Why can't I see my robot in the viewport, even though it's loaded in the stage and code can run successfully?

Omniverse Isaac Sim
1

Isaac Sim Version

[√] 4.5.0
4.2.0
4.1.0
4.0.0
4.5.0
2023.1.1
2023.1.0-hotfix.1
Other (please specify):

Isaac Lab Version

[√] 2.1.0

Operating System

[√] Ubuntu 22.04
Ubuntu 20.04
Windows 11
Windows 10
Other (please specify):

GPU Information

  • Model: RTX2080Ti, CUDA version:12.2
  • Driver Version:535.230.02

Topic Description

Detailed Description

In my environment, I can’t see my drone, even though I clearly added it to the stage. You can check my specific settings and console.However, I believe my code is running normally. The code can train correctly, and it’s effective training, because I mapped the aircraft’s coordinates into a small marker so I can see its trajectory. But I can’t see my aircraft’s attitude/orientation.

Steps to Reproduce

some code :

   class CrazyFlieEnvCfg(DirectRLEnvCfg): 
   robot: ArticulationCfg =  CRAZYFLIE_CFG.replace(prim_path="/World/envs/env_.*/Robot")
   
     **following in _setup_scence**
    self._robot = Articulation(self.cfg.robot)
    self.scene.articulations["robot"] = self._robot

(Add more steps as needed)

Error Messages

Next is console output:
2025-07-20 15:59:59 [Warning] [omni.kit.app.plugin] No crash reporter present, dumps uploading isn’t available.
2025-07-20 15:59:59 [Warning] [omni.ext.plugin] [ext: rendering_modes] Extensions config ‘extension.toml’ doesn’t exist ‘/home/lab317/IsaacLab/apps/rendering_modes’ or ‘/home/lab317/IsaacLab/apps/rendering_modes/config’
2025-07-20 15:59:59 [Warning] [gpu.foundation.plugin] IOMMU is enabled.
2025-07-20 15:59:59 [Warning] [omni.log] Source: omni.hydra was already registered.
2025-07-20 15:59:59 [Warning] [omni.isaac.dynamic_control] omni.isaac.dynamic_control is deprecated as of Isaac Sim 4.5. No action is needed from end-users.
2025-07-20 15:59:59 [Warning] [omni.replicator.core.scripts.extension] No material configuration file, adding configuration to material settings directly.
2025-07-20 15:59:59 [Warning] [omni.kit.menu.utils.app_menu] add_menu_items: menu [<MenuItemDescription name:‘New’>, <MenuItemDescription name:‘Open’>, <MenuItemDescription name:‘Re-open with New Edit Layer’>, <MenuItemDescription name:‘Save’>, <MenuItemDescription name:‘Save With Options’>, <MenuItemDescription name:‘Save As…’>, <MenuItemDescription name:‘Save Flattened As…’>, <MenuItemDescription name:‘Add Reference’>, <MenuItemDescription name:‘Add Payload’>, <MenuItemDescription name:‘Exit’>] cannot change delegate
2025-07-20 16:00:03 [Warning] [rtx.scenedb.plugin] SceneDbContext : TLAS limit buffer size 8287597056
2025-07-20 16:00:03 [Warning] [rtx.scenedb.plugin] SceneDbContext : TLAS limit : valid false, within: false
2025-07-20 16:00:03 [Warning] [rtx.scenedb.plugin] SceneDbContext : TLAS limit : decrement: 167690, decrement size: 8204721408
2025-07-20 16:00:03 [Warning] [rtx.scenedb.plugin] SceneDbContext : New limit 8682532 (slope: 494, intercept: 3699200)
2025-07-20 16:00:03 [Warning] [rtx.scenedb.plugin] SceneDbContext : TLAS limit buffer size 4291087616
2025-07-20 16:00:03 [Warning] [rtx.scenedb.plugin] SceneDbContext : TLAS limit : valid true, within: true
2025-07-20 16:00:03 [Warning] [omni.usd-abi.plugin] No setting was found for ‘/rtx-defaults-transient/meshlights/forceDisable’
2025-07-20 16:01:05 [Warning] [omni.hydra.scene_delegate.plugin] Calling getBypassRenderSkelMeshProcessing for prim /Visuals/Command/goal_position.proto0_mesh_id0 that has not been populated

Screenshots or Videos

image
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2

@xihuanafeng111 i am just another user but wonder if you could take a screenshot of what you see in the viewport (of its entirety, including the viewport HUD) when you have the Robot reference selected?

1 Like
3

Thank you sincerely for your reply. I will attach a screenshot from my viewport, where you will see the effect when I focus on the robot. I made changes based on the official quadcopter_env.py, and the official xform is not fixed to the Crazyflie. I’m not sure if there’s an issue on my end.

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I have no idea to find my robot ,so i put a small a green cube to show it position, so that i know it works.

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4

Thank you very much for your reply. While trying to provide clearer screenshots, I found my robot. It’s so tiny that I didn’t even realize it was there. Even a 0.1 size cube can completely cover it. Now, I have a small problem: how can I place this xform at the center of my aircraft instead of it being fixed on the ground like this, so it can follow me at all times?

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5

my suspicion had to do with the scale, hence hoping the focus/zoom shortcut (F) would allow us to confirm whether the robot is actually in the scene. based on your latest finding, it does look like it’s in the scene. so, i wonder if it’s worth adjusting the default scale of the world or robot to make working with your asset easier. last i checked, Isaac Sim should be using meters as the default unit, so you can make a call yourself.

regarding the xform placement, could it be that the USD you are referencing already had an offset xform?

and off topic - in addition to making a thread here on the forum, i would also encourage you to make a topic over at the github repo where Isaac Lab-specific support is more abundant:

To ensure efficient support and collaboration, please submit your topic to its GitHub repo following the instructions provided on Isaac Lab’s Contributing Guidelines regarding discussions, submitting issues, feature requests, and contributing to the project.

1 Like
6

I’m also not entirely sure if the USD is offset. When I run the official Crazyflie demo, I noticed that focusing on the robot only centers it at the origin, not on the robot itself.

7

i suppose there’s only one way to find out by inspecting/opening the USD file itself and see whether the defaultPrim’s pivot is situated at the center of the robot or at the world origin.

if it is, for some reason, offset from the world origin, you could try moving the robot back to the origin and resaving (or save as a new USD if you’d like to keep the original) and see if the issue persists.

while you are at it, you can also verify the MPU for the source USD to address the possible scaling discrepancies:

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image647×585 27 KB

1 Like
8

Thank you for your answer as well.，Perhaps there’s an issue somewhere in my code. I’ve noticed that in the official demo, Isaac-Quadcopter-Direct-v0, the xform is present at the Crazyflie’s starting position, but it doesn’t seem to move with the Crazyflie. Why is this? My task is to observe the Crazyflie’s pose. If this xform isn’t attached to it, how am I supposed to get this data?