How to quickly prototype/test new envs in IsaacLab - avoid simulation app loading delays?

[meghbhalerao]

Hi,

From what I understand from the documention, if I want to run any standalone scripts (lets call this test_env.py), I need to have the following snippet of code always at the very beginning of the script -

import argparse
from omni.isaac.lab.app import AppLauncher

# add argparse arguments
parser = argparse.ArgumentParser(description="My dummy script.")
# append AppLauncher cli args
AppLauncher.add_app_launcher_args(parser)
# parse the arguments
args_cli = parser.parse_args()

# launch omniverse app
app_launcher = AppLauncher(args_cli)
simulation_app = app_launcher.app

# ^^ above is the snippet which has to be present before running any standalone script
# rest of the code goes after this, including all imports and anything else .... example code 

Now, I have an example code, to test how long it takes to launch the simulation application which is as follows -

import time
x = time.time()
import argparse

from omni.isaac.lab.app import AppLauncher

# add argparse arguments
parser = argparse.ArgumentParser(description="My dummy script.")
# append AppLauncher cli args
AppLauncher.add_app_launcher_args(parser)
# parse the arguments
args_cli = parser.parse_args()

# launch omniverse app
app_launcher = AppLauncher(args_cli)
simulation_app = app_launcher.app
y = time.time()
t = y - x
print(f"starting the simulation app took {t} seconds!")

After I run this I get the following - which I think is expected -

[WARN][AppLauncher]: There are no arguments attached to the ArgumentParser object. If you have your own arguments, please load your own arguments before calling the `AppLauncher.add_app_launcher_args` method. This allows the method to check the validity of the arguments and perform checks for argument names.
[INFO][AppLauncher]: Loading experience file: /home/mb230/projects/pkgs/IsaacLab/source/apps/isaaclab.python.kit
[Warning] [omni.isaac.kit.simulation_app] Modules: ['omni.kit_app'] were loaded before SimulationApp was started and might not be loaded correctly.
[Warning] [omni.isaac.kit.simulation_app] Please check to make sure no extra omniverse or pxr modules are imported before the call to SimulationApp(...)
Loading user config located at: '/home/mb230/anaconda3/envs/isaaclab/lib/python3.10/site-packages/omni/data/Kit/Isaac-Sim/4.2/user.config.json'
[Info] [carb] Logging to file: /home/mb230/anaconda3/envs/isaaclab/lib/python3.10/site-packages/omni/logs/Kit/Isaac-Sim/4.2/kit_20241028_131753.log
2024-10-28 18:17:53 [0ms] [Warning] [omni.kit.app.plugin] No crash reporter present, dumps uploading isn't available.

|---------------------------------------------------------------------------------------------|
| Driver Version: 560.35.03     | Graphics API: Vulkan
|=============================================================================================|
| GPU | Name                             | Active | LDA | GPU Memory | Vendor-ID | LUID       |
|     |                                  |        |     |            | Device-ID | UUID       |
|     |                                  |        |     |            | Bus-ID    |            |
|---------------------------------------------------------------------------------------------|
| 0   | NVIDIA GeForce RTX 4090          | Yes: 0 |     | 24810   MB | 10de      | 0          |
|     |                                  |        |     |            | 2684      | 750c4754.. |
|     |                                  |        |     |            | 1         |            |
|=============================================================================================|
| OS: 24.04.1 LTS (Noble Numbat) ubuntu, Version: 24.04.1, Kernel: 6.8.0-45-generic
| XServer Vendor: The X.Org Foundation, XServer Version: 12101006 (1.21.1.6)
| Processor: Intel(R) Core(TM) i9-14900K | Cores: 24 | Logical: 48
|---------------------------------------------------------------------------------------------|
| Total Memory (MB): 63983 | Free Memory: 60699
| Total Page/Swap (MB): 8191 | Free Page/Swap: 8191
|---------------------------------------------------------------------------------------------|
2024-10-28 18:17:57 [3,497ms] [Warning] [gpu.foundation.plugin] IOMMU is enabled.
2024-10-28 18:17:59 [6,197ms] [Warning] [omni.replicator.core.scripts.annotators] Annotator PostProcessDispatch is already registered, overwriting annotator template
starting the simulation app took 10.306738138198853 seconds!
2024-10-28 18:18:03 [10,207ms] [Warning] [omni.graph.core.plugin] Could not find category 'Replicator:Annotators' for removal
2024-10-28 18:18:03 [10,207ms] [Warning] [omni.graph.core.plugin] Could not find category 'Replicator:Annotators' for removal
2024-10-28 18:18:03 [10,207ms] [Warning] [omni.graph.core.plugin] Could not find category 'Replicator:Annotators' for removal
2024-10-28 18:18:03 [10,207ms] [Warning] [omni.graph.core.plugin] Could not find category 'Replicator:Annotators' for removal
2024-10-28 18:18:03 [10,207ms] [Warning] [omni.graph.core.plugin] Could not find category 'Replicator:Annotators' for removal
2024-10-28 18:18:03 [10,207ms] [Warning] [omni.graph.core.plugin] Could not find category 'Replicator:Annotators' for removal
2024-10-28 18:18:03 [10,207ms] [Warning] [omni.graph.core.plugin] Could not find category 'Replicator:Annotators' for removal
2024-10-28 18:18:03 [10,207ms] [Warning] [omni.graph.core.plugin] Could not find category 'Replicator:Annotators' for removal
2024-10-28 18:18:03 [10,207ms] [Warning] [omni.graph.core.plugin] Could not find category 'Replicator:Annotators' for removal
2024-10-28 18:18:03 [10,207ms] [Warning] [omni.graph.core.plugin] Could not find category 'Replicator:Annotators' for removal
2024-10-28 18:18:03 [10,207ms] [Warning] [omni.graph.core.plugin] Could not find category 'Replicator:Annotators' for removal
2024-10-28 18:18:03 [10,207ms] [Warning] [omni.graph.core.plugin] Could not find category 'Replicator:Annotators' for removal
2024-10-28 18:18:03 [10,207ms] [Warning] [omni.graph.core.plugin] Could not find category 'Replicator:Core' for removal
2024-10-28 18:18:03 [10,319ms] [Warning] [carb] Recursive unloadAllPlugins() detected!

It takes around 10.5 seconds to start the simulation app, which is managable - but this might cause large delays if I want to run this script say multiple times in succession.

So, in essense, my question is -

1. is there any way to avoid the restarting of the simulator everytime I run this script? for example, this would cause delays if I want to quickly prototype and test new envs. is there any way in which this loading of simulator can be cached/in memory so that I can avoid this overhead?

please let me know if such a thing is possible, and thanks for the help!

[garylvov]

Hi,

I would strongly recommend restarting the simulator every time. 10.5 seconds per run really isn't that bad for development; I find that it barely impedes my progress if at all.

That being said,

If you use a manager based RL Env, you can call

env.close()
from omni.isaac.core.utils.stage import create_new_stage
create_new_stage()

like in

IsaacLab/source/standalone/benchmarks/benchmark_cameras.py

Line 853 in 9cc298e

env.close()

To reset the scene completely as if you launched the scene again.

I'm not sure if this would work, but maybe you can try creating the simulator, and a manager based RL env.
You could create a new thread in which you step the manager based RL env.
When you wish to reset, you could simply "pause" the newly created thread ( I wouldn't delete it at first, just set some sort of global flag you check in the thread like keep_going or whatnot, if this doesn't work delete the thread) that you set to false outside of the thread.

Then, call env.close() on your env, delete the thread, and then try creating a new stage and see what happens. If that clears the stage, try repeating the process of creating a new env, and then passing it to a new thread to step, and so on.

This solution is quite hacky, and I would recommend restarting the sim each time, but if you're set on trying to optimize this restart might be worth a shot. If this doesn't work, just restart the env every time sorry!