EventEgoHands++:
Event-based Egocentric 3D Hand Mesh Reconstruction with Real Dataset

Abstract

3D hand mesh reconstruction is a challenging yet essential task for downstream applications, including human-robot interaction and AR/VR. Although conventional cameras (e.g., RGB or depth cameras) have been widely adopted for this task, methods that rely on them struggle in low-light environments and under severe motion blur. To address these limitations, event-based cameras have recently attracted attention for their high dynamic range and high temporal resolution. However, applying event cameras to egocentric hand reconstruction remains challenging because camera wearer’s motion produces dense background events that obscure hand-specific signals. Although the first egocentric event-based approach mitigates this issue using hand segmentation, its binary hand mask does not distinguish between left and right hands. As a result, the model lacks instance-level hand information and predicts both hands even when only one or neither hand is present. This limitation leads to incorrect inter-hand relationships and degraded reconstruction accuracy. In this paper, we propose EventEgoHands++, a framework for event-based 3D hand mesh reconstruction from an egocentric viewpoint that overcomes these limitations. The proposed method incorporates a Hand Detector that estimates instance-level bounding boxes and masks for both the left and right hands. Moreover, we introduce Adaptive Attention, which dynamically gates the attention based on these detection results to accurately learn the spatial relationship and mutual interactions between the hands. To train and evaluate our framework, we extend the synthetic N-HOT3D dataset with bounding-box annotations and refined masks, and newly construct EEH-R, the largest real-world event-based egocentric hand dataset to date, comprising approximately 1M annotated frames captured in environments including low-light conditions. Extensive experiments on both synthetic and real datasets demonstrate that our method consistently outperforms the baselines.

Method

Overview of the proposed method
Architecture of EventEgoHands++. The pipeline consists of two primary stages: (1) Hand Extraction Stage, where a hand detector identifies and extracts hand regions from event data, and (2) Hand Reconstruction Stage, which utilizes a vision encoder for feature extraction and estimates 3D hand poses through Adaptive Attention based on the detection results.

Dataset

Comparison of event-based hand datasets. The asterisk indicates that the corresponding annotation is available for a subset of the frames.

Type Dataset View Hands Subs. Dur. Seq. #GT Annotation
Synthetic EventHands (Synthetic) Third Single - 100 h - 360M MANO
Ev2Hands-S Third Both - - - 28K MANO, Event seg.
N-HOT3D (Ours) Ego Both 9 4.4 h 136 480K MANO, Hand mask/bbox
Real EventHands (Real) Third Single - 12.6 s 4 357 2D keypoints
Ev2Hands-R Third Both 5 20.1 m 8 70K 3D keypoints
EvRealHands Third Single 10 79 m 102 425K MANO
EEH-R (Ours) Ego Both 8 2.36 h 85 1M MANO, (Hand mask/bbox)*
Samples of the N-HOT3D and EEH-R datasets
Dataset samples. The top shows the synthetic dataset N-HOT3D, and the bottom shows the real-world dataset EEH-R.
Capture system setup of the EEH-R real dataset
Capture system setup. (a) Arrangement of OptiTrack cameras, (b) head-mounted DAVIS346 event camera, (c) objects from kitchen and workspace categories, (d) MoCap gloves (left) and plain fabric gloves worn over MoCap gloves (right).

Sample Videos

Results

Results on N-HOT3D

Qualitative evaluation on the N-HOT3D dataset
Qualitative evaluation on N-HOT3D. We compared our method with EventHands, Ev2Hands, and EventEgoHands. RGB images were not used as input and are shown for reference only. In order from the top, the scenes show "pouring from a can", "picking up a can", "holding a pot", and "picking up a carton".

Results on EEH-R

Qualitative evaluation on the EEH-R real dataset
Qualitative evaluation on EEH-R. We compared our method with EventHands, Ev2Hands, and EventEgoHands. Grayscale images were not used as input and are shown for reference only. The grayscale images at the bottom are actual captured images, which appear almost empty due to the low-light environment. In order from the top, the scenes show "typing on a keyboard", "holding a bottle", and "using a spoon".

BibTeX

EventEgoHands++ (IEEE Access 2026)

@article{hara2026eventegohands2,
  title={EventEgoHands++: Event-based Egocentric 3D Hand Mesh Reconstruction with Real Dataset},
  author={Ryosei Hara and Wataru Ikeda and Masashi Hatano and Mariko Isogawa},
  journal={IEEE Access},
  year={2026},
}

EventEgoHands (ICIP 2025)

@inproceedings{Hara2025EventEgoHands,
  author={Hara, Ryosei and Ikeda, Wataru and Hatano, Masashi and Isogawa, Mariko},
  title={EventEgoHands: Event-based Egocentric 3D Hand Mesh Reconstruction},
  booktitle={IEEE International Conference on Image Processing (ICIP)},
  year={2025},
  pages={1199-1204},
  doi={10.1109/ICIP55913.2025.11084751},
}