Physics Backends#
Isaac Lab supports PhysX, Newton, and OvPhysX through shared asset, sensor, and scene APIs. Choose a backend for the runtime and solvers you need, then select a preset supported by your task. See Backends and Presets for launch commands.
Choose a backend#
PhysX simulation through Isaac Sim and Omniverse Kit, with TGS and PGS solvers.
Warp-native simulation without Isaac Sim. Choose from MJWarp, Kamino, VBD, and MPM solvers.
PhysX simulation without Omniverse Kit, configured through USD. Install
with the ovphysx extra.
Follow Installation for the supported installation paths and current optional extras. Do not combine OvPhysX with a Kit runtime in the same process.
For the general PhysX–Newton policy validation workflow, see Transfer Policies Between PhysX and Newton. When a checkpoint’s joint or body ordering differs from the target backend, use the articulation ordering guide.
Isaac Sim PhysX#
Isaac Sim PhysX runs through Isaac Sim and Omniverse Kit. It uses the Temporal
Gauss-Seidel (TGS) solver by default, with Projective Gauss-Seidel (PGS) also
available. Configure scene settings through PhysxCfg
and asset properties through Physics Schemas. Large or contact-rich scenes may
need additional GPU buffer capacity.
See the Isaac Sim PhysX guide for runtime details and Tune the PhysX Solver for solver and buffer settings.
Newton#
Newton runs on Warp without requiring Isaac Sim. Its solvers cover different
simulation needs: MJWarp and Kamino for rigid robots, VBD for cloth and soft bodies,
and MPM for particle materials. Configure the backend with
NewtonCfg and select a solver through
solver_cfg. Native Warp arrays are available for custom simulation code.
See the Newton guide for solver choices, tuning guides, and native data access.
OvPhysX#
OvPhysX runs PhysX without Isaac Sim or Omniverse Kit. It supports rigid objects,
articulations, contact and motion sensors, and CUDA-based deformables, and can
pair with OVRTX for rendering. Scene-level solver settings come primarily from
USD’s PhysicsScene; OvPhysxCfg holds additional
settings such as GPU buffer capacities. It cannot share a process with Kit.
See the OvPhysX guide for installation, supported features, and their configuration limits.
Find supported tasks and APIs#
Backend support is task-specific. Use Environments to browse registered environments and presets, or ask a task for its current choices:
uv run isaaclab train --rl_library rsl_rl \
--task Isaac-Cartpole-Direct --help
The help output is the source of truth for that task’s physics= choices.
For native solver data and views, see the PhysX,
Newton, and OvPhysX
access guides. For field-level configuration,
follow the generated API links for PhysxCfg,
NewtonCfg, its solver configurations, and
OvPhysxCfg.