Interacting with Original Articulation at Isaac Lab

Hello everyone,
I would like to know how to spawn an original robot in Isaac Lab.
I am trying to spawn an original USD file with this configuration based on the tutorial “run_articulation.py”.

World/
└── HexapodRobot_v1/
├── MainBody/
├── Leg1Arm1/
│ └── Leg1_1stJoint/
├── Leg1Arm2/
│ └── Leg1_2ndJoint/
├── Leg1Arm3/
│ └── Leg1_3rdJoint/
├── Leg2Arm1/
│ └── Leg2_1stJoint/
├── Leg2Arm2/
│ └── Leg2_2ndJoint/
├── Leg2Arm3/
│ └── Leg2_3rdJoint/
├── Leg3Arm1/
│ └── Leg3_1stJoint/
├── Leg3Arm2/
│ └── Leg3_2ndJoint/
├── Leg3Arm3/
│ └── Leg3_3rdJoint/
├── Leg4Arm1/
│ └── Leg4_1stJoint/
├── Leg4Arm2/
│ └── Leg4_2ndJoint/
├── Leg4Arm3/
│ └── Leg4_3rdJoint/
├── Leg5Arm1/
│ └── Leg5_1stJoint/
├── Leg5Arm2/
│ └── Leg5_2ndJoint/
├── Leg5Arm3/
│ └── Leg5_3rdJoint/
├── Leg6Arm1/
│ └── Leg6_1stJoint/
├── Leg6Arm2/
│ └── Leg6_2ndJoint/
├── Leg6Arm3/
│ └── Leg6_3rdJoint/

However, I get an error.

2024-06-28 05:09:29 [13,107ms] [Error] [omni.physx.tensors.plugin] Pattern ‘/World/Origin*/Robot/(MainBody|Leg1Arm1|Leg6Arm1|Leg5Arm1|Leg4Arm1|Leg3Arm1|Leg2Arm1|Leg1Arm2|Leg6Arm2|Leg5Arm2|Leg4Arm2|Leg3Arm2|Leg2Arm2|Leg1Arm3|Leg6Arm3|Leg5Arm3|Leg4Arm3|Leg3Arm3|Leg2Arm3)’ did not match any rigid bodies
2024-06-28 05:09:29 [13,107ms] [Error] [omni.physx.tensors.plugin] Provided pattern list did not match any rigid bodies

The USD model works fine in Isaac Sim.
I have also created a dedicated CFD.
Is there an articulation configuration specific to Isaac Lab?

We solved this problem by placing the parts directly under the default prim.

World(Default Prim)(Xform)/
├ MainBody(Xform)/
│ ├ RigidBody/
│ └ Joint/
├ Leg1Arm1(Xform)/
├ RigidBody /
⋮ └Joint/