How to use my own usd assets in object_based_sdg.py?

Omniverse Synthetic Data Generation (SDG)
1

I’m trying to modify the script in order to use my own usd environments and objects. I have tried inputting to url the path of the object but it does not work. What’s the correct way to reference the files?

"env_url": "pathto/env",

"labeled_assets_and_properties": \[

    {

        "url": "/Isaac/Props/YCB/Axis_Aligned/008_pudding_box.usd",

        "label": "pudding_box",

        "count": 5,

        "floating": True,

        "scale_min_max": (0.85, 1.25),

    },

    {

        "url": "/Isaac/Props/YCB/Axis_Aligned_Physics/006_mustard_bottle.usd",

        "label": "mustard_bottle",

        "count": 7,

        "floating": True,

        "scale_min_max": (0.85, 1.25),

    },



    \# {

    \#     "url": "pathto/object1.usd",

    \#     "label": "atm_machine",

    \#     "count": 7,

    \#     "floating": True,

    \#     "scale_min_max": (0.85, 1.25),

    \# },

\],
2

@rryyxz i am just another user, but can you first check to see if your custom USD has a defaultPrim? feel free to look at another post where i’ve outlined the issue if there isn’t one:

if you do, feel free to report back!

3

Thanks for replying, but I’m so confused. Can you go over this step by step? I have an object called ‘object1.usd’. Dp i put it under the World xform and have World as a defaultPrim? And how do i reference ‘object1.usd’ in the python script?

4

here are the pre-existing assets used in your snippet (from the tutorial):

image
image1027×447 59.8 KB

image
image1028×445 67.7 KB

and in both cases, we see the DefaultPrim has been designated to the top prim in the stage hierarchy (with the fewest indentions). and it’s just an xform prim called Root.

so if you were to open object1.usd directly, you can follow the same hierarchy and naming convention (for consistency’s sake) by:

  1. creating an empty xform (right click in stage panel, and choose Create > Xform in the flyout menu)
  2. rename the xform as Root
  3. drag your pre-existing stage hierarchy contained in object1.usd to under Root
  4. make Root the stage’s DefaultPrim by right clicking on Root and Set As Default Prim within the stage panel.
  5. save object1.usd for this change to take effect whenever this USD gets referenced elsewhere

step 4, i believe, is the important step in making sure you designate the DefaultPrim in your USD file.

when you invoke the custom asset’s URL/path, that’ll make sure the children under DefaultPrim comes through, since that’s the path replicator will use to reference the assets into your stage automatically, given that it’s a valid path.

5

this i the error im getting now.

Prim ‘/World/Labeled/object1_05’ has no colliders. Skipping rigid body dynamics properties.
2025-10-28T01:47:38Z [13,749ms] [Warning] [omni.usd] Warning: in _ReportErrors at line 3172 of C:\g\169973693\USD\pxr\usd\usd\stage.cpp – In </World/Labeled/object1_06>: Could not open asset @https://omniverse-content-production.s3-us-west-2.amazonaws.com/Assets/Isaac/5.0C:/Users/Admin/Downloads/atmMachine.usd@ for reference introduced by @anon:0000018CB14741F0:World1.usd@</World/Labeled/object1_06>. (recomposing stage on stage @anon:0000018CB14741F0:World1.usd@ <0000019A1FF3C620>)

2025-10-28T01:47:55Z [29,841ms] [Error] [omni.kit.app._impl] [py stderr]: Traceback (most recent call last):
2025-10-28T01:47:55Z [29,841ms] [Error] [omni.kit.app._impl] [py stderr]: File “C:\Users\Admin\Downloads\isaac-sim-5.0\standalone_examples\replicator\object_based_sdg\object_based_sdg.py”, line 572, in
2025-10-28T01:47:55Z [29,842ms] [Error] [omni.kit.app._impl] [py stderr]: apply_velocities_towards_target(chain(labeled_prims, shape_distractors, mesh_distractors))
2025-10-28T01:47:55Z [29,843ms] [Error] [omni.kit.app._impl] [py stderr]: File “C:\Users\Admin\Downloads\isaac-sim-5.0\standalone_examples\replicator\object_based_sdg\object_based_sdg.py”, line 383, in apply_velocities_towards_target
2025-10-28T01:47:55Z [29,843ms] [Error] [omni.kit.app.impl] [py stderr]: prim.GetAttribute(“physics:velocity”).Set(pull_vel)
2025-10-28T01:47:55Z [29,843ms] [Error] [omni.kit.app.impl] [py stderr]: pxr.Tf.ErrorException:
Error in 'pxrInternal_v0_24__pxrReserved::UsdStage::_SetValueImpl’ at line 6703 in file C:\g\169973693\USD\pxr\usd\usd\stage.cpp : ‘Empty typeName for </World/Labeled/object1.physics:velocity>’

6

@rryyxz the issue relates to Isaac Sim not able to open the USD. if you look at the path above (in green), it doesn’t look correct as it is prefaced with the AWS Isaac Sim is using before the actual path of the asset on your C drive. so you may need to modify your path within your snippet to use the absolute path directly from the C drive rather than concatenate them together.

8

that works out, thank you so much for your help!