.. currentmodule:: isaaclab
Isaac Lab offers several lightweight visualizers for real-time simulation inspection and debugging. Unlike renderers that process sensor data, visualizers are meant for fast, interactive feedback.
You can use any visualizer regardless of your chosen physics engine or rendering backend.
Isaac Lab supports four visualizer backends, each optimized for different use cases:
| Visualizer | Best For | Key Features |
|---|---|---|
| Omniverse | High-fidelity, Isaac Sim integration | USD, visualization markers, live plots |
| Newton | Fast iteration | Low overhead, visualization markers |
| Rerun | Remote viewing, replay | Webviewer, time scrubbing, recording export, visualization markers |
| Viser | Web-based remote visualization, sharing, recording | Warp-based rendering, browser-based, share URL, visualization markers |
The following visualizers are shown training the Isaac-Velocity-Flat-Anymal-D-v0 environment.
Launch visualizers from the command line with --visualizer (or --viz alias):
# Launch all visualizers (comma-delimited list, no spaces)
./isaaclab.sh train --library rsl_rl --task Isaac-Cartpole-v0 --viz kit,newton,rerun
# Launch only the Newton visualizer
./isaaclab.sh train --library rsl_rl --task Isaac-Cartpole-v0 --viz newton
# Launch the Viser web-based visualizer
./isaaclab.sh train --library rsl_rl --task Isaac-Cartpole-v0 --viz viserTo run in headless mode, omit the --viz argument:
./isaaclab.sh train --library rsl_rl --task Isaac-Cartpole-v0Note
The --headless argument is deprecated.
For compatibility, --headless still takes precedence and disables all visualizers.
Launching visualizers with the command line will use default visualizer configurations. Visualizer backends live in the isaaclab_visualizers package (e.g. source/isaaclab_visualizers/isaaclab_visualizers/kit, newton, rerun, viser).
You can also configure custom visualizers in the code by defining VisualizerCfg instances for the SimulationCfg, for example:
from isaaclab.sim import SimulationCfg
from isaaclab_visualizers.kit import KitVisualizerCfg
from isaaclab_visualizers.newton import NewtonVisualizerCfg
from isaaclab_visualizers.rerun import RerunVisualizerCfg
from isaaclab_visualizers.viser import ViserVisualizerCfg
sim_cfg = SimulationCfg(
visualizer_cfgs=[
KitVisualizerCfg(
# Omit create_viewport (default False) to use the active viewport; set
# create_viewport=True and optionally viewport_name to add a dedicated window.
eye=(0.0, 0.0, 20.0), # high top down view
lookat=(0.0, 0.0, 0.0),
),
NewtonVisualizerCfg(
eye=(5.0, 5.0, 5.0), # closer quarter view
lookat=(0.0, 0.0, 0.0),
show_joints=True,
),
RerunVisualizerCfg(
keep_historical_data=True,
keep_scalar_history=True,
record_to_rrd="my_training.rrd",
),
ViserVisualizerCfg(
port=8080,
share=False,
),
]
)The effective visualizer mode is resolved from both CLI and SimulationCfg.visualizer_cfgs:
--viz(alias:--visualizer) uses comma-separated values (for example--viz kit,newton).- If
--vizis omitted, Isaac Lab falls back toSimulationCfg.visualizer_cfgs(see :ref:`visualization-configuration`). --viz noneexplicitly disables all visualizers.- If
--headlessis passed, it overrides--vizand disables visualizers.
For the migration-focused summary and deprecation context, see :doc:`/source/migration/migrating_to_isaaclab_3-0`.
Visualizers can be configured to visualize just a subset of environments. This is called partial visualization.
There are 3 fields exposed in the VisualizerCfg for selecting environments for partial visualization:
max_visible_envscaps how many envs are shown.visible_env_indicesexplicitly selects the envs to visualize.randomly_sample_visible_envs(defaultTrue): whenvisible_env_indicesis unset andmax_visible_envsis set, enables randomly sampling the selected envs. If disabled, the firstmax_visible_envsenvs are selected.
Also, there is a CLI arg --max_visible_envs that overrides VisualizerCfg.max_visible_envs for the run.
| CLI args | visualizer configs | Effective behavior |
|---|---|---|
no --viz |
[] |
Run headless. |
--viz kit,newton |
[] |
Launch default Kit and default Newton visualizers. |
--viz kit,newton |
[NewtonVisualizerCfg(...), RerunVisualizerCfg(...)] |
Launch default Kit and custom Newton; Rerun is not launched. |
no --viz |
[NewtonVisualizerCfg(...), RerunVisualizerCfg(...)] |
Launch custom Newton and custom Rerun visualizers from config. |
--viz none |
[NewtonVisualizerCfg(...), RerunVisualizerCfg(...)] |
Run headless with all visualizers disabled. |
--headless |
any | Run headless with deprecation warning. |
--headless --viz <names> |
any | Run headless; --headless takes precedence. |
Video recording is enabled with the --video flag. When combined with --visualizer,
the visualizer selection also determines which backend captures the video frames:
--visualizer kitenables--videocapture through the Isaac RTX renderer (Omniverse Replicator).--visualizer newtonenables--videocapture through the Newton OpenGL renderer.--visualizer rerundoes not produce--videoclips; it records Rerun.rrddata for replay through the Rerun visualizer.--visualizer viserdoes not currently provide a--videorecording backend.
When both Kit and Newton visualizers are active, Isaac Lab records a single --video stream and
Kit takes precedence. To record from the renderer/physics stack instead of the active visualizer,
set VideoRecorderCfg.backend_source = "renderer" in the task configuration.
--video compatibility: visualizer × renderer preset
| Renderer preset | --visualizer kit --video |
--visualizer newton --video |
|---|---|---|
isaacsim_rtx_renderer |
✅ Kit RTX captures video (default, no change) | ✅ Newton GL captures video (overrides RTX backend) |
newton_renderer |
✅ Kit RTX captures video (overrides Newton backend) | ✅ Newton GL captures video (default, no change) |
ovrtx_renderer |
❌ Raises an error — see note below | ✅ Newton GL captures video; ovrtx provides camera sensor data |
Note
--visualizer kit combined with ovrtx_renderer raises a ValueError at startup.
Both Kit (Isaac Sim) and ovrtx ship conflicting RTX hydra libraries compiled against
different USD namespaces (pxrInternal_v0_25_11 vs ovInternal_v0_25_11), which
causes a dynamic-linker crash when loaded into the same process.
Use --visualizer newton instead — it is compatible with all renderer presets.
Record video with the ovrtx renderer preset
./isaaclab.sh -p scripts/benchmarks/benchmark_rsl_rl.py \
--task=Isaac-Repose-Cube-Shadow-Vision-Direct-v0 \
--enable_cameras \
--visualizer newton \
--video \
--video_length=300 \
--video_interval=2000 \
--max_iterations=5 \
--num_envs=1024 \
--benchmark_backend=summary \
"presets=newton_mjwarp,ovrtx_renderer,rgb"Record video with the Isaac RTX renderer preset using the Newton video backend
./isaaclab.sh -p scripts/benchmarks/benchmark_rsl_rl.py \
--task=Isaac-Repose-Cube-Shadow-Vision-Direct-v0 \
--enable_cameras \
--visualizer newton \
--video \
--video_length=300 \
--video_interval=2000 \
--max_iterations=5 \
--num_envs=1024 \
--benchmark_backend=summary \
"presets=physx,isaacsim_rtx_renderer,rgb"Record video with the Isaac RTX renderer preset using the Kit video backend
./isaaclab.sh -p scripts/benchmarks/benchmark_rsl_rl.py \
--task=Isaac-Repose-Cube-Shadow-Vision-Direct-v0 \
--enable_cameras \
--visualizer kit \
--video \
--video_length=300 \
--video_interval=2000 \
--max_iterations=5 \
--num_envs=1024 \
--benchmark_backend=summary \
"presets=physx,isaacsim_rtx_renderer,rgb"Main Features:
- Native USD stage integration
- Live plots for monitoring training metrics
- Full Isaac Sim rendering capabilities and tooling
- Visualization markers for debugging (arrows, frames, object targets, etc.)
Core Configuration:
from isaaclab_visualizers.kit import KitVisualizerCfg
visualizer_cfg = KitVisualizerCfg(
# Viewport: default is create_viewport=False (use active viewport).
# Set create_viewport=True to create a docked window; viewport_name=None uses the default name.
create_viewport=False,
dock_position="SAME",
window_width=1280,
window_height=720,
eye=(8.0, 8.0, 3.0),
lookat=(0.0, 0.0, 0.0),
enable_markers=True,
enable_live_plots=True,
)Main Features:
- Lightweight OpenGL rendering with low overhead
- Simulation and rendering pause controls
- Adjustable update frequency for performance tuning
- Some customizable rendering options (shadows, sky, wireframe)
- Visualization markers (joints, contacts, springs, COM, debug markers)
Interactive Controls:
| Key/Input | Action |
|---|---|
| W, A, S, D or Arrow Keys | Forward / Left / Back / Right |
| Q, E | Down / Up |
| Left Click + Drag | Look around |
| Mouse Scroll | Zoom in/out |
| H | Toggle UI sidebar |
| ESC | Exit viewer |
Core Configuration:
from isaaclab_visualizers.newton import NewtonVisualizerCfg
visualizer_cfg = NewtonVisualizerCfg(
# Window settings
window_width=1920, # Window width in pixels
window_height=1080, # Window height in pixels
# Camera settings
eye=(8.0, 8.0, 3.0), # Initial camera position (x, y, z)
lookat=(0.0, 0.0, 0.0), # Camera look-at target
# Performance tuning
update_frequency=1, # Update every N frames (1=every frame)
# Physics debug visualization
show_joints=False, # Show joint visualizations
show_contacts=False, # Show contact points and normals
show_springs=False, # Show spring constraints
show_com=False, # Show center of mass markers
# Rendering options
enable_shadows=True, # Enable shadow rendering
enable_sky=True, # Enable sky rendering
enable_wireframe=False, # Enable wireframe mode
# Color customization
background_color=(0.53, 0.81, 0.92), # Sky/background color (RGB [0,1])
ground_color=(0.18, 0.20, 0.25), # Ground plane color (RGB [0,1])
light_color=(1.0, 1.0, 1.0), # Directional light color (RGB [0,1])
)Main Features:
- Web viewer interface accessible from local or remote browser
- Metadata logging and filtering
- Recording to .rrd files for offline replay (.rrd files can be opened with ctrl+O from the web viewer)
- Timeline scrubbing and playback controls of recordings
- Visualization debug markers
Core Configuration:
from isaaclab_visualizers.rerun import RerunVisualizerCfg
visualizer_cfg = RerunVisualizerCfg(
# Server settings
app_id="isaaclab-simulation", # Application identifier for viewer
grpc_port=9876, # gRPC endpoint for logging SDK connection
web_port=9090, # Port for local web viewer (launched in browser)
bind_address="0.0.0.0", # Endpoint host formatting/reuse checks
# Camera settings
eye=(8.0, 8.0, 3.0), # Initial camera position (x, y, z)
lookat=(0.0, 0.0, 0.0), # Camera look-at target
# History settings
keep_historical_data=False, # Keep transforms for time scrubbing
keep_scalar_history=False, # Keep scalar/plot history
# Recording
record_to_rrd="recording.rrd", # Path to save .rrd file (None = no recording)
)Rerun startup uses the Python SDK through newton.viewer.ViewerRerun (no external rerun CLI process
management). If grpc_port is already active, Isaac Lab reuses that server. If web_port is occupied while
starting a new server, initialization fails with a clear port-conflict error.
The Viser visualizer provides a web-based 3D viewer for Isaac Lab simulations powered by the Newton Warp renderer. It streams the simulation state to a local web server, allowing you to view and interact with the scene from any browser.
Key features:
- Browser-based visualization accessible at
http://localhost:8080by default - Optional public share URL for remote viewing
- Recording to
.viserformat for replay - Environment filtering to control which environments are rendered
- Visualization debug markers
Launch with Viser:
./isaaclab.sh -p source/isaaclab_tasks/isaaclab_tasks/direct/cartpole/cartpole_env.py --viz viserConfiguration example:
from isaaclab_visualizers.viser import ViserVisualizerCfg
visualizer_cfg = ViserVisualizerCfg(
port=8080,
open_browser=True,
label="Isaac Lab Simulation",
share=False,
max_visible_envs=16,
)Configuration options:
port(int, default8080): Port of the local Viser web server.open_browser(bool, defaultTrue): Automatically open the viewer URL in a browser.label(str or None, default"Isaac Lab Simulation"): Page title shown in the viewer.share(bool, defaultFalse): Request a public share URL from Viser for remote viewing.record_to_viser(str or None, defaultNone): Path to save a.viserrecording file.verbose(bool, defaultTrue): Print viewer server startup information.
Note
The Viser visualizer does not currently support live plots.
When visualizing large-scale environments, consider:
- Using Newton instead of Omniverse or Rerun
- Reducing window sizes
- Lower update frequencies
- Pausing visualizers while they are not being used
Rerun Visualizer Performance
The Rerun web-based visualizer may experience performance issues or crashes when visualizing large-scale
environments. For large-scale simulations, the Newton visualizer is recommended. Alternatively, to reduce load,
the num of environments can be overwritten and decreased using --num_envs:
./isaaclab.sh train --library rsl_rl --task Isaac-Cartpole-v0 --viz rerun --num_envs 512Rerun Visualizer FPS Control
The FPS control in the Rerun visualizer UI may not affect the visualization frame rate in all configurations.
Live Plots
Currently, live plots are only available in the Kit Visualizer.
Viser Visualizer Renderer Requirement
The Viser visualizer requires a Newton model, which is provided automatically by :class:`~isaaclab.physics.SceneDataProvider` regardless of the active physics backend or renderer. It is compatible with all rendering backends (RTX, Newton Warp, OVRTX).
Newton Visualizer CUDA/OpenGL Interoperability Warnings
On some system configurations, the Newton visualizer may display warnings about CUDA/OpenGL interoperability:
Warning: Could not get MSAA config, falling back to non-AA.
Warp CUDA error 999: unknown error (in function wp_cuda_graphics_register_gl_buffer)
Warp UserWarning: Could not register GL buffer since CUDA/OpenGL interoperability
is not available. Falling back to copy operations between the Warp array and the
OpenGL buffer.
The visualizer will still function correctly but may experience reduced performance due to falling back to CPU copy operations instead of direct GPU memory sharing.
Newton Visualizer on Spark with Conda
When running the Newton visualizer on Spark inside a conda environment, conda-installed X11 libraries may conflict with the system libraries required by pyglet, causing the following error:
pyglet.window.xlib.XlibException: Could not create UTF8 text property
To resolve this, remove the conflicting conda packages so that the system-provided libraries are used instead:
conda remove --force xorg-libx11 libxcb- :doc:`/source/overview/core-concepts/renderers` — renderer backends (RTX, Newton Warp, OVRTX)
- :doc:`/source/overview/core-concepts/scene_data_providers` — how scene data flows from physics to visualizers
- :doc:`/source/experimental-features/newton-physics-integration/index` — Newton physics integration guide
- :doc:`/source/migration/migrating_to_isaaclab_3-0` — migration guide with
--headlessdeprecation details


