AnimationGraph does not work with Standalone Python

Omniverse Isaac Sim
1

I faced following problem. Is there any solutions?

problem

AnimationGraph does not work only in Standalone Python.

Workflow Result
Script Editor work
Extension work
Standalone Python NOT work
  • Character does not change from “T-pose” to expected animation
  • ag.get_character(skel_root_prim) return None (got a warning like below)

[Warning] [omni.anim.graph.core.plugin] getCharacter - biped_demo is not a SkelRoot prim or does not apply AnimationGraphAPI

environment

I tested in 3 environments.

  • Isaac Sim version 2023.1.1
  • Ubuntu 22.04(RTX 3090), Windows10(RTX 4090), Windows11(RTX 4060 laptop)

reproducible steps

  1. run python script
    (script enables omni.anim.graph.bundle extension)
$ isaac_sim-2023.1.1/python.sh minimum.py
minimum.py 
from carb import log_info
from omni.isaac.kit import SimulationApp
sim_app = SimulationApp(launch_config={"headless": False})


log_info('loading omni.anim.graph.bundle extension')
from omni.isaac.core.utils.extensions import enable_extension
enable_extension('omni.anim.graph.bundle')
from omni.isaac.core import SimulationContext
from omni.isaac.core.utils.stage import is_stage_loading


sim_context = SimulationContext()

log_info('wait for loading')
sim_app.update()
while is_stage_loading():
    sim_app.update()

log_info('begin to play physics')
sim_context.initialize_physics()
sim_context.play()

log_info('enter event loop')
while sim_app.is_running():
    sim_context.step(render=True)

log_info('closing app')
sim_context.stop()
sim_app.close()

  1. Stop simulation

    push stop button to stop physics simulation

step 3 has two cases

Case1 add AnimationGraph manually

3-a. add character to Stage
I used omniverse://localhost/NVIDIA/Assets/AnimGraph/Characters/NVIDIA/biped_demo.usd.

3-b. add AnimationGraph to Stage
I created a graph that just outputs single animation.

I used omniverse://localhost/NVIDIA/Assets/AnimGraph/Animations/NVIDIA/biped_demo/stand_idle_loop.skelanim.usd as an Animation.

3-c. setup relation to SkelRoot
I made relation from AnimationGraph to SkelRoot.

Case2 add USD which has already applied AnimationGraph

3-1. add Biped_Setup.usd to Stage

I used omniverse://localhost/NVIDIA/Assets/Isaac/4.0/Isaac/People/Characters/Biped_Setup.usd.

  1. Play simulation again