FenceXR uses Augmented Reality to create 3D movement replays from smartphone video, helping novice fencers detect errors and allowing coaches to give precise, spatially-grounded feedback.

In plain terms

Beginners often struggle to identify their own technical errors in fast-paced activities like fencing, and coaches find it challenging to give specific feedback that truly connects to the student's exact movement. Standard video reviews also have limitations, often lacking different perspectives. To address this, researchers developed FenceXR, an augmented reality (AR) system that reconstructs 3D replays of movements from ordinary smartphone videos. It features a "Trainee module" designed to teach new fencers how to spot common errors in their lunges. Additionally, a "Reviewer module" allows coaches to attach text or voice notes to a specific joint and moment within the 3D replay, offering highly precise and shareable feedback. A study with novice fencers showed their error-detection accuracy significantly improved from 37.5% to 64.1% after one session, with learners focusing more on specific body parts and timing. Fencing experts also found the Reviewer module very useful for conveying feedback that is difficult to explain using traditional video.