Newton backend
   uv run --extra isaacsim isaaclab train --rl_library rsl_rl \
       --task Isaac-Open-Drawer-Franka-Direct physics=newton_mjwarp

   # Run with default (concrete Isaac Sim PhysX) backend
   uv run --extra isaacsim isaaclab train --rl_library rsl_rl \
       --task Isaac-Open-Drawer-Franka-Direct

**Adding Multi-Backend Support to an Environment**

**Step 1 — Physics config**

Replace a plain ``PhysxCfg(...)`` assignment in ``__post_init__`` with a ``PresetCfg``
subclass that carries both a PhysX and a Newton variant.

*Before:*

.. code-block:: python

   def __post_init__(self):
       self.sim.dt = 1 / 60
       self.sim.physics = PhysxCfg(bounce_threshold_velocity=0.2)

.. important::

   The ``After`` example below mirrors the current Reach task, which intentionally
   uses Newton/MJWarp as its default. The ``Before`` snippet only illustrates the
   older single-backend form, so the default differs between the two snippets.
   When migrating a task that should retain PhysX by default, use
   ``default: PhysxCfg = isaacsim_physx`` instead. Adding backend variants should
   not silently change a task's established default.

*After:*

.. code-block:: python

   from isaaclab.physics import PhysxAutoCfg
   from isaaclab_newton.physics import MJWarpSolverCfg, NewtonCfg
   from isaaclab_ov.physics import OvPhysxCfg
   from isaaclab_physx.physics import PhysxCfg
   from isaaclab_tasks.utils import PresetCfg

   @configclass
   class ReachPhysicsCfg(PresetCfg):
       isaacsim_physx: PhysxCfg = PhysxCfg(bounce_threshold_velocity=0.2)
       ovphysx: OvPhysxCfg = OvPhysxCfg()
       physx: PhysxAutoCfg = PhysxAutoCfg(isaacsim_physx=isaacsim_physx, ovphysx=ovphysx)
       newton_mjwarp:  NewtonCfg = NewtonCfg(
           solver_cfg=MJWarpSolverCfg(
               njmax=20, nconmax=20, ls_iterations=20,
               cone="pyramidal", integrator="implicitfast",
               impratio=1,
           ),
           num_substeps=1,
           debug_mode=False,
       )
       default: NewtonCfg = newton_mjwarp

   # In the env cfg __post_init__:
   def __post_init__(self):
       self.sim.dt = 1 / 60
       self.sim.physics = ReachPhysicsCfg()

Key Newton solver parameters:

.. list-table::
   :header-rows: 1
   :widths: 25 75

   * - Parameter
     - Effect
   * - ``njmax``
     - Max constraint rows; set ≥ expected contact count per env
   * - ``nconmax``
     - Max contacts per env
   * - ``ls_iterations``
     - Iterative line search cap; stops early when convergence is reached.
       Tune alongside outer solver iterations for runtime and convergence.
   * - ``cone``
     - ``"pyramidal"`` (fast) or ``"elliptic"`` (more accurate)
   * - ``integrator``
     - ``"implicitfast"`` (recommended) or ``"euler"``
   * - ``impratio``
     - Impedance ratio; >1 improves soft contact stability
   * - ``num_substeps``
     - Physics substeps per environment step

**Step 2 — Differentiating Newton and PhysX Configs**

Not all configurations may be the same between Newton and PhysX simulations.
We can provide a Newton-specific config such as:

.. code-block:: python

   @configclass
   class EventCfg:
       """Full event config (PhysX-compatible)."""
       robot_physics_material = EventTerm(
           func=mdp.randomize_rigid_body_material,
           mode="startup",
           params={...},
       )
       reset_all = EventTerm(func=mdp.reset_scene_to_default, mode="reset")
       reset_robot_joints = EventTerm(
           func=mdp.reset_joints_by_offset, mode="reset", params={...}
       )


   @configclass
   class _EnvNewtonEventCfg:
       """Newton-compatible events."""
       reset_all = EventTerm(func=mdp.reset_scene_to_default, mode="reset")
       reset_robot_joints = EventTerm(
           func=mdp.reset_joints_by_offset, mode="reset", params={...}
       )


   @configclass
   class EnvEventCfg(PresetCfg):
       default: EventCfg = EventCfg()
       physx:   EventCfg = EventCfg()
       newton_mjwarp:  _EnvNewtonEventCfg = _EnvNewtonEventCfg()

Then change the ``events`` field in your env cfg from ``EventCfg`` to ``EnvEventCfg``:

.. code-block:: python

   @configclass
   class MyEnvCfg(ManagerBasedRLEnvCfg):
       events: EnvEventCfg = EnvEventCfg()  # was: EventCfg = EventCfg()


.. rubric:: Isaac Sim API Compatibility

In Isaac Sim 6.0, the legacy ``isaacsim.core.*``, ``isaacsim.sensors.*``, and
``isaacsim.robot.wheeled_robots`` Python module paths are **deprecated** in favor of their
``isaacsim.core.experimental.*`` (and ``*.experimental.*``) equivalents. Isaac Lab 3.0 has
been migrated off the deprecated paths so that Isaac Lab continues to load and run when
those modules are removed in a future Isaac Sim release.

This is mostly a transparent change for users — Isaac Lab's own public Python API
(:mod:`isaaclab`, :mod:`isaaclab_physx`, :mod:`isaaclab_tasks`, :mod:`isaaclab_teleop`,
:mod:`isaaclab_mimic`) is unchanged. The migration is only user-visible if you:

1. Import Isaac Sim symbols **directly** in your project, or
2. Maintain a custom Kit experience (``.kit`` file) that lists Isaac Sim extension
   dependencies, or
3. Imported ``SimulationManager`` from ``isaacsim.core.simulation_manager`` in your own
   PhysX-backed code.


**Python module renames**

Update direct imports in your own code as follows. **Where Isaac Lab provides an in-tree
replacement, prefer the Isaac Lab API** over the ``isaacsim.core.experimental.*`` fallback:

.. list-table::
   :header-rows: 1
   :widths: 45 55

   * - Deprecated Isaac Sim path
     - Recommended replacement
   * - ``isaacsim.core.utils.stage``
     - :mod:`isaaclab.sim.utils.stage` (e.g. ``get_current_stage``,
       ``create_new_stage``, ``open_stage``, ``save_stage``, ``close_stage``,
       ``clear_stage``, ``update_stage``, ``use_stage``)
   * - ``isaacsim.core.utils.prims``
     - :mod:`isaaclab.sim.utils.prims` (e.g. ``create_prim``, ``delete_prim``,
       ``change_prim_property``, ``bind_visual_material``,
       ``bind_physics_material``, ``add_usd_reference``)
   * - ``isaacsim.core.utils.queries``
     - :mod:`isaaclab.sim.utils.queries` (e.g. ``find_matching_prims``,
       ``find_matching_prim_paths``, ``get_first_matching_child_prim``)
   * - ``isaacsim.core.utils.transforms``
     - :mod:`isaaclab.sim.utils.transforms`
   * - ``isaacsim.core.utils.semantics``
     - :mod:`isaaclab.sim.utils.semantics`
   * - ``isaacsim.core.utils.extensions.enable_extension``
     - :func:`isaaclab.sim.utils.enable_extension`
   * - ``isaacsim.core.utils.viewports.set_camera_view``
     - ``isaacsim.core.rendering_manager.ViewportManager.set_camera_view`` (or
       ``omni.kit.viewport.utility.camera_state.ViewportCameraState`` for lower-level control)
   * - ``isaacsim.core.prims.XFormPrim`` / ``XFormPrimView``
     - :class:`~isaaclab.sim.views.FrameView` (Isaac Lab in-tree view; see
       :ref:`migrating-to-isaaclab-3-0` ``Renaming of XformPrimView to FrameView`` above).
       For ``Articulation`` / ``RigidPrim`` use ``isaacsim.core.experimental.prims``.
   * - ``isaacsim.core.simulation_manager.SimulationManager``
     - :class:`isaaclab_physx.physics.PhysxManager` (PhysX backend) or
       ``isaaclab_newton.physics.NewtonManager`` (Newton backend); see local-alias
       pattern below.
   * - ``isaacsim.core.cloner``
     - :mod:`isaaclab.cloner` (Isaac Lab in-tree cloner)
   * - ``isaacsim.replicator.mobility_gen``
     - ``isaacsim.replicator.experimental.mobility_gen``
   * - ``isaacsim.sensors.<name>``
     - ``isaacsim.sensors.experimental.<name>``
   * - ``isaacsim.robot.wheeled_robots``
     - ``isaacsim.robot.experimental.wheeled_robots`` (and
       ``isaacsim.robot.wheeled_robots.nodes`` for OmniGraph nodes)

To keep call-site code symmetric across backends when migrating off
``isaacsim.core.simulation_manager.SimulationManager``, use the local-alias pattern:

.. code-block:: python

   from isaaclab_physx.physics import PhysxManager as SimulationManager
   # or, for the Newton backend
   from isaaclab_newton.physics import NewtonManager as SimulationManager

**Isaac Sim extension modules must be explicitly enabled before direct import**

Isaac Lab 3.0 no longer automatically initializes Isaac Sim extensions only to
make their Python modules importable. Stock Isaac Lab Kit experiences now load a
smaller set of extensions so unused Isaac Sim packages do not pull in
unnecessary dependencies or deprecated aliases.

If your project imports an Isaac Sim extension module directly, enable the
extension after the Kit application has started and before importing from that
module:

.. code-block:: python

   from isaaclab.sim.utils import enable_extension

   enable_extension("isaacsim.core.experimental.prims")
   from isaacsim.core.experimental.prims import XformPrim

This is especially important for migration replacements such as
``isaacsim.core.experimental.*`` and ``isaacsim.sensors.experimental.*``. Do not
import ``enable_extension`` from ``isaacsim.core.experimental.utils.app`` unless
that extension is already enabled; use :func:`isaaclab.sim.utils.enable_extension`
from Isaac Lab instead. The helper requires a running Kit application and raises
``RuntimeError`` if called from plain Python before Kit is launched.


**Kit experience (``.kit``) updates**

If you maintain a custom Kit experience derived from one of the Isaac Lab apps under
``apps/``:

* **Stop registering deprecated extension search paths.** The ``extsDeprecated`` search
  path entry has been removed from all stock Isaac Lab Kit experiences (headless,
  rendering, XR variants). Mirror that change in your own experience.
* **Switch explicit Isaac Sim extension dependencies** to the non-deprecated equivalents
  listed above (``isaacsim.core.experimental.*``, ``isaacsim.sensors.experimental.*``,
  ``isaacsim.robot.experimental.wheeled_robots``).
* **Do not rely on stock Isaac Lab apps to preload Isaac Sim extensions** that your
  project imports directly. Either add those extensions to your custom ``.kit`` file
  or enable them with :func:`isaaclab.sim.utils.enable_extension` before importing
  their Python modules.
* **Remove unused Isaac Sim extensions that pull in** ``isaacsim.core.api`` — Isaac Lab
  no longer depends on those, and keeping them resurrects the deprecated stack.


**``SimulationManager`` is no longer re-exported**

Earlier internal previews of this migration briefly exposed
``isaaclab_physx.physics.SimulationManager`` as a public alias of
:class:`~isaaclab_physx.physics.PhysxManager`. **That alias has been removed**; use
:class:`~isaaclab_physx.physics.PhysxManager` directly (with ``as SimulationManager`` at
the import site if you want backend-agnostic call-site code, as shown above).


**Retired standalone reproducers**

A handful of legacy reproducers under ``source/isaaclab/test/deps/isaacsim`` that
depended on the deprecated Isaac Sim core extensions have been retired:
``check_camera.py``, ``check_floating_base_made_fixed.py``,
``check_legged_robot_clone.py``, ``check_rep_texture_randomizer.py``, and
``check_ref_count.py``. Use :mod:`isaaclab.sim` together with the new
``isaacsim.core.experimental.*`` APIs for the same debugging workflows.


.. rubric:: PhysX Tensors API Module Path

Recent Isaac Sim releases removed the internal ``impl`` submodule of
``omni.physics.tensors`` and now expose the PhysX Tensor API types
(``ArticulationView``, ``RigidBodyView``, ``SimulationView``, etc.) directly
under ``omni.physics.tensors.api``. Importing from the old path raises
``ModuleNotFoundError: No module named 'omni.physics.tensors.impl'`` at import
time.

Isaac Lab has been updated to import from the new path. Downstream code
(custom assets, sensors, or scripts) that imported from the old path must be
updated:

.. code-block:: python

   # Before (Isaac Lab 2.x / older Isaac Sim)
   import omni.physics.tensors.impl.api as physx

   # After (Isaac Lab 3.x / current Isaac Sim)
   import omni.physics.tensors.api as physx

The class identities are unchanged — only the module path moved. Type hints
referencing the old path (``omni.physics.tensors.impl.api.ArticulationView``)
should be similarly updated to ``omni.physics.tensors.api.ArticulationView``.


Assets, Actuators, and Sensors
------------------------------

Update asset-facing APIs after the backend configuration is in place. This includes renamed views, actuator ownership, and sensor replacements.

.. grid:: 2
   :gutter: 2

   .. grid-item-card:: Isaac Lab 2.x

      .. code-block:: python

         from isaaclab.sim.views import XformPrimView
         from isaaclab.sensors import ImuCfg

         view = XformPrimView(...)
         wrench = robot.data.body_incoming_joint_wrench_b

   .. grid-item-card:: Isaac Lab 3.0

      .. code-block:: python

         from isaaclab.sim.views import FrameView
         from isaaclab.sensors import JointWrenchSensorCfg, PvaCfg

         view = FrameView(...)
         wrench = env.scene.sensors["joint_wrench"].data.force.torch


.. rubric:: Renaming of ``XformPrimView`` to ``FrameView``

Isaac Lab's ``XformPrimView`` and related classes have been renamed to ``FrameView`` to
better reflect their purpose and avoid confusion with Isaac Sim's ``XFormPrim`` class
hierarchy. The old ``XformPrimView`` name is kept as a deprecated alias.

The rename applies across all backends:

.. list-table::
   :header-rows: 1
   :widths: 50 50

   * - Isaac Lab 2.x
     - Isaac Lab 3.0
   * - ``BaseXformPrimView``
     - :class:`~isaaclab.sim.views.BaseFrameView`
   * - ``UsdXformPrimView``
     - :class:`~isaaclab.sim.views.UsdFrameView`
   * - ``XformPrimView``
     - :class:`~isaaclab.sim.views.FrameView`
   * - ``FabricXformPrimView``
     - :class:`~isaaclab_physx.sim.views.FabricFrameView`
   * - ``NewtonSiteXformPrimView``
     - :class:`~isaaclab_newton.sim.views.NewtonSiteFrameView`

For most users, the only change needed is updating imports:

.. code-block:: python

   # Before
   from isaaclab.sim.views import XformPrimView

   # After
   from isaaclab.sim.views import FrameView

The :class:`~isaaclab.sim.views.FrameView` factory automatically dispatches to the correct
backend (:class:`~isaaclab_physx.sim.views.FabricFrameView` for PhysX,
:class:`~isaaclab_newton.sim.views.NewtonSiteFrameView` for Newton) based on the active
physics backend. The deprecated ``XformPrimView`` alias continues to work but will be
removed in a future release.


.. _actuators-solver-limit-migration:

.. rubric:: Actuator effort and joint-limit names

Actuator configurations now use joint-qualified names for solver limits. Update active
configurations to the canonical fields below. The former names remain accepted with a
``DeprecationWarning`` through the 3.x release line and will be removed in 4.0.

.. list-table:: Actuator limit migration
   :header-rows: 1
   :widths: 38 38 24

   * - Deprecated configuration field
     - Canonical configuration field
     - Runtime owner
   * - ``effort_limit``
     - ``actuator_effort_limit``
     - Actuator model (rated limit)
   * - ``effort_limit_sim``
     - ``joint_effort_limit``
     - :attr:`~isaaclab.assets.ArticulationData.joint_effort_limits`
   * - ``velocity_limit_sim``
     - ``joint_velocity_limit``
     - :attr:`~isaaclab.assets.ArticulationData.joint_vel_limits`

``actuator_effort_limit`` clips explicit actuator-model output. ``joint_effort_limit`` and
``joint_velocity_limit`` are construction-time joint-property overrides selected by an actuator
group's joint expression. The deprecated aliases ``effort_limit``, ``velocity_limit``,
``effort_limit_sim``, and ``velocity_limit_sim`` remain accepted through 3.x. ``effort_limit``
resolves to the rated ``actuator_effort_limit`` for every actuator type. For an implicit group
without a separately configured solver clamp, the rated value also populates
``joint_effort_limit`` for backward compatibility; configure both fields to author distinct
rated and solver limits. The runtime ``effort_limit`` and ``velocity_limit`` group properties
follow the same mapping and are also deprecated.
``actuator_velocity_limit`` describes rated speed or an implicit soft-limit snapshot.
``joint_velocity_limit`` only requests solver enforcement, which is backend-dependent. See
:ref:`actuators-joint-property-ownership` for the full ownership model.

**Behavior change — explicit groups keep the solver effort limit.** Isaac Lab previously raised the
solver effort limit to ``1.0e9`` on joints driven by an explicit actuator so that only the model
clipped the effort. The solver now keeps the authored or configured ``joint_effort_limit``, so
effort submitted by an explicit model is clipped a second time by the solver. If your asset authors
a tight joint effort limit and your policy relies on the model limit alone, set
``joint_effort_limit`` at least as large as ``actuator_effort_limit`` in the actuator
configuration.

The runtime group properties listed below were removed. Read their live values from articulation
data and use the corresponding indexed articulation writer:

.. list-table:: Removed group-property migration
   :header-rows: 1
   :widths: 26 38 36

   * - Removed runtime group property
     - Read
     - Write
   * - ``effort_limit_sim``
     - :attr:`~isaaclab.assets.ArticulationData.joint_effort_limits`
     - :meth:`~isaaclab.assets.Articulation.write_joint_effort_limit_to_sim_index`
   * - ``velocity_limit_sim``
     - :attr:`~isaaclab.assets.ArticulationData.joint_vel_limits`
     - :meth:`~isaaclab.assets.Articulation.write_joint_velocity_limit_to_sim_index`
   * - ``armature``
     - :attr:`~isaaclab.assets.ArticulationData.joint_armature`
     - :meth:`~isaaclab.assets.Articulation.write_joint_armature_to_sim_index`
   * - ``friction``
     - :attr:`~isaaclab.assets.ArticulationData.joint_friction_coeff`
     - :meth:`~isaaclab.assets.Articulation.write_joint_friction_coefficient_to_sim_index`
   * - ``dynamic_friction``
     - ``data.joint_dynamic_friction_coeff`` (PhysX and OVPhysX)
     - ``write_joint_dynamic_friction_coefficient_to_sim_index`` (PhysX and OVPhysX)
   * - ``viscous_friction``
     - ``data.joint_viscous_friction_coeff``
     - ``write_joint_viscous_friction_coefficient_to_sim_index``

The dynamic-friction view and writer are backend-specific; Newton has no corresponding joint
property.

**Custom actuator models.** The protected helper ``ActuatorBase._parse_joint_parameter`` was
removed together with the constructor rework. Custom actuator subclasses that parsed configuration
fields with it should call :func:`~isaaclab.actuators.resolve_joint_parameter`, which applies the
same resolution semantics as a standalone function:

.. code-block:: python

   from isaaclab.actuators import ActuatorBase, resolve_joint_parameter


   class MyActuator(ActuatorBase):
       def __init__(self, cfg, joint_names, joint_ids, num_envs, device, **kwargs):
           super().__init__(cfg, joint_names, joint_ids, num_envs, device, **kwargs)
           # before: self.my_gain = self._parse_joint_parameter(cfg.my_gain, 0.0)
           self.my_gain = resolve_joint_parameter(cfg.my_gain, 0.0, joint_names, num_envs, device)

The backend articulation methods ``write_actuator_stiffness_to_sim`` and
``write_actuator_damping_to_sim`` are deprecated. Use
:func:`~isaaclab.envs.mdp.events.randomize_actuator_gains` for managed gain randomization; it
updates actuator-owned gains, implicit solver drives, or native-controller parameters as
appropriate. For direct writes to a Newton-executed group's controller, use
:func:`~isaaclab.actuators.newton.write_group_parameter`.

Named regular-expression groups retain their configuration behavior. If both a deprecated name and
its canonical replacement are present in the same group, use only the canonical name; equivalent
values warn and select the canonical value, whereas conflicting values raise :class:`ValueError`.


.. rubric:: Actuator API Moves to ``ActuatorCollection``

In Isaac Lab 3.x, actuator ownership moves from :class:`~isaaclab.assets.Articulation` to a
backend-neutral :class:`~isaaclab.actuators.ActuatorCollection`, available as
:attr:`~isaaclab.assets.Articulation.actuators`. Actuator command setters and per-joint actuator
telemetry now live on the collection, so the same code path drives every physics backend. The
collection setters are keyword-only.


**Method Relocations**

The following methods on :class:`~isaaclab.assets.Articulation` move to the actuator collection.
The old methods are deprecated and will be removed in a future release:

+-------------------------------------------------------------+------------------------------------------------------+
| Deprecated                                                  | New                                                  |
+=============================================================+======================================================+
| ``set_joint_position_target``                               | ``actuators.target_command.set_position_index``      |
+-------------------------------------------------------------+------------------------------------------------------+
| ``set_joint_velocity_target``                               | ``actuators.target_command.set_velocity_index``      |
+-------------------------------------------------------------+------------------------------------------------------+
| ``set_joint_effort_target``                                 | ``actuators.target_command.set_effort_index``        |
+-------------------------------------------------------------+------------------------------------------------------+
| ``set_joint_{position,velocity,effort}_target_index/_mask`` | ``actuators.target_command.set_{position,velocity,`` |
|                                                             | ``effort}_index/_mask``                              |
+-------------------------------------------------------------+------------------------------------------------------+

**Property Relocations (Data Class)**

The following properties on :class:`~isaaclab.assets.ArticulationData` move to the actuator
collection under the command view. The old properties are deprecated and will be removed in a
future release:

+------------------------------+---------------------------------------+
| Deprecated                   | New                                   |
+==============================+=======================================+
| ``data.joint_pos_target``    | ``actuators.target_command.position`` |
+------------------------------+---------------------------------------+
| ``data.joint_vel_target``    | ``actuators.target_command.velocity`` |
+------------------------------+---------------------------------------+
| ``data.joint_effort_target`` | ``actuators.target_command.effort``   |
+------------------------------+---------------------------------------+
| ``data.computed_torque``     | ``actuators.computed_effort``         |
+------------------------------+---------------------------------------+
| ``data.applied_torque``      | ``actuators.applied_effort``          |
+------------------------------+---------------------------------------+

.. note::

   All deprecated methods and properties are forwarders that emit a :class:`DeprecationWarning`
   when used. Your existing code will continue to work, but you should migrate to the new API to
   avoid issues in future releases.

   :attr:`~isaaclab.assets.ArticulationData.soft_joint_vel_limits` remains on
   :class:`~isaaclab.assets.ArticulationData`; do not migrate it to the actuator collection.
   ``ArticulationData.gear_ratio`` was removed: it was legacy :class:`~isaaclab.actuators.DCMotor`
   telemetry that was no longer updated and always read one. Gear ratios are an actuator
   configuration input, not simulation output; read them from your actuator configuration.

.. important::

   LEAPP-exported action terms are a temporary exception. The collection command setters do not
   yet carry LEAPP output annotations, so exportable terms must continue to call the deprecated,
   annotated ``Articulation.set_joint_*_target_index`` or ``*_mask`` methods until collection
   setters are supported by the exporter. Runtime code that is not exported should use the
   collection API.

Actuator group topology is configuration-time state. Add or remove a group on
:attr:`~isaaclab.assets.ArticulationCfg.actuators` before creating the articulation:

.. code-block:: python

   robot_cfg.actuators["gripper"] = ImplicitActuatorCfg(...)
   robot = Articulation(robot_cfg)

At runtime, assignment to or deletion from ``robot.actuators`` raises :class:`TypeError`. Group
membership, joint coverage, native binding, execution slices, and cached launches are
construction-time invariants. Continue to use the public named groups and collection views; private
execution and compatibility-projection details are not migration targets.


**Migration Example**

Here's a complete example showing how to update your code:

**Before (Isaac Lab 2.x):**

.. code-block:: python

   # Setting joint targets on the articulation (deprecated)
   robot = scene["robot"]
   robot.set_joint_effort_target(efforts, joint_ids=joint_ids)

   # Reading actuator telemetry from the data class (deprecated)
   applied = robot.data.applied_torque
   pos_target = robot.data.joint_pos_target

**After (Isaac Lab 3.0):**

.. code-block:: python

   # Sending actuator commands expressed in joint-side coordinates (keyword-only)
   robot = scene["robot"]
   robot.actuators.target_command.set_effort_index(value=efforts, joint_ids=joint_ids)

   # Reading actuator telemetry from the collection
   applied = robot.actuators.applied_effort.torch
   position_command = robot.actuators.target_command.position.torch

For the full runtime API of the actuator collection -- command setters and telemetry buffers --
see :ref:`actuators-runtime-api`.


.. rubric:: RigidObjectCollection API Renaming

The :class:`~isaaclab_physx.assets.RigidObjectCollection` and
:class:`~isaaclab_physx.assets.RigidObjectCollectionData` classes have undergone an API rename
to provide consistency with other asset classes. The ``object_*`` naming convention has been
deprecated in favor of ``body_*``.


**Method Renames**

The following methods have been renamed. The old methods are deprecated and will be removed in a
future release:

+------------------------------------------+------------------------------------------+
| Deprecated (2.x)                         | New (3.0)                                |
+==========================================+==========================================+
| ``write_object_state_to_sim()``          | ``write_body_state_to_sim()``            |
+------------------------------------------+------------------------------------------+
| ``write_object_link_state_to_sim()``     | ``write_body_link_state_to_sim()``       |
+------------------------------------------+------------------------------------------+
| ``write_object_pose_to_sim()``           | ``write_body_pose_to_sim()``             |
+------------------------------------------+------------------------------------------+
| ``write_object_link_pose_to_sim()``      | ``write_body_link_pose_to_sim()``        |
+------------------------------------------+------------------------------------------+
| ``write_object_com_pose_to_sim()``       | ``write_body_com_pose_to_sim()``         |
+------------------------------------------+------------------------------------------+
| ``write_object_velocity_to_sim()``       | ``write_body_com_velocity_to_sim()``     |
+------------------------------------------+------------------------------------------+
| ``write_object_com_velocity_to_sim()``   | ``write_body_com_velocity_to_sim()``     |
+------------------------------------------+------------------------------------------+
| ``write_object_link_velocity_to_sim()``  | ``write_body_link_velocity_to_sim()``    |
+------------------------------------------+------------------------------------------+
| ``find_objects()``                       | ``find_bodies()``                        |
+------------------------------------------+------------------------------------------+


**Property Renames (Data Class)**

The following properties on :class:`~isaaclab_physx.assets.RigidObjectCollectionData` have been
renamed. The old properties are deprecated and will be removed in a future release:

+------------------------------------------+------------------------------------------+
| Deprecated (2.x)                         | New (3.0)                                |
+==========================================+==========================================+
| ``default_object_state``                 | ``default_body_state``                   |
+------------------------------------------+------------------------------------------+
| ``object_names``                         | ``body_names``                           |
+------------------------------------------+------------------------------------------+
| ``object_link_pose_w``                   | ``body_link_pose_w``                     |
+------------------------------------------+------------------------------------------+
| ``object_link_vel_w``                    | ``body_link_vel_w``                      |
+------------------------------------------+------------------------------------------+
| ``object_com_pose_w``                    | ``body_com_pose_w``                      |
+------------------------------------------+------------------------------------------+
| ``object_com_vel_w``                     | ``body_com_vel_w``                       |
+------------------------------------------+------------------------------------------+
| ``object_state_w``                       | ``body_state_w``                         |
+------------------------------------------+------------------------------------------+
| ``object_link_state_w``                  | ``body_link_state_w``                    |
+------------------------------------------+------------------------------------------+
| ``object_com_state_w``                   | ``body_com_state_w``                     |
+------------------------------------------+------------------------------------------+
| ``object_com_acc_w``                     | ``body_com_acc_w``                       |
+------------------------------------------+------------------------------------------+
| ``object_com_pose_b``                    | ``body_com_pose_b``                      |
+------------------------------------------+------------------------------------------+
| ``object_link_pos_w``                    | ``body_link_pos_w``                      |
+------------------------------------------+------------------------------------------+
| ``object_link_quat_w``                   | ``body_link_quat_w``                     |
+------------------------------------------+------------------------------------------+
| ``object_link_lin_vel_w``                | ``body_link_lin_vel_w``                  |
+------------------------------------------+------------------------------------------+
| ``object_link_ang_vel_w``                | ``body_link_ang_vel_w``                  |
+------------------------------------------+------------------------------------------+
| ``object_com_pos_w``                     | ``body_com_pos_w``                       |
+------------------------------------------+------------------------------------------+
| ``object_com_quat_w``                    | ``body_com_quat_w``                      |
+------------------------------------------+------------------------------------------+
| ``object_com_lin_vel_w``                 | ``body_com_lin_vel_w``                   |
+------------------------------------------+------------------------------------------+
| ``object_com_ang_vel_w``                 | ``body_com_ang_vel_w``                   |
+------------------------------------------+------------------------------------------+
| ``object_com_lin_acc_w``                 | ``body_com_lin_acc_w``                   |
+------------------------------------------+------------------------------------------+
| ``object_com_ang_acc_w``                 | ``body_com_ang_acc_w``                   |
+------------------------------------------+------------------------------------------+
| ``object_com_pos_b``                     | ``body_com_pos_b``                       |
+------------------------------------------+------------------------------------------+
| ``object_com_quat_b``                    | ``body_com_quat_b``                      |
+------------------------------------------+------------------------------------------+
| ``object_link_lin_vel_b``                | ``body_link_lin_vel_b``                  |
+------------------------------------------+------------------------------------------+
| ``object_link_ang_vel_b``                | ``body_link_ang_vel_b``                  |
+------------------------------------------+------------------------------------------+
| ``object_com_lin_vel_b``                 | ``body_com_lin_vel_b``                   |
+------------------------------------------+------------------------------------------+
| ``object_com_ang_vel_b``                 | ``body_com_ang_vel_b``                   |
+------------------------------------------+------------------------------------------+
| ``object_pose_w``                        | ``body_pose_w``                          |
+------------------------------------------+------------------------------------------+
| ``object_pos_w``                         | ``body_pos_w``                           |
+------------------------------------------+------------------------------------------+
| ``object_quat_w``                        | ``body_quat_w``                          |
+------------------------------------------+------------------------------------------+
| ``object_vel_w``                         | ``body_vel_w``                           |
+------------------------------------------+------------------------------------------+
| ``object_lin_vel_w``                     | ``body_lin_vel_w``                       |
+------------------------------------------+------------------------------------------+
| ``object_ang_vel_w``                     | ``body_ang_vel_w``                       |
+------------------------------------------+------------------------------------------+
| ``object_lin_vel_b``                     | ``body_lin_vel_b``                       |
+------------------------------------------+------------------------------------------+
| ``object_ang_vel_b``                     | ``body_ang_vel_b``                       |
+------------------------------------------+------------------------------------------+
| ``object_acc_w``                         | ``body_acc_w``                           |
+------------------------------------------+------------------------------------------+
| ``object_lin_acc_w``                     | ``body_lin_acc_w``                       |
+------------------------------------------+------------------------------------------+
| ``object_ang_acc_w``                     | ``body_ang_acc_w``                       |
+------------------------------------------+------------------------------------------+

.. note::

   All deprecated methods and properties will issue a deprecation warning when used. Your existing
   code will continue to work, but you should migrate to the new API to avoid issues in future releases.


**Migration Example**

Here's a complete example showing how to update your code:

**Before (Isaac Lab 2.x):**

.. code-block:: python

   from isaaclab.assets import DeformableObject, DeformableObjectCfg
   from isaaclab.assets import SurfaceGripper, SurfaceGripperCfg
   from isaaclab.assets import RigidObjectCollection

   # Using deprecated root_physx_view
   robot = scene["robot"]
   material_properties = robot.root_physx_view.get_material_properties()

   # Using deprecated object_* API
   collection = scene["object_collection"]
   poses = collection.data.object_pose_w
   collection.write_object_state_to_sim(state, env_ids=env_ids, object_ids=object_ids)

**After (Isaac Lab 3.0):**

.. code-block:: python

   from isaaclab.assets import DeformableObject, DeformableObjectCfg
   from isaaclab_physx.assets import SurfaceGripper, SurfaceGripperCfg
   from isaaclab.assets import RigidObjectCollection  # unchanged

   # Using the new backend-specific root_view property (PhysX shown)
   robot = scene["robot"]
   material_properties = robot.root_view.get_material_properties()

   # Using new body_* API
   collection = scene["object_collection"]
   poses = collection.data.body_pose_w
   collection.write_body_state_to_sim(state, env_ids=env_ids, body_ids=object_ids)

The concrete ``root_view`` type is backend-specific. The
``get_material_properties()`` call above reads each rigid shape's static friction,
dynamic friction, and restitution through the PhysX Tensor API; Newton selections
and OvPhysX bindings use different access methods. See
:doc:`/source/concepts/native-physics-api/index`
before using ``root_view`` in backend-portable code.


.. rubric:: Deformable Object API Changes

The deformable body API is split by backend and follows the new Omni Physics volume and surface
deformable model. See :ref:`migrating-deformables`.


.. _imu-to-pva-migration:

.. rubric:: IMU Sensor Renamed to PVA; New Lightweight IMU Sensor

The old ``Imu`` sensor has been renamed to **PVA** (Pose Velocity Acceleration) because it provided
full pose, velocity, and acceleration data — far more than a real inertial measurement unit measures.
A new lightweight **IMU** sensor has been introduced that only provides the two physical quantities
a real IMU measures: angular velocity (gyroscope) and linear acceleration (accelerometer).

If you were using the old ``Imu`` sensor, you need to decide which new sensor to use:

- Use :class:`~isaaclab.sensors.Pva` / :class:`~isaaclab.sensors.PvaCfg` if you need full state
  data (pose, linear velocity, angular velocity, linear and angular acceleration, projected gravity).
- Use :class:`~isaaclab.sensors.Imu` / :class:`~isaaclab.sensors.ImuCfg` if you only need angular
  velocity and linear acceleration (as a real IMU provides).

For configuration and data access examples, see the :ref:`overview_sensors_pva`.

**Import changes:**

.. code-block:: python

   # Before (Isaac Lab 2.x) — the old IMU provided full state
   from isaaclab.sensors import Imu, ImuCfg, ImuData

   # After (Isaac Lab 3.x) — use PVA for the same full-state sensor
   from isaaclab.sensors import Pva, PvaCfg, PvaData

   # Or use the new lightweight IMU for angular velocity + linear acceleration only
   from isaaclab.sensors import Imu, ImuCfg, ImuData

**Configuration changes:**

The ``gravity_bias`` configuration parameter has been removed from both sensors:

- **PVA** reports raw kinematic acceleration (no gravity contribution), as the acceleration
  is derived from finite differencing of velocities which do not include gravity.
- **IMU** unconditionally includes gravity in its accelerometer readings, matching the behavior
  of a real accelerometer. The gravity vector is automatically queried from the simulation.

.. code-block:: python

   # Before (Isaac Lab 2.x)
   imu_cfg = ImuCfg(
       prim_path="{ENV_REGEX_NS}/Robot/base",
       gravity_bias=(0.0, 0.0, 9.81),  # had to be configured manually
   )

   # After (Isaac Lab 3.x) — PVA (no gravity in acceleration)
   pva_cfg = PvaCfg(prim_path="{ENV_REGEX_NS}/Robot/base")

   # After (Isaac Lab 3.x) — IMU (gravity always included automatically)
   imu_cfg = ImuCfg(prim_path="{ENV_REGEX_NS}/Robot/base")

**Observation function changes:**

.. code-block:: python

   # Before (Isaac Lab 2.x)
   from isaaclab.envs.mdp import imu_orientation, imu_projected_gravity

   # After (Isaac Lab 3.x)
   from isaaclab.envs.mdp import pva_orientation, pva_projected_gravity

**Data property changes:**

The new ``ImuData`` only provides ``ang_vel_b`` and ``lin_acc_b``. If you were accessing other
properties (``pos_w``, ``quat_w``, ``lin_vel_b``, ``ang_acc_b``, ``projected_gravity_b``), switch
to :class:`~isaaclab.sensors.PvaData` which provides all of them.


.. rubric:: Sensor Pose Properties Deprecation

The ``pose_w``, ``pos_w``, and ``quat_w`` properties on :class:`~isaaclab.sensors.ContactSensorData`
are deprecated and will be removed in a future release.

If you need to track sensor poses in world frame, please use a dedicated sensor such as
:class:`~isaaclab.sensors.FrameTransformer` instead.

**Before (deprecated):**

.. code-block:: python

   # Using pose properties directly on sensor data
   sensor_pos = contact_sensor.data.pos_w
   sensor_quat = contact_sensor.data.quat_w

**After (recommended):**

.. code-block:: python

   # Use FrameTransformer to track sensor pose
   frame_transformer = FrameTransformer(FrameTransformerCfg(
       prim_path="{ENV_REGEX_NS}/Robot/base",
       target_frames=[
           FrameTransformerCfg.FrameCfg(prim_path="{ENV_REGEX_NS}/Robot/sensor_link"),
       ],
   ))
   sensor_pos = frame_transformer.data.target_pos_w
   sensor_quat = frame_transformer.data.target_quat_w


.. rubric:: Contact force property names

Contact sensor force properties now state whether they contain aggregate or filtered normal and
friction forces. ``net_forces_w`` is the total contact force (normal + friction). Newton reports
this quantity directly. PhysX and OVPhysX cannot compute a total force, so they return the
corresponding normal-force quantity and warn. ``friction_forces_w`` is the aggregate friction
force. Newton reports it as ``net_friction_forces_w``; PhysX and OVPhysX only provide filtered
friction, so they return ``friction_force_matrix_w`` and warn.

.. list-table::
   :header-rows: 1

   * - Property
     - Meaning
     - PhysX / OVPhysX
     - Newton
   * - ``net_forces_w``
     - Total contact force
     - Returns ``net_normal_forces_w`` (cannot compute total force)
     - Total force (``normal + friction``)
   * - ``net_forces_w_history``
     - Total contact-force history
     - Returns ``net_normal_forces_w_history``
     - Total-force history
   * - ``force_matrix_w``
     - Total filtered force matrix
     - Returns ``normal_force_matrix_w``
     - Total filtered matrix
   * - ``force_matrix_w_history``
     - Total filtered force history
     - Returns ``normal_force_matrix_w_history``
     - Total filtered-matrix history
   * - ``friction_forces_w``
     - Aggregate friction force
     - Returns ``friction_force_matrix_w`` (filtered friction only)
     - Aggregate friction (``net_friction_forces_w``)

Prefer the explicit names ``net_normal_forces_w``, ``net_friction_forces_w``,
``normal_force_matrix_w``, and ``friction_force_matrix_w`` (and their ``*_history`` variants)
when the normal / friction split matters. Newton also exposes ``net_friction_forces_w_history``
and ``friction_force_matrix_w_history``. PhysX cannot report an unfiltered aggregate friction
force and raises ``NotImplementedError`` when ``net_friction_forces_w`` or
``net_friction_forces_w_history`` is accessed; use the filtered friction matrix instead.


.. rubric:: Articulation Joint Wrench Data Moved to ``JointWrenchSensor``

The ``ArticulationData.body_incoming_joint_wrench_b`` property has been removed. In
Isaac Lab 3.0, incoming joint reaction wrenches are exposed through
:class:`~isaaclab.sensors.JointWrenchSensor`, which has PhysX and Newton backend
implementations and returns separate force [N] and torque [N·m] buffers.
The sensor reports wrenches in the child-side incoming joint frame, with torque
referenced at the child-side joint anchor.

For configuration and data access examples, see the :ref:`overview_sensors_joint_wrench`.

**Before (Isaac Lab 2.x):**

.. code-block:: python

   wrench_b = robot.data.body_incoming_joint_wrench_b.torch[:, body_ids]

**After (Isaac Lab 3.x):**

.. code-block:: python

   import torch
   from isaaclab.scene import InteractiveSceneCfg
   from isaaclab.sensors import JointWrenchSensorCfg

   class MySceneCfg(InteractiveSceneCfg):
       robot = ROBOT_CFG.replace(prim_path="{ENV_REGEX_NS}/Robot")
       joint_wrench = JointWrenchSensorCfg(prim_path="{ENV_REGEX_NS}/Robot")

   sensor = env.scene.sensors["joint_wrench"]
   data = sensor.data
   wrench_j = torch.cat(
       (
           data.force.torch[:, body_ids],
           data.torque.torch[:, body_ids],
       ),
       dim=-1,
   )

Use :attr:`~isaaclab.sensors.BaseJointWrenchSensor.body_names` or
:meth:`~isaaclab.sensors.BaseJointWrenchSensor.find_bodies` to map sensor entries to
articulation body names. PhysX reports one entry for every link, including the articulation
root link. Newton reports the child bodies of reportable incoming joints.

For manager-based environments, update observations that used the articulation data property to
depend on the joint-wrench sensor instead:

.. code-block:: python

   import isaaclab.envs.mdp as mdp
   from isaaclab.managers import SceneEntityCfg
   from isaaclab.managers import ObservationTermCfg as ObsTerm
   from isaaclab.scene import InteractiveSceneCfg
   from isaaclab.sensors import JointWrenchSensorCfg

   class MySceneCfg(InteractiveSceneCfg):
       robot = ROBOT_CFG.replace(prim_path="{ENV_REGEX_NS}/Robot")
       joint_wrench = JointWrenchSensorCfg(prim_path="{ENV_REGEX_NS}/Robot")

   feet_body_forces = ObsTerm(
       func=mdp.body_incoming_wrench,
       params={
           "sensor_cfg": SceneEntityCfg(
               "joint_wrench",
               body_names=["left_foot", "right_foot"],
           )
       },
   )


.. rubric:: Ray Caster Warp Backend

The :class:`~isaaclab.sensors.RayCaster`, :class:`~isaaclab.sensors.RayCasterCamera`,
:class:`~isaaclab.sensors.MultiMeshRayCaster`, and
:class:`~isaaclab.sensors.MultiMeshRayCasterCamera` sensors have been transitioned from a
PyTorch/USD-based backend to a native Warp kernel pipeline. This improves performance by
eliminating per-step tensor allocations and torch-to-warp conversions, but introduces several
breaking changes.


**RayCasterData Return Types**

The :attr:`~isaaclab.sensors.RayCasterData.pos_w`,
:attr:`~isaaclab.sensors.RayCasterData.quat_w`, and
:attr:`~isaaclab.sensors.RayCasterData.ray_hits_w` properties now return
:class:`~isaaclab.utils.warp.ProxyArray` instead of ``torch.Tensor``. This follows the same
pattern as the general ProxyArray backend migration described above.

.. code-block:: python

   # Before (Isaac Lab 2.x)
   ray_hits = ray_caster.data.ray_hits_w        # torch.Tensor
   sensor_pos = ray_caster.data.pos_w            # torch.Tensor

   # After (Isaac Lab 3.x)
   ray_hits = ray_caster.data.ray_hits_w         # ProxyArray
   sensor_pos = ray_caster.data.pos_w            # ProxyArray

   # To use with torch operations, access .torch
   ray_hits_torch = ray_caster.data.ray_hits_w.torch
   sensor_pos_torch = ray_caster.data.pos_w.torch


**Ray Alignment Configuration**

The ``attach_yaw_only`` boolean parameter on :class:`~isaaclab.sensors.RayCasterCfg` has been
deprecated in favor of the new ``ray_alignment`` parameter, which accepts one of three string
values:

.. list-table::
   :header-rows: 1
   :widths: 30 30 40

   * - Old (2.x)
     - New (3.0)
     - Behavior
   * - ``attach_yaw_only=False``
     - ``ray_alignment="base"``
     - Rays follow the full sensor orientation.
   * - ``attach_yaw_only=True``
     - ``ray_alignment="yaw"``
     - Rays follow only the yaw component of the sensor orientation.
   * - *(not available)*
     - ``ray_alignment="world"``
     - Rays are always cast in the world frame (no rotation applied).

.. code-block:: python

   # Before (Isaac Lab 2.x)
   cfg = RayCasterCfg(attach_yaw_only=True, ...)

   # After (Isaac Lab 3.x)
   cfg = RayCasterCfg(ray_alignment="yaw", ...)


**Raycasting Kernel Signature Change**

The :func:`~isaaclab.utils.warp.kernels.raycast_dynamic_meshes_kernel` Warp kernel now requires
an ``env_mask`` parameter as its first argument. This is a ``wp.array(dtype=wp.bool)`` that
controls which environments are updated. The public Python wrapper
:func:`~isaaclab.utils.warp.ops.raycast_dynamic_meshes` has been updated to inject an all-True
mask automatically, so code using the wrapper is unaffected.

If you call the kernel directly, update your launch call:

.. code-block:: python

   import warp as wp

   # Before (Isaac Lab 2.x)
   wp.launch(
       raycast_dynamic_meshes_kernel,
       dim=(num_meshes, num_envs, num_rays),
       inputs=[ray_starts, ray_directions, mesh_ids, ...],
   )

   # After (Isaac Lab 3.x) -- env_mask is now the first input
   env_mask = wp.ones(num_envs, dtype=wp.bool, device=device)
   wp.launch(
       raycast_dynamic_meshes_kernel,
       dim=(num_meshes, num_envs, num_rays),
       inputs=[env_mask, ray_starts, ray_directions, mesh_ids, ...],
   )


**RayCaster.meshes Cache Key**

The :attr:`~isaaclab.sensors.RayCaster.meshes` class variable, which caches warp meshes across
all :class:`~isaaclab.sensors.RayCaster` instances, is now keyed by ``(prim_path, device)`` tuples
instead of by ``prim_path`` alone. This prevents a mesh that was built on one device (e.g. CPU)
from being reused by a sensor running on a different device (e.g. CUDA), which caused illegal
memory accesses on systems without unified memory.

Code that reads or writes this cache directly must update both the type annotation and the key:

.. code-block:: python

   # Before (Isaac Lab 2.x)
   meshes: ClassVar[dict[str, wp.Mesh]] = {}
   wp_mesh = RayCaster.meshes[prim_path]

   # After (Isaac Lab 3.x)
   meshes: ClassVar[dict[tuple[str, str], wp.Mesh]] = {}
   wp_mesh = RayCaster.meshes[(prim_path, device)]


Data Access and Math
--------------------

Migrate tensor access, indexed writes, buffers, and quaternion conventions before validating task behavior.

.. grid:: 2
   :gutter: 2

   .. grid-item-card:: Isaac Lab 2.x

      Data properties behaved like Torch tensors, quaternions used WXYZ order, and one write method
      accepted either indices or masks.

      .. code-block:: python

         identity = (1.0, 0.0, 0.0, 0.0)
         root_pos = robot.data.root_pos_w
         robot.write_root_pose_to_sim(pose, env_ids)

   .. grid-item-card:: Isaac Lab 3.0

      Data properties use ``ProxyArray``, quaternions use XYZW order, and writes distinguish index and
      mask selection explicitly.

      .. code-block:: python

         identity = (0.0, 0.0, 0.0, 1.0)
         root_pos = robot.data.root_pos_w.torch
         robot.write_root_pose_to_sim_index(pose, env_ids)


.. rubric:: Quaternion Format

**The quaternion format changed from WXYZ to XYZW.**

+------------------+----------------------------------+----------------------------------+
| Component        | Old Format (WXYZ)                | New Format (XYZW)                |
+==================+==================================+==================================+
| Order            | ``(w, x, y, z)``                 | ``(x, y, z, w)``                 |
+------------------+----------------------------------+----------------------------------+
| Identity         | ``(1.0, 0.0, 0.0, 0.0)``         | ``(0.0, 0.0, 0.0, 1.0)``         |
+------------------+----------------------------------+----------------------------------+


**Why This Change?**

The new XYZW format aligns with:

- **Warp**: NVIDIA's spatial computing framework
- **PhysX**: PhysX physics engine
- **Newton**: Newton multi-solver framework

This alignment removes the need for internal quaternion conversions, making the code simpler,
faster, and less error-prone.


**What You Need to Update**

Any hard-coded quaternion values in your code need to be converted from WXYZ to XYZW.
This includes:

1. **Configuration files** - ``rot`` parameters in asset configs
2. **Task definitions** - Goal poses, initial states
3. **Controller parameters** - Target orientations
4. **Documentation** - Code examples with quaternions

Also, if you were relying on the :func:`~isaaclab.utils.math.convert_quat` function to convert quaternions, this should
no longer be needed. (This would happen if you were pulling values from the views directly.)

**Example: Updating Asset Configuration**

**Before (WXYZ):**

.. code-block:: python

   from isaaclab.assets import AssetBaseCfg

   cfg = AssetBaseCfg(
       init_state=AssetBaseCfg.InitialStateCfg(
           pos=(0.0, 0.0, 0.5),
           rot=(1.0, 0.0, 0.0, 0.0),  # OLD: w, x, y, z
       ),
   )

**After (XYZW):**

.. code-block:: python

   from isaaclab.assets import AssetBaseCfg

   cfg = AssetBaseCfg(
       init_state=AssetBaseCfg.InitialStateCfg(
           pos=(0.0, 0.0, 0.5),
           rot=(0.0, 0.0, 0.0, 1.0),  # NEW: x, y, z, w
       ),
   )


.. rubric:: Using the Quaternion Finder Tool

We provide a tool to help you find and fix quaternions in your codebase automatically. This is not a bulletproof tool,
but it should help you find most of the quaternions that need to be updated. You *should* review the results manually.

.. warning::
  Do not run the tool on the whole codebase! If you run the tool on our own packages (isaaclab, or isaaclab_tasks for
  instance) it will find all the quaternions that we already converted. This tool is only meant to be used on your own
  codebase with no overlap with our own packages.

**Finding Quaternions**

Run the tool to scan your code for potential quaternions:

.. code-block:: bash

   # Scan the 'source' directory (default)
   python scripts/tools/find_quaternions.py

   # Scan a specific path
   python scripts/tools/find_quaternions.py --path my_project/

   # Compare against a different branch
   python scripts/tools/find_quaternions.py --base develop

.. tip::
  We recommend always running the tool with a custom base branch *and* a specific path.


The tool will show you:

- Quaternions that haven't been updated (marked as ``UNCHANGED``)
- Whether each looks like a WXYZ identity quaternion (``WXYZ_IDENTITY``)
- Whether the format is likely WXYZ (``LIKELY_WXYZ``)


**Understanding the Output**

.. code-block:: text

   my_project/robot_cfg.py:42:8 ⚠ UNCHANGED [WXYZ_IDENTITY]
     Values: [1.0, 0.0, 0.0, 0.0]
     Source: rot=(1.0, 0.0, 0.0, 0.0),

This tells you:

- **File and line**: ``my_project/robot_cfg.py:42``
- **Status**: ``UNCHANGED`` means this line hasn't been modified yet
- **Flag**: ``WXYZ_IDENTITY`` means it's the identity quaternion in old WXYZ format
- **Values**: The actual quaternion values found
- **Source**: The line of code for context


**Filtering Results**

Focus on specific types of quaternions:

.. code-block:: bash

   # Only show identity quaternions [1, 0, 0, 0]
   python scripts/tools/find_quaternions.py --check-identity

   # Only show quaternions likely in WXYZ format
   python scripts/tools/find_quaternions.py --likely-wxyz

   # Show ALL potential quaternions (ignore format heuristics)
   python scripts/tools/find_quaternions.py --all-quats


**Fixing Quaternions Automatically**

The tool can automatically convert quaternions from WXYZ to XYZW:

.. code-block:: bash

   # Interactive mode: prompts before each fix
   python scripts/tools/find_quaternions.py --fix

   # Only fix identity quaternions (safest option)
   python scripts/tools/find_quaternions.py --fix-identity-only

   # Preview changes without applying them
   python scripts/tools/find_quaternions.py --fix --dry-run

   # Apply all fixes without prompting
   python scripts/tools/find_quaternions.py --fix --force


**Interactive Fix Example**

When running with ``--fix``, you'll see something like:

.. code-block:: text

   ────────────────────────────────────────────────────────────────────────────────
   📍 my_project/robot_cfg.py:42 [WXYZ_IDENTITY]
   ────────────────────────────────────────────────────────────────────────────────
        40 |     init_state=AssetBaseCfg.InitialStateCfg(
        41 |         pos=(0.0, 0.0, 0.5),
   >>>  42 |         rot=(1.0, 0.0, 0.0, 0.0),
        43 |     ),
        44 | )
   ────────────────────────────────────────────────────────────────────────────────
     Change: [1.0, 0.0, 0.0, 0.0] → [0.0, 0.0, 0.0, 1.0]
     Result: rot=(0.0, 0.0, 0.0, 1.0),
   Apply this fix? [Y/n/a/q]:

Options:

- **Y** (yes): Apply this fix
- **n** (no): Skip this one
- **a** (all): Apply all remaining fixes without asking
- **q** (quit): Stop fixing


**How the Tool Works**

The tool uses several techniques to find quaternions:

1. **Python files**: Parses the code using AST (Abstract Syntax Tree) to find
   4-element tuples and lists with numeric values.

2. **JSON files**: Uses regex to find 4-element arrays.

3. **RST documentation**: Searches for quaternion-like patterns in docs.

To identify if something is a quaternion, the tool checks:

- Is it exactly 4 numeric values?
- Does the sum of squares ≈ 1? (unit quaternion property)
- Does it match known patterns like identity quaternions?

To determine if it's in WXYZ format:

- Is the first value 1.0 and rest are 0? (WXYZ identity)
- Is the first value a common cos(θ/2) value like 0.707, 0.866, etc.?
- Is the pattern consistent with first-element being the scalar part?


.. rubric:: Using the Runtime Quaternion Access Detector

The quaternion finder tool above covers hard-coded values in source files,
but it cannot see quaternions that are *read* from asset/sensor data at
runtime. For those, Isaac Lab ships a
runtime detector hook on :class:`~isaaclab.utils.warp.ProxyArray` that flags
every ``.torch`` access on a ``wp.quatf``-typed property and points at the
exact call site. Use it after the source-level migration to catch the cases
the finder tool can't reach.

Enable it by setting an environment variable before launching your script:

.. tab-set::

   .. tab-item:: uv (Recommended)

      .. code-block:: bash

         export WARN_ON_TORCH_QUATF_ACCESS=1
         uv run python my_script.py

   .. tab-item:: isaaclab.sh / isaaclab.bat

      .. code-block:: bash

         export WARN_ON_TORCH_QUATF_ACCESS=1
         ./isaaclab.sh -p my_script.py

Every read of ``.torch`` on a ``ProxyArray`` whose underlying ``wp.array`` has
dtype ``wp.quatf`` then emits a :class:`UserWarning` with the message:

.. code-block:: text

   Reading .torch on a wp.quatf-typed ProxyArray. The Isaac Lab quaternion
   convention changed from (w, x, y, z) in 2.x to (x, y, z, w) in 3.x. If
   your code assumes the old order, this is likely the source of incorrect
   rotations. Unset WARN_ON_TORCH_QUATF_ACCESS to silence this warning.

The warning's traceback points at the exact line that performed the access
(via ``stacklevel=2``), so you can walk through the matches in your code and
confirm each one uses the new ``(x, y, z, w)`` order.

Typical workflow:

1. Run a representative scene or task with the env var set.
2. Triage every warning location — check whether the call site assumes
   ``(w, x, y, z)`` (Lab 2.x) or ``(x, y, z, w)`` (Lab 3.x).
3. Migrate the call sites that still expect the old order.
4. Re-run with the env var still set; the warnings should be gone (or only
   come from intentionally-handled call sites).
5. Unset the env var for production runs — the detector adds an
   ``os.environ`` lookup per ``.torch`` access, which is cheap but not free.

The detector covers only ``ProxyArray.torch`` reads. Direct accesses on the
underlying ``wp.array`` (via ``ProxyArray.warp``) are not flagged, because
warp uses ``(x, y, z, w)`` natively and so a warp-side read is unaffected
by the convention change.


.. rubric:: Quaternion Utility API Changes

**The ``convert_quat`` function has been removed**

Previously, IsaacLab had a utility function to convert between quaternion formats:

.. code-block:: python

   # OLD - No longer needed
   from isaaclab.utils.math import convert_quat
   quat_xyzw = convert_quat(quat_wxyz, "xyzw")

Since everything now uses XYZW natively, this function is no longer needed.
If you were using it, simply remove the conversion calls.


**Math utility functions now expect XYZW**

All quaternion functions in :mod:`isaaclab.utils.math` now expect and return
quaternions in XYZW format:

- :func:`~isaaclab.utils.math.quat_mul`
- :func:`~isaaclab.utils.math.quat_apply`
- :func:`~isaaclab.utils.math.quat_from_euler_xyz`
- :func:`~isaaclab.utils.math.euler_xyz_from_quat`
- :func:`~isaaclab.utils.math.quat_from_matrix`
- :func:`~isaaclab.utils.math.matrix_from_quat`
- And all other quaternion utilities


.. rubric:: Quaternion Migration Checklist

1. **Start with a clean git state** - Commit your work before running fixes.

2. **Run the tool first without ``--fix``** - Review what will be changed.

3. **Fix identity quaternions first** - They're the most common and safest:

   .. code-block:: bash

      python scripts/tools/find_quaternions.py --fix-identity-only

4. **Review non-identity quaternions manually** - Some 4-element lists might
   not be quaternions (e.g., RGBA colors, bounding boxes).

5. **Test your code** - Run your simulations to verify everything works correctly.

6. **Check documentation** - Update any docs or comments that mention quaternion format.


.. rubric:: ProxyArray Backend for Asset and Sensor Data

All ``.data.*`` properties on asset and sensor classes now return
:class:`~isaaclab.utils.warp.ProxyArray` instead of ``torch.Tensor``. ``ProxyArray`` wraps
the underlying ``wp.array`` and exposes explicit ``.torch`` and ``.warp`` accessors. This
change applies to all asset classes (:class:`~isaaclab.assets.Articulation`,
:class:`~isaaclab.assets.RigidObject`, :class:`~isaaclab.assets.RigidObjectCollection`,
:class:`~isaaclab.assets.DeformableObject`) and all sensor classes
(:class:`~isaaclab_physx.sensors.ContactSensor`, :class:`~isaaclab_physx.sensors.Imu`,
:class:`~isaaclab_physx.sensors.Pva`, :class:`~isaaclab_physx.sensors.FrameTransformer`).

To use a data property as a ``torch.Tensor``, append ``.torch``:

.. code-block:: python

   # Before (Isaac Lab 2.x)
   root_pos = robot.data.root_pos_w             # torch.Tensor
   joint_pos = robot.data.joint_pos              # torch.Tensor
   contact_forces = sensor.data.net_forces_w     # torch.Tensor

   # After (Isaac Lab 3.x)
   root_pos = robot.data.root_pos_w              # ProxyArray
   joint_pos = robot.data.joint_pos              # ProxyArray
   contact_forces = sensor.data.net_normal_forces_w     # ProxyArray

   # To use with torch operations, access .torch
   root_pos_torch = robot.data.root_pos_w.torch        # torch.Tensor
   joint_pos_torch = robot.data.joint_pos.torch        # torch.Tensor
   contact_torch = sensor.data.net_normal_forces_w.torch      # torch.Tensor

Common patterns that need updating:

.. code-block:: python

   # Cloning data
   # Before:
   pos = robot.data.root_pos_w.clone()
   # After:
   pos = robot.data.root_pos_w.torch.clone()

   # Creating zero tensors with matching shape
   # Before:
   zeros = torch.zeros_like(robot.data.root_pos_w)
   # After:
   zeros = torch.zeros_like(robot.data.root_pos_w.torch)

   # Assertions in tests
   # Before:
   torch.testing.assert_close(robot.data.root_pos_w, expected)
   # After:
   torch.testing.assert_close(robot.data.root_pos_w.torch, expected)

.. list-table:: Affected classes
   :header-rows: 1
   :widths: 40 60

   * - Class
     - Package
   * - :class:`~isaaclab.assets.Articulation`
     - ``isaaclab`` / ``isaaclab_physx``
   * - :class:`~isaaclab.assets.RigidObject`
     - ``isaaclab`` / ``isaaclab_physx``
   * - :class:`~isaaclab.assets.RigidObjectCollection`
     - ``isaaclab`` / ``isaaclab_physx``
   * - :class:`~isaaclab.assets.DeformableObject`
     - ``isaaclab`` / ``isaaclab_physx`` / ``isaaclab_newton``
   * - :class:`~isaaclab_physx.sensors.ContactSensor`
     - ``isaaclab_physx``
   * - :class:`~isaaclab_physx.sensors.Imu`
     - ``isaaclab_physx``
   * - :class:`~isaaclab_physx.sensors.Pva`
     - ``isaaclab_physx``
   * - :class:`~isaaclab_physx.sensors.FrameTransformer`
     - ``isaaclab_physx``
   * - :class:`~isaaclab.sensors.RayCaster`
     - ``isaaclab``
   * - :class:`~isaaclab.sensors.RayCasterCamera`
     - ``isaaclab``
   * - :class:`~isaaclab.sensors.MultiMeshRayCaster`
     - ``isaaclab``
   * - :class:`~isaaclab.sensors.MultiMeshRayCasterCamera`
     - ``isaaclab``

.. note::

   ``wp.to_torch(proxy_array)`` is temporarily supported by a compatibility shim. It returns
   the same zero-copy tensor as ``proxy_array.torch`` and emits a one-time
   ``DeprecationWarning``. This shim exists for older migration code and will be removed in a
   future release; prefer ``.torch`` in new code.


.. _torcharray-migration:

.. rubric:: ProxyArray Interop and Temporary Compatibility

Asset and sensor data class properties return :class:`~isaaclab.utils.warp.ProxyArray`, a
lightweight wrapper with explicit ``.torch`` and ``.warp`` accessors:

.. code-block:: python

   # BEFORE (2.x) — properties returned torch.Tensor directly
   joint_pos = robot.data.joint_pos          # torch.Tensor
   root_pos = robot.data.root_pos_w          # torch.Tensor

   # AFTER (3.0) — properties return ProxyArray, use .torch for the tensor
   joint_pos = robot.data.joint_pos.torch    # cached zero-copy torch.Tensor
   root_pos = robot.data.root_pos_w.torch    # cached zero-copy torch.Tensor
   joint_pos_warp = robot.data.joint_pos.warp  # the underlying warp.array

**Automatic interop — in many cases, no changes are needed:**

- **Warp kernels:** ``ProxyArray`` implements ``__cuda_array_interface__``, so it can be passed
  directly to ``wp.launch()`` without calling ``.warp``:

  .. code-block:: python

     # Just works — no .warp needed
     wp.launch(my_kernel, inputs=[robot.data.joint_pos], ...)

- **Torch functions:** ``ProxyArray`` implements ``__torch_function__``, so ``torch.*`` operations
  accept it directly. During the deprecation period this emits a one-time warning, but works:

  .. code-block:: python

     # Works (emits DeprecationWarning once, then silent)
     mean_pos = torch.mean(robot.data.joint_pos, dim=1)
     clipped = torch.clamp(robot.data.joint_pos, -3.14, 3.14)

**What to change:**

1. Append ``.torch`` where you need an explicit ``torch.Tensor`` (e.g., for indexing, slicing,
   or passing to non-torch libraries).
2. Warp kernel calls need no changes — ``ProxyArray`` works transparently.
3. If you need the underlying ``warp.array`` (e.g., for ``ptr``, ``strides``), use ``.warp``.
4. Replace legacy ``wp.to_torch(proxy_array)`` calls with ``proxy_array.torch``.

.. note::

   The ``__torch_function__`` bridge and the temporary ``wp.to_torch(proxy_array)`` shim will
   be removed in a future release. We recommend migrating to explicit ``.torch`` access now.

For a complete guide, see :doc:`/source/how-to/proxy_array`.


.. rubric:: Write Method Index/Mask Split

All asset write methods have been split into two explicit variants:

- ``write_*_to_sim_index(data, env_ids)`` — accepts partial data for a sparse set of
  environment indices. The ``data`` tensor has shape ``(len(env_ids), ...)``.
- ``write_*_to_sim_mask(data, env_mask)`` — accepts full data for all environments with a
  boolean mask selecting which environments to update. The ``data`` tensor has shape
  ``(num_envs, ...)``.

The previous ``write_*_to_sim(data, env_ids)`` methods have been removed.

.. code-block:: python

   # Before (Isaac Lab 2.x)
   robot.write_root_pose_to_sim(pose_data, env_ids)

   # After (Isaac Lab 3.x) — indexed variant (partial data)
   robot.write_root_pose_to_sim_index(root_pose=pose_data, env_ids=env_ids)

   # After (Isaac Lab 3.x) — mask variant (full data, boolean mask)
   robot.write_root_pose_to_sim_mask(root_pose=pose_data, env_mask=env_mask)

.. list-table:: Affected write methods (RigidObject / Articulation)
   :header-rows: 1
   :widths: 50 50

   * - Old method
     - New methods
   * - ``write_root_pose_to_sim``
     - ``write_root_pose_to_sim_index`` / ``write_root_pose_to_sim_mask``
   * - ``write_root_link_pose_to_sim``
     - ``write_root_link_pose_to_sim_index`` / ``write_root_link_pose_to_sim_mask``
   * - ``write_root_com_pose_to_sim``
     - ``write_root_com_pose_to_sim_index`` / ``write_root_com_pose_to_sim_mask``
   * - ``write_root_velocity_to_sim``
     - ``write_root_velocity_to_sim_index`` / ``write_root_velocity_to_sim_mask``
   * - ``write_root_com_velocity_to_sim``
     - ``write_root_com_velocity_to_sim_index`` / ``write_root_com_velocity_to_sim_mask``
   * - ``write_root_link_velocity_to_sim``
     - ``write_root_link_velocity_to_sim_index`` / ``write_root_link_velocity_to_sim_mask``

.. list-table:: Additional Articulation-specific write methods
   :header-rows: 1
   :widths: 50 50

   * - Old method
     - New methods
   * - ``write_joint_position_to_sim``
     - ``write_joint_position_to_sim_index`` / ``write_joint_position_to_sim_mask``
   * - ``write_joint_velocity_to_sim``
     - ``write_joint_velocity_to_sim_index`` / ``write_joint_velocity_to_sim_mask``
   * - ``write_joint_stiffness_to_sim``
     - ``write_joint_stiffness_to_sim_index`` / ``write_joint_stiffness_to_sim_mask``
   * - ``write_joint_damping_to_sim``
     - ``write_joint_damping_to_sim_index`` / ``write_joint_damping_to_sim_mask``
   * - ``write_joint_position_limit_to_sim``
     - ``write_joint_position_limit_to_sim_index`` / ``write_joint_position_limit_to_sim_mask``
   * - ``write_joint_velocity_limit_to_sim``
     - ``write_joint_velocity_limit_to_sim_index`` / ``write_joint_velocity_limit_to_sim_mask``
   * - ``write_joint_effort_limit_to_sim``
     - ``write_joint_effort_limit_to_sim_index`` / ``write_joint_effort_limit_to_sim_mask``
   * - ``write_joint_armature_to_sim``
     - ``write_joint_armature_to_sim_index`` / ``write_joint_armature_to_sim_mask``
   * - ``write_joint_friction_coefficient_to_sim``
     - ``write_joint_friction_coefficient_to_sim_index`` / ``write_joint_friction_coefficient_to_sim_mask``

.. list-table:: RigidObjectCollection write methods
   :header-rows: 1
   :widths: 50 50

   * - Old method
     - New methods
   * - ``write_body_pose_to_sim``
     - ``write_body_pose_to_sim_index`` / ``write_body_pose_to_sim_mask``
   * - ``write_body_link_pose_to_sim``
     - ``write_body_link_pose_to_sim_index`` / ``write_body_link_pose_to_sim_mask``
   * - ``write_body_com_pose_to_sim``
     - ``write_body_com_pose_to_sim_index`` / ``write_body_com_pose_to_sim_mask``
   * - ``write_body_velocity_to_sim``
     - ``write_body_velocity_to_sim_index`` / ``write_body_velocity_to_sim_mask``
   * - ``write_body_com_velocity_to_sim``
     - ``write_body_com_velocity_to_sim_index`` / ``write_body_com_velocity_to_sim_mask``
   * - ``write_body_link_velocity_to_sim``
     - ``write_body_link_velocity_to_sim_index`` / ``write_body_link_velocity_to_sim_mask``


.. rubric:: TimestampedBufferWarp

If you have custom asset or sensor data classes that subclass the Isaac Lab base data classes,
note that internal buffers have changed from :class:`~isaaclab.utils.buffers.TimestampedBuffer`
to :class:`~isaaclab.utils.buffers.TimestampedBufferWarp`. The new class takes ``(shape, device,
wp_dtype)`` as constructor arguments instead of a ``torch.Tensor``:

.. code-block:: python

   import warp as wp
   from isaaclab.utils.buffers import TimestampedBufferWarp

   # Before (Isaac Lab 2.x)
   self._data.root_pos_w = TimestampedBuffer(torch.zeros(num_envs, 3, device=device))

   # After (Isaac Lab 3.x)
   self._data.root_pos_w = TimestampedBufferWarp(
       shape=(num_envs,), device=device, wp_dtype=wp.vec3f
   )


Reinforcement Learning
----------------------

Move training and inference workflows to the unified entrypoints after the environment imports and steps correctly.

.. grid:: 2
   :gutter: 2

   .. grid-item-card:: Isaac Lab 2.x

      Launch a framework-specific script and use framework-specific resume arguments.

      .. code-block:: bash

         ./isaaclab.sh -p scripts/reinforcement_learning/rsl_rl/train.py \
            --task Isaac-Cartpole --resume --load_run RUN

   .. grid-item-card:: Isaac Lab 3.0

      Select the framework through the unified command and use ``--checkpoint`` consistently.

      .. code-block:: bash

         uv run isaaclab train --rl_library rsl_rl \
            --task Isaac-Cartpole --checkpoint RUN/model.pt


.. rubric:: Reinforcement Learning CLI Entrypoints

Isaac Lab 3.0 provides unified reinforcement learning entrypoints for training
and play. Instead of launching library-specific scripts under
``scripts/reinforcement_learning/<library>/``, select the library with
``--rl_library``.

.. tab-set::

   .. tab-item:: uv (Recommended)

      .. code-block:: bash

         # Isaac Lab 3.0
         uv run isaaclab train --rl_library rsl_rl --task Isaac-Cartpole

   .. tab-item:: isaaclab.sh / isaaclab.bat

      .. code-block:: bash

         # Isaac Lab 3.0
         ./isaaclab.sh train --rl_library rsl_rl --task Isaac-Cartpole

The same pattern applies to the play workflow:

.. tab-set::

   .. tab-item:: uv (Recommended)

      .. code-block:: bash

         uv run isaaclab play --rl_library rsl_rl --task Isaac-Cartpole --checkpoint /PATH/TO/model.pt

   .. tab-item:: isaaclab.sh / isaaclab.bat

      .. code-block:: bash

         ./isaaclab.sh play --rl_library rsl_rl --task Isaac-Cartpole --checkpoint /PATH/TO/model.pt

Supported reinforcement learning libraries are ``rsl_rl``, ``rl_games``, ``skrl``,
``sb3``, and ``rlinf``. Backend-local ``train.py`` and ``play.py`` scripts were removed; use these
unified commands instead.

For distributed launchers that execute a Python script directly, use the unified
script path and pass ``--rl_library`` to it:

.. code-block:: bash

   python -m torch.distributed.run --nproc_per_node=2 scripts/reinforcement_learning/train.py \
      --rl_library rsl_rl --task Isaac-Cartpole --distributed


.. rubric:: Unified Checkpoint and Iteration Arguments

RL entrypoints now use ``--checkpoint`` consistently to select a checkpoint
for training, resuming, or play. Update scripts that use the removed arguments
as follows:

.. list-table:: RL command migration
   :header-rows: 1
   :widths: 28 32 40

   * - Previous command
     - Isaac Lab 3.0 command
     - Notes
   * - RSL-RL ``--resume --load_run <run>``
     - ``--checkpoint <path>``, ``--checkpoint latest``, or ``--checkpoint best``
     - Pass a checkpoint path or select one from a compatible recorded run.
   * - ``--use_pretrained_checkpoint``
     - ``--checkpoint pretrained``
     - Use this for play with RL-Games, RSL-RL, skrl, or Stable-Baselines3.
   * - RLinf ``--rl_model_path <checkpoint-dir>`` or ``--resume_dir <checkpoint-dir>``
     - ``--checkpoint <checkpoint-dir>``
     - The directory must contain the RLinf ``full_weights.pt`` checkpoint.
   * - RLinf ``--max_epochs <N>``
     - ``--max_iterations <N>``
     - This is the common training-iteration argument used by the unified API.

For RLinf, ``--model_path`` now identifies the pretrained base VLA model, not
the RL-finetuned weights. Supply both arguments when evaluating a finetuned
policy:

.. code-block:: bash

   uv run --extra rlinf isaaclab play --rl_library rlinf \
      --config_name isaaclab_ppo_gr00t_assemble_trocar \
      --model_path /path/to/base_model \
      --checkpoint /path/to/rlinf_checkpoint

``latest`` and ``best`` select checkpoints from the newest compatible run for
RL-Games, RSL-RL, skrl, Stable-Baselines3, and RLinf. ``pretrained`` selects a
published policy where one is available; RLinf does not support this selector.


Visualizers, Cameras, and Recording
-----------------------------------

Update interactive viewing, headless rendering, camera configuration, and video capture together because they now share the visualizer abstraction.

.. grid:: 2
   :gutter: 2

   .. grid-item-card:: Isaac Lab 2.x

      ``--headless`` controlled viewer creation, viewport pose lived on ``env_cfg.viewer``, and video
      wrapped the environment with Gymnasium's recorder.

      .. code-block:: python

         env_cfg.viewer.eye = (7.5, 7.5, 7.5)
         env = gym.wrappers.RecordVideo(env, "videos")

   .. grid-item-card:: Isaac Lab 3.0

      ``--viz`` selects visualizers independently of headless rendering. Configure the default viewer
      and recorders through ``SimulationCfg`` and the environment config.

      .. code-block:: python

         sim.default_visualizer_cfg.eye = (7.5, 7.5, 7.5)
         env_cfg.video_recorders = [VideoRecorderCfg(...)]


.. rubric:: Visualizer CLI and Headless Behavior

In Isaac Lab 3.0, use ``--visualizer`` / ``--viz`` to determine whether viewer apps are launched
with an Isaac Lab command. Without a visualizer, commands run headless by default.

Visualizers are lightweight viewer apps for monitoring, debugging, and recording workflows
(see :doc:`/source/concepts/visualization`).

The details below describe how CLI visualizer arguments resolve together with
``SimulationCfg.visualizer_cfgs``.

- ``--viz`` accepts **comma-separated** values (for example ``--viz kit,newton_gl``).
  ``"newton"`` is a deprecated alias for ``"newton_gl"``; prefer ``"newton_gl"`` or ``"newton_rtx"``.
- If omitted, visualizers are resolved from ``SimulationCfg.visualizer_cfgs``.
- ``--viz none`` explicitly disables all visualizers, including config-defined ones.

For the full behavior of visualizer resolution with the visualizer CLI argument and visualizer configs,
see :ref:`visualization-common-modes`.

**Breaking change — ``--headless`` no longer suppresses visualizers.**

In Isaac Lab 2.x, passing ``--headless`` disabled all visualizers regardless of ``--viz``.
In Isaac Lab 3.0, ``--headless`` and ``--viz`` are independent:

- ``--headless`` controls the simulation rendering pipeline (Kit app mode, GPU context).
- ``--viz <type>`` controls which visualizer backends to launch.

Passing ``--viz kit --headless`` now launches a Kit visualizer in headless mode using the
Replicator offscreen renderer (no display window required).  Passing ``--viz newton_gl --headless``
launches a Newton GL visualizer using pyglet's EGL headless backend.  To disable all visualizers
explicitly, use ``--viz none``.

.. list-table:: Headless visualizer requirements
   :header-rows: 1
   :widths: 20 25 55

   * - Visualizer
     - Headless mechanism
     - Extra requirement
   * - ``kit``
     - Replicator offscreen renderer (no display)
     - Must also pass ``--enable_cameras``; without it, ``render_rgb_array()`` returns
       black frames. ``--video`` sets this automatically.
   * - ``newton_gl``
     - pyglet EGL backend (no display)
     - None — ``NewtonGLVisualizer`` auto-detects a missing ``$DISPLAY`` and selects EGL.
   * - ``newton_rtx``
     - Not supported headlessly
     - ``render_rgb_array()`` returns ``None``; frame capture requires a display.

**Headless video recording (``--video`` without ``--viz``).**

In Isaac Lab 2.x, ``--video`` alone would use the Kit Replicator pipeline implicitly.
In Isaac Lab 3.0, the equivalent is:

.. code-block:: bash

   # Record from Kit viewport headlessly (equivalent to 2.x --video behaviour)
   uv run isaaclab train --rl_library rsl_rl --task Isaac-Cartpole-Direct \
       --viz kit --enable_cameras --headless --video

As a convenience, passing ``--video`` without ``--viz`` still works: Isaac Lab
auto-creates a headless Kit visualizer (falling back to Newton GL if Kit is unavailable)
and sets ``source="visualizer:kit"`` on the default recorder, printing:

.. code-block:: text

   [INFO] --video specified without --viz: auto-creating a headless Kit visualizer
   for video recording. Pass --viz <type> to choose a different visualizer, or
   set video_recorders in your env config to record from a scene sensor instead.


.. rubric:: Viewport Camera Configuration (``ViewerCfg`` deprecated)

The ``viewer`` field (type :class:`~isaaclab.envs.common.ViewerCfg`) is deprecated on
:class:`~isaaclab.envs.DirectRLEnvCfg`, :class:`~isaaclab.envs.ManagerBasedEnvCfg`, and
:class:`~isaaclab.envs.DirectMARLEnvCfg`.  A backward-compatibility shim re-routes
``viewer.*`` assignments for one release, but the field will be removed in a future version.
Configure the viewport camera through :attr:`~isaaclab.sim.SimulationCfg.default_visualizer_cfg`
on the sim config instead.

Similarly, :class:`~isaaclab.envs.ui.ViewportCameraController` is deprecated.  A shim class
remains so existing imports do not break, but it raises a :class:`DeprecationWarning` at
construction.  Camera tracking is now handled directly by
:class:`~isaaclab_visualizers.kit.KitVisualizer` via ``origin_type`` and
``origin_track_path`` on :class:`~isaaclab_visualizers.kit.KitVisualizerCfg`.

.. code-block:: python

   # Before (Isaac Lab 2.x)
   env_cfg.viewer.eye = (4.5, 0.0, 6.0)
   env_cfg.viewer.lookat = (0.0, 0.0, 2.0)

   # After (Isaac Lab 3.x)
   from isaaclab.visualizers import VisualizerCfg
   env_cfg.sim.default_visualizer_cfg = VisualizerCfg(eye=(4.5, 0.0, 6.0), lookat=(0.0, 0.0, 2.0))

For asset-body tracking (previously ``origin_type="asset_root"`` / ``"asset_body"``), use
:class:`~isaaclab_visualizers.kit.KitVisualizerCfg` with ``origin_type="asset"`` and
``origin_track_path``:

.. code-block:: python

   # Before (Isaac Lab 2.x)
   env_cfg.viewer.origin_type = "asset_root"
   env_cfg.viewer.asset_name = "robot"

   # After (Isaac Lab 3.x)
   from isaaclab_visualizers.kit import KitVisualizerCfg
   env_cfg.sim.visualizer_cfgs = [KitVisualizerCfg(origin_type="asset", origin_track_path="robot")]

The :class:`~isaaclab.envs.ui.ViewportCameraController` class is also deprecated; camera
tracking is handled directly by :class:`~isaaclab_visualizers.kit.KitVisualizer`.


.. rubric:: Streaming Camera View (``tiled_cam_*`` fields removed)

The ``tiled_cam_*`` configuration fields on visualizer configs (e.g. ``tiled_cam_view``,
``tiled_cam_num``, ``tiled_cam_prim_path``) have been removed and replaced by the unified
``streaming_*`` API available on all four visualizer backends.  A one-release deprecation
shim forwards each removed field to its ``streaming_*`` equivalent and emits
:class:`DeprecationWarning`; the shim will be removed in the next major release.

.. list-table:: Field rename reference
   :header-rows: 1
   :widths: 40 40 20

   * - Old field (removed)
     - New field
     - Notes
   * - ``tiled_cam_view``
     - ``streaming_view``
     - Default is now ``False`` (opt-in)
   * - ``tiled_cam_num``
     - ``streaming_envs``
     - Accepts ``int`` or ``list[int]``
   * - ``tiled_cam_prim_path``
     - ``streaming_sensor_prim_path``
     - Existing sensor path; takes priority over auto-created camera
   * - ``tiled_cam_eye``
     - ``streaming_cam_eye``
     -
   * - ``tiled_cam_renderer``
     - ``streaming_cam_renderer``
     - Accepts ``"newton_warp"``, ``"ovrtx"``, ``"isaac_rtx"``, or ``None``

.. code-block:: python

   # Before (Isaac Lab 2.x)
   from isaaclab_visualizers.newton import NewtonVisualizerCfg
   cfg = NewtonVisualizerCfg(
       tiled_cam_view=True,
       tiled_cam_num=16,
       tiled_cam_prim_path="/World/envs/env_.*/Camera",
   )

   # After (Isaac Lab 3.x)
   from isaaclab_visualizers.newton import NewtonGLVisualizerCfg
   cfg = NewtonGLVisualizerCfg(
       streaming_view=True,
       streaming_envs=16,
       streaming_sensor_prim_path="/World/envs/env_.*/Camera",
   )

.. note::
   :class:`~isaaclab_visualizers.newton.NewtonVisualizerCfg` is deprecated in this release.
   Use :class:`~isaaclab_visualizers.newton.NewtonGLVisualizerCfg` (OpenGL rasterizer) or
   :class:`~isaaclab_visualizers.newton.NewtonRTXVisualizerCfg` (OVRTX path tracer) instead.


.. rubric:: Newton Visualizer Type Split (``newton`` → ``newton_gl`` / ``newton_rtx``)

The single ``NewtonVisualizerCfg`` (``visualizer_type="newton"``) has been split into two
dedicated configs with separate type identifiers:

.. list-table::
   :header-rows: 1
   :widths: 30 30 40

   * - Old (removed / deprecated)
     - New
     - Notes
   * - ``NewtonVisualizerCfg`` (``visualizer_type="newton"``)
     - :class:`~isaaclab_visualizers.newton.NewtonGLVisualizerCfg` (``visualizer_type="newton_gl"``)
     - OpenGL rasterizer; default Newton visualizer
   * - —
     - :class:`~isaaclab_visualizers.newton.NewtonRTXVisualizerCfg` (``visualizer_type="newton_rtx"``)
     - OVRTX path tracer (experimental)

The ``--viz newton`` CLI argument remains as a **deprecated alias** for ``--viz newton_gl``.
Update scripts and config files to use the explicit form:

.. code-block:: bash

   # Before (Isaac Lab 2.x)
   uv run isaaclab train --rl_library rsl_rl --task Isaac-Cartpole --viz newton

   # After (Isaac Lab 3.x)
   uv run isaaclab train --rl_library rsl_rl --task Isaac-Cartpole --viz newton_gl

Similarly, when importing the config class directly:

.. code-block:: python

   # Before (Isaac Lab 2.x)
   from isaaclab_visualizers.newton import NewtonVisualizerCfg
   cfg = NewtonVisualizerCfg()

   # After (Isaac Lab 3.x)
   from isaaclab_visualizers.newton import NewtonGLVisualizerCfg  # or NewtonRTXVisualizerCfg
   cfg = NewtonGLVisualizerCfg()

The ``source="visualizer:newton"`` string in :class:`~isaaclab.envs.utils.video_recorder_cfg.VideoRecorderCfg`
continues to work as a backward-compatible alias for ``"visualizer:newton_gl"``, but
``"visualizer:newton_gl"`` and ``"visualizer:newton_rtx"`` are now the canonical source strings.


.. rubric:: Video Recording (``gym.wrappers.RecordVideo`` replaced)

The ``gym.wrappers.RecordVideo`` pattern is no longer supported.  Video recording is now driven
internally by :class:`~isaaclab.envs.utils.video_recorder_cfg.VideoRecorderCfg` entries on the
environment config, sourcing frames from the active visualizer or a scene sensor.

.. code-block:: python

   # Before (Isaac Lab 2.x)
   env = gym.make(task, cfg=env_cfg, render_mode="rgb_array")
   env = gym.wrappers.RecordVideo(env, video_folder="videos/", step_trigger=lambda s: s == 0)

   # After (Isaac Lab 3.x)
   from isaaclab.envs.utils.video_recorder_cfg import VideoRecorderCfg
   env_cfg.video_recorders = [
       VideoRecorderCfg(source="visualizer", output_dir="videos/", video_length=200)
   ]
   env = gym.make(task, cfg=env_cfg)

Available sources: ``"visualizer"`` (auto-pick), ``"visualizer:kit"``, ``"visualizer:newton_gl"``,
``"visualizer:newton_rtx"``, ``"visualizer:newton_gl:tiled"``, ``"sensor:<name>"``.
``"visualizer:newton"`` and ``"visualizer:newton:tiled"`` remain as deprecated backward-compatible
aliases for ``"visualizer:newton_gl"`` and ``"visualizer:newton_gl:tiled"`` respectively.
The ``eye`` and ``lookat`` fields have been removed from ``VideoRecorderCfg``; position the
camera via ``sim.default_visualizer_cfg`` instead.

The ``isaaclab.envs.utils.recording_hooks`` module has been removed.  Physics-backend recording
hooks are now registered via :meth:`~isaaclab.sim.SimulationContext.add_render_callback`.


Tools and Integrations
----------------------

Finish by updating importers, benchmarks, and optional integrations used around the migrated task.

.. grid:: 2
   :gutter: 2

   .. grid-item-card:: Isaac Lab 2.x

      .. code-block:: bash

         ./isaaclab.sh -p scripts/benchmarks/benchmark_rsl_rl.py \
            --task Isaac-Cartpole

   .. grid-item-card:: Isaac Lab 3.0

      .. code-block:: bash

         uv run isaaclab benchmark training --rl_library rsl_rl \
            --task Isaac-Cartpole physics=physx


.. rubric:: URDF Importer

The URDF importer in Isaac Sim was rewritten to version 3.0, using the ``urdf-usd-converter``
library and the ``isaacsim.asset.transformer.rules`` extension to produce structured USD output.
The old C++ binding-based API (using Kit commands ``URDFParseFile``/``URDFImportRobot`` and the
``_urdf`` interface from ``acquire_urdf_interface()``) has been replaced with a new Python-based
pipeline.

The IsaacLab :class:`~sim.converters.UrdfConverter` has been updated to replicate the new
``URDFImporter.import_urdf()`` pipeline, inserting IsaacLab-specific post-processing (fix base,
joint drives, link density) on the intermediate USD stage before the asset transformer
restructures the output.

.. important::

   The previous version-pinning mechanism that locked the URDF importer extension to
   ``isaacsim.asset.importer.urdf-2.4.31`` has been removed. The converter now uses whichever
   version of the extension is available in your Isaac Sim installation.


**Deprecated Settings**

The following :class:`~sim.converters.UrdfConverterCfg` settings are **deprecated** because
the new URDF importer 3.0 no longer supports them. They are kept for backward compatibility
but will log warnings if enabled:

+-----------------------------------------------------------+-----------------------------------------------------+
| Setting                                                   | Notes                                               |
+===========================================================+=====================================================+
| ``convert_mimic_joints_to_normal_joints``                 | No longer supported by the importer.                |
+-----------------------------------------------------------+-----------------------------------------------------+
| ``replace_cylinders_with_capsules``                       | No longer supported by the importer.                |
+-----------------------------------------------------------+-----------------------------------------------------+
| ``root_link_name``                                        | No longer supported by the importer.                |
+-----------------------------------------------------------+-----------------------------------------------------+

.. note::

   The ``merge_fixed_joints`` setting is **still supported**. It is now implemented as a URDF XML
   pre-processing step that runs before the USD conversion. Fixed joints are removed and child
   link elements (visual, collision, inertial) are merged into the parent link with correct
   transform composition.

Additionally, the :class:`~sim.converters.UrdfConverterCfg.JointDriveCfg.NaturalFrequencyGainsCfg`
gains mode is **deprecated**. The ``compute_natural_stiffness`` function that it depended on has
been removed from the importer. If ``NaturalFrequencyGainsCfg`` is used, a
:exc:`DeprecationWarning` is emitted and joint drive gains are left at the values produced by the
URDF importer. Use :class:`~sim.converters.UrdfConverterCfg.JointDriveCfg.PDGainsCfg` instead.

The :attr:`~sim.converters.AssetConverterBaseCfg.make_instanceable` setting from the base class
is also no longer supported and will be ignored. Assets will be made instanceable by default.


**Updated CLI Tool**

The ``convert_urdf.py`` script has been updated. The ``usd_file_name`` is now determined
automatically by the importer based on the robot name and cannot be overridden.

**Before (Isaac Lab 2.x):**

.. tab-set::

   .. tab-item:: uv (Recommended)

      .. code-block:: bash

         uv run --extra importers python scripts/tools/convert_urdf.py \
           robot.urdf \
           /output/dir/robot.usd \
           --fix-base \
           --merge-joints

   .. tab-item:: isaaclab.sh / isaaclab.bat

      .. code-block:: bash

         ./isaaclab.sh -p scripts/tools/convert_urdf.py \
           robot.urdf \
           /output/dir/robot.usd \
           --fix-base \
           --merge-joints

**After (Isaac Lab 3.0):**

.. tab-set::

   .. tab-item:: uv (Recommended)

      .. code-block:: bash

         uv run --extra importers python scripts/tools/convert_urdf.py \
           robot.urdf \
           /output/dir \
           --fix-base \
           --joint-stiffness 100.0 \
           --joint-damping 1.0 \
           --viz kit

   .. tab-item:: isaaclab.sh / isaaclab.bat

      .. code-block:: bash

         ./isaaclab.sh -p scripts/tools/convert_urdf.py \
           robot.urdf \
           /output/dir \
           --fix-base \
           --joint-stiffness 100.0 \
           --joint-damping 1.0 \
           --viz kit

.. note::

   The ``--merge-joints`` flag is still accepted and correctly triggers the pre-processing
   step to merge fixed joints.


**Updated Python API**

If you use :class:`~sim.converters.UrdfConverter` or :class:`~sim.converters.UrdfConverterCfg`
directly in your code, note the following changes:

1. The ``usd_file_name`` is now set automatically by the converter based on the URDF file name.
   The importer generates output at ``{usd_dir}/{robot_name}/{robot_name}.usda``.

2. The ``make_instanceable`` setting is no longer supported. Assets will be made instanceable
   by default.

3. The ``merge_fixed_joints`` parameter is now implemented as a pre-processing step.

**Before (Isaac Lab 2.x):**

.. code-block:: python

   from isaaclab.sim.converters import UrdfConverter, UrdfConverterCfg

   cfg = UrdfConverterCfg(
       asset_path="robot.urdf",
       usd_dir="/output/dir",
       usd_file_name="robot.usd",
       fix_base=True,
       merge_fixed_joints=True,
       make_instanceable=True,
       joint_drive=UrdfConverterCfg.JointDriveCfg(
           gains=UrdfConverterCfg.JointDriveCfg.PDGainsCfg(
               stiffness=None,  # use URDF values
               damping=None,
           ),
       ),
   )

**After (Isaac Lab 3.0):**

.. code-block:: python

   from isaaclab.sim.converters import UrdfConverter, UrdfConverterCfg

   cfg = UrdfConverterCfg(
       asset_path="robot.urdf",
       usd_dir="/output/dir",
       # usd_file_name is determined automatically from the robot name
       fix_base=True,
       merge_fixed_joints=True,  # supported via pre-processing
       joint_drive=UrdfConverterCfg.JointDriveCfg(
           gains=UrdfConverterCfg.JointDriveCfg.PDGainsCfg(
               stiffness=None,  # use URDF values
               damping=None,
           ),
       ),
   )


.. rubric:: MJCF Importer

The MJCF importer in Isaac Sim was rewritten to use the ``mujoco-usd-converter`` library.
The old C++ binding-based API (using Kit commands ``MJCFCreateAsset``/``MJCFCreateImportConfig``
and the ``ImportConfig`` class) has been replaced with a new pure-Python ``MJCFImporter`` class
and ``MJCFImporterConfig`` dataclass.

.. important::

   The new MJCF importer produces USD assets with **nested rigid bodies** (i.e., ``RigidBodyAPI``
   is applied to each link prim individually) instead of a single articulation root with rigid
   body applied only at the top level. This matches how MuJoCo represents bodies and is
   physically more accurate, but it may affect code that assumes a flat rigid body hierarchy.
   If you have downstream logic that traverses the USD structure of MJCF-imported assets,
   verify that it handles nested rigid body prims correctly.

**Removed Settings**

The following :class:`~sim.converters.MjcfConverterCfg` settings have been **removed** because
the new converter handles them automatically based on the MJCF file content:

- ``fix_base`` — base fixedness is now inferred from the MJCF ``<freejoint>`` tag.
- ``link_density`` — density is now read directly from the MJCF model.
- ``import_inertia_tensor`` — inertia tensors are always imported.
- ``import_sites`` — sites are always imported.

The :attr:`~sim.converters.AssetConverterBaseCfg.make_instanceable` setting from the base class
is also no longer supported and will be ignored.


**New Settings**

The following new settings were added to :class:`~sim.converters.MjcfConverterCfg`:

+-----------------------------------------------------------------+------------------------------------------------------+
| Setting                                                         | Description                                          |
+=================================================================+======================================================+
| :attr:`~sim.converters.MjcfConverterCfg.merge_mesh`             | Merge meshes where possible to optimize the model.   |
+-----------------------------------------------------------------+------------------------------------------------------+
| :attr:`~sim.converters.MjcfConverterCfg.collision_from_visuals` | Generate collision geometry from visuals.            |
+-----------------------------------------------------------------+------------------------------------------------------+
| :attr:`~sim.converters.MjcfConverterCfg.collision_type`         | Type of collision geometry (e.g. ``"default"``,      |
|                                                                 | ``"Convex Hull"``, ``"Convex Decomposition"``).      |
+-----------------------------------------------------------------+------------------------------------------------------+


**Renamed Settings**

+------------------------------------------+------------------------------------------+
| Old (2.x)                                | New (3.0)                                |
+==========================================+==========================================+
| ``self_collision``                       | ``self_collision`` (unchanged)           |
+------------------------------------------+------------------------------------------+

.. note::

   The underlying Isaac Sim API renamed ``self_collision`` to ``allow_self_collision``.
   The IsaacLab :class:`~sim.converters.MjcfConverterCfg` keeps using ``self_collision``
   for backward compatibility and maps it to the new name internally.


**Updated CLI Tool**

The ``convert_mjcf.py`` script has been updated to match the new importer settings.
Old command-line flags (``--fix-base``, ``--make-instanceable``, ``--import-sites``)
are no longer available.

**Before (Isaac Lab 2.x):**

.. tab-set::

   .. tab-item:: uv (Recommended)

      .. code-block:: bash

         uv run --extra importers python scripts/tools/convert_mjcf.py \
           ../mujoco_menagerie/unitree_h1/h1.xml \
           source/isaaclab_assets/data/Robots/Unitree/h1.usd \
           --import-sites \
           --make-instanceable

   .. tab-item:: isaaclab.sh / isaaclab.bat

      .. code-block:: bash

         ./isaaclab.sh -p scripts/tools/convert_mjcf.py \
           ../mujoco_menagerie/unitree_h1/h1.xml \
           source/isaaclab_assets/data/Robots/Unitree/h1.usd \
           --import-sites \
           --make-instanceable

**After (Isaac Lab 3.0):**

.. tab-set::

   .. tab-item:: uv (Recommended)

      .. code-block:: bash

         uv run --extra importers python scripts/tools/convert_mjcf.py \
           ../mujoco_menagerie/unitree_h1/h1.xml \
           source/isaaclab_assets/data/Robots/Unitree/h1.usd \
           --merge-mesh \
           --self-collision \
           --viz kit

   .. tab-item:: isaaclab.sh / isaaclab.bat

      .. code-block:: bash

         ./isaaclab.sh -p scripts/tools/convert_mjcf.py \
           ../mujoco_menagerie/unitree_h1/h1.xml \
           source/isaaclab_assets/data/Robots/Unitree/h1.usd \
           --merge-mesh \
           --self-collision \
           --viz kit

New flags: ``--merge-mesh``, ``--collision-from-visuals``, ``--collision-type``, ``--self-collision``.


**Updated Python API**

If you use :class:`~sim.converters.MjcfConverter` or :class:`~sim.converters.MjcfConverterCfg`
directly in your code, update your configuration:

**Before (Isaac Lab 2.x):**

.. code-block:: python

   from isaaclab.sim.converters import MjcfConverter, MjcfConverterCfg

   cfg = MjcfConverterCfg(
       asset_path="robot.xml",
       usd_dir="/output/dir",
       fix_base=True,
       import_sites=True,
       make_instanceable=True,
   )

**After (Isaac Lab 3.0):**

.. code-block:: python

   from isaaclab.sim.converters import MjcfConverter, MjcfConverterCfg

   cfg = MjcfConverterCfg(
       asset_path="robot.xml",
       usd_dir="/output/dir",
       merge_mesh=True,
       collision_from_visuals=False,
       self_collision=False,
   )


.. rubric:: Benchmark Workflows

Isaac Lab 3.0 consolidates the per-backend environment benchmark entry points and their
wrapper shell runners into library-owned, backend-agnostic workflows. Select the physics
configuration at launch with ``physics=NAME`` — the same preset mechanism used by environments —
rather than choosing a backend-specific script.

**What Changed**

The environment benchmark entry points are now exposed through ``isaaclab benchmark`` and
the typed :mod:`isaaclab.benchmark` Python API:

* ``isaaclab benchmark runtime`` — steps an environment with random actions (no policy) and emits a
  ``RuntimeBundle``.
* ``isaaclab benchmark training`` — dispatches a real training run for the RL library selected with
  ``--rl_library`` and emits a ``TrainingBundle``.
* ``isaaclab benchmark startup`` — profiles the five startup phases (``app_launch``, ``python_imports``,
  ``task_config``, ``env_creation``, ``first_step``) with ``cProfile`` and emits a
  ``StartupBundle``.
* ``isaaclab benchmark play`` — **new in 3.0** — loads a trained checkpoint and benchmarks policy inference
  for the RL library selected with ``--rl_library``, emitting a ``PlayBundle`` (inference
  throughput plus the policy's reward, episode length, and success rate). It consumes the
  checkpoints produced by the training workflow; 2.x had no per-backend play benchmark.

The wrapper shell runners that drove these benchmarks — ``run_non_rl_benchmarks.sh`` and
``run_training_benchmarks.sh`` — were removed as well; their behavior is now expressed
directly through command arguments and ``presets=`` tokens.

The benchmark framework itself moved from :mod:`isaaclab.test.benchmark` to
:mod:`isaaclab.benchmark`. The old namespace and the transitional runtime, startup,
training, and play scripts were removed; update imports and invocations to the public
module and unified command.

.. note::

   This consolidation affects only the *environment* benchmark suite. The PhysX
   micro-benchmarks under ``source/isaaclab_physx/benchmark/`` (``benchmark_articulation.py``,
   ``benchmark_rigid_object.py``, and friends) are unchanged — only the
   ``run_physx_benchmarks.sh`` wrapper that invoked them was removed, so run those scripts
   directly. The other standalone benchmark scripts under ``scripts/benchmarks/`` —
   ``benchmark_cameras.py``, ``benchmark_load_robot.py``, ``benchmark_view_comparison.py``,
   ``benchmark_xform_prim_view.py``, ``benchmark_lazy_export.py``, and
   ``benchmark_hydra_resolve.py`` — are independent of the unified suite and likewise
   unaffected.

**Script and Command Mapping**

Map each old invocation to its replacement:

.. list-table::
   :header-rows: 1
   :widths: 45 55

   * - Isaac Lab 2.x
     - Isaac Lab 3.0
   * - ``benchmark_non_rl.py``
     - ``isaaclab benchmark runtime`` (no ``--rl_library`` dispatch)
   * - ``benchmark_startup.py``
     - ``isaaclab benchmark startup``
   * - ``benchmark_rsl_rl.py``
     - ``isaaclab benchmark training --rl_library rsl_rl``
   * - ``benchmark_rlgames.py``
     - ``isaaclab benchmark training --rl_library rl_games``
   * - *(newly supported)*
     - ``isaaclab benchmark training --rl_library skrl``
   * - *(newly supported)*
     - ``isaaclab benchmark training --rl_library sb3``
   * - *(newly supported)*
     - ``isaaclab benchmark play --rl_library {rsl_rl,rl_games,skrl,sb3}``

SKRL and Stable-Baselines3 had no dedicated benchmark script in 2.x; both are now supported
through the same ``--rl_library`` dispatch on ``isaaclab benchmark training``. ``isaaclab benchmark play`` is likewise new in
3.0: it benchmarks inference of a checkpoint trained by the training workflow for any of the four
RL libraries.

**Running Benchmarks**

The physics (and rendering) backend is selected with Hydra preset tokens — ``presets=``,
exactly as for the training workflow. There is no ``--physics`` or ``--render`` flag; pass
``presets=physx``, ``presets=newton_mjwarp``, etc. to choose the backend.

**Before (Isaac Lab 2.x):**

.. tab-set::

   .. tab-item:: uv (Recommended)

      .. code-block:: bash

         # Non-RL (random-action) runtime benchmark
         uv run python scripts/benchmarks/benchmark_non_rl.py --task Isaac-Cartpole-Direct

         # Training benchmark (RSL-RL)
         uv run python scripts/benchmarks/benchmark_rsl_rl.py --task Isaac-Cartpole-Direct

         # Wrapper shell runners
         ./scripts/benchmarks/run_non_rl_benchmarks.sh
         ./scripts/benchmarks/run_training_benchmarks.sh

   .. tab-item:: isaaclab.sh / isaaclab.bat

      .. code-block:: bash

         # Non-RL (random-action) runtime benchmark
         ./isaaclab.sh -p scripts/benchmarks/benchmark_non_rl.py --task Isaac-Cartpole-Direct

         # Training benchmark (RSL-RL)
         ./isaaclab.sh -p scripts/benchmarks/benchmark_rsl_rl.py --task Isaac-Cartpole-Direct

         # Wrapper shell runners
         ./scripts/benchmarks/run_non_rl_benchmarks.sh
         ./scripts/benchmarks/run_training_benchmarks.sh

**After (Isaac Lab 3.0):**

.. code-block:: bash

   # Non-RL (random-action) runtime benchmark — PhysX (default)
   uv run isaaclab benchmark runtime --task Isaac-Cartpole-Direct

   # Same benchmark on Newton/MJWarp — select the backend via presets=
   uv run isaaclab benchmark runtime --task Isaac-Cartpole-Direct presets=newton_mjwarp

   # Training benchmark — choose the RL library with --rl_library
   uv run isaaclab benchmark training --task Isaac-Cartpole-Direct --rl_library rsl_rl
   uv run --extra skrl isaaclab benchmark training --task Isaac-Cartpole-Direct --rl_library skrl presets=newton_mjwarp

   # Play (inference) benchmark — loads a checkpoint produced by training
   uv run isaaclab benchmark play --task Isaac-Cartpole-Direct --rl_library rsl_rl --checkpoint /path/to/model.pt

   # Startup profiling
   uv run isaaclab benchmark startup --task Isaac-Cartpole-Direct presets=newton_mjwarp

**Output Format**

The output format is controlled by ``--benchmark_formatter``, which is independent of the
physics backend. It defaults to ``schema`` (the typed benchmark bundle) and accepts a
comma-separated list to emit several formats at once. Supported values are ``schema``,
``omniperf``, ``osmo``, ``json``, and ``summary`` (legacy long-form aliases such as
``OmniPerfKPIFile`` are still accepted).

.. code-block:: bash

   # Emit the typed schema bundle and an OmniPerf KPI file in one run
   uv run isaaclab benchmark runtime --task Isaac-Cartpole-Direct \
       --benchmark_formatter schema,omniperf

**Migration Steps**

If you have custom benchmark scripts or CI based on Isaac Lab 2.x:

1. **Replace the old entry points** — swap ``benchmark_non_rl.py`` for ``isaaclab benchmark runtime``,
   ``benchmark_startup.py`` for ``isaaclab benchmark startup``, and the per-library training scripts for
   ``isaaclab benchmark training --rl_library <lib>``.

2. **Update benchmark imports** — replace ``isaaclab.test.benchmark`` with
   ``isaaclab.benchmark``. The old namespace is no longer available.

3. **Drop the wrapper runners** — ``run_non_rl_benchmarks.sh`` and
   ``run_training_benchmarks.sh`` no longer exist; express their behavior with script
   arguments and ``presets=`` tokens. ``run_physx_benchmarks.sh`` is also gone — invoke the
   PhysX micro-benchmarks under ``source/isaaclab_physx/benchmark/`` directly instead.

4. **Select the backend with** ``presets=`` — replace any per-backend script choice with a
   ``presets=`` (and, if needed, rendering) token on a single unified script. Update custom
   benchmark configs to the ``PresetCfg`` pattern.

5. **Pick the output format with** ``--benchmark_formatter`` — default ``schema``; pass a
   comma-separated list for multiple formats.

6. **Test both backends** — verify your benchmarks pass with ``presets=physx`` (default) and
   ``presets=newton_mjwarp``.

For a complete guide to multi-backend support, see the "Multi-Backend Support: PresetCfg
Pattern" section above.


.. rubric:: XR Teleoperation: Isaac Teleop Integration

The native XR teleoperation stack in ``isaaclab.devices.openxr`` has been deprecated and replaced
by `Isaac Teleop <https://github.com/NVIDIA/IsaacTeleop>`_, integrated via the ``isaaclab_teleop``
extension. The ``isaac-teleop-device-plugins`` repository has also been deprecated; all device
plugin support is now in Isaac Teleop.

For full documentation on the new stack, see :ref:`isaac-teleop-feature`.


**Installation Requirement**

Isaac Teleop must now be installed in your Isaac Lab environment:

.. code-block:: bash

   pip install isaacteleop~=1.0 --extra-index-url https://pypi.nvidia.com

See :ref:`install-isaac-teleop` for complete installation instructions.


**Import Changes**

.. list-table::
   :header-rows: 1
   :widths: 50 50

   * - Deprecated (2.x)
     - New (3.0)
   * - ``from isaaclab.devices.openxr import OpenXRDevice``
     - ``from isaaclab_teleop import IsaacTeleopDevice``
   * - ``from isaaclab.devices.openxr import OpenXRDeviceCfg``
     - ``from isaaclab_teleop import IsaacTeleopCfg``
   * - ``from isaaclab.devices.openxr import XrCfg``
     - ``from isaaclab_teleop import XrCfg``
   * - ``from isaaclab.devices.openxr import ManusVive``
     - ``from isaaclab_teleop import IsaacTeleopDevice`` (with Manus plugin configured)
   * - ``from isaaclab.devices import RetargeterBase``
     - Use Isaac Teleop ``BaseRetargeter`` and pipeline builder pattern
   * - ``from isaaclab.devices.openxr.retargeters import Se3AbsRetargeter``
     - ``from isaacteleop.retargeters import Se3AbsRetargeter``


**Environment Configuration Changes**

The ``teleop_devices`` field with ``OpenXRDeviceCfg`` has been replaced by the ``isaac_teleop``
field with ``IsaacTeleopCfg`` and a pipeline builder callable.

**Before (Isaac Lab 2.x):**

.. code-block:: python

   from isaaclab.devices import DevicesCfg, OpenXRDeviceCfg
   from isaaclab.devices.openxr import XrCfg
   from isaaclab.devices.openxr.retargeters import Se3AbsRetargeterCfg, GripperRetargeterCfg

   @configclass
   class MyEnvCfg(ManagerBasedRLEnvCfg):

       xr: XrCfg = XrCfg(anchor_pos=[0.0, 0.0, 0.0])

       teleop_devices: DevicesCfg = field(default_factory=lambda: DevicesCfg(
           handtracking=OpenXRDeviceCfg(
               xr_cfg=None,
               retargeters=[
                   Se3AbsRetargeterCfg(bound_hand=0, zero_out_xy_rotation=True),
                   GripperRetargeterCfg(bound_hand=0),
               ]
           ),
       ))

**After (Isaac Lab 3.0):**

.. code-block:: python

   from isaaclab_teleop import IsaacTeleopCfg, XrCfg

   def _build_pipeline():
       from isaacteleop.retargeting_engine.deviceio_source_nodes import ControllersSource, HandsSource
       from isaacteleop.retargeting_engine.interface import OutputCombiner, ValueInput
       from isaacteleop.retargeters import (
           GripperRetargeter, GripperRetargeterConfig,
           Se3AbsRetargeter, Se3RetargeterConfig, TensorReorderer,
       )
       from isaacteleop.retargeting_engine.tensor_types import TransformMatrix

       controllers = ControllersSource(name="controllers")
       hands = HandsSource(name="hands")
       transform = ValueInput("world_T_anchor", TransformMatrix())
       t_controllers = controllers.transformed(transform.output(ValueInput.VALUE))

       se3 = Se3AbsRetargeter(Se3RetargeterConfig(input_device=ControllersSource.RIGHT), name="ee")
       c_se3 = se3.connect({ControllersSource.RIGHT: t_controllers.output(ControllersSource.RIGHT)})

       grip = GripperRetargeter(GripperRetargeterConfig(hand_side="right"), name="grip")
       c_grip = grip.connect({
           ControllersSource.RIGHT: t_controllers.output(ControllersSource.RIGHT),
           HandsSource.RIGHT: hands.output(HandsSource.RIGHT),
       })

       reorder = TensorReorderer(
           input_config={"ee": ["pos_x","pos_y","pos_z","quat_x","quat_y","quat_z","quat_w"],
                         "grip": ["gripper_value"]},
           output_order=["pos_x","pos_y","pos_z","quat_x","quat_y","quat_z","quat_w","gripper_value"],
           name="reorder", input_types={"ee": "array", "grip": "scalar"},
       )
       c_reorder = reorder.connect({"ee": c_se3.output("ee_pose"), "grip": c_grip.output("gripper_command")})
       return OutputCombiner({"action": c_reorder.output("output")})

   @configclass
   class MyEnvCfg(ManagerBasedRLEnvCfg):

       xr: XrCfg = XrCfg(anchor_pos=(0.0, 0.0, 0.0))

       def __post_init__(self):
           super().__post_init__()
           self.isaac_teleop = IsaacTeleopCfg(
               pipeline_builder=_build_pipeline,
               sim_device=self.sim.device,
               xr_cfg=self.xr,
           )


**Backward Compatibility**

The old classes still exist and will issue ``DeprecationWarning`` when used:

* ``isaaclab.devices.openxr.OpenXRDevice`` and ``OpenXRDeviceCfg``
* ``isaaclab.devices.openxr.ManusVive`` and ``ManusViveCfg``
* All retargeters under ``isaaclab.devices.openxr.retargeters``

Deprecated retargeters have been moved to ``isaaclab_teleop.deprecated.openxr.retargeters`` for
compatibility. These will be removed in a future release.


Getting Help
------------

Use these resources when a migration issue remains after the relevant comparison and validation steps above.


.. rubric:: Support Resources

If you encounter issues during migration:

1. Check the `IsaacLab GitHub Issues <https://github.com/isaac-sim/IsaacLab/issues>`_
2. Review the `CHANGELOG <https://github.com/isaac-sim/IsaacLab/blob/main/source/isaaclab/docs/CHANGELOG.rst>`_
3. Join the community on `Discord <https://discord.gg/nvidiaomniverse>`_


.. include:: include/from_isaacgymenvs.rst


.. include:: include/comparing_simulation_isaacgym.rst


.. include:: include/deformables.rst
