Theia Markerless Motion Capture
Theia Markerless Motion Capture – Traditional motion capture requires subjects to wear tight-fitting clothes and dozens of reflective markers that must be applied by a trained operator. This setup process is time-consuming, inconvenient, and often takes longer than the collection itself. With markerless tracking there are no markers, no special clothes, and almost no setup required.
Overview
Simple
Get straight to work collecting data, then process it with a single click. Automatic reporting in Visual3D. Motion capture has never been easier — video is all you need.
Powerful
Intelligent joint detection and labeling. Multi-subject tracking and identification. Automatic model creation and joint detection allows you to focus on answers rather than sift through data.
Anywhere
Study movement in the real world. Measure athletes where they compete. Assess patients at home or in the clinic. With Theia3D you can collect data where it counts.
Why Markerless?
Accurate and General Solution
Theia3D distinguishes itself from the other markerless tracking solutions through its ability to provide a highly accurate and generalized solution to markerless motion capture. Theia3D uses rigid-body tracking and inverse kinematics to fully solve the 3D pose of skeletal segments. Compared to edge-detection and hull-carving techniques, this approach is better for resolving segment rotation to provide an accurate and complete pose estimate. Theia3D is a general solution – it can track a wide range of movements in almost any environment. This is a critical distinction from other specialized markerless tracking solutions that are limited to tracking a specific activity (such as pitching or batting) and cannot be used as a general solution.
Multi-Person Tracking and Automatic Model Creation
When multiple people are visible in the camera views, they are automatically identified and tracked in each view and in 3D. Models are automatically created and scaled for each identified person using parameters inferred from the videos.
Automatic and Batch Processing
The entire analysis pipeline can be executed automatically with no input from the user. This enables efficient batch processing of multiple files. A data maintenance tool is include to automatically organize data for batch analysis.
View and Export Results
Tracked people are rendered in an interactive 3D scene and in 2D video overlays for each of the cameras that are easily exported as video files to visualize results and create presentation materials. Inverse kinematics results can be displayed in the built-in joint and segment angle viewer or exported to a C3D file for further analysis. Export to common animation formats is coming soon.
Integration with Visual3D
Exported C3D files can be opened in Visual3D with automatic model creation for enhanced analysis and reporting. Automatic reports are also available. Visual3D is the premier biomechanics software for measuring movement and offers an unparalleled suite of analysis and reporting tools.
Why Theia3D?
Collect Anywhere
Collect athletes on the court or on the field, assess patients in the clinic, and measure movement in the real world. Unlike traditional motion capture systems, markerless tracking is not limited to a specialized laboratory or studio space so you can study movement where it happens.
Collect Real Movements
Athletes perform best in-game and people behave naturally in familiar environments. Using markerless motion capture, you can record real movements in the the real world without the artifact introduced by the laboratory environment, clothing, and markers required by traditional motion capture systems.
Collect More Data
Little to no setup means you can collect more subjects in a day. Consistent and repeatable results allow you to perform multi-center studies. No markers and no lab so you can collect anyone, anywhere. With markerless motion capture you can do more with less.
Frequently Asked Questions
Q: Has Theia3D been validated?
A: Recent studies have demonstrated the concurrent validity of Theia3D with existing marker based motion capture systems when measuring spatiotemporal gait parameters (engrxiv.org/j4rbg/), shown that the gait kinematics measured with Theia3D are more reliable than those measured with existing marker based systems (biorxiv.org/cgi/content/short/2020.06.23.155358v1), and shown that joint angles for the lower extremity measured with Theia3D are within the error range of uncertainty for marker based motion capture (biorxiv.org/content/10.1101/2020.12.10.420075v1).
Q: Can I use my own cameras?
A: Yes you can, however, the cameras must collect fully synchronized, high-quality video data. We only support data collected using specific camera systems that we have verified the quality and synchronization of the captured videos. We recommend the Optitrack Prime Colour cameras for the highest quality tracking, and most reliable capture system. So, while you can use your own camera system, if it is not on our list of verified equipment it is your responsibility to ensure the system meets the requirements of Theia3D, and we will not be able to provide support to any issues related to data collection or quality.
Q: What is the maximum sampling rate? How about data capture length?
A: The maximum sampling rate and capture length are limitations of the cameras used and thus are different for every camera system. Longer captures will take longer to analyze in Theia3D.
Q: Can the system be used outdoors? (How about low-light situations?)
A: Yes. This system can be used outdoors and will perform well in any environment as long as the lighting is such that the person is clearly visible, and key features, such as the hands and feet, are easily distinguishable in the video.
Q: What are the limitations on the capture volume?
A: The capture volume size will be limited by the number of cameras. Larger volumes and volumes of more complex shape require more cameras.
Q: How long does the analysis take?
A: It depends on the computer, the number of GPUs available, the number of cameras, and the capture frame rate. A typical collection of 10 seconds, collected at 40 frames per second, for 8 cameras will take around 1 minute to process on a single high-end graphics card. An Nvidia RTX 2080Ti or better is the recommended graphics card.
Q: Can I include force data for kinetics?
A: Only if your camera system supports the synchronized collection of external devices. The Qualisys Miqus camera system, that has been verified to work with Theia3D, has hardware options for collecting synchronized data from force plates, instrumented treadmills, EMG, and marker-based cameras.
Q: How fixed are the models? Does it support non-standard subjects like prosthetics, animals, or a multi-segmented foot?
A: Currently, Theia3D supports a single model. That being said, abnormal movements and pathological gait can be tracked using this software.
Q: Can the processing be made automatic?
A: Yes, after the system is setup, the 3D analysis process can be fully automated for single trial or batch processing. User input is only required to start the process.
Q: Can I export data for reporting? Is there built in reporting?
A: Report generation and biomechanical analysis functionality is not built into Theia3D. To generate reports, we recommend using Visual3D (which is included in our packaged offerings) as it can automatically detect the data exported by Theia3D and build the required models. However, we also export C3D files that can be used in other software.
Q: Does Theia3D support animation or gaming development?
A: At this time Theia3D only exports C3D formatted files and AVI video files with segment/skeletal overlays applied. Future versions may export FBX formatted files.
Q: Does this work on multiple people or just one?
A: Yes. Theia3D identifies, tracks, and analyzes every person that satisfies the visibility requirements.
Q: Do I need any other software other than Theia3D?
A: Yes. You need software to run the cameras and collect the video data. Theia3D processes this video data to produce 3D kinematic data (segments and rotation matrices) that is ready for analysis. Additional analysis or 3D processing software (such as Visual3D) can be used to interpret and report the 3D kinematic data.
Q: How accurate are the results compared to other markerless systems?
A: Because of our dedication to data quality for biomechanics, Theia3D is state of the art in terms of accuracy. To our knowledge, no markerless system has been validated to the degree of Theia3D.
Why Markerless?
Learn about the advantages of markerless tracking over traditional motion capture.
FAQs
Read our most frequently asked questions about validation studies, accuracy, and system setups.
