Momentum

Momentum provides foundational algorithms for human kinematic motion and numerical optimization solvers to apply human motion in various applications.

Getting Started

This page guides you through the process of building Momentum and running the examples.

Installing Momentum and PyMomentum

Momentum binary builds are available for Windows, macOS, and Linux via Pixi or the Conda package manager.

For Windows, please install Visual Studio 2022 or greater.

Pixi

# Momentum (C++)
pixi add momentum-cpp

# PyMomentum (Python)
pixi add pymomentum

# Both
pixi add momentum

Conda

conda install -c conda-forge momentum-cpp
conda install -c conda-forge pymomentum # Windows is not supported yet
conda install -c conda-forge momentum

Building Momentum from Source

Prerequisite

Complete the following steps only once:

1. Install Pixi by following the instructions on https://prefix.dev/

2. Clone the repository and navigate to the root directory:

   git clone https://github.com/facebookincubator/momentum
   cd momentum
   

   Ensure that all subsequent commands are executed in the project's root directory unless specified otherwise.

Build and Test

• Build the project with the following command (note that the first run may take a few minutes as it installs all dependencies):

  pixi run build
  

• Run the tests with:

  pixi run test
  

To view all available command lines, run pixi task list.

Hello World Example

To run the hello_world example:

pixi run hello_world

Alternatively, you can directly run the executable:

# Linux and macOS
./build/hello_world

# Windows
./build/Release/hello_world.exe

Running Other Examples

To run other examples:

pixi run glb_viewer --help

For more examples, please refer to the Examples page.

Clean Up

If you need to start over for any reason:

pixi run clean

Momentum uses the build/ directory for CMake builds, and .pixi/ for the Pixi virtual environment. You can clean up everything by either manually removing these directories or by running the command above.

FBX Support

Momentum uses OpenFBX to load Autodesk's FBX file format, which is enabled by default. To save files in FBX format, you must install the FBX SDK 2020.3.

Linux

The FBX SDK will be automatically installed when you run pixi run config, so no additional steps are required.

macOS and Windows

You can download it from Autodesk's website or use direct links (macOS, Windows). After installing the SDK, build Momentum from source with MOMENTUM_BUILD_IO_FBX=ON option as:

# macOS
MOMENTUM_BUILD_IO_FBX=ON pixi run <target>

# Windows (Powershell)
$env:MOMENTUM_BUILD_IO_FBX = "ON"; pixi run <target>

# Windows (cmd)
set MOMENTUM_BUILD_IO_FBX=ON && pixi run <target>

For example, file conversion can be run as follows:

# Windows (Powershell)
$env:MOMENTUM_BUILD_IO_FBX = "ON"; pixi run convert_model -d <input.glb> -o <out.fbx>

📖 Documentation

The full documentation for Momentum can be found on our website and the C++ API documentation is available here.

Contributing

Check our contributing guide to learn about how to contribute to the project.

License

Momentum is licensed under the MIT License. A copy of the license can be found here.