> This page is for version Release 3.0 (default). > For other versions, use one of these documentation indexes: > - Release 3.0 (default): https://docs.nvidia.com/isaaclab/3.0/llms.txt > - Release 2.3: https://docs.nvidia.com/isaaclab/2.3/llms.txt > - Release 2.2: https://docs.nvidia.com/isaaclab/2.2/llms.txt > - Release 2.1: https://docs.nvidia.com/isaaclab/2.1/llms.txt > For clean Markdown of any page, append .md to the page URL. > For a complete documentation index, see https://docs.nvidia.com/isaaclab/llms.txt. > For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.nvidia.com/isaaclab/_mcp/server. # Creating visualization markers This guide shows how to draw visualization markers: debug geometry (frames, arrows, spheres, custom meshes) rendered over the scene through `markers.VisualizationMarkers`. Markers are display-only: they carry no physics and do not affect the simulation. For plain points, lines, and splines, Isaac Sim's own `isaacsim.util.debug_draw` extension is lighter-weight. Use `VisualizationMarkers` when you need more complex shapes. Markers are supported on Kit, Newton GL, Rerun, and Viser, but not yet on Newton RTX. See [https://isaac-sim.github.io/IsaacLab/release/3.0.0/source/concepts/visualization.html](https://isaac-sim.github.io/IsaacLab/release/3.0.0/source/concepts/visualization.html) for how to enable them on a given visualizer. ## Quick Start Run the packaged `markers` example: #### uv (Recommended) ```bash uv run --extra isaacsim isaaclab example markers ``` #### isaaclab.sh / isaaclab.bat ```bash ./isaaclab.sh example markers ``` Pass `--visualizer newton_gl` (or another supported backend) to switch visualizers; defaults to `kit`. ![](/isaaclab/_fern-img/0780b66dc9d3957f9b21ad3f6029050fe8e8cdecead1b8239b4a110a26f2f3e9.webp) To stop, close the window or press `Ctrl+C`. #### Code for markers.py ```python # Copyright (c) 2022-2026, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md). # All rights reserved. # # SPDX-License-Identifier: BSD-3-Clause """This script demonstrates different types of markers. .. code-block:: bash # Usage with default PhysX physics and default kit visualizer. uvx --from 'isaaclab[isaacsim]' isaaclab example markers """ import argparse from typing import TYPE_CHECKING from isaaclab.app import add_launcher_args, launch_simulation from isaaclab.utils import instantiate parser = argparse.ArgumentParser( description="This script demonstrates different types of markers.", conflict_handler="resolve", ) parser.add_argument("--physics", default="isaacsim_physx", choices=["isaacsim_physx"], help="Physics backend.") parser.add_argument("--max_steps", type=int, default=-1, help="Stop after this many steps; negative runs forever.") add_launcher_args(parser) parser.set_defaults(visualizer=["kit"]) args_cli = parser.parse_args() if args_cli.max_steps == 0 or args_cli.max_steps < -1: parser.error("--max_steps must be positive or -1.") import torch import isaaclab.sim as sim_utils from isaaclab.markers.visualization_markers_cfg import VisualizationMarkersCfg from isaaclab.physics import PhysicsCfg from isaaclab.utils.assets import ISAAC_NUCLEUS_DIR, ISAACLAB_NUCLEUS_DIR from isaaclab.utils.math import quat_from_angle_axis if TYPE_CHECKING: from isaaclab.markers import VisualizationMarkers def define_markers() -> "VisualizationMarkers": """Define markers with various different shapes.""" marker_cfg = VisualizationMarkersCfg( prim_path="/Visuals/myMarkers", markers={ "frame": sim_utils.UsdFileCfg( usd_path=f"{ISAAC_NUCLEUS_DIR}/Props/UIElements/frame_prim.usd", scale=(0.5, 0.5, 0.5), ), "arrow_x": sim_utils.UsdFileCfg( usd_path=f"{ISAAC_NUCLEUS_DIR}/Props/UIElements/arrow_x.usd", scale=(1.0, 0.5, 0.5), visual_material=sim_utils.PreviewSurfaceCfg(diffuse_color=(0.0, 1.0, 1.0)), ), "cube": sim_utils.CuboidCfg( size=(1.0, 1.0, 1.0), visual_material=sim_utils.PreviewSurfaceCfg(diffuse_color=(1.0, 0.0, 0.0)), ), "sphere": sim_utils.SphereCfg( radius=0.5, visual_material=sim_utils.PreviewSurfaceCfg(diffuse_color=(0.0, 1.0, 0.0)), ), "cylinder": sim_utils.CylinderCfg( radius=0.5, height=1.0, visual_material=sim_utils.PreviewSurfaceCfg(diffuse_color=(0.0, 0.0, 1.0)), ), "cone": sim_utils.ConeCfg( radius=0.5, height=1.0, visual_material=sim_utils.PreviewSurfaceCfg(diffuse_color=(1.0, 1.0, 0.0)), ), "mesh": sim_utils.UsdFileCfg( usd_path=f"{ISAAC_NUCLEUS_DIR}/Props/Blocks/DexCube/dex_cube_instanceable.usd", scale=(10.0, 10.0, 10.0), ), "mesh_recolored": sim_utils.UsdFileCfg( usd_path=f"{ISAAC_NUCLEUS_DIR}/Props/Blocks/DexCube/dex_cube_instanceable.usd", scale=(10.0, 10.0, 10.0), visual_material=sim_utils.PreviewSurfaceCfg(diffuse_color=(1.0, 0.25, 0.0)), ), "robot_mesh": sim_utils.UsdFileCfg( usd_path=f"{ISAACLAB_NUCLEUS_DIR}/Robots/ANYbotics/ANYmal-C/anymal_c.usd", scale=(2.0, 2.0, 2.0), visual_material=sim_utils.GlassMdlCfg(glass_color=(0.0, 0.1, 0.0)), ), }, ) return instantiate(marker_cfg) def main(): """Main function.""" with launch_simulation(cfg=PhysicsCfg(), launcher_args=args_cli) as physics_cfg: sim_cfg = sim_utils.SimulationCfg(dt=0.01, device=args_cli.device, physics=physics_cfg) sim = sim_utils.SimulationContext(sim_cfg) # Set main camera sim.set_camera_view([0.0, 18.0, 12.0], [0.0, 3.0, 0.0]) # Spawn things into stage # Lights cfg = sim_utils.DomeLightCfg(intensity=3000.0, color=(0.75, 0.75, 0.75)) cfg.func("/World/Light", cfg) # create markers my_visualizer = define_markers() # define a grid of positions where the markers should be placed num_markers_per_type = 5 grid_spacing = 2.0 # Calculate the half-width and half-height half_width = (num_markers_per_type - 1) / 2.0 half_height = (my_visualizer.num_prototypes - 1) / 2.0 # Create the x and y ranges centered around the origin x_range = torch.arange(-half_width * grid_spacing, (half_width + 1) * grid_spacing, grid_spacing) y_range = torch.arange(-half_height * grid_spacing, (half_height + 1) * grid_spacing, grid_spacing) # Create the grid x_grid, y_grid = torch.meshgrid(x_range, y_range, indexing="ij") x_grid = x_grid.reshape(-1) y_grid = y_grid.reshape(-1) z_grid = torch.zeros_like(x_grid) # marker locations marker_locations = torch.stack([x_grid, y_grid, z_grid], dim=1) marker_indices = torch.arange(my_visualizer.num_prototypes).repeat(num_markers_per_type) sim.reset() print("[INFO]: Setup complete...") # Yaw angle yaw = torch.zeros_like(marker_locations[:, 0]) step_count = 0 # Step while a visualizer window is still open (or none exist, e.g. headless); works for kit and newton. while sim.is_running() and (args_cli.max_steps < 0 or step_count < args_cli.max_steps): # rotate the markers around the z-axis for visualization marker_orientations = quat_from_angle_axis(yaw, torch.tensor([0.0, 0.0, 1.0])) # visualize my_visualizer.visualize(marker_locations, marker_orientations, marker_indices=marker_indices) # roll corresponding indices to show how marker prototype can be changed if yaw[0].item() % (0.5 * torch.pi) < 0.01: marker_indices = torch.roll(marker_indices, 1) # perform step sim.step() step_count += 1 # increment yaw yaw += 0.01 if __name__ == "__main__": main() ``` ## Configuring markers `VisualizationMarkersCfg` takes: * `prim_path`: prim path where the marker `UsdGeom.PointInstancer` is created. * `markers`: a dict of marker prototypes. The key names the prototype; the value is its spawn config (any [SpawnerCfg](https://isaac-sim.github.io/IsaacLab/release/3.0.0/source/api/lab/isaaclab.sim.spawners.html#isaaclab.sim.spawners.SpawnerCfg), including USD file references). > **Note** > > Physics properties on a marker prototype's spawn config are stripped on creation, since > markers are not simulated. ```python def define_markers() -> "VisualizationMarkers": """Define markers with various different shapes.""" marker_cfg = VisualizationMarkersCfg( prim_path="/Visuals/myMarkers", markers={ "frame": sim_utils.UsdFileCfg( usd_path=f"{ISAAC_NUCLEUS_DIR}/Props/UIElements/frame_prim.usd", scale=(0.5, 0.5, 0.5), ), "arrow_x": sim_utils.UsdFileCfg( usd_path=f"{ISAAC_NUCLEUS_DIR}/Props/UIElements/arrow_x.usd", scale=(1.0, 0.5, 0.5), visual_material=sim_utils.PreviewSurfaceCfg(diffuse_color=(0.0, 1.0, 1.0)), ), "cube": sim_utils.CuboidCfg( size=(1.0, 1.0, 1.0), visual_material=sim_utils.PreviewSurfaceCfg(diffuse_color=(1.0, 0.0, 0.0)), ), "sphere": sim_utils.SphereCfg( radius=0.5, visual_material=sim_utils.PreviewSurfaceCfg(diffuse_color=(0.0, 1.0, 0.0)), ), "cylinder": sim_utils.CylinderCfg( radius=0.5, height=1.0, visual_material=sim_utils.PreviewSurfaceCfg(diffuse_color=(0.0, 0.0, 1.0)), ), "cone": sim_utils.ConeCfg( radius=0.5, height=1.0, visual_material=sim_utils.PreviewSurfaceCfg(diffuse_color=(1.0, 1.0, 0.0)), ), "mesh": sim_utils.UsdFileCfg( usd_path=f"{ISAAC_NUCLEUS_DIR}/Props/Blocks/DexCube/dex_cube_instanceable.usd", scale=(10.0, 10.0, 10.0), ), "mesh_recolored": sim_utils.UsdFileCfg( usd_path=f"{ISAAC_NUCLEUS_DIR}/Props/Blocks/DexCube/dex_cube_instanceable.usd", scale=(10.0, 10.0, 10.0), visual_material=sim_utils.PreviewSurfaceCfg(diffuse_color=(1.0, 0.25, 0.0)), ), "robot_mesh": sim_utils.UsdFileCfg( usd_path=f"{ISAACLAB_NUCLEUS_DIR}/Robots/ANYbotics/ANYmal-C/anymal_c.usd", scale=(2.0, 2.0, 2.0), visual_material=sim_utils.GlassMdlCfg(glass_color=(0.0, 0.1, 0.0)), ), }, ) return instantiate(marker_cfg) ``` ## Drawing markers `visualize` sets marker poses and, optionally, which prototype each marker instance uses via `marker_indices`. ```python my_visualizer.visualize(marker_locations, marker_orientations, marker_indices=marker_indices) ``` Arguments left as `None` keep their previous value. Passing a different number of rows than the last call resizes the marker instance count. See `visualize`'s docstring for the full argument list (`translations`, `orientations`, `scales`, `marker_indices`, `environment_ids`). ## Markers in practice Markers are commonly used to debug per-environment state during training, such as commanded vs. current velocity, or contact events: ![Velocity arrow marker on an AnymalD robot](/isaaclab/_fern-img/e6b93f266c050db308d7c1f9d3f8aac5e1fc2eb1b522a15015c13a800d7d0f54.webp)![Joint arrow markers on a Franka arm and contact sensor markers on a cube](/isaaclab/_fern-img/b3a4d1b4d58a84b1da76fdd81f5b01767df989520b931a5108c900d7461bd560.webp) ## See also * [https://isaac-sim.github.io/IsaacLab/release/3.0.0/source/concepts/visualization.html](https://isaac-sim.github.io/IsaacLab/release/3.0.0/source/concepts/visualization.html): enabling markers per visualizer, and other visualizer features * [/source/how-to/record_video](/isaaclab/3.0/isaac-lab/recording-video): recording a marker-annotated scene to video