Engineers at Northwestern University have developed a breakthrough system for real-time, full-body motion capture that doesn’t require specialized rooms, expensive equipment, or a complex array of sensors. Called MobilePoser, this system makes motion capture accessible through standard mobile devices—smartphones, smartwatches, and even wireless earbuds.
How MobilePoser Works
Using embedded sensors like accelerometers, gyroscopes, and magnetometers, MobilePoser combines sensor data with machine learning and physics-based optimization to accurately represent full-body motion in real time. Dr. Karan Ahuja, the study’s lead and an assistant professor at Northwestern University, explains, “MobilePoser opens doors for immersive experiences in gaming, fitness, and indoor navigation—all through everyday mobile devices.”
Unveiled on October 15 at the 2024 ACM Symposium on User Interface Software and Technology in Pittsburgh, MobilePoser demonstrates the potential for highly accurate motion capture, achieving tracking errors as low as 8–10 centimeters, with the freedom for users to move without staying within the view of a stationary camera.
Revolutionizing Motion Capture Technology
Current industry-standard motion capture systems involve suits covered in sensors, specialized cameras, and rooms that cost over $100,000 to set up and run. While they produce high-fidelity motion tracking, these systems are only accessible to elite film studios or research facilities. MobilePoser, however, makes this technology affordable and accessible, potentially reshaping industries beyond just gaming.
Instead of requiring a person to stay within a camera’s range—like with systems such as Microsoft Kinect—MobilePoser relies on portable sensors to calculate joint rotations, walking speed, and even foot-ground contact. It adapts based on the number of devices worn, whether just a smartphone or a combination of smartphone, smartwatch, and earbuds.
Potential Use Cases: Bringing Motion Capture to Daily Life
- Gaming and Immersive Experiences: MobilePoser opens up exciting new possibilities in gaming, allowing users to interact with virtual worlds through natural body movements. Imagine using your own running or martial arts moves to control in-game characters, all through the sensors in a smartphone or smartwatch. This enhanced immersion could take augmented and virtual reality gaming to unprecedented levels of realism, making it widely accessible.
- Health and Fitness: For personal fitness, MobilePoser goes beyond counting steps, capturing full-body movements for precise analysis. This could help users improve their exercise form by providing real-time posture and body alignment feedback. Physicians could leverage MobilePoser to assess patients’ mobility, detect gait irregularities, or track recovery progress through noninvasive, widely available devices.
- Daily Life and Navigation: MobilePoser’s ability to track body motion even indoors could make indoor navigation more reliable, addressing the limitations of current GPS systems. This could be particularly useful in large buildings like airports, hospitals, or shopping malls, where users could find their way by simply moving naturally as their device translates their position in real-time.
- Revolutionizing Filmmaking and Animation: By making motion capture affordable and portable, MobilePoser could radically alter the landscape of filmmaking. Independent filmmakers and smaller studios could create high-quality CGI without the need for expensive gear, democratizing visual effects and allowing for more experimental storytelling. MobilePoser’s accurate motion-tracking capabilities empower animators to bring lifelike movements to digital characters directly from their smartphones.
- Sports, Education, and Beyond: MobilePoser could support remote coaching in sports, offering athletes real-time feedback on body positioning and movement. Educationally, it could assist in fields that rely on physical practice, like dance or martial arts, allowing students to see and correct their movements without needing a live instructor.
Future of Mobile Motion Capture
With the app set to be released for iPhone, AirPods, and Apple Watch, MobilePoser is a significant step toward using AI-driven motion capture as a tool for everyone. Ahuja and his team have open-sourced their pre-trained models and software, encouraging other researchers to build upon their work. This accessibility might inspire countless new applications, fueling a future where smartphones could be trusted not just for simple data but as dynamic, real-time motion assistants.
MobilePoser promises to bring a new level of engagement, creativity, and convenience to various fields, from revolutionizing film production to enhancing daily activities. As devices adapt, MobilePoser may start a new era in motion capture—one where anyone, anywhere, can participate.
