Agent Simulation Synthetic Data Generation

Overview

Detection and tracking people in various environments offer tremendous amount of value in many industries. Retail stores benefit from the intelligence of customer traffic, customer trip patterns to design higher revenue driven floor plans, to run more detailed and frequent promotion events, and to improve customer shopping experience. Manufacturers and warehouse operators optimize the interior layout and improve the throughput from the quantitative understanding of worker’s operation routines and potential workflow bottlenecks. As humans and robots collaborating in the same space becomes common, making sure both the workspace safety and the workspace efficiency at the same time is challenging. To realize the aforementioned domain goals, collecting real world data to train people detection and tracking models for different environments is costly and not scalable.

Synthetic data generation provides the flexibility and scalability to solve these exigent data problems. Also, evaluating model accuracy and robustness under abnormal or long-tail situations is critical before the models are deployed in the real-world. Before a new facility, for example, an airport, a warehouse, a factory, a shopping mall, a school campus, even a residential home, breaks ground, simulating the people behavior and robot locomotion in such virtual environments with both normal and rare conditions offer unparalleled values in safety, efficiency, and eventually improving earnings.

The Omni.Replicator.Agent (ORA) extension is designed to generate synthetic data on human characters and robots across a variety of 3D environments. It provides controls over the 3D environments, camera parameters, characters, and robot motions through the use of the configuration and command files. The extension includes a comprehensive set of 2D and 3D data annotation methods to support multiple modalities of sensors, for example, RGB camera, LiDAR, stereo camera. Its primary objective is to provide a GPU-accelerated, computational solution to the synthetic data acquisition problem in computer vision Deep Learning model training and software-in-the-loop testing tasks. In ORA, human characters and robots are classified by the term agent. Prior to ORA, there was no integrated and easy-to-use application or extension in Omniverse to facilitate the synthetic data generation on human characters in various spaces.

ORA provides the following templates for how to customize a simulation with new environments, new characters, and new animations:

Simplified initial setup and low learning curve: the extension is included in Isaac Sim. It provides both a graphical user interface and scripting interface to facilitate both interactive development and scalable headless data production.
High data quality and realism: leveraging Omniverse high quality sim-ready assets, flexible human animation backend, precision-built robot physics engine, and optimized Omniverse rendering engine, ORA produces ever-improving realistic imagery and 100% accurate annotations which formulate high quality data which is essential to efficiently training AI models.
Integration and compatibility: ORA is a Kit extension in Omniverse. It leverages omni.anim.graph, omni.anim.navigation, omni.replicator, omni.isaac.core just to name a few. Such design ensures the compatibility of ORA with the rest of Omniverse ecosystem.

Prior to enabling this extension, read What Is Isaac Sim? to learn about Isaac Sim and follow Installation to install Isaac Sim.

characters and robots move around a warehouse 3D environment.

Note

Omni.Replicator.Agent is in Beta. For more information on pre-release and beta terms, refer to the Omniverse License Agreement.

Enable Omni.Replicator.Agent

Open the extension manager by Window > Extensions. In the extension manager, search for “agent sdg” and enable the omni.replicator.agent.core and omni.replicator.agent.ui extension.
- The extension fetches sample assets from Nucleus during start. Refer to Assets and Nucleus FAQ if you enounter issues for loading assets.
- If loading the UI appears to be hanging, try starting Isaac Sim with the flag --/persistent/isaac/asset_root/timeout=1.0.

A step by step guide on how to enable the extension from Isaac Sim

The ORA UI panel is accessible by Window > AgentSDG and it is opens on the right side of the screen.

A step by step guide on how to enable the ORA UI

Note

To have the extension auto-loaded on startup, click the auto-load button in the extension manager.
Because of extension dependencies, a restart of the Isaac Sim app might be required.

Getting Started

To launch data generation with ORA, load the a .yaml configuration file. Or use the default configuration file that comes with the extension, and follow the steps below. For a more detailed walkthrough, see the Basic Usage section.

Enable the ORA extension and open the UI panel.
Load the configuration file or use the default configuration file.
- A default config file is provided in core/config/default_config.yaml, which comes with the core extension and is automatically loaded when the extension starts.
Click the Set Up Simulation button from the Configuration File panel and it starts loading simulation assets, which might take a while.

Configuration File Panel from the ORA UI

Click the Generate Random Commands button from the Character Settings panel to create commands.
Click the Save Commands button in the Character Settings panel to save commands in the previous step.

Character Settings Panel from the ORA UI

[Optional] Click the Save or Save As button from the Configuration File panel, if you want the configuration for this simulation saved.
Click the Start Data Generation button and the simulation starts. It might take a while to finish.
- Simulation lasts according to the simulation length field in the Configuration File panel.
The output data can be found from the output_dir according to the Replicator Settings panel.

Replicator Settings Panel from the ORA UI

Configuration File

Configuration contains the essential data that defines a simulation. Understanding what each section and row in the configuration file represents helps you understand what ORA can offer. The config file has five sections:

global
scene
replicator
character
robot

The structure of the configuration file is fixed, but the order of each property can vary. For example camera_num can be below the simulation_length. Properties not listed in the format are ignored by our extension.

Note

[Isaac Sim Assets Path] is the path to Isaac Sim Assets. You need to set up Nucleus in order to use them. It can also be retrieved by printing omni.isaac.core.utils.nucleus.get_assets_root_path() with the Isaac Sim script editor.

The following is an example configuration file:

omni.replicator.agent:
    version: 0.2.1
    global:
        seed: 123456
        camera_num: 5
        lidar_num: 0
        simulation_length: 10
    scene:
        asset_path: [Isaac Sim Assets Path]/Isaac/Environments/Simple_Warehouse/full_warehouse.usd
    character:
        asset_path: [Isaac Sim Assets Path]/Isaac/People/Characters/
        command_file:
        filters:
        num: 5
    robot:
        command_file:
        nova_carter_num: 0
        transporter_num: 0
        write_data: false
    replicator:
        writer: TaoWriter
        parameters:
            output_dir:
            rgb: True
            bbox: True
            semantic_segmentation: False
            video: False

Global Properties

Scene Properties

Character Properties

Robot Properties

Replicator Properties

Note

camera_num/lidar_num and camera_list/lidar_list are mutual exclusive. You can toggle the Camera Property Type in the UI to choose between number and list.

../_images/omni_replicator_agent_camera_number_list.gif

Modify the Stage with UI

ORA enables you to quickly modify settings using the UI. Here is a simple example that demonstrates how to adjust the number of characters and cameras in the stage:

Load the default configuration file and click the Set Up Simulation button in the Configuration File panel. This action generates a scene with 5 characters and 5 cameras, as specified by the Character Number and Camera Number values in their respective panels.

To add two more characters and one more camera:

In the Character Settings panel, increase the Character Number value by 2.

In the Configuration File panel, increase the Camera Number value by 1.

You can click the Save button in the Configuration File panel to save current settings into the configuration file.

Click the Set Up Simulation button in the Configuration File panel again. After resetting the scene, you will see 2 additional characters and 1 new camera added to the stage.

Minimum Configuration File

The minimum data required for the configuration file is the header of the extension omni.replicator.agent and the version of the extension. Other fields have default values, if they are not specified explicitly the default values are generated automatically.

The version in the config file must match the major version of the current extension. For example, 0.1.12 works with 0.1.11 but 0.0.12 won’t work with 0.1.12. See Semantic Versioning for the version convention.

A default config file is provided in core/config/default_config.yaml, which comes with the core extension and is automatically loaded when the extension starts. When no command file is specified in the config file, the ‘default_command.txt’ and ‘default_robot_command.txt’ are created at the system default location and its path is added to the config file.

The following is an example of the minimum config file:

omni.replicator.agent:
version: 0.2.1

Data Generation from UI

The ORA UI provides control for all the attributes of the simulation configuration. The attributes provide you with fine grain control over the simulation result. The following steps launch the data generation with simulation configurations:

Follow Enable Omni.Replicator.Agent to install the app and necessary extensions.
Enable the UI extension (omni.replicator.agent.ui) to open the Agent SDG window.
After the extension is enabled, a default config file is loaded into the UI and the default values are reflected in the UI accordingly.
- To load a different configuration file, click the folder icon next to the File Path text field in the Configuration File panel or directly enter the path to the config file in the File Path text field.
Modify other simulation properties in the UI.
- All the fields in the configuration file can be directly edited through the UI. Each UI panel represents a section in the config file. See the Configuration File to review what each field means.
- When changes in the UI are made, the “*” symbol appears on the Save File button. Changes are not written to the config file until the Save File button is clicked. However, if you click Set Up Simulation or Start Data Generation buttons, it uses the configuration set from the UI, even if the changes are not saved to the configuration file.
- When modifying commands, the “*” symbol appears on the Save Commands button instead. This is because modifications in the command file do not reflect the config file itself. When clicking Save File on the Configuration File panel, it also triggers the saving of command files.
- A Generate Random Commands button is provided to generate random commands for agents in the scene. When you click Save Commands, it overwrites the existing commands in the command file.
- Assets (scene, characters, cameras) are not loaded until the Set Up Simulation button is clicked.
  Extension spawns characters, if there are not enough characters in the scene.
  
  Extension spawns cameras to make sure there are enough cameras in the scene.
  
  If there are many characters or cameras in the scene already, the extension does not remove any assets and it uses the first N cameras for the data output.
- When there are unsaved changes, Set Up Simulation and Start Data Generation buttons run according to the information displayed in the UI rather than from the configuration file on disk.
Click the Set Up Simulation button to load the simulation assets and wait the loading to finish. Loading can take a while, depending on the complexity of the assets.
Note
- Before setting up the simulation, ORA requires a navmesh in the stage to spawn agents and control them correctly. Learn how to create your navmesh from Navigation Mesh.
- You can also go to Window > Navigation > NavMesh and turn off Auto Rebake in the NavMesh settings. Auto Bake could make robots stuck and turning it off can increase the performance.
Modify agent (character, robot) commands as you wish.
- When commands are modified, “*” symbol appears in Save Commands button instead. This is because modifications are made for the command file instead of the config file.
- ORA provide a command editor for each agent. You can select the agent name on the tab and use the text editor to edit the command for it.
Set up and run data generation.
[Optional] Click the Save or Save As button from the Configuration File panel, if you want the configuration for this simulation to be saved.
- Saving the configuration file also triggers saving of the command files.
After the assets have been loaded and modified, and the command files have been generated and saved, press the Start Data Generation button in the Configuration File panel to start recording data.
- Agents start executing commands and Replicator starts recording data.
- The simulation automatically stops when enough data has been generated to cover the simulation time set in the config file.
- To end the data generation early, click Stop in the editor menu on the left.
The output data can be found in the output_dir according to the Replicator Settings panel.

Data Generation from Script

For large-scale data generation, it can be more efficient to launch it from script. ORA provides an automatic script (sdg_schedueler.py) to run a series of data generations. Each run happens as an independent process, so failures of some runs do not affect the rest. To run from script, choose open in terminal in the App Selector.

For Linux, in the pop-up command line window, run the following command:
./python.sh tools/isaac_people/sdg_scheduler.py -c [config file path] -n [num_of_run]
For Windows, run the following command:
.\python.bat tools/isaac_people/sdg_scheduler.py -c [config file path] -n [num_of_run]

An example config file is also provided in the isaac_people` folder. For a sample run, you can execute:

./python.sh tools/isaac_people/sdg_scheduler.py -c tools/isaac_people/config.yaml -n 1

The parameters for the command are:

config file path: Config file location. It can be a single config file or a folder of config files.

num_of_run: This is an optional parameter. By default, the script has one run for each config file. If the number of runs is larger than one, the script increases output_dir for each config file automatically to avoid writing in the same location.

Note

The [asyncio] Exception in callback Task.task_wakeup(<Future finis...3333333333333>) error is harmless and can be ignored.

Simulation Control

To further understand simulation control, see:

Agent Simulation Synthetic Data Generation

Overview

Enable Omni.Replicator.Agent

Getting Started

Configuration File

Global Properties

Scene Properties

Character Properties

Robot Properties

Replicator Properties

Modify the Stage with UI

Minimum Configuration File

Data Generation from UI

Data Generation from Script

Simulation Control

Terminology