Isaac Lab? Sim 4.0.0 set force error with quadcopter example

With the quadcopter example for Isaac Lab,
(IsaacLab/sources/standalone/demos/quadcopter.py)

Force only applies to one of the rotors, after

If you change the name of the quadcopter body in Isaacsim,
from body → any name,
and set it back to
any name - > body.

I’ve checked the difference of the .usda file after this; the only difference was the location of the body definition in the file.

Steps to reproduce

Change the prim xform name
body → any_name,
and set it back to
any_name → body.

System Info

Describe the characteristic of your environment:

  • Isaac Sim Version: 4.0.0
  • OS: Ubuntu22.04
    Both happen on CPU & GPU

If anyone is suffering from a similar problem,

move out your prims to which you want to apply forces,
and return it back to its parent.

It fixes the problem, although it does not solve the underlying problem.

Is there any explicit solution for this?

I am again suffering after adding joints and rigid bodies to deal with thruster vectoring. Now, the above bypass solution is no longer working…

bug fixed with below pull request.

It was more general bug with 0.3.0 with Articulation.set_external_force… function

Hi Junghwan,
Thanks for your merge request. The issue is now fixed.

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