Implementation:Isaac sim IsaacGymEnvs Runner Play Mode
| Sources | Domains | Last Updated |
|---|---|---|
| IsaacGymEnvs, train.py | Inference, Integration | 2026-02-15 00:00 GMT |
Overview
The Runner play-mode dispatch and player factory registration that enables inference execution in IsaacGymEnvs.
Description
When test=True, the launch_rlg_hydra function invokes the Runner with play=True. The Runner uses its player_factory to instantiate the appropriate Player class. Custom player types are registered during build_runner() to extend rl_games with IsaacGymEnvs-specific inference behavior.
Usage
Triggered automatically when the CLI includes test=True. The player factory selection is determined by the algorithm name in the training config (e.g., a2c_continuous, amp_continuous, sac).
Code Reference
Source Location: Repository: NVIDIA-Omniverse/IsaacGymEnvs, File: isaacgymenvs/train.py (L210-215)
Play Dispatch:
# In launch_rlg_hydra, when cfg.test is True:
runner.run({
'train': False,
'play': True,
'checkpoint': cfg.checkpoint,
'sigma': cfg.sigma
})
Player Factory Registration (in build_runner):
def build_runner(algo_observer):
runner = Runner(algo_observer=algo_observer)
# Register custom IsaacGymEnvs player types
runner.player_factory.register_builder(
'amp_continuous',
lambda **kwargs: amp_players.AMPPlayerContinuous(**kwargs)
)
# Register custom agent types (for training)
runner.algo_factory.register_builder(
'amp_continuous',
lambda **kwargs: amp_continuous.AMPAgent(**kwargs)
)
return runner
I/O Contract
Inputs:
| Input | Type | Description |
|---|---|---|
| Configured Runner | Runner | Runner instance with registered player factories from build_runner() |
| checkpoint path | str | Path to .pth file containing trained model weights |
| sigma | float or None | Optional exploration noise override |
| algorithm name | str | From training config; selects which Player factory to use |
Outputs:
| Output | Type | Description |
|---|---|---|
| Instantiated Player | CommonPlayer / AMPPlayerContinuous / etc. | Player with loaded model weights, network in eval mode |
| Environment | VecTask | Environment instance ready for rollout evaluation |
Player Factory Mapping
| Algorithm Name | Player Class | Description |
|---|---|---|
| a2c_continuous | CommonPlayer | Standard continuous-action PPO player |
| amp_continuous | AMPPlayerContinuous | AMP-specialized player with discriminator support |
| sac | (rl_games default) | Soft Actor-Critic player from rl_games |