Braid — real-time multi-camera 3D animal tracking
Braid is free, open-source software for synchronized multi-camera acquisition and marker-free 3D tracking. It tracks multiple animals, robots, or other moving objects with sufficiently low latency for closed-loop experiments such as virtual reality for freely moving animals.
Individual cameras are controlled with Strand Camera for low-latency 2D tracking without the use of markers and video recording to disk. Braid synchronizes multiple copies of Strand Camera and provides low-latency 3D tracking.
Braid is the successor of flydra, and is the result of a rewrite focused on performance, ease of use, and flexibility. Unlike conventional motion-capture systems, Braid does not require markers on the tracked animals. Its real-time background-subtraction tracker is designed for fast position measurements.
Science enabled by this tracking lineage
Braid continues the lab's open-source multi-camera tracking work begun with flydra. Methods from this lineage have enabled real-time 3D tracking of multiple flying animals, perspective-correct virtual reality for freely moving animals, and comparative measurements of hummingbird maneuvering. Braid makes the current system available for new experiments and collaborations.
Features
- Hardware synchronized multiple camera acquisition using the lab's open source hardware triggerbox
- All per-camera features from Strand Camera
- Realtime marker-free 3D tracking of multiple animals
- Web based user interface allowing easy remote control
- Integrated Python scripting
Documentation
- User's guide for Braid (and Strand Camera)
- Curated developer-documentation overview
- API documentation for
braid_config_data,
flydra_feature_detector_types::ImPtDetectCfg, andflydra_types::TrackingParams. Follow links for other API documentation.
Online tools
| Name | URL | Description |
|---|---|---|
BRAIDZ viewer | braidz.strawlab.org | Online (and installable) viewer for files saved by Braid. |
| Braid April Tag Calibration Tool | strawlab.org/braid-april-cal-webapp | An online tool to generate Braid calibrations from April tag detection data |
Download
Releases are provided via GitHub.
Supported operating system
Ubuntu Linux (64 bit Intel/AMD) is supported. The lab tests internally on macOS and Windows.
Licensing
Braid is free and open source software.
Support
Support is offered on a best effort basis via the github repository or the online forum. Contact Andrew Straw regarding potential availability for collaboration or custom development.
Funding
Braid development was supported in part by the BeeTracked project, funded by the VolkswagenStiftung. Further support comes from the University of Freiburg.
